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| author | Peter Zijlstra <peterz@infradead.org> | 2021-10-22 17:53:02 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-10-26 22:10:12 +0300 |
| commit | 5d1ceb3969b6b2e47e2df6d17790a7c5a20fcbb4 (patch) | |
| tree | a450eb37142355819b28bfc98233f6ae8d10bdf3 /arch/x86/kernel | |
| parent | 55409ac5c371c6403012d5f4df5e7c6cf0e7dce6 (diff) | |
| download | linux-5d1ceb3969b6b2e47e2df6d17790a7c5a20fcbb4.tar.xz | |
x86: Fix __get_wchan() for !STACKTRACE
Use asm/unwind.h to implement wchan, since we cannot always rely on
STACKTRACE=y.
Fixes: bc9bbb81730e ("x86: Fix get_wchan() to support the ORC unwinder")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20211022152104.137058575@infradead.org
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/process.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index a69885a9d711..8fb6bd4cbc50 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -43,6 +43,7 @@ #include <asm/io_bitmap.h> #include <asm/proto.h> #include <asm/frame.h> +#include <asm/unwind.h> #include "process.h" @@ -944,10 +945,20 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) */ unsigned long __get_wchan(struct task_struct *p) { - unsigned long entry = 0; + struct unwind_state state; + unsigned long addr = 0; - stack_trace_save_tsk(p, &entry, 1, 0); - return entry; + for (unwind_start(&state, p, NULL, NULL); !unwind_done(&state); + unwind_next_frame(&state)) { + addr = unwind_get_return_address(&state); + if (!addr) + break; + if (in_sched_functions(addr)) + continue; + break; + } + + return addr; } long do_arch_prctl_common(struct task_struct *task, int option, |