[patch added to 3.12-stable] openrisc: fix copy_from_user()
From: Jiri Slaby <hidden>
Date: 2016-09-29 09:07:11
Subsystem:
openrisc architecture, the rest · Maintainers:
Jonas Bonn, Stefan Kristiansson, Stafford Horne, Linus Torvalds
From: Al Viro <viro@zeniv.linux.org.uk> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit acb2505d0119033a80c85ac8d02dccae41271667 upstream. ... 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... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <redacted> --- 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 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; }
--
2.10.0