[PATCH v4 1/4] uaccess: Always inline strn*_user() helper functions

Josh Poimboeuf
2021-05-05T03:54:55Z

CONFIG_DEBUG_SECTION_MISMATCH uses -fno-inline-functions-called-once,
causing these single-called helper functions to not get inlined:

lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0xa3: call to do_strncpy_from_user() with UACCESS enabled
lib/strnlen_user.o: warning: objtool: strnlen_user()+0x73: call to do_strnlen_user() with UACCESS enabled

Always inline them regardless.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
lib/strncpy_from_user.c | 6 ++++--
lib/strnlen_user.c | 4 +++-
2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 122d8d0e253c..388539951116 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -25,8 +25,10 @@
* hit it), 'max' is the address space maximum (and we return
* -EFAULT if we hit it).
*/
-static inline long do_strncpy_from_user(char *dst, const char __user *src,
- unsigned long count, unsigned long max)
+static __always_inline long do_strncpy_from_user(char *dst,
+ const char __user *src,
+ unsigned long count,
+ unsigned long max)
{
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
unsigned long res = 0;
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 1616710b8a82..378744e96039 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -20,7 +20,9 @@
* if it fits in a aligned 'long'. The caller needs to check
* the return value against "> max".
*/
-static inline long do_strnlen_user(const char __user *src, unsigned long count, unsigned long max)
+static __always_inline long do_strnlen_user(const char __user *src,
+ unsigned long count,
+ unsigned long max)
{
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
unsigned long align, res = 0;
--
2.31.1