[PATCH] initity: try to improve __nocapture annotations

[Arnd Bergmann]

There are some additional declarations that got missed in the original patch,
and some annotated functions that use the pointer is a correct but nonobvious
way:

mm/kasan/kasan.c: In function 'memmove':
mm/kasan/kasan.c:346:7: error: 'memmove' captures its 2 ('src') parameter, please remove it from the nocapture attribute. [-Werror]
 void *memmove(void *dest, const void *src, size_t len)
       ^~~~~~~
mm/kasan/kasan.c: In function 'memcpy':
mm/kasan/kasan.c:355:7: error: 'memcpy' captures its 2 ('src') parameter, please remove it from the nocapture attribute. [-Werror]
 void *memcpy(void *dest, const void *src, size_t len)
       ^~~~~~
drivers/acpi/acpica/utdebug.c: In function 'acpi_debug_print':
drivers/acpi/acpica/utdebug.c:158:1: error: 'acpi_debug_print' captures its 3 ('function_name') parameter, please remove it from the nocapture attribute. [-Werror]

lib/string.c:893:7: error: 'memchr_inv' captures its 1 ('start') parameter, please remove it from the nocapture attribute. [-Werror]
 void *memchr_inv(const void *start, int c, size_t bytes)
lib/string.c: In function 'strnstr':
lib/string.c:832:7: error: 'strnstr' captures its 1 ('s1') parameter, please remove it from the nocapture attribute. [-Werror]
 char *strnstr(const char *s1, const char *s2, size_t len)
       ^~~~~~~
lib/string.c:832:7: error: 'strnstr' captures its 2 ('s2') parameter, please remove it from the nocapture attribute. [-Werror]

I'm not sure if these are all appropriate fixes, please have a careful look

Fixes: c2bc07665495 ("initify: Mark functions with the __nocapture attribute")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/acpi/acpica/utdebug.c        | 2 +-
 include/acpi/acpixf.h                | 2 +-
 include/asm-generic/asm-prototypes.h | 8 ++++----
 include/linux/string.h               | 2 +-
 lib/string.c                         | 2 +-
 mm/kasan/kasan.c                     | 4 ++--
 6 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/acpica/utdebug.c b/drivers/acpi/acpica/utdebug.c
index 044df9b0356e..de3c9cb305a2 100644
--- a/drivers/acpi/acpica/utdebug.c
+++ b/drivers/acpi/acpica/utdebug.c
@@ -154,7 +154,7 @@ static const char *acpi_ut_trim_function_name(const char *function_name)
  *
  ******************************************************************************/
 
-void ACPI_INTERNAL_VAR_XFACE
+void __unverified_nocapture(3) ACPI_INTERNAL_VAR_XFACE
 acpi_debug_print(u32 requested_debug_level,
 		 u32 line_number,
 		 const char *function_name,
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 9f4637e9dd92..9644cec5b082 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -946,7 +946,7 @@ ACPI_DBG_DEPENDENT_RETURN_VOID(ACPI_PRINTF_LIKE(6) __nocapture(3)
 						const char *module_name,
 						u32 component_id,
 						const char *format, ...))
-ACPI_DBG_DEPENDENT_RETURN_VOID(ACPI_PRINTF_LIKE(6)
+ACPI_DBG_DEPENDENT_RETURN_VOID(ACPI_PRINTF_LIKE(6) __nocapture(3)
 				void ACPI_INTERNAL_VAR_XFACE
 				acpi_debug_print_raw(u32 requested_debug_level,
 						     u32 line_number,
diff --git a/include/asm-generic/asm-prototypes.h b/include/asm-generic/asm-prototypes.h
index 939869c772b1..ffc0dd7e8ed2 100644
--- a/include/asm-generic/asm-prototypes.h
+++ b/include/asm-generic/asm-prototypes.h
@@ -2,12 +2,12 @@
 #undef __memset
 extern void *__memset(void *, int, __kernel_size_t);
 #undef __memcpy
-extern void *__memcpy(void *, const void *, __kernel_size_t);
+extern void *__memcpy(void *, const void *, __kernel_size_t) __nocapture(2);
 #undef __memmove
-extern void *__memmove(void *, const void *, __kernel_size_t);
+extern void *__memmove(void *, const void *, __kernel_size_t) __nocapture(2);
 #undef memset
 extern void *memset(void *, int, __kernel_size_t);
 #undef memcpy
-extern void *memcpy(void *, const void *, __kernel_size_t);
+extern void *memcpy(void *, const void *, __kernel_size_t) __nocapture(2);
 #undef memmove
-extern void *memmove(void *, const void *, __kernel_size_t);
+extern void *memmove(void *, const void *, __kernel_size_t) __nocapture(2);
diff --git a/include/linux/string.h b/include/linux/string.h
index 8b3b97e7b2b0..0ee877593464 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -76,7 +76,7 @@ static inline __must_check char *strstrip(char *str)
 extern char * strstr(const char *, const char *) __nocapture(-1, 2);
 #endif
 #ifndef __HAVE_ARCH_STRNSTR
-extern char * strnstr(const char *, const char *, size_t) __nocapture(-1, 2);
+extern char * strnstr(const char *, const char *, size_t);
 #endif
 #ifndef __HAVE_ARCH_STRLEN
 extern __kernel_size_t strlen(const char *) __nocapture(1);
diff --git a/lib/string.c b/lib/string.c
index ed83562a53ae..01151a1a0b61 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -870,7 +870,7 @@ void *memchr(const void *s, int c, size_t n)
 EXPORT_SYMBOL(memchr);
 #endif
 
-static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
+static __always_inline void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
 {
 	while (bytes) {
 		if (*start != value)
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 5f6e09c88d25..ebc02ee1118e 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -343,7 +343,7 @@ void *memset(void *addr, int c, size_t len)
 }
 
 #undef memmove
-void *memmove(void *dest, const void *src, size_t len)
+__unverified_nocapture(2) void *memmove(void *dest, const void *src, size_t len)
 {
 	check_memory_region((unsigned long)src, len, false, _RET_IP_);
 	check_memory_region((unsigned long)dest, len, true, _RET_IP_);
@@ -352,7 +352,7 @@ void *memmove(void *dest, const void *src, size_t len)
 }
 
 #undef memcpy
-void *memcpy(void *dest, const void *src, size_t len)
+__unverified_nocapture(2) void *memcpy(void *dest, const void *src, size_t len)
 {
 	check_memory_region((unsigned long)src, len, false, _RET_IP_);
 	check_memory_region((unsigned long)dest, len, true, _RET_IP_);
-- 
2.9.0