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| author |   AKASHI Takahiro <takahiro.akashi@linaro.org> | 2013-09-24 10:00:50 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2013-09-25 16:42:21 +0100 |
| commit | 1f65c13efef69b6dc908e588f91a133641d8475c (patch) | |
| tree | a0d11a91b177acb70c29643b426e9c6834930f68 /arch/arm64 | |
| parent | arm64: Widen hwcap to be 64 bit (diff) | |
| download | linux-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 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 10 |
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; \ }) |