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String param#1
adamrk wants to merge 2 commits into
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string-param

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@adamrk adamrk commented Jan 15, 2021

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This is a big PR, but most of it is interdependent to the rest.

  - Shared Rust infrastructure: `libkernel`, `libmodule`, `libcore`,
    `liballoc`, `libcompiler_builtins`.

      + The Rust modules are now much smaller since they do not contain
        several copies of those libraries. Our example `.ko` on release
        is just 12 KiB, down from 1.3 MiB. For reference:

            `vmlinux` on release w/  Rust is 23 MiB (compressed: 2.1 MiB)
            `vmlinux` on release w/o Rust is 22 MiB (compressed: 1.9 MiB)

        i.e. the bulk is now shared.

      + Multiple builtin modules are now supported since their symbols
        do not collide against each other (fixes #9).

      + Faster compilation (less crates to compile & less repetition).

      + We achieve this by compiling all the shared code to `.rlib`s
        (and the `.so` for the proc macro). For loadable modules,
        we need to rely on the upcoming v0 Rust mangling scheme,
        plus we need to export the Rust symbols needed by the `.ko`s.

  - Simpler, flat file structure: now a small driver may only need
    a single file like `drivers/char/rust_example.rs`, like in C.

      + All the `rust/*` and `driver/char/rust_example/*` files moved
        to fit in the new structure: less files around.

  - Only `rust-lang/{rust,rust-bindgen,compiler-builtins}` as dependencies.

      + Also helps with the faster compilation.

  - Dependency handling integration with `Kbuild`/`fixdep`.

      + Changes to the Rust standard library, kernel headers (bindings),
        `rust/` source files, `.rs` changes, command-line changes,
        flag changes, etc. all trigger recompilation as needed.

      + Works as expected with parallel support (`-j`).

  - Automatic generation of the `exports.c` list:

      + Instead of manually handling the list, all non-local functions
        available in `core`, `alloc` and `kernel` are exported, so all
        modules should work, regardless of what they need, and without
        failing linking due to symbols in the manual list not existing
        (e.g. due to differences in config options).

      + They are a lot, though:

          * ~6k Rust symbols vs. ~4k C symbols in release.

          * However, 4k of those are `bindings_raw` (i.e. duplicated C
            ones), which shouldn't be exported. Thus we should look
            into making `bindings_raw` private to the crate (at the
            moment, the (first) Rust example requires
            `<kernel::bindings...::miscdevice as Default>::default`).

      + Licensing:

          * `kernel`'s symbols are exported as GPL.

          * `core`'s and `alloc`'s symbols are exported as non-GPL so
            that third-parties can build Rust modules as long as they
            write their own kernel support infrastructure, i.e. without
            taking advantage of `kernel`. This seemed to make the most
            sense compared to other exports from the kernel, plus it
            follows more closely the original licence of the crates.

  - Support for GCC-compiled kernels:

    + The generated bindings do not have meaningful differences in our
      release config, between GCC 10.1 and Clang 11.

    + Other configs (e.g. our debug one) may add/remove types and functions.
      That is fine unless we use them form our bindings.

    + However, there are config options that may not work (e.g.
      the randstruct GCC plugin if we use one of those structs).

  - Support for `arm64` architecture:

    + Added to the CI: BusyBox is cross-compiled on the fly (increased
      timeout a bit to match).

    + Requires weakening of a few compiler builtins and adding
      `copy_{from,to}_user` helpers.

  - Proper `make clean` support.

  - Offline builds by default (there is no "online compilation" anymore;
    fixes #17).

  - No interleaved Cargo output (fixes Rust-for-Linux#29).

  - No nightly dependency on Cargo's `build-std`; since now we manage
    the cross-compilation ourselves (should fix Rust-for-Linux#27).

  - "Big" kallsyms symbol support:

    + I already raised ksym names from 128 to 256 back when I wrote the first
      integration. However, Rust symbols can be huge in debug/non-optimized,
      so I increased it again to 512; plus the module name from 56 to 248.

    + In turn, this required tuning the table format to support 2-byte lengths
      for ksyms. Compression at generation and kernel decompression is covered,
      although it may be the case that some script/tool also requires changes
      to understand the new table format.

  - Since now a kernel can be "Rust-enabled", a new `CONFIG_RUST` option
    is added to enable/disable it manually, regardless of whether one has
    `rustc` available or not (`CONFIG_HAS_RUST`).

  - Improved handling of `rustc` flags (`opt-level`, `debuginfo`, etc.),
    by default following what the user selected for C, but customizable
    through a Kconfig menu. As well as options for tweaking overflow
    checks and debug assertions.

  - This rewrite of the Kbuild support is cleaner, i.e. less hacks
    in general handling paths (e.g. no more `shell readlink` for `O=`).

  - Duplicated the example driver 3 times so that we can test in the CI
    that 2 builtins and 2 loadables work, all at the same time.

  - Do not export any helpers' symbols.

  - Updated the quick start guide.

  - Updated CI:

      + Now we always test with 2 builtins and 2 loadables Rust example
        drivers, removing the matrix test for builtin/loadable.

      + Added `toolchain` to matrix: now we test building with GCC,
        Clang or a full LLVM toolchain.

      + Added `arch` to matrix: now we test both arm64 and x86_64.

      + Added `rustc` to matrix: now we test with a very recent nightly
        as well.

      + Only build `output == build` once to reduce the number
        of combinations.

      + Debug x86_64 config: more things enabled (debuginfo, kgdb,
        unit testing, etc.) that mimic more what a developer would have.
        Running the CI will be slightly slower, but should be OK.
        Also enable `-C opt-level=0` to test that such an extreme works
        and also to see how much bloated everything becomes.

      + Release x86_64 config: disabled `EXPERT` and changed a few things
        to make it look more like a normal desktop configuration,
        although it is still pretty minimal.

      + The configs for arm64 are `EXPERT` and `EMBEDDED` ones,
        very minimal, for the particular CPU we are simulating.

      + Update configs to v5.10.

      + Use `$GITHUB_ENV` to simplify.

  - Less `extern crate`s needed since we pass it via `rustc`
    (closer to idiomatic 2018 edition Rust code).

Things to note:

  - There is two more nightly features used:

      + The new Rust mangling scheme: we know it will be stable
        (and the default on, later on).

      + The binary dep-info output: if we remove all other nightly
        features, this one can easily go too.

  - The hack at `exports.c` to export symbols to loadable modules.

  - The hack at `allocator.rs` to get the `__rust_*()` functions.

  - The hack to get the proper flags for bindgen on GCC builds.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
@adamrk adamrk force-pushed the string-param branch 3 times, most recently from 0150b7f to c7e18ff Compare January 15, 2021 21:37
@adamrk adamrk force-pushed the rust-rustc-kbuild branch from 9ea67cb to 7c6155b Compare January 20, 2021 08:22
@adamrk adamrk closed this Jan 21, 2021
adamrk pushed a commit that referenced this pull request Mar 16, 2021
Similar to bpf_prog_realloc(), bpf_prog_clone_create() also copies
the percpu pointers, but the clone still shares them with the original
prog, so we have to clear these two percpu pointers in
bpf_prog_clone_free(). Otherwise we would get a double free:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 13 PID: 8140 Comm: kworker/13:247 Kdump: loaded Tainted: G                W    OE
  5.11.0-rc4.bm.1-amd64+ #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 test_bpf: #1 TXA
 Workqueue: events bpf_prog_free_deferred
 RIP: 0010:percpu_ref_get_many.constprop.97+0x42/0xf0
 Code: [...]
 RSP: 0018:ffffa6bce1f9bda0 EFLAGS: 00010002
 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000021dfc7b
 RDX: ffffffffae2eeb90 RSI: 867f92637e338da5 RDI: 0000000000000046
 RBP: ffffa6bce1f9bda8 R08: 0000000000000000 R09: 0000000000000001
 R10: 0000000000000046 R11: 0000000000000000 R12: 0000000000000280
 R13: 0000000000000000 R14: 0000000000000000 R15: ffff9b5f3ffdedc0
 FS:    0000000000000000(0000) GS:ffff9b5f2fb40000(0000) knlGS:0000000000000000
 CS:    0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000027c36c002 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
    refill_obj_stock+0x5e/0xd0
    free_percpu+0xee/0x550
    __bpf_prog_free+0x4d/0x60
    process_one_work+0x26a/0x590
    worker_thread+0x3c/0x390
    ? process_one_work+0x590/0x590
    kthread+0x130/0x150
    ? kthread_park+0x80/0x80
    ret_from_fork+0x1f/0x30

This bug is 100% reproducible with test_kmod.sh.

Fixes: 700d479 ("bpf: Optimize program stats")
Fixes: ca06f55 ("bpf: Add per-program recursion prevention mechanism")
Reported-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210218001647.71631-1-xiyou.wangcong@gmail.com
adamrk pushed a commit that referenced this pull request Mar 16, 2021
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various fixes for mlxsw.

Patch #1 fixes a race condition in a selftest. The race and fix are
explained in detail in the changelog.

Patch #2 re-adds a link mode that was wrongly removed, resulting in a
regression in some setups.

Patch #3 fixes a race condition in route installation with nexthop
objects.

Please consider patches #2 and #3 for stable.
====================

Link: https://lore.kernel.org/r/20210225165721.1322424-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
nested target/match_revfn() calls work with xt[NFPROTO_UNSPEC] lists
without taking xt[NFPROTO_UNSPEC].mutex. This can race with module unload
and cause host to crash:

general protection fault: 0000 [#1]
Modules linked in: ... [last unloaded: xt_cluster]
CPU: 0 PID: 542455 Comm: iptables
RIP: 0010:[<ffffffff8ffbd518>]  [<ffffffff8ffbd518>] strcmp+0x18/0x40
RDX: 0000000000000003 RSI: ffff9a5a5d9abe10 RDI: dead000000000111
R13: ffff9a5a5d9abe10 R14: ffff9a5a5d9abd8c R15: dead000000000100
(VvS: %R15 -- &xt_match,  %RDI -- &xt_match.name,
xt_cluster unregister match in xt[NFPROTO_UNSPEC].match list)
Call Trace:
 [<ffffffff902ccf44>] match_revfn+0x54/0xc0
 [<ffffffff902ccf9f>] match_revfn+0xaf/0xc0
 [<ffffffff902cd01e>] xt_find_revision+0x6e/0xf0
 [<ffffffffc05a5be0>] do_ipt_get_ctl+0x100/0x420 [ip_tables]
 [<ffffffff902cc6bf>] nf_getsockopt+0x4f/0x70
 [<ffffffff902dd99e>] ip_getsockopt+0xde/0x100
 [<ffffffff903039b5>] raw_getsockopt+0x25/0x50
 [<ffffffff9026c5da>] sock_common_getsockopt+0x1a/0x20
 [<ffffffff9026b89d>] SyS_getsockopt+0x7d/0xf0
 [<ffffffff903cbf92>] system_call_fastpath+0x25/0x2a

Fixes: 656caff ("netfilter 04/09: x_tables: fix match/target revision lookup")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
lanai_dev_open() can fail. When it fail, lanai->base is unmapped and the
pci device is disabled. The caller, lanai_init_one(), then tries to run
atm_dev_deregister(). This will subsequently call lanai_dev_close() and
use the already released MMIO area.

To fix this issue, set the lanai->base to NULL if open fail,
and test the flag in lanai_dev_close().

[    8.324153] lanai: lanai_start() failed, err=19
[    8.324819] lanai(itf 0): shutting down interface
[    8.325211] BUG: unable to handle page fault for address: ffffc90000180024
[    8.325781] #PF: supervisor write access in kernel mode
[    8.326215] #PF: error_code(0x0002) - not-present page
[    8.326641] PGD 100000067 P4D 100000067 PUD 100139067 PMD 10013a067 PTE 0
[    8.327206] Oops: 0002 [#1] SMP KASAN NOPTI
[    8.327557] CPU: 0 PID: 95 Comm: modprobe Not tainted 5.11.0-rc7-00090-gdcc0b49040c7 #12
[    8.328229] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-4
[    8.329145] RIP: 0010:lanai_dev_close+0x4f/0xe5 [lanai]
[    8.329587] Code: 00 48 c7 c7 00 d3 01 c0 e8 49 4e 0a c2 48 8d bd 08 02 00 00 e8 6e 52 14 c1 48 80
[    8.330917] RSP: 0018:ffff8881029ef680 EFLAGS: 00010246
[    8.331196] RAX: 000000000003fffe RBX: ffff888102fb4800 RCX: ffffffffc001a98a
[    8.331572] RDX: ffffc90000180000 RSI: 0000000000000246 RDI: ffff888102fb4000
[    8.331948] RBP: ffff888102fb4000 R08: ffffffff8115da8a R09: ffffed102053deaa
[    8.332326] R10: 0000000000000003 R11: ffffed102053dea9 R12: ffff888102fb48a4
[    8.332701] R13: ffffffffc00123c0 R14: ffff888102fb4b90 R15: ffff888102fb4b88
[    8.333077] FS:  00007f08eb9056a0(0000) GS:ffff88815b400000(0000) knlGS:0000000000000000
[    8.333502] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.333806] CR2: ffffc90000180024 CR3: 0000000102a28000 CR4: 00000000000006f0
[    8.334182] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    8.334557] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    8.334932] Call Trace:
[    8.335066]  atm_dev_deregister+0x161/0x1a0 [atm]
[    8.335324]  lanai_init_one.cold+0x20c/0x96d [lanai]
[    8.335594]  ? lanai_send+0x2a0/0x2a0 [lanai]
[    8.335831]  local_pci_probe+0x6f/0xb0
[    8.336039]  pci_device_probe+0x171/0x240
[    8.336255]  ? pci_device_remove+0xe0/0xe0
[    8.336475]  ? kernfs_create_link+0xb6/0x110
[    8.336704]  ? sysfs_do_create_link_sd.isra.0+0x76/0xe0
[    8.336983]  really_probe+0x161/0x420
[    8.337181]  driver_probe_device+0x6d/0xd0
[    8.337401]  device_driver_attach+0x82/0x90
[    8.337626]  ? device_driver_attach+0x90/0x90
[    8.337859]  __driver_attach+0x60/0x100
[    8.338065]  ? device_driver_attach+0x90/0x90
[    8.338298]  bus_for_each_dev+0xe1/0x140
[    8.338511]  ? subsys_dev_iter_exit+0x10/0x10
[    8.338745]  ? klist_node_init+0x61/0x80
[    8.338956]  bus_add_driver+0x254/0x2a0
[    8.339164]  driver_register+0xd3/0x150
[    8.339370]  ? 0xffffffffc0028000
[    8.339550]  do_one_initcall+0x84/0x250
[    8.339755]  ? trace_event_raw_event_initcall_finish+0x150/0x150
[    8.340076]  ? free_vmap_area_noflush+0x1a5/0x5c0
[    8.340329]  ? unpoison_range+0xf/0x30
[    8.340532]  ? ____kasan_kmalloc.constprop.0+0x84/0xa0
[    8.340806]  ? unpoison_range+0xf/0x30
[    8.341014]  ? unpoison_range+0xf/0x30
[    8.341217]  do_init_module+0xf8/0x350
[    8.341419]  load_module+0x3fe6/0x4340
[    8.341621]  ? vm_unmap_ram+0x1d0/0x1d0
[    8.341826]  ? ____kasan_kmalloc.constprop.0+0x84/0xa0
[    8.342101]  ? module_frob_arch_sections+0x20/0x20
[    8.342358]  ? __do_sys_finit_module+0x108/0x170
[    8.342604]  __do_sys_finit_module+0x108/0x170
[    8.342841]  ? __ia32_sys_init_module+0x40/0x40
[    8.343083]  ? file_open_root+0x200/0x200
[    8.343298]  ? do_sys_open+0x85/0xe0
[    8.343491]  ? filp_open+0x50/0x50
[    8.343675]  ? exit_to_user_mode_prepare+0xfc/0x130
[    8.343935]  do_syscall_64+0x33/0x40
[    8.344132]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[    8.344401] RIP: 0033:0x7f08eb887cf7
[    8.344594] Code: 48 89 57 30 48 8b 04 24 48 89 47 38 e9 1d a0 02 00 48 89 f8 48 89 f7 48 89 d6 41
[    8.345565] RSP: 002b:00007ffcd5c98ad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[    8.345962] RAX: ffffffffffffffda RBX: 00000000008fea70 RCX: 00007f08eb887cf7
[    8.346336] RDX: 0000000000000000 RSI: 00000000008fd9e0 RDI: 0000000000000003
[    8.346711] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
[    8.347085] R10: 00007f08eb8eb300 R11: 0000000000000246 R12: 00000000008fd9e0
[    8.347460] R13: 0000000000000000 R14: 00000000008fddd0 R15: 0000000000000001
[    8.347836] Modules linked in: lanai(+) atm
[    8.348065] CR2: ffffc90000180024
[    8.348244] ---[ end trace 7fdc1c668f2003e5 ]---
[    8.348490] RIP: 0010:lanai_dev_close+0x4f/0xe5 [lanai]
[    8.348772] Code: 00 48 c7 c7 00 d3 01 c0 e8 49 4e 0a c2 48 8d bd 08 02 00 00 e8 6e 52 14 c1 48 80
[    8.349745] RSP: 0018:ffff8881029ef680 EFLAGS: 00010246
[    8.350022] RAX: 000000000003fffe RBX: ffff888102fb4800 RCX: ffffffffc001a98a
[    8.350397] RDX: ffffc90000180000 RSI: 0000000000000246 RDI: ffff888102fb4000
[    8.350772] RBP: ffff888102fb4000 R08: ffffffff8115da8a R09: ffffed102053deaa
[    8.351151] R10: 0000000000000003 R11: ffffed102053dea9 R12: ffff888102fb48a4
[    8.351525] R13: ffffffffc00123c0 R14: ffff888102fb4b90 R15: ffff888102fb4b88
[    8.351918] FS:  00007f08eb9056a0(0000) GS:ffff88815b400000(0000) knlGS:0000000000000000
[    8.352343] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.352647] CR2: ffffc90000180024 CR3: 0000000102a28000 CR4: 00000000000006f0
[    8.353022] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    8.353397] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    8.353958] modprobe (95) used greatest stack depth: 26216 bytes left

Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
Ido Schimmel says:

====================
nexthop: Do not flush blackhole nexthops when loopback goes down

Patch #1 prevents blackhole nexthops from being flushed when the
loopback device goes down given that as far as user space is concerned,
these nexthops do not have a nexthop device.

Patch #2 adds a test case.

There are no regressions in fib_nexthops.sh with this change:

 # ./fib_nexthops.sh
 ...
 Tests passed: 165
 Tests failed:   0
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
When using jumbo packets and overrunning rx queue with napi enabled,
the following sequence is observed in gfar_add_rx_frag:

   | lstatus                              |       | skb                   |
t  | lstatus,  size, flags                | first | len, data_len, *ptr   |
---+--------------------------------------+-------+-----------------------+
13 | 18002348, 9032, INTERRUPT LAST       | 0     | 9600, 8000,  f554c12e |
12 | 10000640, 1600, INTERRUPT            | 0     | 8000, 6400,  f554c12e |
11 | 10000640, 1600, INTERRUPT            | 0     | 6400, 4800,  f554c12e |
10 | 10000640, 1600, INTERRUPT            | 0     | 4800, 3200,  f554c12e |
09 | 10000640, 1600, INTERRUPT            | 0     | 3200, 1600,  f554c12e |
08 | 14000640, 1600, INTERRUPT FIRST      | 0     | 1600, 0,     f554c12e |
07 | 14000640, 1600, INTERRUPT FIRST      | 1     | 0,    0,     f554c12e |
06 | 1c000080, 128,  INTERRUPT LAST FIRST | 1     | 0,    0,     abf3bd6e |
05 | 18002348, 9032, INTERRUPT LAST       | 0     | 8000, 6400,  c5a57780 |
04 | 10000640, 1600, INTERRUPT            | 0     | 6400, 4800,  c5a57780 |
03 | 10000640, 1600, INTERRUPT            | 0     | 4800, 3200,  c5a57780 |
02 | 10000640, 1600, INTERRUPT            | 0     | 3200, 1600,  c5a57780 |
01 | 10000640, 1600, INTERRUPT            | 0     | 1600, 0,     c5a57780 |
00 | 14000640, 1600, INTERRUPT FIRST      | 1     | 0,    0,     c5a57780 |

So at t=7 a new packets is started but not finished, probably due to rx
overrun - but rx overrun is not indicated in the flags. Instead a new
packets starts at t=8. This results in skb->len to exceed size for the LAST
fragment at t=13 and thus a negative fragment size added to the skb.

This then crashes:

kernel BUG at include/linux/skbuff.h:2277!
Oops: Exception in kernel mode, sig: 5 [#1]
...
NIP [c04689f4] skb_pull+0x2c/0x48
LR [c03f62ac] gfar_clean_rx_ring+0x2e4/0x844
Call Trace:
[ec4bfd38] [c06a84c4] _raw_spin_unlock_irqrestore+0x60/0x7c (unreliable)
[ec4bfda8] [c03f6a44] gfar_poll_rx_sq+0x48/0xe4
[ec4bfdc8] [c048d504] __napi_poll+0x54/0x26c
[ec4bfdf8] [c048d908] net_rx_action+0x138/0x2c0
[ec4bfe68] [c06a8f34] __do_softirq+0x3a4/0x4fc
[ec4bfed8] [c0040150] run_ksoftirqd+0x58/0x70
[ec4bfee8] [c0066ecc] smpboot_thread_fn+0x184/0x1cc
[ec4bff08] [c0062718] kthread+0x140/0x144
[ec4bff38] [c0012350] ret_from_kernel_thread+0x14/0x1c

This patch fixes this by checking for computed LAST fragment size, so a
negative sized fragment is never added.
In order to prevent the newer rx frame from getting corrupted, the FIRST
flag is checked to discard the incomplete older frame.

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
netif_device_attach() will unpause the queues so we can't call
it before __alx_open(). This went undetected until
commit b099922 ("alx: add ability to allocate and free
alx_napi structures") but now if stack tries to xmit immediately
on resume before __alx_open() we'll crash on the NAPI being null:

 BUG: kernel NULL pointer dereference, address: 0000000000000198
 CPU: 0 PID: 12 Comm: ksoftirqd/0 Tainted: G           OE 5.10.0-3-amd64 #1 Debian 5.10.13-1
 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77-D3H, BIOS F15 11/14/2013
 RIP: 0010:alx_start_xmit+0x34/0x650 [alx]
 Code: 41 56 41 55 41 54 55 53 48 83 ec 20 0f b7 57 7c 8b 8e b0
0b 00 00 39 ca 72 06 89 d0 31 d2 f7 f1 89 d2 48 8b 84 df
 RSP: 0018:ffffb09240083d28 EFLAGS: 00010297
 RAX: 0000000000000000 RBX: ffffa04d80ae7800 RCX: 0000000000000004
 RDX: 0000000000000000 RSI: ffffa04d80afa000 RDI: ffffa04e92e92a00
 RBP: 0000000000000042 R08: 0000000000000100 R09: ffffa04ea3146700
 R10: 0000000000000014 R11: 0000000000000000 R12: ffffa04e92e92100
 R13: 0000000000000001 R14: ffffa04e92e92a00 R15: ffffa04e92e92a00
 FS:  0000000000000000(0000) GS:ffffa0508f600000(0000) knlGS:0000000000000000
 i915 0000:00:02.0: vblank wait timed out on crtc 0
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000198 CR3: 000000004460a001 CR4: 00000000001706f0
 Call Trace:
  dev_hard_start_xmit+0xc7/0x1e0
  sch_direct_xmit+0x10f/0x310

Cc: <stable@vger.kernel.org> # 4.9+
Fixes: bc2bebe ("alx: remove WoL support")
Reported-by: Zbynek Michl <zbynek.michl@gmail.com>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983595
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Zbynek Michl <zbynek.michl@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL.  Otherwise following error was reported by Asan.

  # perf test -v 4
   4: Read samples using the mmap interface      :
  --- start ---
  test child forked, pid 139782
  mmap size 528384B

  =================================================================
  ==139782==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f1f76daee8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x564ba21a0fea in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
    #2 0x564ba21a1a0f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
    #3 0x564ba21a21cf in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
    #4 0x564ba21a21cf in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
    #5 0x564ba1e48298 in test__basic_mmap tests/mmap-basic.c:55
    #6 0x564ba1e278fb in run_test tests/builtin-test.c:428
    #7 0x564ba1e278fb in test_and_print tests/builtin-test.c:458
    #8 0x564ba1e29a53 in __cmd_test tests/builtin-test.c:679
    #9 0x564ba1e29a53 in cmd_test tests/builtin-test.c:825
    #10 0x564ba1e95cb4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #11 0x564ba1d1fa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #12 0x564ba1d1fa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #13 0x564ba1d1fa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #14 0x7f1f768e4d09 in __libc_start_main ../csu/libc-start.c:308

    ...
  test child finished with 1
  ---- end ----
  Read samples using the mmap interface: FAILED!
  failed to open shell test directory: /home/namhyung/libexec/perf-core/tests/shell

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210301140409.184570-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The get_argv_exec_path() returns a dynamic memory so it should be
freed after use.

  $ perf test -v 17
  ...
  ==141682==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 33 byte(s) in 1 object(s) allocated from:
    #0 0x7f09107d2e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x7f091035f6a7 in __vasprintf_internal libio/vasprintf.c:71

  SUMMARY: AddressSanitizer: 33 byte(s) leaked in 1 allocation(s).

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL.  Otherwise following error was reported by Asan.

Also change the goto label since it doesn't need to have two.

  # perf test -v 24
  24: Number of exit events of a simple workload :
  --- start ---
  test child forked, pid 145915
  mmap size 528384B

  =================================================================
  ==145915==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fc44e50d1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
    #1 0x561cf50f4d2e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
    #2 0x561cf4eeb949 in thread_map__new_by_tid util/thread_map.c:63
    #3 0x561cf4db7fd2 in test__task_exit tests/task-exit.c:74
    #4 0x561cf4d798fb in run_test tests/builtin-test.c:428
    #5 0x561cf4d798fb in test_and_print tests/builtin-test.c:458
    #6 0x561cf4d7ba53 in __cmd_test tests/builtin-test.c:679
    #7 0x561cf4d7ba53 in cmd_test tests/builtin-test.c:825
    #8 0x561cf4de7d04 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #9 0x561cf4c71a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #10 0x561cf4c71a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #11 0x561cf4c71a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #12 0x7fc44e042d09 in __libc_start_main ../csu/libc-start.c:308

    ...
  test child finished with 1
  ---- end ----
  Number of exit events of a simple workload: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL.  Otherwise following error was reported by Asan.

Also change the goto label since it doesn't need to have two.

  # perf test -v 25
  25: Software clock events period values        :
  --- start ---
  test child forked, pid 149154
  mmap size 528384B
  mmap size 528384B

  =================================================================
  ==149154==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fef5cd071f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
    #1 0x56260d5e8b8e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
    #2 0x56260d3df7a9 in thread_map__new_by_tid util/thread_map.c:63
    #3 0x56260d2ac6b2 in __test__sw_clock_freq tests/sw-clock.c:65
    #4 0x56260d26d8fb in run_test tests/builtin-test.c:428
    #5 0x56260d26d8fb in test_and_print tests/builtin-test.c:458
    #6 0x56260d26fa53 in __cmd_test tests/builtin-test.c:679
    #7 0x56260d26fa53 in cmd_test tests/builtin-test.c:825
    #8 0x56260d2dbb64 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #9 0x56260d165a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #10 0x56260d165a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #11 0x56260d165a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #12 0x7fef5c83cd09 in __libc_start_main ../csu/libc-start.c:308

    ...
  test child finished with 1
  ---- end ----
  Software clock events period values      : FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist and the cpu/thread maps should be released together.
Otherwise following error was reported by Asan.

Note that this test still has memory leaks in DSOs so it still fails
even after this change.  I'll take a look at that too.

  # perf test -v 26
  26: Object code reading                        :
  --- start ---
  test child forked, pid 154184
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: build id mismatch for vmlinux.
  symsrc__init: cannot get elf header.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
  Parsing event 'cycles'
  mmap size 528384B
  ...
  =================================================================
  ==154184==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 439 byte(s) in 1 object(s) allocated from:
    #0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x55ad9b7e821e in dso__new_id util/dso.c:1256
    #2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132
    #3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347
    #4 0x55ad9b845b7e in map__new util/map.c:176
    #5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787
    #6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64
    #7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499
    #8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741
    #9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833
    #10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608
    #11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722
    #12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428
    #13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458
    #14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679
    #15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825
    #16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308

    ...
  SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Object code reading: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist and the cpu/thread maps should be released together.
Otherwise following error was reported by Asan.

  $ perf test -v 28
  28: Use a dummy software event to keep tracking:
  --- start ---
  test child forked, pid 156810
  mmap size 528384B

  =================================================================
  ==156810==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f637d2bce8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x55cc6295cffa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
    #2 0x55cc6295da1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
    #3 0x55cc6295e1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
    #4 0x55cc6295e1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
    #5 0x55cc626287cf in test__keep_tracking tests/keep-tracking.c:84
    #6 0x55cc625e38fb in run_test tests/builtin-test.c:428
    #7 0x55cc625e38fb in test_and_print tests/builtin-test.c:458
    #8 0x55cc625e5a53 in __cmd_test tests/builtin-test.c:679
    #9 0x55cc625e5a53 in cmd_test tests/builtin-test.c:825
    #10 0x55cc62651cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #11 0x55cc624dba88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #12 0x55cc624dba88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #13 0x55cc624dba88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #14 0x7f637cdf2d09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Use a dummy software event to keep tracking: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The evlist and cpu/thread maps should be released together.
Otherwise the following error was reported by Asan.

  $ perf test -v 35
  35: Track with sched_switch                    :
  --- start ---
  test child forked, pid 159287
  Using CPUID GenuineIntel-6-8E-C
  mmap size 528384B
  1295 events recorded

  =================================================================
  ==159287==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7fa28d9a2e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x5652f5a5affa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
    #2 0x5652f5a5ba1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
    #3 0x5652f5a5c1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
    #4 0x5652f5a5c1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
    #5 0x5652f5723bbf in test__switch_tracking tests/switch-tracking.c:350
    #6 0x5652f56e18fb in run_test tests/builtin-test.c:428
    #7 0x5652f56e18fb in test_and_print tests/builtin-test.c:458
    #8 0x5652f56e3a53 in __cmd_test tests/builtin-test.c:679
    #9 0x5652f56e3a53 in cmd_test tests/builtin-test.c:825
    #10 0x5652f574fcc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #11 0x5652f55d9a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #12 0x5652f55d9a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #13 0x5652f55d9a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #14 0x7fa28d4d8d09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Track with sched_switch: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
It missed to call perf_thread_map__put() after using the map.

  $ perf test -v 43
  43: Synthesize thread map                      :
  --- start ---
  test child forked, pid 162640

  =================================================================
  ==162640==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fd48cdaa1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
    #1 0x563e6d5f8d0e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
    #2 0x563e6d3ef69a in thread_map__new_by_pid util/thread_map.c:46
    #3 0x563e6d2cec90 in test__thread_map_synthesize tests/thread-map.c:97
    #4 0x563e6d27d8fb in run_test tests/builtin-test.c:428
    #5 0x563e6d27d8fb in test_and_print tests/builtin-test.c:458
    #6 0x563e6d27fa53 in __cmd_test tests/builtin-test.c:679
    #7 0x563e6d27fa53 in cmd_test tests/builtin-test.c:825
    #8 0x563e6d2ebce4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #9 0x563e6d175a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #10 0x563e6d175a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #11 0x563e6d175a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #12 0x7fd48c8dfd09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 8224 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Synthesize thread map: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
The str should be freed after creating a thread map.  Also change the
open-coded thread map deletion to a call to perf_thread_map__put().

  $ perf test -v 44
  44: Remove thread map                          :
  --- start ---
  test child forked, pid 165536
  2 threads: 165535, 165536
  1 thread: 165536
  0 thread:

  =================================================================
  ==165536==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 14 byte(s) in 1 object(s) allocated from:
    #0 0x7f54453ffe8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x7f5444f8c6a7 in __vasprintf_internal libio/vasprintf.c:71

  SUMMARY: AddressSanitizer: 14 byte(s) leaked in 1 allocation(s).
  test child finished with 1
  ---- end ----
  Remove thread map: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-10-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
It should be released after printing the map.

  $ perf test -v 52
  52: Print cpu map                              :
  --- start ---
  test child forked, pid 172233

  =================================================================
  ==172233==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 156 byte(s) in 1 object(s) allocated from:
    #0 0x7fc472518e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x55e63b378f7a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
    #2 0x55e63b37a05c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237
    #3 0x55e63b056d16 in cpu_map_print tests/cpumap.c:102
    #4 0x55e63b056d16 in test__cpu_map_print tests/cpumap.c:120
    #5 0x55e63afff8fb in run_test tests/builtin-test.c:428
    #6 0x55e63afff8fb in test_and_print tests/builtin-test.c:458
    #7 0x55e63b001a53 in __cmd_test tests/builtin-test.c:679
    #8 0x55e63b001a53 in cmd_test tests/builtin-test.c:825
    #9 0x55e63b06dc44 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #10 0x55e63aef7a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #11 0x55e63aef7a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #12 0x55e63aef7a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #13 0x7fc47204ed09 in __libc_start_main ../csu/libc-start.c:308
  ...

  SUMMARY: AddressSanitizer: 448 byte(s) leaked in 7 allocation(s).
  test child finished with 1
  ---- end ----
  Print cpu map: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-11-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
It should release the maps at the end.

  $ perf test -v 71
  71: Convert perf time to TSC                   :
  --- start ---
  test child forked, pid 178744
  mmap size 528384B
  1st event perf time 59207256505278 tsc 13187166645142
  rdtsc          time 59207256542151 tsc 13187166723020
  2nd event perf time 59207256543749 tsc 13187166726393

  =================================================================
  ==178744==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7faf601f9e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x55b620cfc00a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
    #2 0x55b620cfca2f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
    #3 0x55b620cfd1ef in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
    #4 0x55b620cfd1ef in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
    #5 0x55b6209ef1b2 in test__perf_time_to_tsc tests/perf-time-to-tsc.c:73
    #6 0x55b6209828fb in run_test tests/builtin-test.c:428
    #7 0x55b6209828fb in test_and_print tests/builtin-test.c:458
    #8 0x55b620984a53 in __cmd_test tests/builtin-test.c:679
    #9 0x55b620984a53 in cmd_test tests/builtin-test.c:825
    #10 0x55b6209f0cd4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #11 0x55b62087aa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #12 0x55b62087aa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #13 0x55b62087aa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #14 0x7faf5fd2fd09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Convert perf time to TSC: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
I got a segfault when using -r option with event groups.  The option
makes it run the workload multiple times and it will reuse the evlist
and evsel for each run.

While most of resources are allocated and freed properly, the id hash
in the evlist was not and it resulted in the bug.  You can see it with
the address sanitizer like below:

  $ perf stat -r 100 -e '{cycles,instructions}' true
  =================================================================
  ==693052==ERROR: AddressSanitizer: heap-use-after-free on
      address 0x6080000003d0 at pc 0x558c57732835 bp 0x7fff1526adb0 sp 0x7fff1526ada8
  WRITE of size 8 at 0x6080000003d0 thread T0
    #0 0x558c57732834 in hlist_add_head /home/namhyung/project/linux/tools/include/linux/list.h:644
    #1 0x558c57732834 in perf_evlist__id_hash /home/namhyung/project/linux/tools/lib/perf/evlist.c:237
    #2 0x558c57732834 in perf_evlist__id_add /home/namhyung/project/linux/tools/lib/perf/evlist.c:244
    #3 0x558c57732834 in perf_evlist__id_add_fd /home/namhyung/project/linux/tools/lib/perf/evlist.c:285
    #4 0x558c5747733e in store_evsel_ids util/evsel.c:2765
    #5 0x558c5747733e in evsel__store_ids util/evsel.c:2782
    #6 0x558c5730b717 in __run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:895
    #7 0x558c5730b717 in run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:1014
    #8 0x558c5730b717 in cmd_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:2446
    #9 0x558c57427c24 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #10 0x558c572b1a48 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #11 0x558c572b1a48 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #12 0x558c572b1a48 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #13 0x7fcadb9f7d09 in __libc_start_main ../csu/libc-start.c:308
    #14 0x558c572b60f9 in _start (/home/namhyung/project/linux/tools/perf/perf+0x45d0f9)

Actually the nodes in the hash table are struct perf_stream_id and
they were freed in the previous run.  Fix it by resetting the hash.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210225035148.778569-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
[ 6684.493350] Unable to handle kernel paging request at virtual address ffff800011c5b0f0
[ 6684.498531] mmc0: card 0001 removed
[ 6684.501556] Mem abort info:
[ 6684.509681]   ESR = 0x96000047
[ 6684.512786]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 6684.518394]   SET = 0, FnV = 0
[ 6684.521707]   EA = 0, S1PTW = 0
[ 6684.524998] Data abort info:
[ 6684.528236]   ISV = 0, ISS = 0x00000047
[ 6684.532986]   CM = 0, WnR = 1
[ 6684.536129] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081b22000
[ 6684.543923] [ffff800011c5b0f0] pgd=00000000bffff003, p4d=00000000bffff003, pud=00000000bfffe003, pmd=00000000900e1003, pte=0000000000000000
[ 6684.557915] Internal error: Oops: 96000047 [#1] PREEMPT SMP
[ 6684.564240] Modules linked in: sdhci_esdhc_imx(-) sdhci_pltfm sdhci cqhci mmc_block mmc_core fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine rng_core authenc libdes crct10dif_ce flexcan can_dev caam error [last unloaded: mmc_core]
[ 6684.587281] CPU: 0 PID: 79138 Comm: kworker/0:3H Not tainted 5.10.9-01410-g3ba33182767b-dirty #10
[ 6684.596160] Hardware name: Freescale i.MX8DXL EVK (DT)
[ 6684.601320] Workqueue: kblockd blk_mq_run_work_fn

[ 6684.606094] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--)
[ 6684.612286] pc : cqhci_request+0x148/0x4e8 [cqhci]
^GMessage from syslogd@  at Thu Jan  1 01:51:24 1970 ...[ 6684.617085] lr : cqhci_request+0x314/0x4e8 [cqhci]
[ 6684.626734] sp : ffff80001243b9f0
[ 6684.630049] x29: ffff80001243b9f0 x28: ffff00002c3dd000
[ 6684.635367] x27: 0000000000000001 x26: 0000000000000001
[ 6684.640690] x25: ffff00002c451000 x24: 000000000000000f
[ 6684.646007] x23: ffff000017e71c80 x22: ffff00002c451000
[ 6684.651326] x21: ffff00002c0f3550 x20: ffff00002c0f3550
[ 6684.656651] x19: ffff000017d46880 x18: ffff00002cea1500
[ 6684.661977] x17: 0000000000000000 x16: 0000000000000000
[ 6684.667294] x15: 000001ee628e3ed1 x14: 0000000000000278
[ 6684.672610] x13: 0000000000000001 x12: 0000000000000001
[ 6684.677927] x11: 0000000000000000 x10: 0000000000000000
[ 6684.683243] x9 : 000000000000002b x8 : 0000000000001000
[ 6684.688560] x7 : 0000000000000010 x6 : ffff00002c0f3678
[ 6684.693886] x5 : 000000000000000f x4 : ffff800011c5b000
[ 6684.699211] x3 : 000000000002d988 x2 : 0000000000000008
[ 6684.704537] x1 : 00000000000000f0 x0 : 0002d9880008102f
[ 6684.709854] Call trace:
[ 6684.712313]  cqhci_request+0x148/0x4e8 [cqhci]
[ 6684.716803]  mmc_cqe_start_req+0x58/0x68 [mmc_core]
[ 6684.721698]  mmc_blk_mq_issue_rq+0x460/0x810 [mmc_block]
[ 6684.727018]  mmc_mq_queue_rq+0x118/0x2b0 [mmc_block]

The problem occurs when cqhci_request() get called after cqhci_disable() as
it leads to access of allocated memory that has already been freed. Let's
fix the problem by calling cqhci_disable() a bit later in the remove path.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Diagnosed-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20210303174248.542175-1-Frank.Li@nxp.com
Fixes: f690f44 ("mmc: mmc: Enable CQE's")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
Freed pages are not subtracted from the allocated_pages counter in
ttm_pool_type_fini(), causing a leak in the count on device removal.
The next shrinker invocation loops forever trying to free pages that are
no longer in the pool:

  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu:  3-....: (9998 ticks this GP) idle=54e/1/0x4000000000000000 softirq=434857/434857 fqs=2237
    (t=10001 jiffies g=2194533 q=49211)
  NMI backtrace for cpu 3
  CPU: 3 PID: 1034 Comm: kswapd0 Tainted: P           O      5.11.0-com #1
  Hardware name: System manufacturer System Product Name/PRIME X570-PRO, BIOS 1405 11/19/2019
  Call Trace:
   <IRQ>
   ...
   </IRQ>
   sysvec_apic_timer_interrupt+0x77/0x80
   asm_sysvec_apic_timer_interrupt+0x12/0x20
  RIP: 0010:mutex_unlock+0x16/0x20
  Code: e7 48 8b 70 10 e8 7a 53 77 ff eb aa e8 43 6c ff ff 0f 1f 00 65 48 8b 14 25 00 6d 01 00 31 c9 48 89 d0 f0 48 0f b1 0f 48 39 c2 <74> 05 e9 e3 fe ff ff c3 66 90 48 8b 47 20 48 85 c0 74 0f 8b 50 10
  RSP: 0018:ffffbdb840797be8 EFLAGS: 00000246
  RAX: ffff9ff445a41c00 RBX: ffffffffc02a9ef8 RCX: 0000000000000000
  RDX: ffff9ff445a41c00 RSI: ffffbdb840797c78 RDI: ffffffffc02a9ac0
  RBP: 0000000000000080 R08: 0000000000000000 R09: ffffbdb840797c80
  R10: 0000000000000000 R11: fffffffffffffff5 R12: 0000000000000000
  R13: 0000000000000000 R14: 0000000000000084 R15: ffffffffc02a9a60
   ttm_pool_shrink+0x7d/0x90 [ttm]
   ttm_pool_shrinker_scan+0x5/0x20 [ttm]
   do_shrink_slab+0x13a/0x1a0
...

debugfs shows the incorrect total:

  $ cat /sys/kernel/debug/dri/0/ttm_page_pool
            --- 0--- --- 1--- --- 2--- --- 3--- --- 4--- --- 5--- --- 6--- --- 7--- --- 8--- --- 9--- ---10---
  wc      :        0        0        0        0        0        0        0        0        0        0        0
  uc      :        0        0        0        0        0        0        0        0        0        0        0
  wc 32   :        0        0        0        0        0        0        0        0        0        0        0
  uc 32   :        0        0        0        0        0        0        0        0        0        0        0
  DMA uc  :        0        0        0        0        0        0        0        0        0        0        0
  DMA wc  :        0        0        0        0        0        0        0        0        0        0        0
  DMA     :        0        0        0        0        0        0        0        0        0        0        0

  total   :     3029 of  8244261

Using ttm_pool_type_take() to remove pages from the pool before freeing
them correctly accounts for the freed pages.

Fixes: d099fc8 ("drm/ttm: new TT backend allocation pool v3")
Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303011723.22512-1-ajderossi@gmail.com
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
adamrk pushed a commit that referenced this pull request Mar 16, 2021
Commit b0841ee ("configfs: provide exclusion between IO and removals")
uses ->frag_dead to mark the fragment state, thus no bothering with extra
refcount on config_item when opening a file. The configfs_get_config_item
was removed in __configfs_open_file, but not with config_item_put. So the
refcount on config_item will lost its balance, causing use-after-free
issues in some occasions like this:

Test:
1. Mount configfs on /config with read-only items:
drwxrwx--- 289 root   root            0 2021-04-01 11:55 /config
drwxr-xr-x   2 root   root            0 2021-04-01 11:54 /config/a
--w--w--w-   1 root   root         4096 2021-04-01 11:53 /config/a/1.txt
......

2. Then run:
for file in /config
do
echo $file
grep -R 'key' $file
done

3. __configfs_open_file will be called in parallel, the first one
got called will do:
if (file->f_mode & FMODE_READ) {
	if (!(inode->i_mode & S_IRUGO))
		goto out_put_module;
			config_item_put(buffer->item);
				kref_put()
					package_details_release()
						kfree()

the other one will run into use-after-free issues like this:
BUG: KASAN: use-after-free in __configfs_open_file+0x1bc/0x3b0
Read of size 8 at addr fffffff155f02480 by task grep/13096
CPU: 0 PID: 13096 Comm: grep VIP: 00 Tainted: G        W       4.14.116-kasan #1
TGID: 13096 Comm: grep
Call trace:
dump_stack+0x118/0x160
kasan_report+0x22c/0x294
__asan_load8+0x80/0x88
__configfs_open_file+0x1bc/0x3b0
configfs_open_file+0x28/0x34
do_dentry_open+0x2cc/0x5c0
vfs_open+0x80/0xe0
path_openat+0xd8c/0x2988
do_filp_open+0x1c4/0x2fc
do_sys_open+0x23c/0x404
SyS_openat+0x38/0x48

Allocated by task 2138:
kasan_kmalloc+0xe0/0x1ac
kmem_cache_alloc_trace+0x334/0x394
packages_make_item+0x4c/0x180
configfs_mkdir+0x358/0x740
vfs_mkdir2+0x1bc/0x2e8
SyS_mkdirat+0x154/0x23c
el0_svc_naked+0x34/0x38

Freed by task 13096:
kasan_slab_free+0xb8/0x194
kfree+0x13c/0x910
package_details_release+0x524/0x56c
kref_put+0xc4/0x104
config_item_put+0x24/0x34
__configfs_open_file+0x35c/0x3b0
configfs_open_file+0x28/0x34
do_dentry_open+0x2cc/0x5c0
vfs_open+0x80/0xe0
path_openat+0xd8c/0x2988
do_filp_open+0x1c4/0x2fc
do_sys_open+0x23c/0x404
SyS_openat+0x38/0x48
el0_svc_naked+0x34/0x38

To fix this issue, remove the config_item_put in
__configfs_open_file to balance the refcount of config_item.

Fixes: b0841ee ("configfs: provide exclusion between IO and removals")
Signed-off-by: Daiyue Zhang <zhangdaiyue1@huawei.com>
Signed-off-by: Yi Chen <chenyi77@huawei.com>
Signed-off-by: Ge Qiu <qiuge@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
adamrk pushed a commit that referenced this pull request Mar 26, 2021
[ This problem is in mainline, but only rt has the chops to be
able to detect it. ]

Lockdep reports a circular lock dependency between serv->sv_lock and
softirq_ctl.lock on system shutdown, when using a kernel built with
CONFIG_PREEMPT_RT=y, and a nfs mount exists.

This is due to the definition of spin_lock_bh on rt:

	local_bh_disable();
	rt_spin_lock(lock);

which forces a softirq_ctl.lock -> serv->sv_lock dependency.  This is
not a problem as long as _every_ lock of serv->sv_lock is a:

	spin_lock_bh(&serv->sv_lock);

but there is one of the form:

	spin_lock(&serv->sv_lock);

This is what is causing the circular dependency splat.  The spin_lock()
grabs the lock without first grabbing softirq_ctl.lock via local_bh_disable.
If later on in the critical region,  someone does a local_bh_disable, we
get a serv->sv_lock -> softirq_ctrl.lock dependency established.  Deadlock.

Fix is to make serv->sv_lock be locked with spin_lock_bh everywhere, no
exceptions.

[  OK  ] Stopped target NFS client services.
         Stopping Logout off all iSCSI sessions on shutdown...
         Stopping NFS server and services...
[  109.442380]
[  109.442385] ======================================================
[  109.442386] WARNING: possible circular locking dependency detected
[  109.442387] 5.10.16-rt30 #1 Not tainted
[  109.442389] ------------------------------------------------------
[  109.442390] nfsd/1032 is trying to acquire lock:
[  109.442392] ffff994237617f60 ((softirq_ctrl.lock).lock){+.+.}-{2:2}, at: __local_bh_disable_ip+0xd9/0x270
[  109.442405]
[  109.442405] but task is already holding lock:
[  109.442406] ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90
[  109.442415]
[  109.442415] which lock already depends on the new lock.
[  109.442415]
[  109.442416]
[  109.442416] the existing dependency chain (in reverse order) is:
[  109.442417]
[  109.442417] -> #1 (&serv->sv_lock){+.+.}-{0:0}:
[  109.442421]        rt_spin_lock+0x2b/0xc0
[  109.442428]        svc_add_new_perm_xprt+0x42/0xa0
[  109.442430]        svc_addsock+0x135/0x220
[  109.442434]        write_ports+0x4b3/0x620
[  109.442438]        nfsctl_transaction_write+0x45/0x80
[  109.442440]        vfs_write+0xff/0x420
[  109.442444]        ksys_write+0x4f/0xc0
[  109.442446]        do_syscall_64+0x33/0x40
[  109.442450]        entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  109.442454]
[  109.442454] -> #0 ((softirq_ctrl.lock).lock){+.+.}-{2:2}:
[  109.442457]        __lock_acquire+0x1264/0x20b0
[  109.442463]        lock_acquire+0xc2/0x400
[  109.442466]        rt_spin_lock+0x2b/0xc0
[  109.442469]        __local_bh_disable_ip+0xd9/0x270
[  109.442471]        svc_xprt_do_enqueue+0xc0/0x4d0
[  109.442474]        svc_close_list+0x60/0x90
[  109.442476]        svc_close_net+0x49/0x1a0
[  109.442478]        svc_shutdown_net+0x12/0x40
[  109.442480]        nfsd_destroy+0xc5/0x180
[  109.442482]        nfsd+0x1bc/0x270
[  109.442483]        kthread+0x194/0x1b0
[  109.442487]        ret_from_fork+0x22/0x30
[  109.442492]
[  109.442492] other info that might help us debug this:
[  109.442492]
[  109.442493]  Possible unsafe locking scenario:
[  109.442493]
[  109.442493]        CPU0                    CPU1
[  109.442494]        ----                    ----
[  109.442495]   lock(&serv->sv_lock);
[  109.442496]                                lock((softirq_ctrl.lock).lock);
[  109.442498]                                lock(&serv->sv_lock);
[  109.442499]   lock((softirq_ctrl.lock).lock);
[  109.442501]
[  109.442501]  *** DEADLOCK ***
[  109.442501]
[  109.442501] 3 locks held by nfsd/1032:
[  109.442503]  #0: ffffffff93b49258 (nfsd_mutex){+.+.}-{3:3}, at: nfsd+0x19a/0x270
[  109.442508]  #1: ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90
[  109.442512]  #2: ffffffff93a81b20 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0x5/0xc0
[  109.442518]
[  109.442518] stack backtrace:
[  109.442519] CPU: 0 PID: 1032 Comm: nfsd Not tainted 5.10.16-rt30 #1
[  109.442522] Hardware name: Supermicro X9DRL-3F/iF/X9DRL-3F/iF, BIOS 3.2 09/22/2015
[  109.442524] Call Trace:
[  109.442527]  dump_stack+0x77/0x97
[  109.442533]  check_noncircular+0xdc/0xf0
[  109.442546]  __lock_acquire+0x1264/0x20b0
[  109.442553]  lock_acquire+0xc2/0x400
[  109.442564]  rt_spin_lock+0x2b/0xc0
[  109.442570]  __local_bh_disable_ip+0xd9/0x270
[  109.442573]  svc_xprt_do_enqueue+0xc0/0x4d0
[  109.442577]  svc_close_list+0x60/0x90
[  109.442581]  svc_close_net+0x49/0x1a0
[  109.442585]  svc_shutdown_net+0x12/0x40
[  109.442588]  nfsd_destroy+0xc5/0x180
[  109.442590]  nfsd+0x1bc/0x270
[  109.442595]  kthread+0x194/0x1b0
[  109.442600]  ret_from_fork+0x22/0x30
[  109.518225] nfsd: last server has exited, flushing export cache
[  OK  ] Stopped NFSv4 ID-name mapping service.
[  OK  ] Stopped GSSAPI Proxy Daemon.
[  OK  ] Stopped NFS Mount Daemon.
[  OK  ] Stopped NFS status monitor for NFSv2/3 locking..

Fixes: 719f8bc ("svcrpc: fix xpt_list traversal locking on shutdown")
Signed-off-by: Joe Korty <joe.korty@concurrent-rt.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
adamrk pushed a commit that referenced this pull request Mar 26, 2021
The following BUG message was triggered repeatedly when complete counter
sets are extracted from the CPUMF:

BUG: using smp_processor_id() in preemptible [00000000]
     code: psvc-readsets/7759
 caller is cf_diag_needspace+0x2c/0x100
 CPU: 7 PID: 7759 Comm: psvc-readsets Not tainted 5.12.0
 Hardware name: IBM 3906 M03 703 (LPAR)
 Call Trace:
  [<00000000c7043f78>] show_stack+0x90/0xf8
  [<00000000c705776a>] dump_stack+0xba/0x108
  [<00000000c705d91c>] check_preemption_disabled+0xec/0xf0
  [<00000000c63eb1c4>] cf_diag_needspace+0x2c/0x100
  [<00000000c63ecbcc>] cf_diag_ioctl_start+0x10c/0x240
  [<00000000c63ece9a>] cf_diag_ioctl+0x19a/0x238
  [<00000000c675f3f4>] __s390x_sys_ioctl+0xc4/0x100
  [<00000000c63ca762>] do_syscall+0x82/0xd0
  [<00000000c705bdd8>] __do_syscall+0xc0/0xd8
  [<00000000c706d532>] system_call+0x72/0x98
 2 locks held by psvc-readsets/7759:
  #0: 00000000c75a57c0 (cpu_hotplug_lock){++++}-{0:0},
      at: cf_diag_ioctl+0x44/0x238
  #1: 00000000c75a3078 (cf_diag_ctrset_mutex){+.+.}-{3:3},
	            at: cf_diag_ioctl+0x54/0x238

This issue is a missing get_cpu_ptr/put_cpu_ptr pair in function
cf_diag_needspace. Add it.

Fixes: cf6acb8 ("s390/cpumf: Add support for complete counter set extraction")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
adamrk pushed a commit that referenced this pull request Mar 26, 2021
While resolving backreferences, as part of a logical ino ioctl call or
fiemap, we can end up hitting a BUG_ON() when replaying tree mod log
operations of a root, triggering a stack trace like the following:

  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:1210!
  invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 19054 Comm: crawl_335 Tainted: G        W         5.11.0-2d11c0084b02-misc-next+ Rust-for-Linux#89
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  RIP: 0010:__tree_mod_log_rewind+0x3b1/0x3c0
  Code: 05 48 8d 74 10 (...)
  RSP: 0018:ffffc90001eb70b8 EFLAGS: 00010297
  RAX: 0000000000000000 RBX: ffff88812344e400 RCX: ffffffffb28933b6
  RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88812344e42c
  RBP: ffffc90001eb7108 R08: 1ffff11020b60a20 R09: ffffed1020b60a20
  R10: ffff888105b050f9 R11: ffffed1020b60a1f R12: 00000000000000ee
  R13: ffff8880195520c0 R14: ffff8881bc958500 R15: ffff88812344e42c
  FS:  00007fd1955e8700(0000) GS:ffff8881f5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007efdb7928718 CR3: 000000010103a006 CR4: 0000000000170ee0
  Call Trace:
   btrfs_search_old_slot+0x265/0x10d0
   ? lock_acquired+0xbb/0x600
   ? btrfs_search_slot+0x1090/0x1090
   ? free_extent_buffer.part.61+0xd7/0x140
   ? free_extent_buffer+0x13/0x20
   resolve_indirect_refs+0x3e9/0xfc0
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? add_prelim_ref.part.11+0x150/0x150
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? do_raw_spin_unlock+0xa8/0x140
   ? rb_insert_color+0x30/0x360
   ? prelim_ref_insert+0x12d/0x430
   find_parent_nodes+0x5c3/0x1830
   ? resolve_indirect_refs+0xfc0/0xfc0
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x160/0x210
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? poison_range+0x38/0x40
   ? unpoison_range+0x14/0x40
   ? trace_hardirqs_on+0x55/0x120
   btrfs_find_all_roots_safe+0x142/0x1e0
   ? find_parent_nodes+0x1830/0x1830
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   iterate_extent_inodes+0x20e/0x580
   ? tree_backref_for_extent+0x230/0x230
   ? lock_downgrade+0x3d0/0x3d0
   ? read_extent_buffer+0xdd/0x110
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? _raw_spin_unlock+0x22/0x30
   ? __kasan_check_write+0x14/0x20
   iterate_inodes_from_logical+0x129/0x170
   ? iterate_inodes_from_logical+0x129/0x170
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   ? iterate_extent_inodes+0x580/0x580
   ? __vmalloc_node+0x92/0xb0
   ? init_data_container+0x34/0xb0
   ? init_data_container+0x34/0xb0
   ? kvmalloc_node+0x60/0x80
   btrfs_ioctl_logical_to_ino+0x158/0x230
   btrfs_ioctl+0x205e/0x4040
   ? __might_sleep+0x71/0xe0
   ? btrfs_ioctl_get_supported_features+0x30/0x30
   ? getrusage+0x4b6/0x9c0
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __might_fault+0x64/0xd0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? do_vfs_ioctl+0xfc/0x9d0
   ? ioctl_file_clone+0xe0/0xe0
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __task_pid_nr_ns+0xd3/0x250
   ? lock_acquire+0xc7/0x510
   ? __fget_files+0x160/0x230
   ? __fget_light+0xf2/0x110
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7fd1976e2427
  Code: 00 00 90 48 8b 05 (...)
  RSP: 002b:00007fd1955e5cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007fd1955e5f40 RCX: 00007fd1976e2427
  RDX: 00007fd1955e5f48 RSI: 00000000c038943b RDI: 0000000000000004
  RBP: 0000000001000000 R08: 0000000000000000 R09: 00007fd1955e6120
  R10: 0000557835366b00 R11: 0000000000000246 R12: 0000000000000004
  R13: 00007fd1955e5f48 R14: 00007fd1955e5f40 R15: 00007fd1955e5ef8
  Modules linked in:
  ---[ end trace ec8931a1c36e57be ]---

  (gdb) l *(__tree_mod_log_rewind+0x3b1)
  0xffffffff81893521 is in __tree_mod_log_rewind (fs/btrfs/ctree.c:1210).
  1205                     * the modification. as we're going backwards, we do the
  1206                     * opposite of each operation here.
  1207                     */
  1208                    switch (tm->op) {
  1209                    case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
  1210                            BUG_ON(tm->slot < n);
  1211                            fallthrough;
  1212                    case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
  1213                    case MOD_LOG_KEY_REMOVE:
  1214                            btrfs_set_node_key(eb, &tm->key, tm->slot);

Here's what happens to hit that BUG_ON():

1) We have one tree mod log user (through fiemap or the logical ino ioctl),
   with a sequence number of 1, so we have fs_info->tree_mod_seq == 1;

2) Another task is at ctree.c:balance_level() and we have eb X currently as
   the root of the tree, and we promote its single child, eb Y, as the new
   root.

   Then, at ctree.c:balance_level(), we call:

      tree_mod_log_insert_root(eb X, eb Y, 1);

3) At tree_mod_log_insert_root() we create tree mod log elements for each
   slot of eb X, of operation type MOD_LOG_KEY_REMOVE_WHILE_FREEING each
   with a ->logical pointing to ebX->start. These are placed in an array
   named tm_list.
   Lets assume there are N elements (N pointers in eb X);

4) Then, still at tree_mod_log_insert_root(), we create a tree mod log
   element of operation type MOD_LOG_ROOT_REPLACE, ->logical set to
   ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set
   to the level of eb X and ->generation set to the generation of eb X;

5) Then tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
   tm_list as argument. After that, tree_mod_log_free_eb() calls
   __tree_mod_log_insert() for each member of tm_list in reverse order,
   from highest slot in eb X, slot N - 1, to slot 0 of eb X;

6) __tree_mod_log_insert() sets the sequence number of each given tree mod
   log operation - it increments fs_info->tree_mod_seq and sets
   fs_info->tree_mod_seq as the sequence number of the given tree mod log
   operation.

   This means that for the tm_list created at tree_mod_log_insert_root(),
   the element corresponding to slot 0 of eb X has the highest sequence
   number (1 + N), and the element corresponding to the last slot has the
   lowest sequence number (2);

7) Then, after inserting tm_list's elements into the tree mod log rbtree,
   the MOD_LOG_ROOT_REPLACE element is inserted, which gets the highest
   sequence number, which is N + 2;

8) Back to ctree.c:balance_level(), we free eb X by calling
   btrfs_free_tree_block() on it. Because eb X was created in the current
   transaction, has no other references and writeback did not happen for
   it, we add it back to the free space cache/tree;

9) Later some other task T allocates the metadata extent from eb X, since
   it is marked as free space in the space cache/tree, and uses it as a
   node for some other btree;

10) The tree mod log user task calls btrfs_search_old_slot(), which calls
    get_old_root(), and finally that calls __tree_mod_log_oldest_root()
    with time_seq == 1 and eb_root == eb Y;

11) First iteration of the while loop finds the tree mod log element with
    sequence number N + 2, for the logical address of eb Y and of type
    MOD_LOG_ROOT_REPLACE;

12) Because the operation type is MOD_LOG_ROOT_REPLACE, we don't break out
    of the loop, and set root_logical to point to tm->old_root.logical
    which corresponds to the logical address of eb X;

13) On the next iteration of the while loop, the call to
    tree_mod_log_search_oldest() returns the smallest tree mod log element
    for the logical address of eb X, which has a sequence number of 2, an
    operation type of MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to
    the old slot N - 1 of eb X (eb X had N items in it before being freed);

14) We then break out of the while loop and return the tree mod log operation
    of type MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot N - 1 of
    eb X, to get_old_root();

15) At get_old_root(), we process the MOD_LOG_ROOT_REPLACE operation
    and set "logical" to the logical address of eb X, which was the old
    root. We then call tree_mod_log_search() passing it the logical
    address of eb X and time_seq == 1;

16) Then before calling tree_mod_log_search(), task T adds a key to eb X,
    which results in adding a tree mod log operation of type
    MOD_LOG_KEY_ADD to the tree mod log - this is done at
    ctree.c:insert_ptr() - but after adding the tree mod log operation
    and before updating the number of items in eb X from 0 to 1...

17) The task at get_old_root() calls tree_mod_log_search() and gets the
    tree mod log operation of type MOD_LOG_KEY_ADD just added by task T.
    Then it enters the following if branch:

    if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
       (...)
    } (...)

    Calls read_tree_block() for eb X, which gets a reference on eb X but
    does not lock it - task T has it locked.
    Then it clones eb X while it has nritems set to 0 in its header, before
    task T sets nritems to 1 in eb X's header. From hereupon we use the
    clone of eb X which no other task has access to;

18) Then we call __tree_mod_log_rewind(), passing it the MOD_LOG_KEY_ADD
    mod log operation we just got from tree_mod_log_search() in the
    previous step and the cloned version of eb X;

19) At __tree_mod_log_rewind(), we set the local variable "n" to the number
    of items set in eb X's clone, which is 0. Then we enter the while loop,
    and in its first iteration we process the MOD_LOG_KEY_ADD operation,
    which just decrements "n" from 0 to (u32)-1, since "n" is declared with
    a type of u32. At the end of this iteration we call rb_next() to find the
    next tree mod log operation for eb X, that gives us the mod log operation
    of type MOD_LOG_KEY_REMOVE_WHILE_FREEING, for slot 0, with a sequence
    number of N + 1 (steps 3 to 6);

20) Then we go back to the top of the while loop and trigger the following
    BUG_ON():

        (...)
        switch (tm->op) {
        case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
                 BUG_ON(tm->slot < n);
                 fallthrough;
        (...)

    Because "n" has a value of (u32)-1 (4294967295) and tm->slot is 0.

Fix this by taking a read lock on the extent buffer before cloning it at
ctree.c:get_old_root(). This should be done regardless of the extent
buffer having been freed and reused, as a concurrent task might be
modifying it (while holding a write lock on it).

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210227155037.GN28049@hungrycats.org/
Fixes: 834328a ("Btrfs: tree mod log's old roots could still be part of the tree")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
adamrk pushed a commit that referenced this pull request Mar 26, 2021
Starting with commit f295c8c
("drm/nouveau: fix dma syncing warning with debugging on.")
the following oops occures:

   BUG: kernel NULL pointer dereference, address: 0000000000000000
   #PF: supervisor read access in kernel mode
   #PF: error_code(0x0000) - not-present page
   PGD 0 P4D 0
   Oops: 0000 [#1] PREEMPT SMP PTI
   CPU: 6 PID: 1013 Comm: Xorg.bin Tainted: G E     5.11.0-desktop-rc0+ #2
   Hardware name: Acer Aspire VN7-593G/Pluto_KLS, BIOS V1.11 08/01/2018
   RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau]
   Call Trace:
    nouveau_bo_validate+0x5d/0x80 [nouveau]
    nouveau_gem_ioctl_pushbuf+0x662/0x1120 [nouveau]
    ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau]
    drm_ioctl_kernel+0xa6/0xf0 [drm]
    drm_ioctl+0x1f4/0x3a0 [drm]
    ? nouveau_gem_ioctl_new+0xf0/0xf0 [nouveau]
    nouveau_drm_ioctl+0x50/0xa0 [nouveau]
    __x64_sys_ioctl+0x7e/0xb0
    do_syscall_64+0x33/0x80
    entry_SYSCALL_64_after_hwframe+0x44/0xae
   ---[ end trace ccfb1e7f4064374f ]---
   RIP: 0010:nouveau_bo_sync_for_device+0x40/0xb0 [nouveau]

The underlying problem is not introduced by the commit, yet it uncovered the
underlying issue. The cited commit relies on valid pages. This is not given for
due to some bugs. For now, just warn and work around the issue by just ignoring
the bad ttm objects.
Below is some debug info gathered while debugging this issue:

nouveau 0000:01:00.0: DRM: ttm_dma->num_pages: 2048
nouveau 0000:01:00.0: DRM: ttm_dma->pages is NULL
nouveau 0000:01:00.0: DRM: ttm_dma: 00000000e96058e7
nouveau 0000:01:00.0: DRM: ttm_dma->page_flags:
nouveau 0000:01:00.0: DRM: ttm_dma:   Populated: 1
nouveau 0000:01:00.0: DRM: ttm_dma:   No Retry: 0
nouveau 0000:01:00.0: DRM: ttm_dma:   SG: 256
nouveau 0000:01:00.0: DRM: ttm_dma:   Zero Alloc: 0
nouveau 0000:01:00.0: DRM: ttm_dma:   Swapped: 0

Signed-off-by: Tobias Klausmann <tobias.klausmann@freenet.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210313222159.3346-1-tobias.klausmann@freenet.de
adamrk pushed a commit that referenced this pull request Apr 16, 2021
For now only using clang.

Adds -vga none to the qemu command for all targets. But AFAICS that's
safe as both x86 and arm use serial consoles already.

Uses RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C, not RUST_OPT_LEVEL_0 like
other configs. In order to avoid crashes like:

  Rust Example (init)
  Am I built-in? true
  Parameters:
    my_bool:    true
    my_i32:     123321
    my_str:     🦀mod
    my_usize:   42
    my_array:   [0, 1]
  Value: 10
  Value: 10
  Large array has length: 514
  Kernel panic - not syncing: corrupted stack end detected inside scheduler
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc3+ #1

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
adamrk pushed a commit that referenced this pull request Apr 22, 2021
At least on ppc64le, RUST_OPT_LEVEL_0/1 causes some functions to be
generated that use up to 20KB of stack. This leads to stack overflow,
which may exhibit as a panic:

  Kernel panic - not syncing: corrupted stack end detected inside scheduler
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc3+ #1

But may also cause other crashes, depending on what is overwritten by
the overflow.

Add a note to the Kconfig for RUST_OPT_LEVEL_0/1 that this can happen.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
I'm was on the receiving end of a lockdep splat from this driver and after
scratching my head I couldn't be entirely sure it was a false positive
given we would also have to think about whether the regulator locking is
safe (since the notifier is called whilst holding regulator locks which
are also needed for regulator_is_enabled() ).

Regardless of whether it is a real bug or not, the mutex isn't needed.
We can use reference counting tricks instead to avoid races with the
notifier calls.

The observed splat follows:

------------------------------------------------------
kworker/u16:3/127 is trying to acquire lock:
ffff00008021fb20 (&ihid_goodix->regulator_mutex){+.+.}-{4:4}, at: ihid_goodix_vdd_notify+0x30/0x94

but task is already holding lock:
ffff0000835c60c0 (&(&rdev->notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x30/0x70

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&(&rdev->notifier)->rwsem){++++}-{4:4}:
       down_write+0x68/0x8c
       blocking_notifier_chain_register+0x54/0x70
       regulator_register_notifier+0x1c/0x24
       devm_regulator_register_notifier+0x58/0x98
       i2c_hid_of_goodix_probe+0xdc/0x158
       i2c_device_probe+0x25d/0x270
       really_probe+0x174/0x2cc
       __driver_probe_device+0xc0/0xd8
       driver_probe_device+0x50/0xe4
       __device_attach_driver+0xa8/0xc0
       bus_for_each_drv+0x9c/0xc0
       __device_attach_async_helper+0x6c/0xbc
       async_run_entry_fn+0x38/0x100
       process_one_work+0x294/0x438
       worker_thread+0x180/0x258
       kthread+0x120/0x130
       ret_from_fork+0x10/0x20

-> #0 (&ihid_goodix->regulator_mutex){+.+.}-{4:4}:
       __lock_acquire+0xd24/0xfe8
       lock_acquire+0x288/0x2f4
       __mutex_lock+0xa0/0x338
       mutex_lock_nested+0x3c/0x5c
       ihid_goodix_vdd_notify+0x30/0x94
       notifier_call_chain+0x6c/0x8c
       blocking_notifier_call_chain+0x48/0x70
       _notifier_call_chain.isra.0+0x18/0x20
       _regulator_enable+0xc0/0x178
       regulator_enable+0x40/0x7c
       goodix_i2c_hid_power_up+0x18/0x20
       i2c_hid_core_power_up.isra.0+0x1c/0x2c
       i2c_hid_core_probe+0xd8/0x3d4
       i2c_hid_of_goodix_probe+0x14c/0x158
       i2c_device_probe+0x25c/0x270
       really_probe+0x174/0x2cc
       __driver_probe_device+0xc0/0xd8
       driver_probe_device+0x50/0xe4
       __device_attach_driver+0xa8/0xc0
       bus_for_each_drv+0x9c/0xc0
       __device_attach_async_helper+0x6c/0xbc
       async_run_entry_fn+0x38/0x100
       process_one_work+0x294/0x438
       worker_thread+0x180/0x258
       kthread+0x120/0x130
       ret_from_fork+0x10/0x20

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&rdev->notifier)->rwsem);
                               lock(&ihid_goodix->regulator_mutex);
                               lock(&(&rdev->notifier)->rwsem);
  lock(&ihid_goodix->regulator_mutex);

 *** DEADLOCK ***

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Fixes: 18eeef4 ("HID: i2c-hid: goodix: Tie the reset line to true state of the regulator")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
As explained in commits:
74b6d7d ("net: dsa: realtek: register the MDIO bus under devres")
5135e96 ("net: dsa: don't allocate the slave_mii_bus using devres")

mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.

The mv88e6xxx is an MDIO device, so the initial set of constraints that
I thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.

If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the Marvell switch driver on shutdown.

systemd-shutdown[1]: Powering off.
mv88e6085 0x0000000008b96000:00 sw_gl0: Link is Down
fsl-mc dpbp.9: Removing from iommu group 7
fsl-mc dpbp.8: Removing from iommu group 7
------------[ cut here ]------------
kernel BUG at drivers/net/phy/mdio_bus.c:677!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00040-gdc05f73788e5 #15
pc : mdiobus_free+0x44/0x50
lr : devm_mdiobus_free+0x10/0x20
Call trace:
 mdiobus_free+0x44/0x50
 devm_mdiobus_free+0x10/0x20
 devres_release_all+0xa0/0x100
 __device_release_driver+0x190/0x220
 device_release_driver_internal+0xac/0xb0
 device_links_unbind_consumers+0xd4/0x100
 __device_release_driver+0x4c/0x220
 device_release_driver_internal+0xac/0xb0
 device_links_unbind_consumers+0xd4/0x100
 __device_release_driver+0x94/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_device_remove+0x24/0x40
 __fsl_mc_device_remove+0xc/0x20
 device_for_each_child+0x58/0xa0
 dprc_remove+0x90/0xb0
 fsl_mc_driver_remove+0x20/0x5c
 __device_release_driver+0x21c/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_bus_remove+0x80/0x100
 fsl_mc_bus_shutdown+0xc/0x1c
 platform_shutdown+0x20/0x30
 device_shutdown+0x154/0x330
 kernel_power_off+0x34/0x6c
 __do_sys_reboot+0x15c/0x250
 __arm64_sys_reboot+0x20/0x30
 invoke_syscall.constprop.0+0x4c/0xe0
 do_el0_svc+0x4c/0x150
 el0_svc+0x24/0xb0
 el0t_64_sync_handler+0xa8/0xb0
 el0t_64_sync+0x178/0x17c

So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.

The Marvell driver already has a good structure for mdiobus removal, so
just plug in mdiobus_free and get rid of devres.

Fixes: ac3a68d ("net: phy: don't abuse devres in devm_mdiobus_register()")
Reported-by: Rafael Richter <Rafael.Richter@gin.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Daniel Klauer <daniel.klauer@gin.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
If __ibmvnic_open() encounters an error such as when setting link state,
it calls release_resources() which frees the napi structures needlessly.
Instead, have __ibmvnic_open() only clean up the work it did so far (i.e.
disable napi and irqs) and leave the rest to the callers.

If caller of __ibmvnic_open() is ibmvnic_open(), it should release the
resources immediately. If the caller is do_reset() or do_hard_reset(),
they will release the resources on the next reset.

This fixes following crash that occurred when running the drmgr command
several times to add/remove a vnic interface:

	[102056] ibmvnic 30000003 env3: Disabling rx_scrq[6] irq
	[102056] ibmvnic 30000003 env3: Disabling rx_scrq[7] irq
	[102056] ibmvnic 30000003 env3: Replenished 8 pools
	Kernel attempted to read user page (10) - exploit attempt? (uid: 0)
	BUG: Kernel NULL pointer dereference on read at 0x00000010
	Faulting instruction address: 0xc000000000a3c840
	Oops: Kernel access of bad area, sig: 11 [#1]
	LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
	...
	CPU: 9 PID: 102056 Comm: kworker/9:2 Kdump: loaded Not tainted 5.16.0-rc5-autotest-g6441998e2e37 #1
	Workqueue: events_long __ibmvnic_reset [ibmvnic]
	NIP:  c000000000a3c840 LR: c0080000029b5378 CTR: c000000000a3c820
	REGS: c0000000548e37e0 TRAP: 0300   Not tainted  (5.16.0-rc5-autotest-g6441998e2e37)
	MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28248484  XER: 00000004
	CFAR: c0080000029bdd24 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
	GPR00: c0080000029b55d0 c0000000548e3a80 c0000000028f0200 0000000000000000
	...
	NIP [c000000000a3c840] napi_enable+0x20/0xc0
	LR [c0080000029b5378] __ibmvnic_open+0xf0/0x430 [ibmvnic]
	Call Trace:
	[c0000000548e3a80] [0000000000000006] 0x6 (unreliable)
	[c0000000548e3ab0] [c0080000029b55d0] __ibmvnic_open+0x348/0x430 [ibmvnic]
	[c0000000548e3b40] [c0080000029bcc28] __ibmvnic_reset+0x500/0xdf0 [ibmvnic]
	[c0000000548e3c60] [c000000000176228] process_one_work+0x288/0x570
	[c0000000548e3d00] [c000000000176588] worker_thread+0x78/0x660
	[c0000000548e3da0] [c0000000001822f0] kthread+0x1c0/0x1d0
	[c0000000548e3e10] [c00000000000cf64] ret_from_kernel_thread+0x5c/0x64
	Instruction dump:
	7d2948f8 792307e0 4e800020 60000000 3c4c01eb 384239e0 f821ffd1 39430010
	38a0fff6 e92d1100 f9210028 39200000 <e9030010> f9010020 60420000 e9210020
	---[ end trace 5f8033b08fd27706 ]---

Fixes: ed651a1 ("ibmvnic: Updated reset handling")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Link: https://lore.kernel.org/r/20220208001918.900602-1-sukadev@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Rafael reports that on a system with LX2160A and Marvell DSA switches,
if a reboot occurs while the DSA master (dpaa2-eth) is up, the following
panic can be seen:

systemd-shutdown[1]: Rebooting.
Unable to handle kernel paging request at virtual address 00a0000800000041
[00a0000800000041] address between user and kernel address ranges
Internal error: Oops: 96000004 [#1] PREEMPT SMP
CPU: 6 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00042-g8f5585009b24 Rust-for-Linux#32
pc : dsa_slave_netdevice_event+0x130/0x3e4
lr : raw_notifier_call_chain+0x50/0x6c
Call trace:
 dsa_slave_netdevice_event+0x130/0x3e4
 raw_notifier_call_chain+0x50/0x6c
 call_netdevice_notifiers_info+0x54/0xa0
 __dev_close_many+0x50/0x130
 dev_close_many+0x84/0x120
 unregister_netdevice_many+0x130/0x710
 unregister_netdevice_queue+0x8c/0xd0
 unregister_netdev+0x20/0x30
 dpaa2_eth_remove+0x68/0x190
 fsl_mc_driver_remove+0x20/0x5c
 __device_release_driver+0x21c/0x220
 device_release_driver_internal+0xac/0xb0
 device_links_unbind_consumers+0xd4/0x100
 __device_release_driver+0x94/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_device_remove+0x24/0x40
 __fsl_mc_device_remove+0xc/0x20
 device_for_each_child+0x58/0xa0
 dprc_remove+0x90/0xb0
 fsl_mc_driver_remove+0x20/0x5c
 __device_release_driver+0x21c/0x220
 device_release_driver+0x28/0x40
 bus_remove_device+0x118/0x124
 device_del+0x174/0x420
 fsl_mc_bus_remove+0x80/0x100
 fsl_mc_bus_shutdown+0xc/0x1c
 platform_shutdown+0x20/0x30
 device_shutdown+0x154/0x330
 __do_sys_reboot+0x1cc/0x250
 __arm64_sys_reboot+0x20/0x30
 invoke_syscall.constprop.0+0x4c/0xe0
 do_el0_svc+0x4c/0x150
 el0_svc+0x24/0xb0
 el0t_64_sync_handler+0xa8/0xb0
 el0t_64_sync+0x178/0x17c

It can be seen from the stack trace that the problem is that the
deregistration of the master causes a dev_close(), which gets notified
as NETDEV_GOING_DOWN to dsa_slave_netdevice_event().
But dsa_switch_shutdown() has already run, and this has unregistered the
DSA slave interfaces, and yet, the NETDEV_GOING_DOWN handler attempts to
call dev_close_many() on those slave interfaces, leading to the problem.

The previous attempt to avoid the NETDEV_GOING_DOWN on the master after
dsa_switch_shutdown() was called seems improper. Unregistering the slave
interfaces is unnecessary and unhelpful. Instead, after the slaves have
stopped being uppers of the DSA master, we can now reset to NULL the
master->dsa_ptr pointer, which will make DSA start ignoring all future
notifier events on the master.

Fixes: 0650bf5 ("net: dsa: be compatible with masters which unregister on shutdown")
Reported-by: Rafael Richter <rafael.richter@gin.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
When using the flushoncommit mount option, during almost every transaction
commit we trigger a warning from __writeback_inodes_sb_nr():

  $ cat fs/fs-writeback.c:
  (...)
  static void __writeback_inodes_sb_nr(struct super_block *sb, ...
  {
        (...)
        WARN_ON(!rwsem_is_locked(&sb->s_umount));
        (...)
  }
  (...)

The trace produced in dmesg looks like the following:

  [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3
  [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif
  [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 Rust-for-Linux#186
  [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3
  [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...)
  [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246
  [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000
  [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50
  [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000
  [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488
  [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460
  [947.553621] FS:  0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000
  [947.560537] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0
  [947.571072] Call Trace:
  [947.572354]  <TASK>
  [947.573266]  btrfs_commit_transaction+0x1f1/0x998
  [947.576785]  ? start_transaction+0x3ab/0x44e
  [947.579867]  ? schedule_timeout+0x8a/0xdd
  [947.582716]  transaction_kthread+0xe9/0x156
  [947.585721]  ? btrfs_cleanup_transaction.isra.0+0x407/0x407
  [947.590104]  kthread+0x131/0x139
  [947.592168]  ? set_kthread_struct+0x32/0x32
  [947.595174]  ret_from_fork+0x22/0x30
  [947.597561]  </TASK>
  [947.598553] ---[ end trace 644721052755541c ]---

This is because we started using writeback_inodes_sb() to flush delalloc
when committing a transaction (when using -o flushoncommit), in order to
avoid deadlocks with filesystem freeze operations. This change was made
by commit ce8ea7c ("btrfs: don't call btrfs_start_delalloc_roots
in flushoncommit"). After that change we started producing that warning,
and every now and then a user reports this since the warning happens too
often, it spams dmesg/syslog, and a user is unsure if this reflects any
problem that might compromise the filesystem's reliability.

We can not just lock the sb->s_umount semaphore before calling
writeback_inodes_sb(), because that would at least deadlock with
filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem()
is called while we are holding that semaphore in write mode, and that can
trigger a transaction commit, resulting in a deadlock. It would also
trigger the same type of deadlock in the unmount path. Possibly, it could
also introduce some other locking dependencies that lockdep would report.

To fix this call try_to_writeback_inodes_sb() instead of
writeback_inodes_sb(), because that will try to read lock sb->s_umount
and then will only call writeback_inodes_sb() if it was able to lock it.
This is fine because the cases where it can't read lock sb->s_umount
are during a filesystem unmount or during a filesystem freeze - in those
cases sb->s_umount is write locked and sync_filesystem() is called, which
calls writeback_inodes_sb(). In other words, in all cases where we can't
take a read lock on sb->s_umount, writeback is already being triggered
elsewhere.

An alternative would be to call btrfs_start_delalloc_roots() with a
number of pages different from LONG_MAX, for example matching the number
of delalloc bytes we currently have, in which case we would end up
starting all delalloc with filemap_fdatawrite_wbc() and not with an
async flush via filemap_flush() - that is only possible after the rather
recent commit e076ab2 ("btrfs: shrink delalloc pages instead of
full inodes"). However that creates a whole new can of worms due to new
lock dependencies, which lockdep complains, like for example:

[ 8948.247280] ======================================================
[ 8948.247823] WARNING: possible circular locking dependency detected
[ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted
[ 8948.248786] ------------------------------------------------------
[ 8948.249320] kworker/u16:18/933570 is trying to acquire lock:
[ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.250638]
               but task is already holding lock:
[ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.252018]
               which lock already depends on the new lock.

[ 8948.252710]
               the existing dependency chain (in reverse order) is:
[ 8948.253343]
               -> #2 (&root->delalloc_mutex){+.+.}-{3:3}:
[ 8948.253950]        __mutex_lock+0x90/0x900
[ 8948.254354]        start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.254859]        btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.255408]        btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.255942]        btrfs_mksubvol+0x380/0x570 [btrfs]
[ 8948.256406]        btrfs_mksnapshot+0x81/0xb0 [btrfs]
[ 8948.256870]        __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs]
[ 8948.257413]        btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[ 8948.257961]        btrfs_ioctl+0x1196/0x3630 [btrfs]
[ 8948.258418]        __x64_sys_ioctl+0x83/0xb0
[ 8948.258793]        do_syscall_64+0x3b/0xc0
[ 8948.259146]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.259709]
               -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}:
[ 8948.260330]        __mutex_lock+0x90/0x900
[ 8948.260692]        btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.261234]        btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.261766]        btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs]
[ 8948.262379]        btrfs_start_pre_rw_mount+0x119/0x180 [btrfs]
[ 8948.262909]        open_ctree+0x1511/0x171e [btrfs]
[ 8948.263359]        btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 8948.263863]        legacy_get_tree+0x30/0x50
[ 8948.264242]        vfs_get_tree+0x28/0xc0
[ 8948.264594]        vfs_kern_mount.part.0+0x71/0xb0
[ 8948.265017]        btrfs_mount+0x11d/0x3a0 [btrfs]
[ 8948.265462]        legacy_get_tree+0x30/0x50
[ 8948.265851]        vfs_get_tree+0x28/0xc0
[ 8948.266203]        path_mount+0x2d4/0xbe0
[ 8948.266554]        __x64_sys_mount+0x103/0x140
[ 8948.266940]        do_syscall_64+0x3b/0xc0
[ 8948.267300]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.267790]
               -> #0 (sb_internal#2){.+.+}-{0:0}:
[ 8948.268322]        __lock_acquire+0x12e8/0x2260
[ 8948.268733]        lock_acquire+0xd7/0x310
[ 8948.269092]        start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.269591]        find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.270087]        btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.270588]        cow_file_range+0x17e/0x490 [btrfs]
[ 8948.271051]        btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.271586]        writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.272071]        __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.272579]        extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.273113]        extent_writepages+0x76/0x130 [btrfs]
[ 8948.273573]        do_writepages+0xd2/0x1c0
[ 8948.273942]        filemap_fdatawrite_wbc+0x68/0x90
[ 8948.274371]        start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.274876]        btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.275417]        flush_space+0x1f2/0x630 [btrfs]
[ 8948.275863]        btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.276438]        process_one_work+0x252/0x5a0
[ 8948.276829]        worker_thread+0x55/0x3b0
[ 8948.277189]        kthread+0xf2/0x120
[ 8948.277506]        ret_from_fork+0x22/0x30
[ 8948.277868]
               other info that might help us debug this:

[ 8948.278548] Chain exists of:
                 sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex

[ 8948.279601]  Possible unsafe locking scenario:

[ 8948.280102]        CPU0                    CPU1
[ 8948.280508]        ----                    ----
[ 8948.280915]   lock(&root->delalloc_mutex);
[ 8948.281271]                                lock(&fs_info->delalloc_root_mutex);
[ 8948.281915]                                lock(&root->delalloc_mutex);
[ 8948.282487]   lock(sb_internal#2);
[ 8948.282800]
                *** DEADLOCK ***

[ 8948.283333] 4 locks held by kworker/u16:18/933570:
[ 8948.283750]  #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.284609]  #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.285637]  #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.286674]  #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.287596]
              stack backtrace:
[ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1
[ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[ 8948.290298] Call Trace:
[ 8948.290517]  <TASK>
[ 8948.290700]  dump_stack_lvl+0x59/0x73
[ 8948.291026]  check_noncircular+0xf3/0x110
[ 8948.291375]  ? start_transaction+0x228/0x6e0 [btrfs]
[ 8948.291826]  __lock_acquire+0x12e8/0x2260
[ 8948.292241]  lock_acquire+0xd7/0x310
[ 8948.292714]  ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.293241]  ? lock_is_held_type+0xea/0x140
[ 8948.293601]  start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.294055]  ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294518]  find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294957]  ? _raw_spin_unlock+0x29/0x40
[ 8948.295312]  ? btrfs_get_alloc_profile+0x124/0x290 [btrfs]
[ 8948.295813]  btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.296270]  cow_file_range+0x17e/0x490 [btrfs]
[ 8948.296691]  btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.297175]  ? find_lock_delalloc_range+0x247/0x270 [btrfs]
[ 8948.297678]  writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.298123]  __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.298570]  extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.299061]  extent_writepages+0x76/0x130 [btrfs]
[ 8948.299495]  do_writepages+0xd2/0x1c0
[ 8948.299817]  ? sched_clock_cpu+0xd/0x110
[ 8948.300160]  ? lock_release+0x155/0x4a0
[ 8948.300494]  filemap_fdatawrite_wbc+0x68/0x90
[ 8948.300874]  ? do_raw_spin_unlock+0x4b/0xa0
[ 8948.301243]  start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.301706]  ? lock_release+0x155/0x4a0
[ 8948.302055]  btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.302564]  flush_space+0x1f2/0x630 [btrfs]
[ 8948.302970]  btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.303510]  process_one_work+0x252/0x5a0
[ 8948.303860]  ? process_one_work+0x5a0/0x5a0
[ 8948.304221]  worker_thread+0x55/0x3b0
[ 8948.304543]  ? process_one_work+0x5a0/0x5a0
[ 8948.304904]  kthread+0xf2/0x120
[ 8948.305184]  ? kthread_complete_and_exit+0x20/0x20
[ 8948.305598]  ret_from_fork+0x22/0x30
[ 8948.305921]  </TASK>

It all comes from the fact that btrfs_start_delalloc_roots() takes the
delalloc_root_mutex, in the transaction commit path we are holding a
read lock on one of the superblock's freeze semaphores (via
sb_start_intwrite()), the async reclaim task can also do a call to
btrfs_start_delalloc_roots(), which ends up triggering writeback with
calls to filemap_fdatawrite_wbc(), resulting in extent allocation which
in turn can call btrfs_start_transaction(), which will result in taking
the freeze semaphore via sb_start_intwrite(), forming a nasty dependency
on all those locks which can be taken in different orders by different
code paths.

So just adopt the simple approach of calling try_to_writeback_inodes_sb()
at btrfs_start_delalloc_flush().

Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/
Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gmail.com/
Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gmail.com/
Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[ add more link reports ]
Signed-off-by: David Sterba <dsterba@suse.com>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
…ction

I was made aware of the following lockdep splat:

[ 2516.308763] =====================================================
[ 2516.309085] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
[ 2516.309433] 5.14.0-51.el9.aarch64+debug #1 Not tainted
[ 2516.309703] -----------------------------------------------------
[ 2516.310149] stress-ng/153663 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[ 2516.310512] ffff0000e422b198 (&newf->file_lock){+.+.}-{2:2}, at: fd_install+0x368/0x4f0
[ 2516.310944]
               and this task is already holding:
[ 2516.311248] ffff0000c08140d8 (&sighand->siglock){-.-.}-{2:2}, at: copy_process+0x1e2c/0x3e80
[ 2516.311804] which would create a new lock dependency:
[ 2516.312066]  (&sighand->siglock){-.-.}-{2:2} -> (&newf->file_lock){+.+.}-{2:2}
[ 2516.312446]
               but this new dependency connects a HARDIRQ-irq-safe lock:
[ 2516.312983]  (&sighand->siglock){-.-.}-{2:2}
   :
[ 2516.330700]  Possible interrupt unsafe locking scenario:

[ 2516.331075]        CPU0                    CPU1
[ 2516.331328]        ----                    ----
[ 2516.331580]   lock(&newf->file_lock);
[ 2516.331790]                                local_irq_disable();
[ 2516.332231]                                lock(&sighand->siglock);
[ 2516.332579]                                lock(&newf->file_lock);
[ 2516.332922]   <Interrupt>
[ 2516.333069]     lock(&sighand->siglock);
[ 2516.333291]
                *** DEADLOCK ***
[ 2516.389845]
               stack backtrace:
[ 2516.390101] CPU: 3 PID: 153663 Comm: stress-ng Kdump: loaded Not tainted 5.14.0-51.el9.aarch64+debug #1
[ 2516.390756] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 2516.391155] Call trace:
[ 2516.391302]  dump_backtrace+0x0/0x3e0
[ 2516.391518]  show_stack+0x24/0x30
[ 2516.391717]  dump_stack_lvl+0x9c/0xd8
[ 2516.391938]  dump_stack+0x1c/0x38
[ 2516.392247]  print_bad_irq_dependency+0x620/0x710
[ 2516.392525]  check_irq_usage+0x4fc/0x86c
[ 2516.392756]  check_prev_add+0x180/0x1d90
[ 2516.392988]  validate_chain+0x8e0/0xee0
[ 2516.393215]  __lock_acquire+0x97c/0x1e40
[ 2516.393449]  lock_acquire.part.0+0x240/0x570
[ 2516.393814]  lock_acquire+0x90/0xb4
[ 2516.394021]  _raw_spin_lock+0xe8/0x154
[ 2516.394244]  fd_install+0x368/0x4f0
[ 2516.394451]  copy_process+0x1f5c/0x3e80
[ 2516.394678]  kernel_clone+0x134/0x660
[ 2516.394895]  __do_sys_clone3+0x130/0x1f4
[ 2516.395128]  __arm64_sys_clone3+0x5c/0x7c
[ 2516.395478]  invoke_syscall.constprop.0+0x78/0x1f0
[ 2516.395762]  el0_svc_common.constprop.0+0x22c/0x2c4
[ 2516.396050]  do_el0_svc+0xb0/0x10c
[ 2516.396252]  el0_svc+0x24/0x34
[ 2516.396436]  el0t_64_sync_handler+0xa4/0x12c
[ 2516.396688]  el0t_64_sync+0x198/0x19c
[ 2517.491197] NET: Registered PF_ATMPVC protocol family
[ 2517.491524] NET: Registered PF_ATMSVC protocol family
[ 2591.991877] sched: RT throttling activated

One way to solve this problem is to move the fd_install() call out of
the sighand->siglock critical section.

Before commit 6fd2fe4 ("copy_process(): don't use ksys_close()
on cleanups"), the pidfd installation was done without holding both
the task_list lock and the sighand->siglock. Obviously, holding these
two locks are not really needed to protect the fd_install() call.
So move the fd_install() call down to after the releases of both locks.

Link: https://lore.kernel.org/r/20220208163912.1084752-1-longman@redhat.com
Fixes: 6fd2fe4 ("copy_process(): don't use ksys_close() on cleanups")
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Yonghong Song says:

====================

The patch [1] exposed a bpf_timer initialization bug in function
check_and_init_map_value(). With bug fix here, the patch [1]
can be applied with all selftests passed. Please see individual
patches for fix details.

  [1] https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com/

Changelog:
  v3 -> v4:
    . move header file in patch #1 to avoid bpf-next merge conflict
  v2 -> v3:
    . switch patch #1 and patch #2 for better bisecting
  v1 -> v2:
    . add Fixes tag for patch #1
    . rebase against bpf tree
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
The syzbot reported the below BUG:

  kernel BUG at include/linux/page-flags.h:785!
  invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  CPU: 1 PID: 4392 Comm: syz-executor560 Not tainted 5.16.0-rc6-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:PageDoubleMap include/linux/page-flags.h:785 [inline]
  RIP: 0010:__page_mapcount+0x2d2/0x350 mm/util.c:744
  Call Trace:
    page_mapcount include/linux/mm.h:837 [inline]
    smaps_account+0x470/0xb10 fs/proc/task_mmu.c:466
    smaps_pte_entry fs/proc/task_mmu.c:538 [inline]
    smaps_pte_range+0x611/0x1250 fs/proc/task_mmu.c:601
    walk_pmd_range mm/pagewalk.c:128 [inline]
    walk_pud_range mm/pagewalk.c:205 [inline]
    walk_p4d_range mm/pagewalk.c:240 [inline]
    walk_pgd_range mm/pagewalk.c:277 [inline]
    __walk_page_range+0xe23/0x1ea0 mm/pagewalk.c:379
    walk_page_vma+0x277/0x350 mm/pagewalk.c:530
    smap_gather_stats.part.0+0x148/0x260 fs/proc/task_mmu.c:768
    smap_gather_stats fs/proc/task_mmu.c:741 [inline]
    show_smap+0xc6/0x440 fs/proc/task_mmu.c:822
    seq_read_iter+0xbb0/0x1240 fs/seq_file.c:272
    seq_read+0x3e0/0x5b0 fs/seq_file.c:162
    vfs_read+0x1b5/0x600 fs/read_write.c:479
    ksys_read+0x12d/0x250 fs/read_write.c:619
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x44/0xae

The reproducer was trying to read /proc/$PID/smaps when calling
MADV_FREE at the mean time.  MADV_FREE may split THPs if it is called
for partial THP.  It may trigger the below race:

           CPU A                         CPU B
           -----                         -----
  smaps walk:                      MADV_FREE:
  page_mapcount()
    PageCompound()
                                   split_huge_page()
    page = compound_head(page)
    PageDoubleMap(page)

When calling PageDoubleMap() this page is not a tail page of THP anymore
so the BUG is triggered.

This could be fixed by elevated refcount of the page before calling
mapcount, but that would prevent it from counting migration entries, and
it seems overkilling because the race just could happen when PMD is
split so all PTE entries of tail pages are actually migration entries,
and smaps_account() does treat migration entries as mapcount == 1 as
Kirill pointed out.

Add a new parameter for smaps_account() to tell this entry is migration
entry then skip calling page_mapcount().  Don't skip getting mapcount
for device private entries since they do track references with mapcount.

Pagemap also has the similar issue although it was not reported.  Fixed
it as well.

[shy828301@gmail.com: v4]
  Link: https://lkml.kernel.org/r/20220203182641.824731-1-shy828301@gmail.com
[nathan@kernel.org: avoid unused variable warning in pagemap_pmd_range()]
  Link: https://lkml.kernel.org/r/20220207171049.1102239-1-nathan@kernel.org
Link: https://lkml.kernel.org/r/20220120202805.3369-1-shy828301@gmail.com
Fixes: e9b61f1 ("thp: reintroduce split_huge_page()")
Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: syzbot+1f52b3a18d5633fa7f82@syzkaller.appspotmail.com
Acked-by: David Hildenbrand <david@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Alexander reported a circular lock dependency revealed by the mmap1 ltp
test:

  LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1))
          WARNING: possible circular locking dependency detected
          5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1 Not tainted
          ------------------------------------------------------
          mmap1/202299 is trying to acquire lock:
          00000001892c0188 (css_set_lock){..-.}-{2:2}, at: obj_cgroup_release+0x4a/0xe0
          but task is already holding lock:
          00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
          which lock already depends on the new lock.
          the existing dependency chain (in reverse order) is:
          -> #1 (&sighand->siglock){-.-.}-{2:2}:
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 __lock_task_sighand+0x90/0x190
                 cgroup_freeze_task+0x2e/0x90
                 cgroup_migrate_execute+0x11c/0x608
                 cgroup_update_dfl_csses+0x246/0x270
                 cgroup_subtree_control_write+0x238/0x518
                 kernfs_fop_write_iter+0x13e/0x1e0
                 new_sync_write+0x100/0x190
                 vfs_write+0x22c/0x2d8
                 ksys_write+0x6c/0xf8
                 __do_syscall+0x1da/0x208
                 system_call+0x82/0xb0
          -> #0 (css_set_lock){..-.}-{2:2}:
                 check_prev_add+0xe0/0xed8
                 validate_chain+0x736/0xb20
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 obj_cgroup_release+0x4a/0xe0
                 percpu_ref_put_many.constprop.0+0x150/0x168
                 drain_obj_stock+0x94/0xe8
                 refill_obj_stock+0x94/0x278
                 obj_cgroup_charge+0x164/0x1d8
                 kmem_cache_alloc+0xac/0x528
                 __sigqueue_alloc+0x150/0x308
                 __send_signal+0x260/0x550
                 send_signal+0x7e/0x348
                 force_sig_info_to_task+0x104/0x180
                 force_sig_fault+0x48/0x58
                 __do_pgm_check+0x120/0x1f0
                 pgm_check_handler+0x11e/0x180
          other info that might help us debug this:
           Possible unsafe locking scenario:
                 CPU0                    CPU1
                 ----                    ----
            lock(&sighand->siglock);
                                         lock(css_set_lock);
                                         lock(&sighand->siglock);
            lock(css_set_lock);
           *** DEADLOCK ***
          2 locks held by mmap1/202299:
           #0: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
           #1: 00000001892ad560 (rcu_read_lock){....}-{1:2}, at: percpu_ref_put_many.constprop.0+0x0/0x168
          stack backtrace:
          CPU: 15 PID: 202299 Comm: mmap1 Not tainted 5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1
          Hardware name: IBM 3906 M04 704 (LPAR)
          Call Trace:
            dump_stack_lvl+0x76/0x98
            check_noncircular+0x136/0x158
            check_prev_add+0xe0/0xed8
            validate_chain+0x736/0xb20
            __lock_acquire+0x604/0xbd8
            lock_acquire.part.0+0xe2/0x238
            lock_acquire+0xb0/0x200
            _raw_spin_lock_irqsave+0x6a/0xd8
            obj_cgroup_release+0x4a/0xe0
            percpu_ref_put_many.constprop.0+0x150/0x168
            drain_obj_stock+0x94/0xe8
            refill_obj_stock+0x94/0x278
            obj_cgroup_charge+0x164/0x1d8
            kmem_cache_alloc+0xac/0x528
            __sigqueue_alloc+0x150/0x308
            __send_signal+0x260/0x550
            send_signal+0x7e/0x348
            force_sig_info_to_task+0x104/0x180
            force_sig_fault+0x48/0x58
            __do_pgm_check+0x120/0x1f0
            pgm_check_handler+0x11e/0x180
          INFO: lockdep is turned off.

In this example a slab allocation from __send_signal() caused a
refilling and draining of a percpu objcg stock, resulted in a releasing
of another non-related objcg.  Objcg release path requires taking the
css_set_lock, which is used to synchronize objcg lists.

This can create a circular dependency with the sighandler lock, which is
taken with the locked css_set_lock by the freezer code (to freeze a
task).

In general it seems that using css_set_lock to synchronize objcg lists
makes any slab allocations and deallocation with the locked css_set_lock
and any intervened locks risky.

To fix the problem and make the code more robust let's stop using
css_set_lock to synchronize objcg lists and use a new dedicated spinlock
instead.

Link: https://lkml.kernel.org/r/Yfm1IHmoGdyUR81T@carbon.dhcp.thefacebook.com
Fixes: bf4f059 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Some time ago 8965779 ("ipv6,mcast: always hold idev->lock before mca_lock")
switched ipv6_get_lladdr() to __ipv6_get_lladdr(), which is rcu-unsafe
version. That was OK, because idev->lock was held for these codepaths.

In 88e2ca3 ("mld: convert ifmcaddr6 to RCU") these external locks were
removed, so we probably need to restore the original rcu-safe call.

Otherwise, we occasionally get a machine crashed/stalled with the following
in dmesg:

[ 3405.966610][T230589] general protection fault, probably for non-canonical address 0xdead00000000008c: 0000 [#1] SMP NOPTI
[ 3405.982083][T230589] CPU: 44 PID: 230589 Comm: kworker/44:3 Tainted: G           O      5.15.19-cloudflare-2022.2.1 #1
[ 3405.998061][T230589] Hardware name: SUPA-COOL-SERV
[ 3406.009552][T230589] Workqueue: mld mld_ifc_work
[ 3406.017224][T230589] RIP: 0010:__ipv6_get_lladdr+0x34/0x60
[ 3406.025780][T230589] Code: 57 10 48 83 c7 08 48 89 e5 48 39 d7 74 3e 48 8d 82 38 ff ff ff eb 13 48 8b 90 d0 00 00 00 48 8d 82 38 ff ff ff 48 39 d7 74 22 <66> 83 78 32 20 77 1b 75 e4 89 ca 23 50 2c 75 dd 48 8b 50 08 48 8b
[ 3406.055748][T230589] RSP: 0018:ffff94e4b3fc3d10 EFLAGS: 00010202
[ 3406.065617][T230589] RAX: dead00000000005a RBX: ffff94e4b3fc3d30 RCX: 0000000000000040
[ 3406.077477][T230589] RDX: dead000000000122 RSI: ffff94e4b3fc3d30 RDI: ffff8c3a31431008
[ 3406.089389][T230589] RBP: ffff94e4b3fc3d10 R08: 0000000000000000 R09: 0000000000000000
[ 3406.101445][T230589] R10: ffff8c3a31430000 R11: 000000000000000b R12: ffff8c2c37887100
[ 3406.113553][T230589] R13: ffff8c3a39537000 R14: 00000000000005dc R15: ffff8c3a31431000
[ 3406.125730][T230589] FS:  0000000000000000(0000) GS:ffff8c3b9fc80000(0000) knlGS:0000000000000000
[ 3406.138992][T230589] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3406.149895][T230589] CR2: 00007f0dfea1db60 CR3: 000000387b5f2000 CR4: 0000000000350ee0
[ 3406.162421][T230589] Call Trace:
[ 3406.170235][T230589]  <TASK>
[ 3406.177736][T230589]  mld_newpack+0xfe/0x1a0
[ 3406.186686][T230589]  add_grhead+0x87/0xa0
[ 3406.195498][T230589]  add_grec+0x485/0x4e0
[ 3406.204310][T230589]  ? newidle_balance+0x126/0x3f0
[ 3406.214024][T230589]  mld_ifc_work+0x15d/0x450
[ 3406.223279][T230589]  process_one_work+0x1e6/0x380
[ 3406.232982][T230589]  worker_thread+0x50/0x3a0
[ 3406.242371][T230589]  ? rescuer_thread+0x360/0x360
[ 3406.252175][T230589]  kthread+0x127/0x150
[ 3406.261197][T230589]  ? set_kthread_struct+0x40/0x40
[ 3406.271287][T230589]  ret_from_fork+0x22/0x30
[ 3406.280812][T230589]  </TASK>
[ 3406.288937][T230589] Modules linked in: ... [last unloaded: kheaders]
[ 3406.476714][T230589] ---[ end trace 3525a7655f2f3b9e ]---

Fixes: 88e2ca3 ("mld: convert ifmcaddr6 to RCU")
Reported-by: David Pinilla Caparros <dpini@cloudflare.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
alg_memory_allocated does not seem to be really used.

alg_proto does have a .memory_allocated field, but no
corresponding .sysctl_mem.

This means sk_has_account() returns true, but all sk_prot_mem_limits()
users will trigger a NULL dereference [1].

THis was not a problem until SO_RESERVE_MEM addition.

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 3591 Comm: syz-executor153 Not tainted 5.17.0-rc3-syzkaller-00316-gb81b1829e7e3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:sk_prot_mem_limits include/net/sock.h:1523 [inline]
RIP: 0010:sock_reserve_memory+0x1d7/0x330 net/core/sock.c:1000
Code: 08 00 74 08 48 89 ef e8 27 20 bb f9 4c 03 7c 24 10 48 8b 6d 00 48 83 c5 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fb 1f bb f9 48 8b 6d 00 4c 89 ff 48
RSP: 0018:ffffc90001f1fb68 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88814aabc000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff90e18120
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff21c3025
R10: fffffbfff21c3025 R11: 0000000000000000 R12: ffffffff8d109840
R13: 0000000000001002 R14: 0000000000000001 R15: 0000000000000001
FS:  0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sock_setsockopt+0x14a9/0x3a30 net/core/sock.c:1446
 __sys_setsockopt+0x5af/0x980 net/socket.c:2176
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc7440fddc9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe98f07968 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc7440fddc9
RDX: 0000000000000049 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000004 R09: 00007ffe98f07990
R10: 0000000020000000 R11: 0000000000000246 R12: 00007ffe98f0798c
R13: 00007ffe98f079a0 R14: 00007ffe98f079e0 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:sk_prot_mem_limits include/net/sock.h:1523 [inline]
RIP: 0010:sock_reserve_memory+0x1d7/0x330 net/core/sock.c:1000
Code: 08 00 74 08 48 89 ef e8 27 20 bb f9 4c 03 7c 24 10 48 8b 6d 00 48 83 c5 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fb 1f bb f9 48 8b 6d 00 4c 89 ff 48
RSP: 0018:ffffc90001f1fb68 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88814aabc000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff90e18120
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff21c3025
R10: fffffbfff21c3025 R11: 0000000000000000 R12: ffffffff8d109840
R13: 0000000000001002 R14: 0000000000000001 R15: 0000000000000001
FS:  0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

Fixes: 2bb2f5f ("net: add new socket option SO_RESERVE_MEM")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Compressed length can be corrupted to be a lot larger than memory
we have allocated for buffer.
This will cause memcpy in copy_compressed_segment to write outside
of allocated memory.

This mostly results in stuck read syscall but sometimes when using
btrfs send can get #GP

  kernel: general protection fault, probably for non-canonical address 0x841551d5c1000: 0000 [#1] PREEMPT SMP NOPTI
  kernel: CPU: 17 PID: 264 Comm: kworker/u256:7 Tainted: P           OE     5.17.0-rc2-1 #12
  kernel: Workqueue: btrfs-endio btrfs_work_helper [btrfs]
  kernel: RIP: 0010:lzo_decompress_bio (./include/linux/fortify-string.h:225 fs/btrfs/lzo.c:322 fs/btrfs/lzo.c:394) btrfs
  Code starting with the faulting instruction
  ===========================================
     0:*  48 8b 06                mov    (%rsi),%rax              <-- trapping instruction
     3:   48 8d 79 08             lea    0x8(%rcx),%rdi
     7:   48 83 e7 f8             and    $0xfffffffffffffff8,%rdi
     b:   48 89 01                mov    %rax,(%rcx)
     e:   44 89 f0                mov    %r14d,%eax
    11:   48 8b 54 06 f8          mov    -0x8(%rsi,%rax,1),%rdx
  kernel: RSP: 0018:ffffb110812efd50 EFLAGS: 00010212
  kernel: RAX: 0000000000001000 RBX: 000000009ca264c8 RCX: ffff98996e6d8ff8
  kernel: RDX: 0000000000000064 RSI: 000841551d5c1000 RDI: ffffffff9500435d
  kernel: RBP: ffff989a3be856c0 R08: 0000000000000000 R09: 0000000000000000
  kernel: R10: 0000000000000000 R11: 0000000000001000 R12: ffff98996e6d8000
  kernel: R13: 0000000000000008 R14: 0000000000001000 R15: 000841551d5c1000
  kernel: FS:  0000000000000000(0000) GS:ffff98a09d640000(0000) knlGS:0000000000000000
  kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  kernel: CR2: 00001e9f984d9ea8 CR3: 000000014971a000 CR4: 00000000003506e0
  kernel: Call Trace:
  kernel:  <TASK>
  kernel: end_compressed_bio_read (fs/btrfs/compression.c:104 fs/btrfs/compression.c:1363 fs/btrfs/compression.c:323) btrfs
  kernel: end_workqueue_fn (fs/btrfs/disk-io.c:1923) btrfs
  kernel: btrfs_work_helper (fs/btrfs/async-thread.c:326) btrfs
  kernel: process_one_work (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:212 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2312)
  kernel: worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2455)
  kernel: ? process_one_work (kernel/workqueue.c:2397)
  kernel: kthread (kernel/kthread.c:377)
  kernel: ? kthread_complete_and_exit (kernel/kthread.c:332)
  kernel: ret_from_fork (arch/x86/entry/entry_64.S:301)
  kernel:  </TASK>

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
Booting a MACCHIATObin with 5.17, the system OOPs with
a null pointer deref when the network is started. This
is caused by the pcs->ops structure being null in
mcpp2_acpi_start() when it tries to call pcs_config().

Hoisting the code which sets pcs_gmac.ops and pcs_xlg.ops,
assuring they are always set, fixes the problem.

The OOPs looks like:
[   18.687760] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000010
[   18.698561] Mem abort info:
[   18.698564]   ESR = 0x96000004
[   18.698567]   EC = 0x25: DABT (current EL), IL = 32 bits
[   18.709821]   SET = 0, FnV = 0
[   18.714292]   EA = 0, S1PTW = 0
[   18.718833]   FSC = 0x04: level 0 translation fault
[   18.725126] Data abort info:
[   18.729408]   ISV = 0, ISS = 0x00000004
[   18.734655]   CM = 0, WnR = 0
[   18.738933] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000111bbf000
[   18.745409] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
[   18.752235] Internal error: Oops: 96000004 [#1] SMP
[   18.757134] Modules linked in: rfkill ip_set nf_tables nfnetlink qrtr sunrpc vfat fat omap_rng fuse zram xfs crct10dif_ce mvpp2 ghash_ce sbsa_gwdt phylink xhci_plat_hcd ahci_plam
[   18.773481] CPU: 0 PID: 681 Comm: NetworkManager Not tainted 5.17.0-0.rc3.89.fc36.aarch64 #1
[   18.781954] Hardware name: Marvell                         Armada 7k/8k Family Board      /Armada 7k/8k Family Board      , BIOS EDK II Jun  4 2019
[   18.795222] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   18.802213] pc : mvpp2_start_dev+0x2b0/0x300 [mvpp2]
[   18.807208] lr : mvpp2_start_dev+0x298/0x300 [mvpp2]
[   18.812197] sp : ffff80000b4732c0
[   18.815522] x29: ffff80000b4732c0 x28: 0000000000000000 x27: ffffccab38ae57f8
[   18.822689] x26: ffff6eeb03065a10 x25: ffff80000b473a30 x24: ffff80000b4735b8
[   18.829855] x23: 0000000000000000 x22: 00000000000001e0 x21: ffff6eeb07b6ab68
[   18.837021] x20: ffff6eeb07b6ab30 x19: ffff6eeb07b6a9c0 x18: 0000000000000014
[   18.844187] x17: 00000000f6232bfe x16: ffffccab899b1dc0 x15: 000000006a30f9fa
[   18.851353] x14: 000000003b77bd50 x13: 000006dc896f0e8e x12: 001bbbfccfd0d3a2
[   18.858519] x11: 0000000000001528 x10: 0000000000001548 x9 : ffffccab38ad0fb0
[   18.865685] x8 : ffff80000b473330 x7 : 0000000000000000 x6 : 0000000000000000
[   18.872851] x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80000b4732f8
[   18.880017] x2 : 000000000000001a x1 : 0000000000000002 x0 : ffff6eeb07b6ab68
[   18.887183] Call trace:
[   18.889637]  mvpp2_start_dev+0x2b0/0x300 [mvpp2]
[   18.894279]  mvpp2_open+0x134/0x2b4 [mvpp2]
[   18.898483]  __dev_open+0x128/0x1e4
[   18.901988]  __dev_change_flags+0x17c/0x1d0
[   18.906187]  dev_change_flags+0x30/0x70
[   18.910038]  do_setlink+0x278/0xa7c
[   18.913540]  __rtnl_newlink+0x44c/0x7d0
[   18.917391]  rtnl_newlink+0x5c/0x8c
[   18.920892]  rtnetlink_rcv_msg+0x254/0x314
[   18.925006]  netlink_rcv_skb+0x48/0x10c
[   18.928858]  rtnetlink_rcv+0x24/0x30
[   18.932449]  netlink_unicast+0x290/0x2f4
[   18.936386]  netlink_sendmsg+0x1d0/0x41c
[   18.940323]  sock_sendmsg+0x60/0x70
[   18.943825]  ____sys_sendmsg+0x248/0x260
[   18.947762]  ___sys_sendmsg+0x74/0xa0
[   18.951438]  __sys_sendmsg+0x64/0xcc
[   18.955027]  __arm64_sys_sendmsg+0x30/0x40
[   18.959140]  invoke_syscall+0x50/0x120
[   18.962906]  el0_svc_common.constprop.0+0x4c/0xf4
[   18.967629]  do_el0_svc+0x30/0x9c
[   18.970958]  el0_svc+0x28/0xb0
[   18.974025]  el0t_64_sync_handler+0x10c/0x140
[   18.978400]  el0t_64_sync+0x1a4/0x1a8
[   18.982078] Code: 52800004 b9416262 aa1503e0 52800041 (f94008a5)
[   18.988196] ---[ end trace 0000000000000000 ]---

Fixes: cff0563 ("net: mvpp2: use .mac_select_pcs() interface")
Suggested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/20220214231852.3331430-1-jeremy.linton@arm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
If an attempt is made to a sensor with a thermal zone and it fails,
the call to devm_thermal_zone_of_sensor_register() may return -ENODEV.
This may result in crashes similar to the following.

Unable to handle kernel NULL pointer dereference at virtual address 00000000000003cd
...
Internal error: Oops: 96000021 [#1] PREEMPT SMP
...
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mutex_lock+0x18/0x60
lr : thermal_zone_device_update+0x40/0x2e0
sp : ffff800014c4fc60
x29: ffff800014c4fc60 x28: ffff365ee3f6e000 x27: ffffdde218426790
x26: ffff365ee3f6e000 x25: 0000000000000000 x24: ffff365ee3f6e000
x23: ffffdde218426870 x22: ffff365ee3f6e000 x21: 00000000000003cd
x20: ffff365ee8bf3308 x19: ffffffffffffffed x18: 0000000000000000
x17: ffffdde21842689c x16: ffffdde1cb7a0b7c x15: 0000000000000040
x14: ffffdde21a4889a0 x13: 0000000000000228 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000001120000 x7 : 0000000000000001 x6 : 0000000000000000
x5 : 0068000878e20f07 x4 : 0000000000000000 x3 : 00000000000003cd
x2 : ffff365ee3f6e000 x1 : 0000000000000000 x0 : 00000000000003cd
Call trace:
 mutex_lock+0x18/0x60
 hwmon_notify_event+0xfc/0x110
 0xffffdde1cb7a0a90
 0xffffdde1cb7a0b7c
 irq_thread_fn+0x2c/0xa0
 irq_thread+0x134/0x240
 kthread+0x178/0x190
 ret_from_fork+0x10/0x20
Code: d503201f d503201f d2800001 aa0103e4 (c8e47c02)

Jon Hunter reports that the exact call sequence is:

hwmon_notify_event()
  --> hwmon_thermal_notify()
    --> thermal_zone_device_update()
      --> update_temperature()
        --> mutex_lock()

The hwmon core needs to handle all errors returned from calls
to devm_thermal_zone_of_sensor_register(). If the call fails
with -ENODEV, report that the sensor was not attached to a
thermal zone  but continue to register the hwmon device.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Cc: Dmitry Osipenko <digetx@gmail.com>
Fixes: 1597b37 ("hwmon: Add notification support")
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
If a bridged port is not offloaded to the hardware - either because the
underlying driver does not implement the port_bridge_{join,leave} ops,
or because the operation failed - then its dp->bridge pointer will be
NULL when dsa_port_bridge_leave() is called. Avoid dereferncing NULL.

This fixes the following splat when removing a port from a bridge:

 Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000
 Internal error: Oops: 96000004 [#1] PREEMPT_RT SMP
 CPU: 3 PID: 1119 Comm: brctl Tainted: G           O      5.17.0-rc4-rt4 #1
 Call trace:
  dsa_port_bridge_leave+0x8c/0x1e4
  dsa_slave_changeupper+0x40/0x170
  dsa_slave_netdevice_event+0x494/0x4d4
  notifier_call_chain+0x80/0xe0
  raw_notifier_call_chain+0x1c/0x24
  call_netdevice_notifiers_info+0x5c/0xac
  __netdev_upper_dev_unlink+0xa4/0x200
  netdev_upper_dev_unlink+0x38/0x60
  del_nbp+0x1b0/0x300
  br_del_if+0x38/0x114
  add_del_if+0x60/0xa0
  br_ioctl_stub+0x128/0x2dc
  br_ioctl_call+0x68/0xb0
  dev_ifsioc+0x390/0x554
  dev_ioctl+0x128/0x400
  sock_do_ioctl+0xb4/0xf4
  sock_ioctl+0x12c/0x4e0
  __arm64_sys_ioctl+0xa8/0xf0
  invoke_syscall+0x4c/0x110
  el0_svc_common.constprop.0+0x48/0xf0
  do_el0_svc+0x28/0x84
  el0_svc+0x1c/0x50
  el0t_64_sync_handler+0xa8/0xb0
  el0t_64_sync+0x17c/0x180
 Code: f9402f00 f0002261 f9401302 913cc021 (a9401404)
 ---[ end trace 0000000000000000 ]---

Fixes: d3eed0e ("net: dsa: keep the bridge_dev and bridge_num as part of the same structure")
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220221203539.310690-1-alvin@pqrs.dk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
adamrk pushed a commit that referenced this pull request Mar 11, 2022
The trace_hardirqs_{on,off}() require the caller to setup frame pointer
properly. This because these two functions use macro 'CALLER_ADDR1' (aka.
__builtin_return_address(1)) to acquire caller info. If the $fp is used
for other purpose, the code generated this macro (as below) could trigger
memory access fault.

   0xffffffff8011510e <+80>:    ld      a1,-16(s0)
   0xffffffff80115112 <+84>:    ld      s2,-8(a1)  # <-- paging fault here

The oops message during booting if compiled with 'irqoff' tracer enabled:
[    0.039615][    T0] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8
[    0.041925][    T0] Oops [#1]
[    0.042063][    T0] Modules linked in:
[    0.042864][    T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-rc1-00233-g9a20c48d1ed2 Rust-for-Linux#29
[    0.043568][    T0] Hardware name: riscv-virtio,qemu (DT)
[    0.044343][    T0] epc : trace_hardirqs_on+0x56/0xe2
[    0.044601][    T0]  ra : restore_all+0x12/0x6e
[    0.044721][    T0] epc : ffffffff80126a5c ra : ffffffff80003b94 sp : ffffffff81403db0
[    0.044801][    T0]  gp : ffffffff8163acd8 tp : ffffffff81414880 t0 : 0000000000000020
[    0.044882][    T0]  t1 : 0098968000000000 t2 : 0000000000000000 s0 : ffffffff81403de0
[    0.044967][    T0]  s1 : 0000000000000000 a0 : 0000000000000001 a1 : 0000000000000100
[    0.045046][    T0]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.045124][    T0]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000054494d45
[    0.045210][    T0]  s2 : ffffffff80003b94 s3 : ffffffff81a8f1b0 s4 : ffffffff80e27b50
[    0.045289][    T0]  s5 : ffffffff81414880 s6 : ffffffff8160fa00 s7 : 00000000800120e8
[    0.045389][    T0]  s8 : 0000000080013100 s9 : 000000000000007f s10: 0000000000000000
[    0.045474][    T0]  s11: 0000000000000000 t3 : 7fffffffffffffff t4 : 0000000000000000
[    0.045548][    T0]  t5 : 0000000000000000 t6 : ffffffff814aa368
[    0.045620][    T0] status: 0000000200000100 badaddr: 00000000000000f8 cause: 000000000000000d
[    0.046402][    T0] [<ffffffff80003b94>] restore_all+0x12/0x6e

This because the $fp(aka. $s0) register is not used as frame pointer in the
assembly entry code.

	resume_kernel:
		REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
		bnez s0, restore_all
		REG_L s0, TASK_TI_FLAGS(tp)
                andi s0, s0, _TIF_NEED_RESCHED
                beqz s0, restore_all
                call preempt_schedule_irq
                j restore_all

To fix above issue, here we add one extra level wrapper for function
trace_hardirqs_{on,off}() so they can be safely called by low level entry
code.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: 3c46979 ("riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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