[tip: objtool/core] Revert "objtool: Support addition to set CFA base"

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/core branch of tip:

Commit-ID:     e18398e80c73e3cc7d9c3d2e0bc06a4af8f4f1cb
Gitweb:        https://git.kernel.org/tip/e18398e80c73e3cc7d9c3d2e0bc06a4af8f4f1cb
Author:        Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate:    Wed, 12 Apr 2023 10:29:01 -07:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 14 Apr 2023 16:08:27 +02:00

Revert "objtool: Support addition to set CFA base"

Commit 468af56a7bba ("objtool: Support addition to set CFA base") was
added as a preparatory patch for arm64 support, but that support never
came.  It triggers a false positive warning on x86, so just revert it
for now.

Fixes the following warning:

  vmlinux.o: warning: objtool: cdce925_regmap_i2c_write+0xdb: stack state mismatch: cfa1=4+120 cfa2=5+40

Fixes: 468af56a7bba ("objtool: Support addition to set CFA base")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/oe-kbuild-all/202304080538.j5G6h1AB-lkp@xxxxxxxxx/
---
 tools/objtool/check.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index cae6ac6..9440b07 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3002,17 +3002,6 @@ static int update_cfi_state(struct instruction *insn,
 				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 */