Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH] x86/alternative: Report missing return thunk details | Date | Wed, 13 Jul 2022 14:38:19 -0700 |
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Debugging missing return thunks is easier if we can see where they're happening.
Suggested-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/lkml/Ys66hwtFcGbYmoiZ@hirez.programming.kicks-ass.net/ Cc: Peter Zijlstra <peterz@infradead.org> Cc: x86@kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/x86/kernel/alternative.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index d6858533e6e5..62f6b8b7c4a5 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -555,7 +555,9 @@ void __init_or_module noinline apply_returns(s32 *start, s32 *end) dest = addr + insn.length + insn.immediate.value; if (__static_call_fixup(addr, op, dest) || - WARN_ON_ONCE(dest != &__x86_return_thunk)) + WARN_ONCE(dest != &__x86_return_thunk, + "missing return thunk: %pS-%pS: %*ph", + addr, dest, 5, addr)) continue; DPRINTK("return thunk at: %pS (%px) len: %d to: %pS", -- 2.32.0
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