Messages in this thread Patch in this message | | | From | Josh Poimboeuf <> | Subject | [PATCH 1/2] unwind: prevent KASAN false positive warnings in guess unwinder | Date | Thu, 17 Nov 2016 09:57:23 -0600 |
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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> --- arch/x86/kernel/unwind_guess.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index 2d721e5..b80e8bf 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; -- 2.7.4
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