From 5743654f5e2ebd56df99f56fca5ba4b23fe3c815 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 12 Apr 2023 13:26:15 -0700 Subject: objtool: Generate ORC data for __pfx code Allow unwinding from prefix code by copying the CFI from the starting instruction of the corresponding function. Even when the NOPs are replaced, they're still stack-invariant instructions so the same ORC entry can be reused everywhere. Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/bc3344e51f3e87102f1301a0be0f72a7689ea4a4.1681331135.git.jpoimboe@kernel.org --- tools/objtool/check.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8ee4d51de6fa..df634dafefc4 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4117,6 +4117,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio static int add_prefix_symbol(struct objtool_file *file, struct symbol *func) { struct instruction *insn, *prev; + struct cfi_state *cfi; insn = find_insn(file, func->sec, func->offset); if (!insn) @@ -4145,6 +4146,19 @@ static int add_prefix_symbol(struct objtool_file *file, struct symbol *func) if (!prev) return -1; + if (!insn->cfi) { + /* + * This can happen if stack validation isn't enabled or the + * function is annotated with STACK_FRAME_NON_STANDARD. + */ + return 0; + } + + /* Propagate insn->cfi to the prefix code */ + cfi = cfi_hash_find_or_add(insn->cfi); + for (; prev != insn; prev = next_insn_same_sec(file, prev)) + prev->cfi = cfi; + return 0; } -- cgit