Merge tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "Improvements and fixes to pstore subsystem:

   - add additional checks for bad platform data

   - remove bounce buffer in console writer

   - protect read/unlink race with a mutex

   - correctly give up during dump locking failures

   - increase ftrace bandwidth by splitting ftrace buffers per CPU"

* tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  ramoops: add pdata NULL check to ramoops_probe
  pstore: Convert console write to use ->write_buf
  pstore: Protect unlink with read_mutex
  pstore: Use global ftrace filters for function trace filtering
  ftrace: Provide API to use global filtering for ftrace ops
  pstore: Clarify context field przs as dprzs
  pstore: improve error report for failed setup
  pstore: Merge per-CPU ftrace records into one
  pstore: Add ftrace timestamp counter
  ramoops: Split ftrace buffer space into per-CPU zones
  pstore: Make ramoops_init_przs generic for other prz arrays
  pstore: Allow prz to control need for locking
  pstore: Warn on PSTORE_TYPE_PMSG using deprecated function
  pstore: Make spinlock per zone instead of global
  pstore: Actually give up during locking failure

Author: torvalds

Documentation/devicetree/bindings/reserved-memory/ramoops.txt

@@ -46,3 +46,6 @@ Optional properties:
   (defaults to buffered mappings)
 
 - no-dump-oops: if present, only dump panics (defaults to panics and oops)
+
+- flags: if present, pass ramoops behavioral flags (defaults to 0,
+  see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values).

fs/pstore/ftrace.c

@@ -27,6 +27,9 @@
 #include <asm/barrier.h>
 #include "internal.h"
 
+/* This doesn't need to be atomic: speed is chosen over correctness here. */
+static u64 pstore_ftrace_stamp;
+
 static void notrace pstore_ftrace_call(unsigned long ip,
 				       unsigned long parent_ip,
 				       struct ftrace_ops *op,
@@ -42,6 +45,7 @@ static void notrace pstore_ftrace_call(unsigned long ip,
 
 	rec.ip = ip;
 	rec.parent_ip = parent_ip;
+	pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++);
 	pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
 	psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec,
 			  0, sizeof(rec), psinfo);
@@ -71,10 +75,13 @@ static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
 	if (!on ^ pstore_ftrace_enabled)
 		goto out;
 
-	if (on)
+	if (on) {
+		ftrace_ops_set_global_filter(&pstore_ftrace_ops);
 		ret = register_ftrace_function(&pstore_ftrace_ops);
-	else
+	} else {
 		ret = unregister_ftrace_function(&pstore_ftrace_ops);
+	}
+
 	if (ret) {
 		pr_err("%s: unable to %sregister ftrace ops: %zd\n",
 		       __func__, on ? "" : "un", ret);

fs/pstore/inode.c

@@ -107,9 +107,11 @@ static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
 	struct pstore_ftrace_seq_data *data = v;
 	struct pstore_ftrace_record *rec = (void *)(ps->data + data->off);
 
-	seq_printf(s, "%d %08lx  %08lx  %pf <- %pF\n",
-		pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
-		(void *)rec->ip, (void *)rec->parent_ip);
+	seq_printf(s, "CPU:%d ts:%llu %08lx  %08lx  %pf <- %pF\n",
+		   pstore_ftrace_decode_cpu(rec),
+		   pstore_ftrace_read_timestamp(rec),
+		   rec->ip, rec->parent_ip, (void *)rec->ip,
+		   (void *)rec->parent_ip);
 
 	return 0;
 }
@@ -197,11 +199,14 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 	if (err)
 		return err;
 
-	if (p->psi->erase)
+	if (p->psi->erase) {
+		mutex_lock(&p->psi->read_mutex);
 		p->psi->erase(p->type, p->id, p->count,
 			      d_inode(dentry)->i_ctime, p->psi);
-	else
+		mutex_unlock(&p->psi->read_mutex);
+	} else {
 		return -EPERM;
+	}
 
 	return simple_unlink(dir, dentry);
 }

fs/pstore/internal.h

@@ -5,40 +5,6 @@
 #include <linux/time.h>
 #include <linux/pstore.h>
 
-#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
-#define PSTORE_CPU_IN_IP 0x1
-#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
-#define PSTORE_CPU_IN_IP 0x3
-#endif
-
-struct pstore_ftrace_record {
-	unsigned long ip;
-	unsigned long parent_ip;
-#ifndef PSTORE_CPU_IN_IP
-	unsigned int cpu;
-#endif
-};
-
-static inline void
-pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
-{
-#ifndef PSTORE_CPU_IN_IP
-	rec->cpu = cpu;
-#else
-	rec->ip |= cpu;
-#endif
-}
-
-static inline unsigned int
-pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
-{
-#ifndef PSTORE_CPU_IN_IP
-	return rec->cpu;
-#else
-	return rec->ip & PSTORE_CPU_IN_IP;
-#endif
-}
-
 #ifdef CONFIG_PSTORE_FTRACE
 extern void pstore_register_ftrace(void);
 extern void pstore_unregister_ftrace(void);

fs/pstore/platform.c

@@ -493,6 +493,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 		if (!is_locked) {
 			pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
 				       , in_nmi() ? "NMI" : why);
+			return;
 		}
 	} else {
 		spin_lock_irqsave(&psinfo->buf_lock, flags);
@@ -584,8 +585,8 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
 		} else {
 			spin_lock_irqsave(&psinfo->buf_lock, flags);
 		}
-		memcpy(psinfo->buf, s, c);
-		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
+		psinfo->write_buf(PSTORE_TYPE_CONSOLE, 0, &id, 0,
+				  s, 0, c, psinfo);
 		spin_unlock_irqrestore(&psinfo->buf_lock, flags);
 		s += c;
 		c = e - s;