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authorJulien Thierry <jthierry@redhat.com>2020-10-14 10:38:01 +0300
committerJosh Poimboeuf <jpoimboe@redhat.com>2021-01-14 03:13:10 +0300
commit468af56a7bbaa626da5a4578bedc930d731fba13 (patch)
treed928c9ef930731168ca94e101e24b2b2e8704abf /tools
parentfb084fde0c8106bc86df243411751c3421c07c08 (diff)
downloadlinux-468af56a7bbaa626da5a4578bedc930d731fba13.tar.xz
objtool: Support addition to set CFA base
On arm64, the compiler can set the frame pointer either with a move operation or with and add operation like: add (SP + constant), BP For a simple move operation, the CFA base is changed from SP to BP. Handle also changing the CFA base when the frame pointer is set with an addition instruction. Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/check.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 88210b0856f7..00d00f904536 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1960,6 +1960,17 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
}
+ if (!cfi->drap && op->src.reg == CFI_SP &&
+ op->dest.reg == CFI_BP && cfa->base == CFI_SP &&
+ check_reg_frame_pos(&regs[CFI_BP], -cfa->offset + op->src.offset)) {
+
+ /* lea disp(%rsp), %rbp */
+ cfa->base = CFI_BP;
+ cfa->offset -= op->src.offset;
+ cfi->bp_scratch = false;
+ break;
+ }
+
if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
/* drap: lea disp(%rsp), %drap */