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Rust for linux arm 32bit (rebased)#3

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TheSven73 wants to merge 6 commits into
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rust-for-linux-arm-32bit
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Rust for linux arm 32bit (rebased)#3
TheSven73 wants to merge 6 commits into
rust-for-linuxfrom
rust-for-linux-arm-32bit

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@TheSven73

@TheSven73 TheSven73 commented Apr 14, 2021

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v1 -> v2:

  • minimize arm-release defconfig

Sven Van Asbroeck added 6 commits April 14, 2021 19:42
This is simply based on output from:
 $ rustc +nightly -Z unstable-options \
     --target=arm-unknown-linux-gnueabi \
     --print target-spec-json

Changes made:
- removed "unsupported-abis"
  (does not build)
- added   "function-sections": false
  (all kernel functions should go in the .text section)
- added   "relocation-model": "static"
  (kernel does not support .data.rel.ro sections)

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
The bug which this guard protects against
(rust-lang/rust-bindgen#1671)
was fixed upstream as of rust-bindgen v0.53:
rust-lang/rust-bindgen#1688
d650823839f7 ("Remove size_t to usize conversion")

The current recommended rust-bindgen version for building
the Linux kernel is v0.56, so the guard can be safely
dropped.

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Add panic handlers for the following 32-bit arm intrinsics:
- __aeabi_ul2f, __aeabi_ul2d  : floating-point operations
- __aeabi_uldivmod, __mulodi4 : 64-bit division

Neither floating point operations, nor native 64-bit
division are supported inside the kernel, so we can
safely implement these with a panic handler.

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Remove the assumption that c_types::c_ulong is u64. This is true
only on 64-bit cpu architectures.

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Everything is now in place to enable Rust support on 32-bit
arm.

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
qemu emulates the virt machine running a cortex-a7.

kernel-arm-release.config corresponds to:
- arch/arm/configs/multi_v7_defconfig (includes cortex-a7 virt support)
- enable rust support, enable rust samples (as modules)
- enable android/binder rust support

Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
@TheSven73 TheSven73 force-pushed the rust-for-linux-arm-32bit branch 3 times, most recently from 832d8d4 to d94b886 Compare April 15, 2021 14:46
@TheSven73 TheSven73 closed this Apr 15, 2021
TheSven73 pushed a commit that referenced this pull request Jun 29, 2021
Merge branch 'mlxsw-fixes'

Ido Schimmel says:

====================
mlxsw: Thermal and qdisc fixes

Patches #1-#2 fix wrong validation of burst size in qdisc code and a
user triggerable WARN_ON().

Patch #3 fixes a regression in thermal monitoring of transceiver modules
and gearboxes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
TheSven73 pushed a commit that referenced this pull request Jun 29, 2021
In vc4_atomic_commit_tail() we iterate of the set of old CRTCs, and
attempt to wait on any channels which are still in use. When we iterate
over the CRTCs, we have:

* `i` - the index of the CRTC
* `channel` - the channel a CRTC is using

When we check the channel state, we consult:

  old_hvs_state->fifo_state[channel].in_use

... but when we wait for the channel, we erroneously wait on:

  old_hvs_state->fifo_state[i].pending_commit

... rather than:

   old_hvs_state->fifo_state[channel].pending_commit

... and this bogus access has been observed to result in boot-time hangs
on some arm64 configurations, and can be detected using KASAN. FIx this
by using the correct index.

I've tested this on a Raspberry Pi 3 model B v1.2 with KASAN.

Trimmed KASAN splat:

| ==================================================================
| BUG: KASAN: slab-out-of-bounds in vc4_atomic_commit_tail+0x1cc/0x910
| Read of size 8 at addr ffff000007360440 by task kworker/u8:0/7
| CPU: 2 PID: 7 Comm: kworker/u8:0 Not tainted 5.13.0-rc3-00009-g694c523e7267 #3
|
| Hardware name: Raspberry Pi 3 Model B (DT)
| Workqueue: events_unbound deferred_probe_work_func
| Call trace:
|  dump_backtrace+0x0/0x2b4
|  show_stack+0x1c/0x30
|  dump_stack+0xfc/0x168
|  print_address_description.constprop.0+0x2c/0x2c0
|  kasan_report+0x1dc/0x240
|  __asan_load8+0x98/0xd4
|  vc4_atomic_commit_tail+0x1cc/0x910
|  commit_tail+0x100/0x210
| ...
|
| Allocated by task 7:
|  kasan_save_stack+0x2c/0x60
|  __kasan_kmalloc+0x90/0xb4
|  vc4_hvs_channels_duplicate_state+0x60/0x1a0
|  drm_atomic_get_private_obj_state+0x144/0x230
|  vc4_atomic_check+0x40/0x73c
|  drm_atomic_check_only+0x998/0xe60
|  drm_atomic_commit+0x34/0x94
|  drm_client_modeset_commit_atomic+0x2f4/0x3a0
|  drm_client_modeset_commit_locked+0x8c/0x230
|  drm_client_modeset_commit+0x38/0x60
|  drm_fb_helper_set_par+0x104/0x17c
|  fbcon_init+0x43c/0x970
|  visual_init+0x14c/0x1e4
| ...
|
| The buggy address belongs to the object at ffff000007360400
|  which belongs to the cache kmalloc-128 of size 128
| The buggy address is located 64 bytes inside of
|  128-byte region [ffff000007360400, ffff000007360480)
| The buggy address belongs to the page:
| page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7360
| flags: 0x3fffc0000000200(slab|node=0|zone=0|lastcpupid=0xffff)
| raw: 03fffc0000000200 dead000000000100 dead000000000122 ffff000004c02300
| raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
| page dumped because: kasan: bad access detected
|
| Memory state around the buggy address:
|  ffff000007360300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
|  ffff000007360380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
| >ffff000007360400: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
|                                            ^
|  ffff000007360480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
|  ffff000007360500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
| ==================================================================

Link: https://lore.kernel.org/r/4d0c8318-bad8-2be7-e292-fc8f70c198de@samsung.com
Link: https://lore.kernel.org/linux-arm-kernel/20210607151740.moncryl5zv3ahq4s@gilmour
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Emma Anholt <emma@anholt.net>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Will Deacon <will@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608085513.2069-1-mark.rutland@arm.com
TheSven73 pushed a commit that referenced this pull request Jun 29, 2021
I see a "virt_to_phys used for non-linear address" warning from
check_usemap_section_nr() on arm64 platforms.

In current implementation of NODE_DATA, if CONFIG_NEED_MULTIPLE_NODES=y,
pglist_data is dynamically allocated and assigned to node_data[].

For example, in arch/arm64/include/asm/mmzone.h:

  extern struct pglist_data *node_data[];
  #define NODE_DATA(nid)          (node_data[(nid)])

If CONFIG_NEED_MULTIPLE_NODES=n, pglist_data is defined as a global
variable named "contig_page_data".

For example, in include/linux/mmzone.h:

  extern struct pglist_data contig_page_data;
  #define NODE_DATA(nid)          (&contig_page_data)

If CONFIG_DEBUG_VIRTUAL is not enabled, __pa() can handle both
dynamically allocated linear addresses and symbol addresses.  However,
if (CONFIG_DEBUG_VIRTUAL=y && CONFIG_NEED_MULTIPLE_NODES=n) we can see
the "virt_to_phys used for non-linear address" warning because that
&contig_page_data is not a linear address on arm64.

Warning message:

  virt_to_phys used for non-linear address: (contig_page_data+0x0/0x1c00)
  WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Tainted: G        W         5.13.0-rc1-00074-g1140ab592e2e #3
  Hardware name: linux,dummy-virt (DT)
  pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
  Call trace:
     __virt_to_phys+0x58/0x68
     check_usemap_section_nr+0x50/0xfc
     sparse_init_nid+0x1ac/0x28c
     sparse_init+0x1c4/0x1e0
     bootmem_init+0x60/0x90
     setup_arch+0x184/0x1f0
     start_kernel+0x78/0x488

To fix it, create a small function to handle both translation.

Link: https://lkml.kernel.org/r/1623058729-27264-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Kazu <k-hagio-ab@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
TheSven73 pushed a commit that referenced this pull request Jun 29, 2021
ASan reported a memory leak of BPF-related ksymbols map and dso. The
leak is caused by refount never reaching 0, due to missing __put calls
in the function machine__process_ksymbol_register.

Once the dso is inserted in the map, dso__put() should be called
(map__new2() increases the refcount to 2).

The same thing applies for the map when it's inserted into maps
(maps__insert() increases the refcount to 2).

  $ sudo ./perf record -- sleep 5
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]

  =================================================================
  ==297735==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 6992 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x8e4e53 in map__new2 /home/user/linux/tools/perf/util/map.c:216:20
      #2 0x8cf68c in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:778:10
      [...]

  Indirect leak of 8702 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x8728d7 in dso__new_id /home/user/linux/tools/perf/util/dso.c:1256:20
      #2 0x872015 in dso__new /home/user/linux/tools/perf/util/dso.c:1295:9
      #3 0x8cf623 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:774:21
      [...]

  Indirect leak of 1520 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
      #2 0x888954 in map__process_kallsym_symbol /home/user/linux/tools/perf/util/symbol.c:710:8
      [...]

  Indirect leak of 1406 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
      #2 0x8cfbd8 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:803:8
      [...]

Signed-off-by: Riccardo Mancini <rickyman7@gmail.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: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Link: http://lore.kernel.org/lkml/20210612173751.188582-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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