Hi,
On Thu, May 26, 2016 at 11:43:51AM -0700, Yang Shi wrote:
The upstream commit 1771c6e1a567ea0ba2cccc0a4ffe68a1419fd8ef ("x86/kasan: instrument user memory access API") added KASAN instrument to x86 user memory access API, so added such instrument to ARM64 too.
Tested by test_kasan module.
I just gave this a go atop of the current HEAD (dc03c0f9d12d8528) on a Juno R1 board. I hit the expected exceptions when using the test_kasan module (once I remembered to rebuild it), and things seem to run smoothly otherwise.
I don't see any built issues when !CONFIG_KASAN, and the patch itself looks right to me.
So FWIW:
Acked-by: Mark Rutland mark.rutland@arm.com Tested-by: Mark Rutland mark.rutland@arm.com
As an aside, it's a shame that each architecture has to duplicate this logic, rather than having something in the generic code like:
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) { kasan_check_read(from, n); arch_copy_from_user(to, from, n); }
Thanks, Mark.
Signed-off-by: Yang Shi yang.shi@linaro.org
arch/arm64/include/asm/uaccess.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 0685d74..ec352fa 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -23,6 +23,7 @@ */ #include <linux/string.h> #include <linux/thread_info.h> +#include <linux/kasan-checks.h> #include <asm/alternative.h> #include <asm/cpufeature.h> @@ -276,6 +277,8 @@ extern unsigned long __must_check __clear_user(void __user *addr, unsigned long static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) {
- kasan_check_write(to, n);
- if (access_ok(VERIFY_READ, from, n)) n = __copy_from_user(to, from, n); else /* security hole - plug it */
@@ -285,6 +288,8 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) {
- kasan_check_read(from, n);
- if (access_ok(VERIFY_WRITE, to, n)) n = __copy_to_user(to, from, n); return n;
@@ -297,8 +302,17 @@ static inline unsigned long __must_check copy_in_user(void __user *to, const voi return n; } -#define __copy_to_user_inatomic __copy_to_user -#define __copy_from_user_inatomic __copy_from_user +static inline unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) +{
- kasan_check_read(from, n);
- return __copy_to_user(to, from, n);
+}
+static inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) +{
- kasan_check_write(to, n);
- return __copy_from_user(to, from, n);
+} static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) { -- 2.0.2
linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel