* [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
@ 2014-09-23 7:44 Zefan Li
2014-09-23 7:44 ` [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags Zefan Li
` (2 more replies)
0 siblings, 3 replies; 12+ messages in thread
From: Zefan Li @ 2014-09-23 7:44 UTC (permalink / raw)
To: Tejun Heo
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
because it is used as bit number. Redefine it as decimal bit number.
Note this changes the bit position of PFA_NOW_NEW_PRIVS from 1 to 0.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Kees Cook <keescook@chromium.org>
[ lizf: slightly modified subject and changelog ]
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
include/linux/sched.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5c2c885..4557765 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1957,7 +1957,7 @@ static inline void memalloc_noio_restore(unsigned int flags)
}
/* Per-process atomic flags. */
-#define PFA_NO_NEW_PRIVS 0x00000001 /* May not gain new privileges. */
+#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
static inline bool task_no_new_privs(struct task_struct *p)
{
--
1.8.0.2
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags
2014-09-23 7:44 [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Zefan Li
@ 2014-09-23 7:44 ` Zefan Li
2014-09-23 10:01 ` Peter Zijlstra
2014-09-23 7:45 ` [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be " Zefan Li
2014-09-24 13:22 ` [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Tejun Heo
2 siblings, 1 reply; 12+ messages in thread
From: Zefan Li @ 2014-09-23 7:44 UTC (permalink / raw)
To: Tejun Heo
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups
This will simplify code when we add new flags.
v3:
- Kees pointed out that no_new_privs should never be cleared, so we
shouldn't define task_clear_no_new_privs(). we define 3 macros instead
of a single one.
v2:
- updated scripts/tags.sh, suggested by Peter.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
include/linux/sched.h | 21 ++++++++++++---------
scripts/tags.sh | 6 ++++++
2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4557765..5630763 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1959,15 +1959,18 @@ static inline void memalloc_noio_restore(unsigned int flags)
/* Per-process atomic flags. */
#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
-static inline bool task_no_new_privs(struct task_struct *p)
-{
- return test_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
-}
-
-static inline void task_set_no_new_privs(struct task_struct *p)
-{
- set_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
-}
+#define TASK_PFA_TEST(name, func) \
+ static inline bool task_##func(struct task_struct *p) \
+ { return test_bit(PFA_##name, &p->atomic_flags); }
+#define TASK_PFA_SET(name, func) \
+ static inline void task_set_##func(struct task_struct *p) \
+ { set_bit(PFA_##name, &p->atomic_flags); }
+#define TASK_PFA_CLEAR(name, func) \
+ static inline void task_clear_##func(struct task_struct *p) \
+ { clear_bit(PFA_##name, &p->atomic_flags); }
+
+TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
+TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
/*
* task->jobctl flags
diff --git a/scripts/tags.sh b/scripts/tags.sh
index cbfd269..293828b 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -197,6 +197,9 @@ exuberant()
--regex-c++='/SETPCGFLAG\(([^,)]*).*/SetPageCgroup\1/' \
--regex-c++='/CLEARPCGFLAG\(([^,)]*).*/ClearPageCgroup\1/' \
--regex-c++='/TESTCLEARPCGFLAG\(([^,)]*).*/TestClearPageCgroup\1/' \
+ --regex-c++='/TASK_PFA_TEST\([^,]*,\s*([^)]*)\)/task_\1/' \
+ --regex-c++='/TASK_PFA_SET\([^,]*,\s*([^)]*)\)/task_set_\1/' \
+ --regex-c++='/TASK_PFA_CLEAR\([^,]*,\s*([^)]*)\)/task_clear_\1/'\
--regex-c='/PCI_OP_READ\((\w*).*[1-4]\)/pci_bus_read_config_\1/' \
--regex-c='/PCI_OP_WRITE\((\w*).*[1-4]\)/pci_bus_write_config_\1/' \
--regex-c='/DEFINE_(MUTEX|SEMAPHORE|SPINLOCK)\((\w*)/\2/v/' \
@@ -260,6 +263,9 @@ emacs()
--regex='/SETPCGFLAG\(([^,)]*).*/SetPageCgroup\1/' \
--regex='/CLEARPCGFLAG\(([^,)]*).*/ClearPageCgroup\1/' \
--regex='/TESTCLEARPCGFLAG\(([^,)]*).*/TestClearPageCgroup\1/' \
+ --regex='/TASK_PFA_TEST\([^,]*,\s*([^)]*)\)/task_\1/' \
+ --regex='/TASK_PFA_SET\([^,]*,\s*([^)]*)\)/task_set_\1/' \
+ --regex='/TASK_PFA_CLEAR\([^,]*,\s*([^)]*)\)/task_clear_\1/' \
--regex='/_PE(\([^,)]*\).*/PEVENT_ERRNO__\1/' \
--regex='/PCI_OP_READ(\([a-z]*[a-z]\).*[1-4])/pci_bus_read_config_\1/' \
--regex='/PCI_OP_WRITE(\([a-z]*[a-z]\).*[1-4])/pci_bus_write_config_\1/'\
--
1.8.0.2
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags
2014-09-23 7:44 [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Zefan Li
2014-09-23 7:44 ` [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags Zefan Li
@ 2014-09-23 7:45 ` Zefan Li
2014-09-23 22:10 ` David Rientjes
2014-09-24 13:22 ` [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Tejun Heo
2 siblings, 1 reply; 12+ messages in thread
From: Zefan Li @ 2014-09-23 7:45 UTC (permalink / raw)
To: Tejun Heo
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups
When we change cpuset.memory_spread_{page,slab}, cpuset will flip
PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset.
This should be done using atomic bitops, but currently we don't,
which is broken.
Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happend
when one thread tried to clear PF_USED_MATH while at the same time another
thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
the same task.
Here's the full report:
https://lkml.org/lkml/2014/9/19/230
To fix this, we make PF_SPREAD_PAGE and PF_SPARED_SLAB atomic flags.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Kees Cook <keescook@chromium.org>
Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")
Cc: <stable@vger.kernel.org> # 2.6.31+
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
include/linux/cpuset.h | 4 ++--
include/linux/sched.h | 13 +++++++++++--
kernel/cpuset.c | 9 +++++----
3 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 0d4e067..2f073db 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -94,12 +94,12 @@ extern int cpuset_slab_spread_node(void);
static inline int cpuset_do_page_mem_spread(void)
{
- return current->flags & PF_SPREAD_PAGE;
+ return task_spread_page(current);
}
static inline int cpuset_do_slab_mem_spread(void)
{
- return current->flags & PF_SPREAD_SLAB;
+ return task_spread_slab(current);
}
extern int current_cpuset_is_being_rebound(void);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5630763..7b1cafe 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1903,8 +1903,6 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut,
#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
#define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
-#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
-#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
@@ -1958,6 +1956,9 @@ static inline void memalloc_noio_restore(unsigned int flags)
/* Per-process atomic flags. */
#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
+#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
+#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
+
#define TASK_PFA_TEST(name, func) \
static inline bool task_##func(struct task_struct *p) \
@@ -1972,6 +1973,14 @@ static inline void memalloc_noio_restore(unsigned int flags)
TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
+TASK_PFA_TEST(SPREAD_PAGE, spread_page)
+TASK_PFA_SET(SPREAD_PAGE, spread_page)
+TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
+
+TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
+TASK_PFA_SET(SPREAD_SLAB, spread_slab)
+TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
+
/*
* task->jobctl flags
*/
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a37f4ed..1f107c7 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -365,13 +365,14 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
struct task_struct *tsk)
{
if (is_spread_page(cs))
- tsk->flags |= PF_SPREAD_PAGE;
+ task_set_spread_page(tsk);
else
- tsk->flags &= ~PF_SPREAD_PAGE;
+ task_clear_spread_page(tsk);
+
if (is_spread_slab(cs))
- tsk->flags |= PF_SPREAD_SLAB;
+ task_set_spread_slab(tsk);
else
- tsk->flags &= ~PF_SPREAD_SLAB;
+ task_clear_spread_slab(tsk);
}
/*
--
1.8.0.2
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags
2014-09-23 7:44 ` [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags Zefan Li
@ 2014-09-23 10:01 ` Peter Zijlstra
2014-09-23 16:58 ` Kees Cook
0 siblings, 1 reply; 12+ messages in thread
From: Peter Zijlstra @ 2014-09-23 10:01 UTC (permalink / raw)
To: Zefan Li
Cc: Tejun Heo, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa, LKML, Cgroups
On Tue, Sep 23, 2014 at 03:44:59PM +0800, Zefan Li wrote:
> This will simplify code when we add new flags.
>
> v3:
> - Kees pointed out that no_new_privs should never be cleared, so we
> shouldn't define task_clear_no_new_privs(). we define 3 macros instead
> of a single one.
>
> v2:
> - updated scripts/tags.sh, suggested by Peter.
>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Miao Xie <miaox@cn.fujitsu.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Zefan Li <lizefan@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags
2014-09-23 10:01 ` Peter Zijlstra
@ 2014-09-23 16:58 ` Kees Cook
0 siblings, 0 replies; 12+ messages in thread
From: Kees Cook @ 2014-09-23 16:58 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Zefan Li, Tejun Heo, Ingo Molnar, Miao Xie, Tetsuo Handa, LKML, Cgroups
On Tue, Sep 23, 2014 at 3:01 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, Sep 23, 2014 at 03:44:59PM +0800, Zefan Li wrote:
>> This will simplify code when we add new flags.
>>
>> v3:
>> - Kees pointed out that no_new_privs should never be cleared, so we
>> shouldn't define task_clear_no_new_privs(). we define 3 macros instead
>> of a single one.
Thanks! This looks good to me.
>>
>> v2:
>> - updated scripts/tags.sh, suggested by Peter.
>>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Miao Xie <miaox@cn.fujitsu.com>
>> Cc: Kees Cook <keescook@chromium.org>
>> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>> Signed-off-by: Zefan Li <lizefan@huawei.com>
>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
-Kees
--
Kees Cook
Chrome OS Security
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags
2014-09-23 7:45 ` [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be " Zefan Li
@ 2014-09-23 22:10 ` David Rientjes
2014-09-24 3:15 ` Zefan Li
0 siblings, 1 reply; 12+ messages in thread
From: David Rientjes @ 2014-09-23 22:10 UTC (permalink / raw)
To: Zefan Li
Cc: Tejun Heo, Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie,
Tetsuo Handa, LKML, Cgroups
On Tue, 23 Sep 2014, Zefan Li wrote:
> When we change cpuset.memory_spread_{page,slab}, cpuset will flip
> PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset.
> This should be done using atomic bitops, but currently we don't,
> which is broken.
>
> Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happend
> when one thread tried to clear PF_USED_MATH while at the same time another
> thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
> the same task.
>
> Here's the full report:
> https://lkml.org/lkml/2014/9/19/230
>
> To fix this, we make PF_SPREAD_PAGE and PF_SPARED_SLAB atomic flags.
>
s/SPARED/SPREAD/
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Miao Xie <miaox@cn.fujitsu.com>
> Cc: Kees Cook <keescook@chromium.org>
> Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")
> Cc: <stable@vger.kernel.org> # 2.6.31+
> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Zefan Li <lizefan@huawei.com>
> ---
> include/linux/cpuset.h | 4 ++--
> include/linux/sched.h | 13 +++++++++++--
> kernel/cpuset.c | 9 +++++----
> 3 files changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
> index 0d4e067..2f073db 100644
> --- a/include/linux/cpuset.h
> +++ b/include/linux/cpuset.h
> @@ -94,12 +94,12 @@ extern int cpuset_slab_spread_node(void);
>
> static inline int cpuset_do_page_mem_spread(void)
> {
> - return current->flags & PF_SPREAD_PAGE;
> + return task_spread_page(current);
> }
>
> static inline int cpuset_do_slab_mem_spread(void)
> {
> - return current->flags & PF_SPREAD_SLAB;
> + return task_spread_slab(current);
> }
>
> extern int current_cpuset_is_being_rebound(void);
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 5630763..7b1cafe 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1903,8 +1903,6 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut,
> #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
> #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
> #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
> -#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
> -#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
> #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
> #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
> #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
> @@ -1958,6 +1956,9 @@ static inline void memalloc_noio_restore(unsigned int flags)
>
> /* Per-process atomic flags. */
> #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
> +#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
> +#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
> +
>
> #define TASK_PFA_TEST(name, func) \
> static inline bool task_##func(struct task_struct *p) \
> @@ -1972,6 +1973,14 @@ static inline void memalloc_noio_restore(unsigned int flags)
> TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
> TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
>
> +TASK_PFA_TEST(SPREAD_PAGE, spread_page)
> +TASK_PFA_SET(SPREAD_PAGE, spread_page)
> +TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
> +
> +TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
> +TASK_PFA_SET(SPREAD_SLAB, spread_slab)
> +TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
> +
> /*
> * task->jobctl flags
> */
> diff --git a/kernel/cpuset.c b/kernel/cpuset.c
> index a37f4ed..1f107c7 100644
> --- a/kernel/cpuset.c
> +++ b/kernel/cpuset.c
> @@ -365,13 +365,14 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
> struct task_struct *tsk)
> {
> if (is_spread_page(cs))
> - tsk->flags |= PF_SPREAD_PAGE;
> + task_set_spread_page(tsk);
> else
> - tsk->flags &= ~PF_SPREAD_PAGE;
> + task_clear_spread_page(tsk);
> +
> if (is_spread_slab(cs))
> - tsk->flags |= PF_SPREAD_SLAB;
> + task_set_spread_slab(tsk);
> else
> - tsk->flags &= ~PF_SPREAD_SLAB;
> + task_clear_spread_slab(tsk);
> }
>
> /*
This most certainly needs commentary to specify why these have to be
atomic ops.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags
2014-09-23 22:10 ` David Rientjes
@ 2014-09-24 3:15 ` Zefan Li
0 siblings, 0 replies; 12+ messages in thread
From: Zefan Li @ 2014-09-24 3:15 UTC (permalink / raw)
To: David Rientjes
Cc: Tejun Heo, Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie,
Tetsuo Handa, LKML, Cgroups
于 2014/9/24 6:10, David Rientjes wrote:
> On Tue, 23 Sep 2014, Zefan Li wrote:
>
>> When we change cpuset.memory_spread_{page,slab}, cpuset will flip
>> PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset.
>> This should be done using atomic bitops, but currently we don't,
>> which is broken.
>>
>> Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happend
>> when one thread tried to clear PF_USED_MATH while at the same time another
>> thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
>> the same task.
>>
>> Here's the full report:
>> https://lkml.org/lkml/2014/9/19/230
>>
>> To fix this, we make PF_SPREAD_PAGE and PF_SPARED_SLAB atomic flags.
>>
>
> s/SPARED/SPREAD/
>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Miao Xie <miaox@cn.fujitsu.com>
>> Cc: Kees Cook <keescook@chromium.org>
>> Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")
>> Cc: <stable@vger.kernel.org> # 2.6.31+
>> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>> Signed-off-by: Zefan Li <lizefan@huawei.com>
>> ---
>> include/linux/cpuset.h | 4 ++--
>> include/linux/sched.h | 13 +++++++++++--
>> kernel/cpuset.c | 9 +++++----
>> 3 files changed, 18 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
>> index 0d4e067..2f073db 100644
>> --- a/include/linux/cpuset.h
>> +++ b/include/linux/cpuset.h
>> @@ -94,12 +94,12 @@ extern int cpuset_slab_spread_node(void);
>>
>> static inline int cpuset_do_page_mem_spread(void)
>> {
>> - return current->flags & PF_SPREAD_PAGE;
>> + return task_spread_page(current);
>> }
>>
>> static inline int cpuset_do_slab_mem_spread(void)
>> {
>> - return current->flags & PF_SPREAD_SLAB;
>> + return task_spread_slab(current);
>> }
>>
>> extern int current_cpuset_is_being_rebound(void);
>> diff --git a/include/linux/sched.h b/include/linux/sched.h
>> index 5630763..7b1cafe 100644
>> --- a/include/linux/sched.h
>> +++ b/include/linux/sched.h
>> @@ -1903,8 +1903,6 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut,
>> #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
>> #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
>> #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
>> -#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
>> -#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
>> #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
>> #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
>> #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
>> @@ -1958,6 +1956,9 @@ static inline void memalloc_noio_restore(unsigned int flags)
>>
>> /* Per-process atomic flags. */
>> #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
>> +#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
>> +#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
>> +
>>
>> #define TASK_PFA_TEST(name, func) \
>> static inline bool task_##func(struct task_struct *p) \
>> @@ -1972,6 +1973,14 @@ static inline void memalloc_noio_restore(unsigned int flags)
>> TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
>> TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
>>
>> +TASK_PFA_TEST(SPREAD_PAGE, spread_page)
>> +TASK_PFA_SET(SPREAD_PAGE, spread_page)
>> +TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
>> +
>> +TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
>> +TASK_PFA_SET(SPREAD_SLAB, spread_slab)
>> +TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
>> +
>> /*
>> * task->jobctl flags
>> */
>> diff --git a/kernel/cpuset.c b/kernel/cpuset.c
>> index a37f4ed..1f107c7 100644
>> --- a/kernel/cpuset.c
>> +++ b/kernel/cpuset.c
>> @@ -365,13 +365,14 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
>> struct task_struct *tsk)
>> {
>> if (is_spread_page(cs))
>> - tsk->flags |= PF_SPREAD_PAGE;
>> + task_set_spread_page(tsk);
>> else
>> - tsk->flags &= ~PF_SPREAD_PAGE;
>> + task_clear_spread_page(tsk);
>> +
>> if (is_spread_slab(cs))
>> - tsk->flags |= PF_SPREAD_SLAB;
>> + task_set_spread_slab(tsk);
>> else
>> - tsk->flags &= ~PF_SPREAD_SLAB;
>> + task_clear_spread_slab(tsk);
>> }
>>
>> /*
>
> This most certainly needs commentary to specify why these have to be
> atomic ops.
> .
It won't hurt to add more comment, but I don't think it's necessary, because
the reason to use atomic bitops seems obvious to me. Besides there's no such
comment for no_new_privs, which was tsk->atomic_flags introduced for.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-23 7:44 [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Zefan Li
2014-09-23 7:44 ` [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags Zefan Li
2014-09-23 7:45 ` [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be " Zefan Li
@ 2014-09-24 13:22 ` Tejun Heo
2014-09-24 13:35 ` Tejun Heo
2 siblings, 1 reply; 12+ messages in thread
From: Tejun Heo @ 2014-09-24 13:22 UTC (permalink / raw)
To: Zefan Li
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups, David Rientjes
On Tue, Sep 23, 2014 at 03:44:19PM +0800, Zefan Li wrote:
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>
> Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
> defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
> because it is used as bit number. Redefine it as decimal bit number.
>
> Note this changes the bit position of PFA_NOW_NEW_PRIVS from 1 to 0.
>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Miao Xie <miaox@cn.fujitsu.com>
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Acked-by: Kees Cook <keescook@chromium.org>
> [ lizf: slightly modified subject and changelog ]
> Signed-off-by: Zefan Li <lizefan@huawei.com>
Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr
fixed.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-24 13:22 ` [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Tejun Heo
@ 2014-09-24 13:35 ` Tejun Heo
2014-09-24 14:09 ` Tetsuo Handa
2014-09-25 1:42 ` Zefan Li
0 siblings, 2 replies; 12+ messages in thread
From: Tejun Heo @ 2014-09-24 13:35 UTC (permalink / raw)
To: Zefan Li
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups, David Rientjes
On Wed, Sep 24, 2014 at 09:22:18AM -0400, Tejun Heo wrote:
> On Tue, Sep 23, 2014 at 03:44:19PM +0800, Zefan Li wrote:
> > From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> >
> > Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
> > defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
> > because it is used as bit number. Redefine it as decimal bit number.
> >
> > Note this changes the bit position of PFA_NOW_NEW_PRIVS from 1 to 0.
> >
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Ingo Molnar <mingo@kernel.org>
> > Cc: Miao Xie <miaox@cn.fujitsu.com>
> > Cc: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> > Acked-by: Kees Cook <keescook@chromium.org>
> > [ lizf: slightly modified subject and changelog ]
> > Signed-off-by: Zefan Li <lizefan@huawei.com>
>
> Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr
> fixed.
Reverted due to build failure. Will wait for a refreshed version. :(
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-24 13:35 ` Tejun Heo
@ 2014-09-24 14:09 ` Tetsuo Handa
2014-09-24 14:32 ` Tejun Heo
2014-09-25 1:42 ` Zefan Li
1 sibling, 1 reply; 12+ messages in thread
From: Tetsuo Handa @ 2014-09-24 14:09 UTC (permalink / raw)
To: tj
Cc: lizefan, peterz, mingo, keescook, miaox, linux-kernel, cgroups, rientjes
Tejun Heo wrote:
> > Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr
> > fixed.
s/happend/happened/
>
> Reverted due to build failure. Will wait for a refreshed version. :(
I can build with 1-3 patches using HEAD of linux.git. What failure did you see?
$ make kernel/seccomp.o kernel/sys.o security/apparmor/domain.o kernel/cpuset.o
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-24 14:09 ` Tetsuo Handa
@ 2014-09-24 14:32 ` Tejun Heo
0 siblings, 0 replies; 12+ messages in thread
From: Tejun Heo @ 2014-09-24 14:32 UTC (permalink / raw)
To: Tetsuo Handa
Cc: lizefan, peterz, mingo, keescook, miaox, linux-kernel, cgroups, rientjes
On Wed, Sep 24, 2014 at 11:09:25PM +0900, Tetsuo Handa wrote:
> Tejun Heo wrote:
> > > Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr
> > > fixed.
>
> s/happend/happened/
>
> >
> > Reverted due to build failure. Will wait for a refreshed version. :(
>
> I can build with 1-3 patches using HEAD of linux.git. What failure did you see?
>
> $ make kernel/seccomp.o kernel/sys.o security/apparmor/domain.o kernel/cpuset.o
Got the following failure report from the build bot.
tree: git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-3.17-fixes
head: ed91a06989e253cde811d492414adcf94f34eb03
commit: ed91a06989e253cde811d492414adcf94f34eb03 [8/8] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB
+should be atomic flags
config: x86_64-randconfig-hxb2-0924 (attached as .config)
reproduce:
git checkout ed91a06989e253cde811d492414adcf94f34eb03
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings:
In file included from include/linux/linkage.h:4:0,
from include/linux/preempt.h:9,
from include/linux/spinlock.h:50,
from include/linux/mmzone.h:7,
from include/linux/gfp.h:5,
from include/linux/slab.h:14,
from mm/slab.c:89:
mm/slab.c: In function '__do_cache_alloc':
>> mm/slab.c:3229:54: error: 'PF_SPREAD_SLAB' undeclared (first use in this function)
if (current->mempolicy || unlikely(current->flags & PF_SPREAD_SLAB)) {
^
include/linux/compiler.h:131:45: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
mm/slab.c:3229:54: note: each undeclared identifier is reported only once for each function it ap
+pears in
if (current->mempolicy || unlikely(current->flags & PF_SPREAD_SLAB)) {
^
include/linux/compiler.h:131:45: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
vim +/PF_SPREAD_SLAB +3229 mm/slab.c
8c8cc2c1 Pekka Enberg 2007-02-10 3223
8c8cc2c1 Pekka Enberg 2007-02-10 3224 static __always_inline void *
8c8cc2c1 Pekka Enberg 2007-02-10 3225 __do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
8c8cc2c1 Pekka Enberg 2007-02-10 3226 {
8c8cc2c1 Pekka Enberg 2007-02-10 3227 void *objp;
8c8cc2c1 Pekka Enberg 2007-02-10 3228
f0432d15 David Rientjes 2014-04-07 @3229 if (current->mempolicy || unlikely(current->flags &
+PF_SPREAD_SLAB)) {
8c8cc2c1 Pekka Enberg 2007-02-10 3230 objp = alternate_node_alloc(cache, flags);
8c8cc2c1 Pekka Enberg 2007-02-10 3231 if (objp)
8c8cc2c1 Pekka Enberg 2007-02-10 3232 goto out;
--
tejun
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant
2014-09-24 13:35 ` Tejun Heo
2014-09-24 14:09 ` Tetsuo Handa
@ 2014-09-25 1:42 ` Zefan Li
1 sibling, 0 replies; 12+ messages in thread
From: Zefan Li @ 2014-09-25 1:42 UTC (permalink / raw)
To: Tejun Heo
Cc: Peter Zijlstra, Ingo Molnar, Kees Cook, Miao Xie, Tetsuo Handa,
LKML, Cgroups, David Rientjes
On 2014/9/24 21:35, Tejun Heo wrote:
> On Wed, Sep 24, 2014 at 09:22:18AM -0400, Tejun Heo wrote:
>> On Tue, Sep 23, 2014 at 03:44:19PM +0800, Zefan Li wrote:
>>> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>>>
>>> Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
>>> defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
>>> because it is used as bit number. Redefine it as decimal bit number.
>>>
>>> Note this changes the bit position of PFA_NOW_NEW_PRIVS from 1 to 0.
>>>
>>> Cc: Peter Zijlstra <peterz@infradead.org>
>>> Cc: Ingo Molnar <mingo@kernel.org>
>>> Cc: Miao Xie <miaox@cn.fujitsu.com>
>>> Cc: Kees Cook <keescook@chromium.org>
>>> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>>> Acked-by: Kees Cook <keescook@chromium.org>
>>> [ lizf: slightly modified subject and changelog ]
>>> Signed-off-by: Zefan Li <lizefan@huawei.com>
>>
>> Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr
>> fixed.
>
> Reverted due to build failure. Will wait for a refreshed version. :(
>
Didn't notice mm/slab.c uses PF_SPREAD_SLAB without the cpuset wrapper...
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2014-09-25 1:42 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-09-23 7:44 [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Zefan Li
2014-09-23 7:44 ` [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags Zefan Li
2014-09-23 10:01 ` Peter Zijlstra
2014-09-23 16:58 ` Kees Cook
2014-09-23 7:45 ` [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be " Zefan Li
2014-09-23 22:10 ` David Rientjes
2014-09-24 3:15 ` Zefan Li
2014-09-24 13:22 ` [PATCH v3 1/3] sched: fix confusing PFA_NO_NEW_PRIVS constant Tejun Heo
2014-09-24 13:35 ` Tejun Heo
2014-09-24 14:09 ` Tetsuo Handa
2014-09-24 14:32 ` Tejun Heo
2014-09-25 1:42 ` Zefan Li
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).