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authorPeter Zijlstra <peterz@infradead.org>2023-08-16 13:59:21 +0200
committerBorislav Petkov (AMD) <bp@alien8.de>2023-08-17 00:44:35 +0200
commitdbf46008775516f7f25c95b7760041c286299783 (patch)
tree6265d866cbcdee6a2cc59298219576055c0807ee /tools
parent9dbd23e42ff0b10c9b02c9e649c76e5228241a8e (diff)
objtool/x86: Fixup frame-pointer vs rethunk
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
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/check.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 7a9aaf400873..1384090530db 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2650,12 +2650,17 @@ static int decode_sections(struct objtool_file *file)
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) &&
- insn_call_dest(insn)->fentry)
- return true;
+ if (insn->type == INSN_CALL) {
+ struct symbol *dest = insn_call_dest(insn);
+
+ if (!dest)
+ return false;
+
+ if (dest->fentry || dest->embedded_insn)
+ return true;
+ }
return false;
}
@@ -3656,7 +3661,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
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_INSN(insn, "call without frame pointer save/setup");
return 1;