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 --- arch/arm64/include/asm/uaccess.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c..bbeab83 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -166,9 +166,11 @@ do { \ #define get_user(x, ptr) \ ({ \ + __typeof__(*(ptr)) *optr = (ptr); \ + \ might_fault(); \ - access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \ - __get_user((x), (ptr)) : \ + access_ok(VERIFY_READ, optr, sizeof(*optr)) ? \ + __get_user((x), optr) : \ ((x) = 0, -EFAULT); \ }) @@ -227,9 +229,11 @@ do { \ #define put_user(x, ptr) \ ({ \ + __typeof__(*(ptr)) *optr = (ptr); \ + \ might_fault(); \ - access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ - __put_user((x), (ptr)) : \ + access_ok(VERIFY_WRITE, optr, sizeof(*optr)) ? \ + __put_user((x), optr) : \ -EFAULT; \ }) -- 1.7.9.5
On Tue, Sep 24, 2013 at 10:00:50AM +0100, AKASHI Takahiro wrote:
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
arch/arm64/include/asm/uaccess.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c..bbeab83 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -166,9 +166,11 @@ do { \ #define get_user(x, ptr) \ ({ \
- __typeof__(*(ptr)) *optr = (ptr); \
I think this should be:
__typeof__(*(ptr)) __user *optr = (ptr);
Otherwise the patch looks fine. I can fix the above.
Thanks.
On Tue, Sep 24, 2013 at 10:00:50AM +0100, AKASHI Takahiro wrote:
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
arch/arm64/include/asm/uaccess.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c..bbeab83 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -166,9 +166,11 @@ do { \ #define get_user(x, ptr) \ ({ \
- __typeof__(*(ptr)) *optr = (ptr); \
\
- access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \
__get_user((x), (ptr)) : \
- access_ok(VERIFY_READ, optr, sizeof(*optr)) ? \
__get_user((x), optr) : \- __typeof__(*(ptr)) *optr = (ptr); \
\
- access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \
__put_user((x), (ptr)) : \
- access_ok(VERIFY_WRITE, optr, sizeof(*optr)) ? \
__put_user((x), optr) : \
BTW, please use git send-email or other email client, the diff above is heavily corrupted (too many spaces at the beginning of the line, removed empty lines; I managed to fix it up this time but only because it was a small patch).
Catalin,
Thank you for your comments, and let me send a revised patch again because my original message didn't reach MLs due to my screw-up.
BTW, I will submit a patch of ftrace support on arm64 once gcc supports gprof (-pg) options.
-Takahiro AKASHI
On 09/24/2013 11:25 PM, Catalin Marinas wrote:
On Tue, Sep 24, 2013 at 10:00:50AM +0100, AKASHI Takahiro wrote:
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
arch/arm64/include/asm/uaccess.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c..bbeab83 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -166,9 +166,11 @@ do { \ #define get_user(x, ptr) \ ({ \
- __typeof__(*(ptr)) *optr = (ptr); \
\
- access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \
__get_user((x), (ptr)) : \
- access_ok(VERIFY_READ, optr, sizeof(*optr)) ? \
__get_user((x), optr) : \ ((x) = 0, -EFAULT); \- __typeof__(*(ptr)) *optr = (ptr); \
\
- access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \
__put_user((x), (ptr)) : \
- access_ok(VERIFY_WRITE, optr, sizeof(*optr)) ? \
__put_user((x), optr) : \ -EFAULT; \BTW, please use git send-email or other email client, the diff above is heavily corrupted (too many spaces at the beginning of the line, removed empty lines; I managed to fix it up this time but only because it was a small patch).
On Wed, Sep 25, 2013 at 10:29:52AM +0100, AKASHI Takahiro wrote:
Thank you for your comments, and let me send a revised patch again because my original message didn't reach MLs due to my screw-up.
You can send it if you want but I already merged it in my tree (should appear in -next this week as well).
linaro-kernel@lists.linaro.org
-
AKASHI Takahiro -
Catalin Marinas