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| author | Peter Zijlstra <peterz@infradead.org> | 2023-08-16 13:59:21 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-08-17 00:44:35 +0200 |
| commit | dbf46008775516f7f25c95b7760041c286299783 (patch) | |
| tree | 6265d866cbcdee6a2cc59298219576055c0807ee /tools/objtool | |
| parent | 9dbd23e42ff0b10c9b02c9e649c76e5228241a8e (diff) | |
| download | linux-dbf46008775516f7f25c95b7760041c286299783.tar.gz linux-dbf46008775516f7f25c95b7760041c286299783.tar.bz2 linux-dbf46008775516f7f25c95b7760041c286299783.zip | |
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/objtool')
| -rw-r--r-- | tools/objtool/check.c | 17 |
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; |