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authorAKASHI Takahiro <takahiro.akashi@linaro.org>2013-09-24 10:00:50 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2013-09-25 16:42:21 +0100
commit1f65c13efef69b6dc908e588f91a133641d8475c (patch)
treea0d11a91b177acb70c29643b426e9c6834930f68 /arch/arm64/include/asm/uaccess.h
parentarm64: Widen hwcap to be 64 bit (diff)
downloadlinux-dev-1f65c13efef69b6dc908e588f91a133641d8475c.tar.xz
linux-dev-1f65c13efef69b6dc908e588f91a133641d8475c.zip
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 <takahiro.akashi@linaro.org> [catalin.marinas@arm.com: added __user type annotation and s/optr/__p/] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/include/asm/uaccess.h10
1 files changed, 6 insertions, 4 deletions
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; \
})