arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()
adjust copy_from_user(), obviously
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index a93c0f9..1f59ea05 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -533,11 +533,12 @@
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
- if (access_ok(VERIFY_READ, from, n))
- n = __copy_from_user(to, from, n);
- else /* security hole - plug it */
- memset(to, 0, n);
- return n;
+ unsigned long res = n;
+ if (likely(access_ok(VERIFY_READ, from, n)))
+ res = __copy_from_user(to, from, n);
+ if (unlikely(res))
+ memset(to + (n - res), 0, res);
+ return res;
}
static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
diff --git a/arch/arm/lib/copy_from_user.S b/arch/arm/lib/copy_from_user.S
index 1512beb..7a4b060 100644
--- a/arch/arm/lib/copy_from_user.S
+++ b/arch/arm/lib/copy_from_user.S
@@ -98,12 +98,9 @@
.pushsection .fixup,"ax"
.align 0
copy_abort_preamble
- ldmfd sp!, {r1, r2}
- sub r3, r0, r1
- rsb r1, r3, r2
- str r1, [sp]
- bl __memzero
- ldr r0, [sp], #4
+ ldmfd sp!, {r1, r2, r3}
+ sub r0, r0, r1
+ rsb r0, r0, r2
copy_abort_end
.popsection