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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/check.c | |
| parent | b17c2baa305cccbd16bafa289fd743cc2db77966 (diff) | |
| download | linux-stable-1cc1e4c8aab4213bd4e6353dec2620476a233d6d.tar.gz linux-stable-1cc1e4c8aab4213bd4e6353dec2620476a233d6d.tar.bz2 linux-stable-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/check.c')
| -rw-r--r-- | tools/objtool/check.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 21735829b860..e28172f6e792 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3084,6 +3084,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, switch (insn->type) { case INSN_RETURN: + if (next_insn && next_insn->type == INSN_TRAP) { + next_insn->ignore = true; + } else if (sls && !insn->retpoline_safe) { + WARN_FUNC("missing int3 after ret", + insn->sec, insn->offset); + } return validate_return(func, insn, &state); case INSN_CALL: @@ -3127,6 +3133,14 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; case INSN_JUMP_DYNAMIC: + if (next_insn && next_insn->type == INSN_TRAP) { + next_insn->ignore = true; + } else if (sls && !insn->retpoline_safe) { + WARN_FUNC("missing int3 after indirect jump", + insn->sec, insn->offset); + } + + /* fallthrough */ case INSN_JUMP_DYNAMIC_CONDITIONAL: if (is_sibling_call(insn)) { ret = validate_sibling_call(file, insn, &state); |