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>
(cherry picked from commit 1f65c13efef69b6dc908e588f91a133641d8475c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
arch/arm64/include/asm/uaccess.h
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 008f848..7ecc2b2 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -166,9 +166,10 @@
#define get_user(x, ptr) \
({ \
- might_sleep(); \
- access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \
- __get_user((x), (ptr)) : \
+ __typeof__(*(ptr)) __user *__p = (ptr); \
+ might_fault(); \
+ access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \
+ __get_user((x), __p) : \
((x) = 0, -EFAULT); \
})
@@ -227,9 +228,10 @@
#define put_user(x, ptr) \
({ \
- might_sleep(); \
- access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \
- __put_user((x), (ptr)) : \
+ __typeof__(*(ptr)) __user *__p = (ptr); \
+ might_fault(); \
+ access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \
+ __put_user((x), __p) : \
-EFAULT; \
})