diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2021-10-30 09:47:58 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-11-11 13:09:31 +0100 |
| commit | 2105a92748e83e2e3ee6be539da959706bbb3898 (patch) | |
| tree | 04dd3c3a9a55be81189d30054b015b2587dc5968 /tools/objtool | |
| parent | debe436e77c72fcee804fb867f275e6d31aa999c (diff) | |
static_call,x86: Robustify trampoline patching
Add a few signature bytes after the static call trampoline and verify
those bytes match before patching the trampoline. This avoids patching
random other JMPs (such as CFI jump-table entries) instead.
These bytes decode as:
d: 53 push %rbx
e: 43 54 rex.XB push %r12
And happen to spell "SCT".
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211030074758.GT174703@worktop.programming.kicks-ass.net
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/check.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index add39902166d..21735829b860 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3310,6 +3310,9 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio if (!insn->func) return false; + if (insn->func->static_call_tramp) + return true; + /* * CONFIG_UBSAN_TRAP inserts a UD2 when it sees * __builtin_unreachable(). The BUG() macro has an unreachable() after |