FROMGIT: printk: introduce dump_stack_lvl()

dump_stack() is used for many different cases, which may require a log
level consistent with other kernel messages surrounding the dump_stack()
call.  Without that, certain systems that are configured to ignore the
default level messages will miss stack traces in critical error reports.

This patch introduces dump_stack_lvl() that behaves similarly to
dump_stack(), but accepts a custom log level.  The old dump_stack()
becomes equal to dump_stack_lvl(KERN_DEFAULT).

A somewhat similar patch has been proposed in 2012:
https://lore.kernel.org/lkml/1332493269.2359.9.camel@hebo/ , but wasn't
merged.

Link: https://lkml.kernel.org/r/20210506105405.3535023-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: he, bo <bo.he@intel.com>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: Prasad Sodagudi <psodagud@quicinc.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Bug: 186674719
Test: Treehugger
(cherry picked from commit e8c4bbbd160c8a29b606a8d7ef8dcdd75f2b7044
 https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm)
Signed-off-by: Alexander Potapenko <glider@google.com>
Change-Id: I6f5cc76cd50d446caf41c8a709c3bf6542fae6f8
This commit is contained in:
Alexander Potapenko 2021-05-14 10:39:38 +10:00 committed by Todd Kjos
parent 0aa48437bf
commit 359a038bbf
2 changed files with 14 additions and 7 deletions

View File

@ -206,6 +206,7 @@ void __init setup_log_buf(int early);
__printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...);
void dump_stack_print_info(const char *log_lvl);
void show_regs_print_info(const char *log_lvl);
extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold;
extern asmlinkage void dump_stack(void) __cold;
extern void printk_safe_flush(void);
extern void printk_safe_flush_on_panic(void);

View File

@ -71,10 +71,10 @@ void show_regs_print_info(const char *log_lvl)
dump_stack_print_info(log_lvl);
}
static void __dump_stack(void)
static void __dump_stack(const char *log_lvl)
{
dump_stack_print_info(KERN_DEFAULT);
show_stack(NULL, NULL, KERN_DEFAULT);
dump_stack_print_info(log_lvl);
show_stack(NULL, NULL, log_lvl);
}
/**
@ -85,7 +85,7 @@ static void __dump_stack(void)
#ifdef CONFIG_SMP
static atomic_t dump_lock = ATOMIC_INIT(-1);
asmlinkage __visible void dump_stack(void)
asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
{
unsigned long flags;
int was_locked;
@ -115,7 +115,7 @@ asmlinkage __visible void dump_stack(void)
goto retry;
}
__dump_stack();
__dump_stack(log_lvl);
if (!was_locked)
atomic_set(&dump_lock, -1);
@ -123,9 +123,15 @@ asmlinkage __visible void dump_stack(void)
local_irq_restore(flags);
}
#else
asmlinkage __visible void dump_stack(void)
asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
{
__dump_stack();
__dump_stack(log_lvl);
}
#endif
EXPORT_SYMBOL(dump_stack_lvl);
asmlinkage __visible void dump_stack(void)
{
dump_stack_lvl(KERN_DEFAULT);
}
EXPORT_SYMBOL(dump_stack);