After adding mcsafe_handle_tail() to the objtool uaccess safe list,
objtool reports:
arch/x86/lib/usercopy_64.o: warning: objtool: mcsafe_handle_tail()+0x0: call
to __fentry__() with UACCESS enabled
With SMAP, this function is called with AC=1, so it needs to be careful
about which functions it calls. Disable the ftrace entry hook, which
can potentially pull in a lot of extra code.
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
arch/x86/lib/usercopy_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index e0e006f1624e..fff28c6f73a2 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -60,7 +60,7 @@ EXPORT_SYMBOL(clear_user);
* but reuse __memcpy_mcsafe in case a new read error is encountered.
* clac() is handled in _copy_to_iter_mcsafe().
*/
-__visible unsigned long
+__visible notrace unsigned long
mcsafe_handle_tail(char *to, char *from, unsigned len)
{
for (; len; --len, to++, from++) {
--
2.20.1
