[PATCH 4.4 116/118] ppc32: fix copy_from_user()
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-09-22 18:53:31
Also in:
lkml
4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro <viro@zeniv.linux.org.uk> commit 224264657b8b228f949b42346e09ed8c90136a8e upstream. should clear on access_ok() failures. Also remove the useless range truncation logics. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/powerpc/include/asm/uaccess.h | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h@@ -323,30 +323,17 @@ extern unsigned long __copy_tofrom_user( 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; }
@@ -437,10 +424,6 @@ static inline unsigned long clear_user(v 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; }