From 6882b9a54f40f23f8b10f5b7df411cad3b52c5a7 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 20 Aug 2016 17:05:21 -0400 Subject: [PATCH] openrisc: fix copy_from_user() commit acb2505d0119033a80c85ac8d02dccae41271667 upstream. ... that should zero on faults. Also remove the 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... Signed-off-by: Al Viro Signed-off-by: Ben Hutchings --- arch/openrisc/include/asm/uaccess.h | 35 +++++++++-------------------- 1 file changed, 11 insertions(+), 24 deletions(-) diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h index c310e45b538e..0bcc64803dc1 100644 --- a/arch/openrisc/include/asm/uaccess.h +++ b/arch/openrisc/include/asm/uaccess.h @@ -274,28 +274,20 @@ __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; } @@ -304,13 +296,8 @@ 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; } -- 2.39.2