Messages in this thread Patch in this message | | | Date | Fri, 22 Oct 2021 09:43:50 +0200 | From | Ingo Molnar <> | Subject | [PATCH] stacktrace: Provide stack_trace_save_tsk() stub in the !CONFIG_STACKTRACE case too |
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* Qi Zheng <zhengqi.arch@bytedance.com> wrote:
> > > On 10/18/21 2:23 PM, Stephen Rothwell wrote: > > Hi all, > > > > After merging the tip tree, today's linux-next build (x86_64 allnoconfig) > > failed like this: > > > > arch/x86/kernel/process.c: In function '__get_wchan': > > arch/x86/kernel/process.c:950:2: error: implicit declaration of function 'stack_trace_save_tsk' [-Werror=implicit-function-declaration] > > 950 | stack_trace_save_tsk(p, &entry, 1, 0); > > | ^~~~~~~~~~~~~~~~~~~~ > > cc1: some warnings being treated as errors > > > > Caused by commit > > > > bc9bbb81730e ("x86: Fix get_wchan() to support the ORC unwinder") > > > > stack_trace_save_tsk() requires CONFIG_STACKTRACE which is not set for > > this build. > > Maybe get_wchan() can be updated to: > > unsigned long get_wchan(struct task_struct *p) > { > #ifdef CONFIG_STACKTRACE > unsigned long entry = 0; > > stack_trace_save_tsk(p, &entry, 1, 0); > return entry; > #else /* CONFIG_STACKTRACE */ > return 0; > #endif > }
And repeat the same ugliness in every single function that happens to use the stack_trace_save_tsk() API??
The correct solution is to define stack_trace_save_tsk() in the !CONFIG_STACKTRACE case too, as the patch below does.
Thanks,
Ingo
==============================> From: Ingo Molnar <mingo@kernel.org> Date: Fri, 22 Oct 2021 09:40:27 +0200 Subject: [PATCH] stacktrace: Provide stack_trace_save_tsk() stub in the !CONFIG_STACKTRACE case too
The following commit:
bc9bbb81730e ("x86: Fix get_wchan() to support the ORC unwinder")
Added stack_trace_save_tsk() use to __get_wchan(), while this method is not unconditionally defined: it's not available in the !CONFIG_STACKTRACE case.
Give a default implementation that does nothing.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: bc9bbb81730e ("x86: Fix get_wchan() to support the ORC unwinder") Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> --- include/linux/stacktrace.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index 9edecb494e9e..3ccaf599630f 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -91,8 +91,19 @@ extern void save_stack_trace_tsk(struct task_struct *tsk, extern int save_stack_trace_tsk_reliable(struct task_struct *tsk, struct stack_trace *trace); extern void save_stack_trace_user(struct stack_trace *trace); + #endif /* !CONFIG_ARCH_STACKWALK */ -#endif /* CONFIG_STACKTRACE */ + +#else /* !CONFIG_STACKTRACE: */ +static inline unsigned int +stack_trace_save_tsk(struct task_struct *task, + unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + return -ENOSYS; +} + +#endif /* !CONFIG_STACKTRACE */ #if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE) int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
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