Messages in this thread | | | From | Marco Elver <> | Date | Wed, 5 May 2021 12:37:18 +0200 | Subject | Re: [PATCH 1/2] printk: introduce dump_stack_lvl() |
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On Wed, 5 May 2021 at 11:22, Alexander Potapenko <glider@google.com> wrote: > 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. > > Cc: Andrew Morton <akpm@linux-foundation.org> > 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: Marco Elver <elver@google.com> > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Alexander Potapenko <glider@google.com> > --- > include/linux/printk.h | 1 + > lib/dump_stack.c | 19 ++++++++++++------- > 2 files changed, 13 insertions(+), 7 deletions(-) > > diff --git a/include/linux/printk.h b/include/linux/printk.h > index fe7eb2351610..abe274305d79 100644 > --- a/include/linux/printk.h > +++ b/include/linux/printk.h > @@ -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); > diff --git a/lib/dump_stack.c b/lib/dump_stack.c > index f5a33b6f773f..3d2c324a4929 100644 > --- a/lib/dump_stack.c > +++ b/lib/dump_stack.c > @@ -73,10 +73,10 @@ 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); > } > > /** > @@ -87,7 +87,7 @@ 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; > @@ -117,7 +117,7 @@ asmlinkage __visible void dump_stack(void) > goto retry; > } > > - __dump_stack(); > + __dump_stack(log_lvl); > > if (!was_locked) > atomic_set(&dump_lock, -1); > @@ -125,9 +125,14 @@ 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);
is missing here?
> + > +asmlinkage __visible void dump_stack(void) > +{ > + dump_stack_lvl(KERN_DEFAULT); > +} > EXPORT_SYMBOL(dump_stack); > -- > 2.31.1.527.g47e6f16901-goog >
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