lkml.org 
[lkml]   [2021]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip: objtool/core] objtool,x86: Additionally decode: mov %rsp, (%reg)
The following commit has been merged into the objtool/core branch of tip:

Commit-ID: 2a512829840eb97a8b52eca7058e56d484468f2d
Gitweb: https://git.kernel.org/tip/2a512829840eb97a8b52eca7058e56d484468f2d
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Wed, 03 Feb 2021 12:02:18 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 10 Feb 2021 20:53:52 +01:00

objtool,x86: Additionally decode: mov %rsp, (%reg)

Where we already decode: mov %rsp, %reg, also decode mov %rsp, (%reg).

Nothing should match for this new stack-op.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
tools/objtool/arch/x86/decode.c | 42 +++++++++++++++++++++++++-------
1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 9637e3b..549813c 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -222,15 +222,38 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
break;

case 0x89:
- if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) {
+ if (rex_w && !rex_r && modrm_reg == 4) {

- /* mov %rsp, reg */
- ADD_OP(op) {
- op->src.type = OP_SRC_REG;
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ if (modrm_mod == 3) {
+ /* mov %rsp, reg */
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ }
+ break;
+
+ } else {
+ /* skip nontrivial SIB */
+ if (modrm_rm == 4 && !(sib == 0x24 && rex_b == rex_x))
+ break;
+
+ /* skip RIP relative displacement */
+ if (modrm_rm == 5 && modrm_mod == 0)
+ break;
+
+ /* mov %rsp, disp(%reg) */
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_SP;
+ op->dest.type = OP_DEST_REG_INDIRECT;
+ op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ op->dest.offset = insn.displacement.value;
+ }
+ break;
}
+
break;
}

@@ -259,8 +282,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->dest.reg = CFI_BP;
op->dest.offset = insn.displacement.value;
}
+ break;
+ }

- } else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
+ if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {

/* mov reg, disp(%rsp) */
ADD_OP(op) {
@@ -270,6 +295,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->dest.reg = CFI_SP;
op->dest.offset = insn.displacement.value;
}
+ break;
}

break;
\
 
 \ /
  Last update: 2021-02-10 21:03    [W:1.226 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site