The following commit has been merged into the objtool/core branch of tip:
Commit-ID: 5743654f5e2ebd56df99f56fca5ba4b23fe3c815
Gitweb: https://git.kernel.org/tip/5743654f5e2ebd56df99f56fca5ba4b23fe3c815
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 12 Apr 2023 13:26:15 -07:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 14 Apr 2023 16:08:30 +02:00
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 <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/bc3344e51f3e87102f1301a0be0f72a7689ea4a4.1681331135.git.jpoimboe@xxxxxxxxxx
---
tools/objtool/check.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 8ee4d51..df634da 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;
}
|