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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-07-27 22:56:55 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-28 08:33:32 +0200 |
| commit | 5b8de48e82ba322483c925ce33f193e28e59a5fd (patch) | |
| tree | 27123a9427335b2d74a829af560a0d2dd117df8a /tools/objtool | |
| parent | objtool: Skip unreachable warnings for 'alt' instructions (diff) | |
| download | linux-5b8de48e82ba322483c925ce33f193e28e59a5fd.tar.xz linux-5b8de48e82ba322483c925ce33f193e28e59a5fd.zip | |
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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index e4b400b67e41..7841e5d31973 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) { |