Arnd Bergmann reported a bunch of warnings like:
crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without
frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without
frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call
without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call
without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19:
call without frame pointer save/setup
and
arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch
register
arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call
without frame pointer save/setup
With certain rare configurations, GCC sometimes sets up the frame
pointer with:
lea (%rsp),%rbp
instead of:
mov %rsp,%rbp
The instructions are equivalent, so treat the former like the latter.
Reported-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
tools/objtool/arch/x86/decode.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 0e8c8ec4fd4e..97a1fdb3db63 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -284,11 +284,16 @@ int arch_decode_instruction(struct elf *elf, struct
section *sec,
case 0x8d:
if (sib == 0x24 && rex_w && !rex_b && !rex_x) {
- /* lea disp(%rsp), reg */
*type = INSN_STACK;
- op->src.type = OP_SRC_ADD;
+ if (!insn.displacement.value) {
+ /* lea (%rsp), reg */
+ op->src.type = OP_SRC_REG;
+ } else {
+ /* lea disp(%rsp), reg */
+ op->src.type = OP_SRC_ADD;
+ op->src.offset = insn.displacement.value;
+ }
op->src.reg = CFI_SP;
- op->src.offset = insn.displacement.value;
op->dest.type = OP_DEST_REG;
op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
--
2.13.5
