* [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock
@ 2014-08-11 3:50 Guenter Roeck
[not found] ` <CAGUYZuSx3rMiLaPdDcmQYAZyTW9-6tZ_AL=8KQ_Mvv5FO0YHgA@mail.gmail.com>
2014-08-11 20:06 ` Kees Cook
0 siblings, 2 replies; 3+ messages in thread
From: Guenter Roeck @ 2014-08-11 3:50 UTC (permalink / raw)
To: Kees Cook; +Cc: Andrew Morton, linux-kernel, Guenter Roeck
Current upstream kernel hangs with mips and powerpc targets in
uniprocessor mode if SECCOMP is configured.
Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking").
Turns out that code such as
BUG_ON(!spin_is_locked(&list_lock));
can not be used in uniprocessor mode because spin_is_locked() always
returns false in this configuration, and that assert_spin_locked()
exists for that very purpose and must be used instead.
Fixes: dbd952127d11 ("seccomp: introduce writer locking")
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
kernel/fork.c | 2 +-
kernel/seccomp.c | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 1380d8a..0cf9cdb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1105,7 +1105,7 @@ static void copy_seccomp(struct task_struct *p)
* needed because this new task is not yet running and cannot
* be racing exec.
*/
- BUG_ON(!spin_is_locked(¤t->sighand->siglock));
+ assert_spin_locked(¤t->sighand->siglock);
/* Ref-count the new filter user, and assign it. */
get_seccomp_filter(current);
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 25b0043..44eb005 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -203,7 +203,7 @@ static u32 seccomp_run_filters(int syscall)
static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
{
- BUG_ON(!spin_is_locked(¤t->sighand->siglock));
+ assert_spin_locked(¤t->sighand->siglock);
if (current->seccomp.mode && current->seccomp.mode != seccomp_mode)
return false;
@@ -214,7 +214,7 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
static inline void seccomp_assign_mode(struct task_struct *task,
unsigned long seccomp_mode)
{
- BUG_ON(!spin_is_locked(&task->sighand->siglock));
+ assert_spin_locked(&task->sighand->siglock);
task->seccomp.mode = seccomp_mode;
/*
@@ -253,7 +253,7 @@ static inline pid_t seccomp_can_sync_threads(void)
struct task_struct *thread, *caller;
BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
- BUG_ON(!spin_is_locked(¤t->sighand->siglock));
+ assert_spin_locked(¤t->sighand->siglock);
/* Validate all threads being eligible for synchronization. */
caller = current;
@@ -294,7 +294,7 @@ static inline void seccomp_sync_threads(void)
struct task_struct *thread, *caller;
BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
- BUG_ON(!spin_is_locked(¤t->sighand->siglock));
+ assert_spin_locked(¤t->sighand->siglock);
/* Synchronize all threads. */
caller = current;
@@ -464,7 +464,7 @@ static long seccomp_attach_filter(unsigned int flags,
unsigned long total_insns;
struct seccomp_filter *walker;
- BUG_ON(!spin_is_locked(¤t->sighand->siglock));
+ assert_spin_locked(¤t->sighand->siglock);
/* Validate resulting filter length. */
total_insns = filter->prog->len;
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock
[not found] ` <CAGUYZuSx3rMiLaPdDcmQYAZyTW9-6tZ_AL=8KQ_Mvv5FO0YHgA@mail.gmail.com>
@ 2014-08-11 14:01 ` Guenter Roeck
0 siblings, 0 replies; 3+ messages in thread
From: Guenter Roeck @ 2014-08-11 14:01 UTC (permalink / raw)
To: sanjeev sharma; +Cc: Kees Cook, Andrew Morton, linux-kernel
On 08/10/2014 11:19 PM, sanjeev sharma wrote:
> Hello Guenter Roeck
>
> The same thing should be taken care in futex.c
>
That is using WARN_ON_SMP which is provided for that purpose.
Guenter
> Regards
> Sanjeev Sharma
>
>
> On Mon, Aug 11, 2014 at 9:20 AM, Guenter Roeck <linux@roeck-us.net <mailto:linux@roeck-us.net>> wrote:
>
> Current upstream kernel hangs with mips and powerpc targets in
> uniprocessor mode if SECCOMP is configured.
>
> Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking").
> Turns out that code such as
> BUG_ON(!spin_is_locked(&list_lock));
> can not be used in uniprocessor mode because spin_is_locked() always
> returns false in this configuration, and that assert_spin_locked()
> exists for that very purpose and must be used instead.
>
> Fixes: dbd952127d11 ("seccomp: introduce writer locking")
> Cc: Kees Cook <keescook@chromium.org <mailto:keescook@chromium.org>>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net <mailto:linux@roeck-us.net>>
> ---
> kernel/fork.c | 2 +-
> kernel/seccomp.c | 10 +++++-----
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 1380d8a..0cf9cdb 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1105,7 +1105,7 @@ static void copy_seccomp(struct task_struct *p)
> * needed because this new task is not yet running and cannot
> * be racing exec.
> */
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Ref-count the new filter user, and assign it. */
> get_seccomp_filter(current);
> diff --git a/kernel/seccomp.c b/kernel/seccomp.c
> index 25b0043..44eb005 100644
> --- a/kernel/seccomp.c
> +++ b/kernel/seccomp.c
> @@ -203,7 +203,7 @@ static u32 seccomp_run_filters(int syscall)
>
> static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
> {
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> if (current->seccomp.mode && current->seccomp.mode != seccomp_mode)
> return false;
> @@ -214,7 +214,7 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
> static inline void seccomp_assign_mode(struct task_struct *task,
> unsigned long seccomp_mode)
> {
> - BUG_ON(!spin_is_locked(&task->sighand->siglock));
> + assert_spin_locked(&task->sighand->siglock);
>
> task->seccomp.mode = seccomp_mode;
> /*
> @@ -253,7 +253,7 @@ static inline pid_t seccomp_can_sync_threads(void)
> struct task_struct *thread, *caller;
>
> BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Validate all threads being eligible for synchronization. */
> caller = current;
> @@ -294,7 +294,7 @@ static inline void seccomp_sync_threads(void)
> struct task_struct *thread, *caller;
>
> BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Synchronize all threads. */
> caller = current;
> @@ -464,7 +464,7 @@ static long seccomp_attach_filter(unsigned int flags,
> unsigned long total_insns;
> struct seccomp_filter *walker;
>
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Validate resulting filter length. */
> total_insns = filter->prog->len;
> --
> 1.9.1
>
> --
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>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock
2014-08-11 3:50 [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock Guenter Roeck
[not found] ` <CAGUYZuSx3rMiLaPdDcmQYAZyTW9-6tZ_AL=8KQ_Mvv5FO0YHgA@mail.gmail.com>
@ 2014-08-11 20:06 ` Kees Cook
1 sibling, 0 replies; 3+ messages in thread
From: Kees Cook @ 2014-08-11 20:06 UTC (permalink / raw)
To: Guenter Roeck; +Cc: Andrew Morton, LKML
On Sun, Aug 10, 2014 at 8:50 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> Current upstream kernel hangs with mips and powerpc targets in
> uniprocessor mode if SECCOMP is configured.
>
> Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking").
> Turns out that code such as
> BUG_ON(!spin_is_locked(&list_lock));
> can not be used in uniprocessor mode because spin_is_locked() always
> returns false in this configuration, and that assert_spin_locked()
> exists for that very purpose and must be used instead.
>
> Fixes: dbd952127d11 ("seccomp: introduce writer locking")
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Applied, thanks! Should be visible here shortly:
http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=seccomp/tip
-Kees
> ---
> kernel/fork.c | 2 +-
> kernel/seccomp.c | 10 +++++-----
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 1380d8a..0cf9cdb 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1105,7 +1105,7 @@ static void copy_seccomp(struct task_struct *p)
> * needed because this new task is not yet running and cannot
> * be racing exec.
> */
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Ref-count the new filter user, and assign it. */
> get_seccomp_filter(current);
> diff --git a/kernel/seccomp.c b/kernel/seccomp.c
> index 25b0043..44eb005 100644
> --- a/kernel/seccomp.c
> +++ b/kernel/seccomp.c
> @@ -203,7 +203,7 @@ static u32 seccomp_run_filters(int syscall)
>
> static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
> {
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> if (current->seccomp.mode && current->seccomp.mode != seccomp_mode)
> return false;
> @@ -214,7 +214,7 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
> static inline void seccomp_assign_mode(struct task_struct *task,
> unsigned long seccomp_mode)
> {
> - BUG_ON(!spin_is_locked(&task->sighand->siglock));
> + assert_spin_locked(&task->sighand->siglock);
>
> task->seccomp.mode = seccomp_mode;
> /*
> @@ -253,7 +253,7 @@ static inline pid_t seccomp_can_sync_threads(void)
> struct task_struct *thread, *caller;
>
> BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Validate all threads being eligible for synchronization. */
> caller = current;
> @@ -294,7 +294,7 @@ static inline void seccomp_sync_threads(void)
> struct task_struct *thread, *caller;
>
> BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Synchronize all threads. */
> caller = current;
> @@ -464,7 +464,7 @@ static long seccomp_attach_filter(unsigned int flags,
> unsigned long total_insns;
> struct seccomp_filter *walker;
>
> - BUG_ON(!spin_is_locked(¤t->sighand->siglock));
> + assert_spin_locked(¤t->sighand->siglock);
>
> /* Validate resulting filter length. */
> total_insns = filter->prog->len;
> --
> 1.9.1
>
--
Kees Cook
Chrome OS Security
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-08-11 3:50 [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock Guenter Roeck
[not found] ` <CAGUYZuSx3rMiLaPdDcmQYAZyTW9-6tZ_AL=8KQ_Mvv5FO0YHgA@mail.gmail.com>
2014-08-11 14:01 ` Guenter Roeck
2014-08-11 20:06 ` Kees Cook
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