From 040793b49fd39f00afebc0a1d6870f247ddb9a43 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() commit 224264657b8b228f949b42346e09ed8c90136a8e upstream. should clear on access_ok() failures. Also remove the useless range truncation logics. Signed-off-by: Al Viro [bwh: Backported to 3.2: no calls to check_object_size()] Signed-off-by: Ben Hutchings --- arch/powerpc/include/asm/uaccess.h | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index bd0fb8495154..4d4a30ccc249 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -332,30 +332,17 @@ 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))) return __copy_tofrom_user((__force void __user *)to, from, n); - if ((unsigned long)from < TASK_SIZE) { - over = (unsigned long)from + n - TASK_SIZE; - 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)) return __copy_tofrom_user(to, (__force void __user *)from, n); - if ((unsigned long)to < TASK_SIZE) { - over = (unsigned long)to + n - TASK_SIZE; - return __copy_tofrom_user(to, (__force void __user *)from, - n - over) + over; - } return n; } @@ -446,10 +433,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size) might_sleep(); 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; } -- 2.43.0