diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2016-08-21 00:05:21 +0300 |
---|---|---|
committer | Sasha Levin <alexander.levin@verizon.com> | 2016-10-06 05:40:20 +0300 |
commit | 499e590cbe0052d4343cc5cab0e7baf1d48d7061 (patch) | |
tree | 8bc90650ff2c25c74566fdfbc285fca3e1e7d3b4 /arch/openrisc/include/asm/uaccess.h | |
parent | 8260a515dd670f2994e50a7783ddbe75eb6d4e0d (diff) | |
download | linux-499e590cbe0052d4343cc5cab0e7baf1d48d7061.tar.xz |
openrisc: fix copy_from_user()
[ Upstream commit acb2505d0119033a80c85ac8d02dccae41271667 ]
... that should zero on faults. Also remove the <censored> helpful
logics wrt range truncation copied from ppc32. Where it had ever
been needed only in case of copy_from_user() *and* had not been merged
into the mainline until a month after the need had disappeared.
A decade before openrisc went into mainline, I might add...
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'arch/openrisc/include/asm/uaccess.h')
-rw-r--r-- | arch/openrisc/include/asm/uaccess.h | 35 |
1 files changed, 11 insertions, 24 deletions
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h index ab2e7a198a4c..908c0904bdd6 100644 --- a/arch/openrisc/include/asm/uaccess.h +++ b/arch/openrisc/include/asm/uaccess.h @@ -273,28 +273,20 @@ __copy_tofrom_user(void *to, const void *from, unsigned long size); static inline unsigned long copy_from_user(void *to, const void *from, unsigned long n) { - unsigned long over; - - if (access_ok(VERIFY_READ, from, n)) - return __copy_tofrom_user(to, from, n); - if ((unsigned long)from < TASK_SIZE) { - over = (unsigned long)from + n - TASK_SIZE; - return __copy_tofrom_user(to, from, n - over) + over; - } - return n; + unsigned long res = n; + + if (likely(access_ok(VERIFY_READ, from, n))) + n = __copy_tofrom_user(to, from, n); + if (unlikely(res)) + memset(to + (n - res), 0, res); + return res; } static inline unsigned long copy_to_user(void *to, const void *from, unsigned long n) { - unsigned long over; - - if (access_ok(VERIFY_WRITE, to, n)) - return __copy_tofrom_user(to, from, n); - if ((unsigned long)to < TASK_SIZE) { - over = (unsigned long)to + n - TASK_SIZE; - return __copy_tofrom_user(to, from, n - over) + over; - } + if (likely(access_ok(VERIFY_WRITE, to, n))) + n = __copy_tofrom_user(to, from, n); return n; } @@ -303,13 +295,8 @@ extern unsigned long __clear_user(void *addr, unsigned long size); static inline __must_check unsigned long clear_user(void *addr, unsigned long size) { - - if (access_ok(VERIFY_WRITE, addr, size)) - return __clear_user(addr, size); - if ((unsigned long)addr < TASK_SIZE) { - unsigned long over = (unsigned long)addr + size - TASK_SIZE; - return __clear_user(addr, size - over) + over; - } + if (likely(access_ok(VERIFY_WRITE, addr, size))) + size = __clear_user(addr, size); return size; } |