From 224264657b8b228f949b42346e09ed8c90136a8e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 21 Aug 2016 19:16:26 -0400 Subject: [PATCH] ppc32: fix copy_from_user() should clear on access_ok() failures. Also remove the useless range truncation logics. Cc: stable@vger.kernel.org Signed-off-by: Al Viro --- arch/powerpc/include/asm/uaccess.h | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index c1dc6c14deb8..c2ce5dd33673 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -308,40 +308,23 @@ extern unsigned long __copy_tofrom_user(void __user *to, static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) { - unsigned long over; - - if (access_ok(VERIFY_READ, from, n)) { + if (likely(access_ok(VERIFY_READ, from, n))) { if (!__builtin_constant_p(n)) check_object_size(to, n, false); return __copy_tofrom_user((__force void __user *)to, from, n); } - if ((unsigned long)from < TASK_SIZE) { - over = (unsigned long)from + n - TASK_SIZE; - if (!__builtin_constant_p(n - over)) - check_object_size(to, n - over, false); - return __copy_tofrom_user((__force void __user *)to, from, - n - over) + over; - } + memset(to, 0, n); return n; } static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) { - unsigned long over; - if (access_ok(VERIFY_WRITE, to, n)) { if (!__builtin_constant_p(n)) check_object_size(from, n, true); return __copy_tofrom_user(to, (__force void __user *)from, n); } - if ((unsigned long)to < TASK_SIZE) { - over = (unsigned long)to + n - TASK_SIZE; - if (!__builtin_constant_p(n)) - check_object_size(from, n - over, true); - return __copy_tofrom_user(to, (__force void __user *)from, - n - over) + over; - } return n; } @@ -439,10 +422,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size) might_fault(); if (likely(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; - } return size; } -- 2.20.1