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| author | Peter Zijlstra <peterz@infradead.org> | 2021-12-04 14:43:42 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-12-08 19:26:50 +0100 |
| commit | 1cc1e4c8aab4213bd4e6353dec2620476a233d6d (patch) | |
| tree | 098107adb9d0272c25287606abad1b846b3595e3 /tools/objtool/arch | |
| parent | b17c2baa305cccbd16bafa289fd743cc2db77966 (diff) | |
| download | lwn-1cc1e4c8aab4213bd4e6353dec2620476a233d6d.tar.gz lwn-1cc1e4c8aab4213bd4e6353dec2620476a233d6d.zip | |
objtool: Add straight-line-speculation validation
Teach objtool to validate the straight-line-speculation constraints:
- speculation trap after indirect calls
- speculation trap after RET
Notable: when an instruction is annotated RETPOLINE_SAFE, indicating
speculation isn't a problem, also don't care about sls for that
instruction.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.023037659@infradead.org
Diffstat (limited to 'tools/objtool/arch')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 4d6d7fc13255..c10ef78df050 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -531,6 +531,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec } break; + case 0xcc: + /* int3 */ + *type = INSN_TRAP; + break; + case 0xe3: /* jecxz/jrcxz */ *type = INSN_JUMP_CONDITIONAL; @@ -697,10 +702,10 @@ const char *arch_ret_insn(int len) { static const char ret[5][5] = { { BYTE_RET }, - { BYTE_RET, BYTES_NOP1 }, - { BYTE_RET, BYTES_NOP2 }, - { BYTE_RET, BYTES_NOP3 }, - { BYTE_RET, BYTES_NOP4 }, + { BYTE_RET, 0xcc }, + { BYTE_RET, 0xcc, BYTES_NOP1 }, + { BYTE_RET, 0xcc, BYTES_NOP2 }, + { BYTE_RET, 0xcc, BYTES_NOP3 }, }; if (len < 1 || len > 5) { |