| Message ID | 20220713213819.460771-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 65cdf0d623bedf0e069bb64ed52e8bb20105e2ba |
| Headers | show |
| Series | x86/alternative: Report missing return thunk details | expand |
On Wed, Jul 13, 2022 at 02:38:19PM -0700, Kees Cook wrote: > 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)) String needs a newline?
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",
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(-)