diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2020-01-16 13:18:38 +0100 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2021-07-23 14:39:56 +0200 |
| commit | f27180dd63e1e6eca3230b9d3fdcc33564a81117 (patch) | |
| tree | 32f334f2fad44c2b989b546970e830a165ebc1ce /arch/um | |
| parent | 2734d6c1b1a089fb593ef6a23d4b70903526fe0c (diff) | |
asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_user
This is a preparation for changing over architectures to the
generic implementation one at a time. As there are no callers
of either __strncpy_from_user() or __strnlen_user(), fold these
into the strncpy_from_user() and strnlen_user() functions to make
each implementation independent of the others.
Many of these implementations have known bugs, but the intention
here is to not change behavior at all and stay compatible with
those bugs for the moment.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/include/asm/uaccess.h | 8 | ||||
| -rw-r--r-- | arch/um/kernel/skas/uaccess.c | 14 |
2 files changed, 14 insertions, 8 deletions
diff --git a/arch/um/include/asm/uaccess.h b/arch/um/include/asm/uaccess.h index fe66d659acad..3bf209f683f8 100644 --- a/arch/um/include/asm/uaccess.h +++ b/arch/um/include/asm/uaccess.h @@ -23,16 +23,16 @@ extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n); extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n); -extern long __strncpy_from_user(char *dst, const char __user *src, long count); -extern long __strnlen_user(const void __user *str, long len); +extern long strncpy_from_user(char *dst, const char __user *src, long count); +extern long strnlen_user(const void __user *str, long len); extern unsigned long __clear_user(void __user *mem, unsigned long len); static inline int __access_ok(unsigned long addr, unsigned long size); /* Teach asm-generic/uaccess.h that we have C functions for these. */ #define __access_ok __access_ok #define __clear_user __clear_user -#define __strnlen_user __strnlen_user -#define __strncpy_from_user __strncpy_from_user +#define strnlen_user strnlen_user +#define strncpy_from_user strncpy_from_user #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index 6c76df96e858..a509be911026 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -189,11 +189,14 @@ static int strncpy_chunk_from_user(unsigned long from, int len, void *arg) return 0; } -long __strncpy_from_user(char *dst, const char __user *src, long count) +long strncpy_from_user(char *dst, const char __user *src, long count) { long n; char *ptr = dst; + if (!access_ok(src, 1)) + return -EFAULT; + if (uaccess_kernel()) { strncpy(dst, (__force void *) src, count); return strnlen(dst, count); @@ -205,7 +208,7 @@ long __strncpy_from_user(char *dst, const char __user *src, long count) return -EFAULT; return strnlen(dst, count); } -EXPORT_SYMBOL(__strncpy_from_user); +EXPORT_SYMBOL(strncpy_from_user); static int clear_chunk(unsigned long addr, int len, void *unused) { @@ -236,10 +239,13 @@ static int strnlen_chunk(unsigned long str, int len, void *arg) return 0; } -long __strnlen_user(const void __user *str, long len) +long strnlen_user(const char __user *str, long len) { int count = 0, n; + if (!access_ok(str, 1)) + return -EFAULT; + if (uaccess_kernel()) return strnlen((__force char*)str, len) + 1; @@ -248,7 +254,7 @@ long __strnlen_user(const void __user *str, long len) return count + 1; return 0; } -EXPORT_SYMBOL(__strnlen_user); +EXPORT_SYMBOL(strnlen_user); /** * arch_futex_atomic_op_inuser() - Atomic arithmetic operation with constant |