commit
dbf46008775516f7f25c95b7760041c286299783 upstream.
For stack-validation of a frame-pointer build, objtool validates that
every CALL instruction is preceded by a frame-setup. The new SRSO
return thunks violate this with their RSB stuffing trickery.
Extend the __fentry__ exception to also cover the embedded_insn case
used for this. This cures:
vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup
Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
return 0;
}
-static bool is_fentry_call(struct instruction *insn)
+static bool is_special_call(struct instruction *insn)
{
- if (insn->type == INSN_CALL &&
- insn->call_dest &&
- insn->call_dest->fentry)
- return true;
+ if (insn->type == INSN_CALL) {
+ struct symbol *dest = insn->call_dest;
+
+ if (!dest)
+ return false;
+
+ if (dest->fentry)
+ return true;
+ }
return false;
}
if (ret)
return ret;
- if (opts.stackval && func && !is_fentry_call(insn) &&
+ if (opts.stackval && func && !is_special_call(insn) &&
!has_valid_stack_frame(&state)) {
WARN_FUNC("call without frame pointer save/setup",
sec, insn->offset);