diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-10 16:44:03 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-15 19:51:56 -0400 |
| commit | 91344493b7da9487a8dbc1109d7486e51c8e5235 (patch) | |
| tree | 134a2ad5c7ecd0f304fa69118b66acc92544b60c | |
| parent | 7798bf2140ebcc36eafec6a4194fffd8d585d471 (diff) | |
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>
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 11 | ||||
| -rw-r--r-- | arch/arm/lib/copy_from_user.S | 9 |
2 files changed, 9 insertions, 11 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index a93c0f99acf7..1f59ea051bab 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -533,11 +533,12 @@ __clear_user(void __user *addr, unsigned long n) 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 1512bebfbf1b..7a4b06049001 100644 --- a/arch/arm/lib/copy_from_user.S +++ b/arch/arm/lib/copy_from_user.S @@ -98,12 +98,9 @@ ENDPROC(arm_copy_from_user) .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 |