[PATCH] objtool,x86: Verify poke_int3_handler() is self contained

peterz
2020-07-27T10:40:59Z

Abuse the SMAP rules to ensure poke_int3_handler() doesn't call out to
anything.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
tools/objtool/check.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -551,6 +551,14 @@ static const char *uaccess_safe_builtin[
"__memcpy_mcsafe",
"mcsafe_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
+ /*
+ * Abuse alert!
+ *
+ * poke_int3_handler() is not in fact related to uaccess at all, we
+ * abuse the uaccess rules to ensure poke_int3_handler() is self
+ * contained and doesn't CALL out to other code.
+ */
+ "poke_int3_handler",
NULL
};