From 1f65c13efef69b6dc908e588f91a133641d8475c Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Tue, 24 Sep 2013 10:00:50 +0100 Subject: arm64: avoid multiple evaluation of ptr in get_user/put_user() get_user() is defined as a function macro in arm64, and trace_get_user() calls it as followed: get_user(ch, ptr++); Since the second parameter occurs twice in the definition, 'ptr++' is unexpectedly evaluated twice and trace_get_user() will generate a bogus string from user-provided one. As a result, some ftrace sysfs operations, like "echo FUNCNAME > set_ftrace_filter," hit this case and eventually fail. This patch fixes the issue both in get_user() and put_user(). Signed-off-by: AKASHI Takahiro [catalin.marinas@arm.com: added __user type annotation and s/optr/__p/] Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/uaccess.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c73a32..7ecc2b23882e 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -166,9 +166,10 @@ do { \ #define get_user(x, ptr) \ ({ \ + __typeof__(*(ptr)) __user *__p = (ptr); \ might_fault(); \ - access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \ - __get_user((x), (ptr)) : \ + access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \ + __get_user((x), __p) : \ ((x) = 0, -EFAULT); \ }) @@ -227,9 +228,10 @@ do { \ #define put_user(x, ptr) \ ({ \ + __typeof__(*(ptr)) __user *__p = (ptr); \ might_fault(); \ - access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ - __put_user((x), (ptr)) : \ + access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \ + __put_user((x), __p) : \ -EFAULT; \ }) -- cgit v1.2.3