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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-07-27 15:56:55 -0500
committerIngo Molnar <mingo@kernel.org>2017-08-21 16:07:27 +0200
commitdeecd4d71b12626db48544faa66bb897e2cafd07 (patch)
treefb351bffbae38eec99a99b63bec7a2c3039d172d /tools
parent14ccee78fc82f5512908f4424f541549a5705b89 (diff)
objtool: Fix '-mtune=atom' decoding support in objtool 2.0
With '-mtune=atom', which is enabled with CONFIG_MATOM=y, GCC uses some unusual instructions for setting up the stack. Instead of: mov %rsp, %rbp it does: lea (%rsp), %rbp And instead of: add imm, %rsp it does: lea disp(%rsp), %rsp Add support for these instructions to the objtool decoder. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: baa41469a7b9 ("objtool: Implement stack validation 2.0") Link: http://lkml.kernel.org/r/4ea1db896e821226efe1f8e09f270771bde47e65.1501188854.git.jpoimboe@redhat.com [ This is a cherry-picked version of upcoming commit 5b8de48e82ba. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/arch/x86/decode.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index a36c2eba64e7..4559a21a8de2 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -271,7 +271,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
case 0x8d:
if (rex == 0x48 && modrm == 0x65) {
- /* lea -disp(%rbp), %rsp */
+ /* lea disp(%rbp), %rsp */
*type = INSN_STACK;
op->src.type = OP_SRC_ADD;
op->src.reg = CFI_BP;
@@ -281,6 +281,30 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
break;
}
+ if (rex == 0x48 && (modrm == 0xa4 || modrm == 0x64) &&
+ sib == 0x24) {
+
+ /* lea disp(%rsp), %rsp */
+ *type = INSN_STACK;
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_SP;
+ op->src.offset = insn.displacement.value;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ break;
+ }
+
+ if (rex == 0x48 && modrm == 0x2c && sib == 0x24) {
+
+ /* lea (%rsp), %rbp */
+ *type = INSN_STACK;
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_BP;
+ break;
+ }
+
if (rex == 0x4c && modrm == 0x54 && sib == 0x24 &&
insn.displacement.value == 8) {