[PATCH v4 01/24] fix default __strnlen_user macro
From: Mark Salter <hidden>
Date: 2011-10-04 16:44:18
Also in:
lkml
Subsystem:
generic include/asm header files, the rest · Maintainers:
Arnd Bergmann, Linus Torvalds
The existing __strnlen_user macro simply resolved to strnlen. However, the count returned by strnlen_user should include the NULL byte. This patch fixes the __strnlen_user macro to include the NULL byte in the count. Signed-off-by: Mark Salter <redacted> Acked-by: Arnd Bergmann <arnd@arndb.de> --- include/asm-generic/uaccess.h | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index ac68c99..9788568 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h@@ -289,9 +289,14 @@ strncpy_from_user(char *dst, const char __user *src, long count) * Return 0 on exception, a value greater than N if too long */ #ifndef __strnlen_user -#define __strnlen_user strnlen +#define __strnlen_user(s, n) (strnlen((s), (n)) + 1) #endif +/* + * Unlike strnlen, strnlen_user includes the nul terminator in + * its returned count. Callers should check for a returned value + * greater than N as an indication the string is too long. + */ static inline long strnlen_user(const char __user *src, long n) { if (!access_ok(VERIFY_READ, src, 1))
--
1.7.6.2