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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2016-11-17 09:57:23 -0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-11-18 09:38:00 +0100 |
| commit | c2d75e03d6307bda0e14b616818a6f7b09fd623a (patch) | |
| tree | b4b4449cd37b7d008eb11b7e20127818ec48e0e9 | |
| parent | 553bbc11aa6c1f9e0f529a06aeeca15fbe4a3985 (diff) | |
| download | linux-c2d75e03d6307bda0e14b616818a6f7b09fd623a.tar.gz | |
x86/unwind: Prevent KASAN false positive warnings in guess unwinder
The guess unwinder scans the entire stack, which can cause KASAN "stack-out-of-bounds" false positive warnings. Tell KASAN to ignore it. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: davej@codemonkey.org.uk Cc: dvyukov@google.com Link: http://lkml.kernel.org/r/61939c0b2b2d63ce97ba59cba3b00fd47c2962cf.1479398226.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/unwind_guess.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index 2d721e533cf4..b80e8bf43cc6 100644 --- a/arch/x86/kernel/unwind_guess.c +++ b/arch/x86/kernel/unwind_guess.c @@ -7,11 +7,13 @@ unsigned long unwind_get_return_address(struct unwind_state *state) { + unsigned long addr = READ_ONCE_NOCHECK(*state->sp); + if (unwind_done(state)) return 0; return ftrace_graph_ret_addr(state->task, &state->graph_idx, - *state->sp, state->sp); + addr, state->sp); } EXPORT_SYMBOL_GPL(unwind_get_return_address); @@ -23,8 +25,10 @@ bool unwind_next_frame(struct unwind_state *state) return false; do { + unsigned long addr = READ_ONCE_NOCHECK(*state->sp); + for (state->sp++; state->sp < info->end; state->sp++) - if (__kernel_text_address(*state->sp)) + if (__kernel_text_address(addr)) return true; state->sp = info->next_sp; |