When multiple callbacks are registered on the same tracepoint, probestub
will be indirectly called via traceiter helper.
Pointer to probestub callback resides in __tracepoints section, which is
excluded from ENDBR checks in objtool. Pointers to regfunc/unregfunc
callbacks reside in extended structure however, which is not affected.
Registering multiple callbacks will result in a #CP exception due to
missed ENDBR in __probestub helper on a CFI-enabled machine.
Fix this by adding CFI_NOSEAL annotation to probestub declaration.
Fixes: d5173f753750 ("objtool: Exclude __tracepoints data from ENDBR checks")
Signed-off-by: Eva Kurchatova <[email protected]>
---
include/linux/tracepoint.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 583d962abcc3..5a32a709759c 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -19,6 +19,7 @@
#include <linux/rcupdate.h>
#include <linux/tracepoint-defs.h>
#include <linux/static_call.h>
+#include <asm/cfi.h>
struct module;
struct tracepoint;
@@ -356,6 +357,7 @@ static inline struct tracepoint
*tracepoint_ptr_deref(tracepoint_ptr_t *p)
void __probestub_##_name(void *__data, proto) \
{ \
} \
+ CFI_NOSEAL(__probestub_##_name); \
DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
#define DEFINE_TRACE_FN(_name, _reg, _unreg, _proto, _args) \
--
2.54.0
