| Message ID | 1494251815-55961-2-git-send-email-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, May 08, 2017 at 09:56:55PM +0800, Kefeng Wang wrote: > When the system trigger a softlockup(eg, infinite loop when > PREEMPT_NONE), it only shows regs without stack trace, which > makes it difficult to adress the issue. How about: Generic code expects show_regs() to dump the stack, but arm64's show_regs() does not. This makes it hard to debug softlockups and other issues that reesult in show_regs() being called. This patch updates arm64's show_regs() to dump the stack, as common code expects. > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/arm64/include/asm/stacktrace.h | 1 + > arch/arm64/kernel/process.c | 1 + > arch/arm64/kernel/traps.c | 2 +- > 3 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h > index 801a16db..5b6eafc 100644 > --- a/arch/arm64/include/asm/stacktrace.h > +++ b/arch/arm64/include/asm/stacktrace.h > @@ -30,5 +30,6 @@ struct stackframe { > extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); > extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, > int (*fn)(struct stackframe *, void *), void *data); > +extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); > > #endif /* __ASM_STACKTRACE_H */ > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c > index ae2a835..af1ea25 100644 > --- a/arch/arm64/kernel/process.c > +++ b/arch/arm64/kernel/process.c > @@ -210,6 +210,7 @@ void __show_regs(struct pt_regs *regs) > void show_regs(struct pt_regs * regs) > { > __show_regs(regs); > + dump_backtrace(regs, NULL); > } I believe that as we pass the regs down, this should trigger the frame skipping that we want, as I mentioned in reply to v1 [1]. So FWIW, with the commit message fixup: Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-March/496377.html > static void tls_thread_flush(void) > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index d4d6ae0..368c3c8 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -140,7 +140,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) > } > } > > -static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) > +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) > { > struct stackframe frame; > unsigned long irq_stack_ptr; > -- > 1.7.12.4 >
On 2017/5/8 23:04, Mark Rutland wrote: > On Mon, May 08, 2017 at 09:56:55PM +0800, Kefeng Wang wrote: >> When the system trigger a softlockup(eg, infinite loop when >> PREEMPT_NONE), it only shows regs without stack trace, which >> makes it difficult to adress the issue. > > How about: > > Generic code expects show_regs() to dump the stack, but arm64's > show_regs() does not. This makes it hard to debug softlockups and > other issues that reesult in show_regs() being called. > > This patch updates arm64's show_regs() to dump the stack, as common > code expects. > Will update, thanks. >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> arch/arm64/include/asm/stacktrace.h | 1 + >> arch/arm64/kernel/process.c | 1 + >> arch/arm64/kernel/traps.c | 2 +- >> 3 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h >> index 801a16db..5b6eafc 100644 >> --- a/arch/arm64/include/asm/stacktrace.h >> +++ b/arch/arm64/include/asm/stacktrace.h >> @@ -30,5 +30,6 @@ struct stackframe { >> extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); >> extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, >> int (*fn)(struct stackframe *, void *), void *data); >> +extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); >> >> #endif /* __ASM_STACKTRACE_H */ >> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c >> index ae2a835..af1ea25 100644 >> --- a/arch/arm64/kernel/process.c >> +++ b/arch/arm64/kernel/process.c >> @@ -210,6 +210,7 @@ void __show_regs(struct pt_regs *regs) >> void show_regs(struct pt_regs * regs) >> { >> __show_regs(regs); >> + dump_backtrace(regs, NULL); >> } > > I believe that as we pass the regs down, this should trigger the frame > skipping that we want, as I mentioned in reply to v1 [1]. > > So FWIW, with the commit message fixup: > > Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks for your careful guidance, will update both. Kefeng > > Thanks, > Mark. > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-March/496377.html > >> static void tls_thread_flush(void) >> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c >> index d4d6ae0..368c3c8 100644 >> --- a/arch/arm64/kernel/traps.c >> +++ b/arch/arm64/kernel/traps.c >> @@ -140,7 +140,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) >> } >> } >> >> -static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) >> +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) >> { >> struct stackframe frame; >> unsigned long irq_stack_ptr; >> -- >> 1.7.12.4 >> > > . >
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 801a16db..5b6eafc 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -30,5 +30,6 @@ struct stackframe { extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, int (*fn)(struct stackframe *, void *), void *data); +extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); #endif /* __ASM_STACKTRACE_H */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index ae2a835..af1ea25 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -210,6 +210,7 @@ void __show_regs(struct pt_regs *regs) void show_regs(struct pt_regs * regs) { __show_regs(regs); + dump_backtrace(regs, NULL); } static void tls_thread_flush(void) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d4d6ae0..368c3c8 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -140,7 +140,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) } } -static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; unsigned long irq_stack_ptr;
When the system trigger a softlockup(eg, infinite loop when PREEMPT_NONE), it only shows regs without stack trace, which makes it difficult to adress the issue. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/arm64/include/asm/stacktrace.h | 1 + arch/arm64/kernel/process.c | 1 + arch/arm64/kernel/traps.c | 2 +- 3 files changed, 3 insertions(+), 1 deletion(-)