sched: fix confusing PFA_NO_NEW_PRIVS constant

PATCH Superseded Zefan Li 6 participants 12 messages Sep 23, 2014 – Sep 25, 2014

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Scheduler cgroup Control group - cpuset

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Zefan Li

author

2014-09-23 07:44 UTC #0 lore raw

PATCH v3 1/3 sched: fix confusing PFA_NO_NEW_PRIVS constant

From: Tetsuo Handa <[email protected]>

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 <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Miao Xie <[email protected]>

Cc Kees Cook <[email protected]>

Signed-off-by Tetsuo Handa <[email protected]>

Acked-by Kees Cook <[email protected]>

[ lizf: slightly modified subject and changelog ]

Signed-off-by Zefan Li <[email protected]>

---
 include/linux/sched.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

include/linux/sched.h +1 -1

index 5c2c885..4557765 100644
@@ -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)
 {

Signature · 1 line

1.8.0.2

Zefan Li

author

2014-09-23 07:44 UTC #1 lore raw

PATCH v3 2/3 sched: add macros to define bitops for task atomic flags

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 <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Miao Xie <[email protected]>

Cc Kees Cook <[email protected]>

Cc Tetsuo Handa <[email protected]>

Signed-off-by Zefan Li <[email protected]>

---
 include/linux/sched.h | 21 ++++++++++++---------
 scripts/tags.sh       |  6 ++++++
 2 files changed, 18 insertions(+), 9 deletions(-)

include/linux/sched.h +12 -9

index 4557765..5630763 100644
@@ -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

scripts/tags.sh +6 -0

index cbfd269..293828b 100755
@@ -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/'\

Signature · 1 line

1.8.0.2

Peter Zijlstra

maintainer Acked-by on v3 2/3

2014-09-23 10:01 UTC #2 lore raw

Re: [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags

Quoted 10 lines · Zefan Li

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.

Quoted 6 lines

Cc Peter Zijlstra <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Miao Xie <[email protected]>
Cc Kees Cook <[email protected]>
Cc Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
Signed-off-by Zefan Li <[email protected]>

Acked-by Peter Zijlstra (Intel) <[email protected]>

Kees Cook

Acked-by

2014-09-23 16:58 UTC #3 lore raw

Re: [PATCH v3 2/3] sched: add macros to define bitops for task atomic flags

Quoted 7 lines · Peter Zijlstra

Quoted 6 lines · Zefan Li
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.

Quoted 4 lines

Quoted 4 lines
v2:
- updated scripts/tags.sh, suggested by Peter.

Quoted 8 lines

Quoted 6 lines
Cc Peter Zijlstra <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Miao Xie <[email protected]>
Cc Kees Cook <[email protected]>
Cc Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
Signed-off-by Zefan Li <[email protected]>
Acked-by Peter Zijlstra (Intel) <[email protected]>

Acked-by Kees Cook <[email protected]>

-Kees

Signature · 2 lines

Kees Cook
Chrome OS Security

Zefan Li

author

2014-09-23 07:45 UTC #4 lore raw

PATCH v3 3/3 cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

In reply to Zefan Li

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 <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Miao Xie <[email protected]>

Cc Kees Cook <[email protected]>

Fixes 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")

Cc <[email protected]> # 2.6.31+

Reported-by Tetsuo Handa <[email protected]>

Signed-off-by Zefan Li <[email protected]>

---
 include/linux/cpuset.h |  4 ++--
 include/linux/sched.h  | 13 +++++++++++--
 kernel/cpuset.c        |  9 +++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

include/linux/cpuset.h +2 -2

index 0d4e067..2f073db 100644
@@ -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);

include/linux/sched.h +11 -2

index 5630763..7b1cafe 100644
@@ -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
  */

kernel/cpuset.c +5 -4

index a37f4ed..1f107c7 100644
@@ -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);
 }
 
 /*

Signature · 1 line

1.8.0.2

David Rientjes

2014-09-23 22:10 UTC #5 lore raw

Re: [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

Quoted 10 lines · Zefan Li

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.

Quoted 5 lines

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/

Quoted 84 lines

Cc Peter Zijlstra <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Miao Xie <[email protected]>

Cc Kees Cook <[email protected]>

Fixes 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")

Cc <[email protected]> # 2.6.31+

Reported-by Tetsuo Handa <[email protected]>

Signed-off-by Zefan Li <[email protected]>

---
 include/linux/cpuset.h |  4 ++--
 include/linux/sched.h  | 13 +++++++++++--
 kernel/cpuset.c        |  9 +++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

include/linux/cpuset.h +2 -2

index 0d4e067..2f073db 100644
@@ -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);

include/linux/sched.h +11 -2

index 5630763..7b1cafe 100644
@@ -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
  */

kernel/cpuset.c +2 -2

index a37f4ed..1f107c7 100644
@@ -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);

kernel/cpuset.c static void cpuset_update_task_spread_flag(struct cpuset *cs, · line 378

Quoted 10 lines

kernel/cpuset.c +3 -2

+
 	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.

Zefan Li

author

2014-09-24 03:15 UTC #6 lore raw

Re: [PATCH v3 3/3] cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

Quoted 113 lines · David Rientjes

Quoted 10 lines · Zefan Li

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.

Quoted 5 lines

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/

Quoted 93 lines

Cc Peter Zijlstra <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Miao Xie <[email protected]>

Cc Kees Cook <[email protected]>

Fixes 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")

Cc <[email protected]> # 2.6.31+

Reported-by Tetsuo Handa <penguin-kernel-JPay3/[email protected]>

Signed-off-by Zefan Li <[email protected]>

---
 include/linux/cpuset.h |  4 ++--
 include/linux/sched.h  | 13 +++++++++++--
 kernel/cpuset.c        |  9 +++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

include/linux/cpuset.h +2 -2

index 0d4e067..2f073db 100644
@@ -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);

include/linux/sched.h +11 -2

index 5630763..7b1cafe 100644
@@ -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
  */

kernel/cpuset.c +5 -4

index a37f4ed..1f107c7 100644
@@ -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);
 }

Quoted 5 lines

kernel/cpuset.c static void cpuset_update_task_spread_flag(struct cpuset *cs, · line 378
Quoted 1 line
kernel/cpuset.c +0 -0
 /*
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.

Tejun Heo

maintainer

2014-09-24 13:22 UTC #7 lore raw

In reply to Zefan Li

Quoted 8 lines · Zefan Li

From: Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
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.

Quoted 8 lines

Cc Peter Zijlstra <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Miao Xie <[email protected]>
Cc Kees Cook <[email protected]>
Signed-off-by Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
Acked-by Kees Cook <[email protected]>
[ lizf: slightly modified subject and changelog ]
Signed-off-by Zefan Li <[email protected]>

Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr fixed.

Thanks.

Signature · 1 line

tejun

Tejun Heo

maintainer

2014-09-24 13:35 UTC #8 lore raw

Quoted 18 lines · Tejun Heo

Quoted 8 lines · Zefan Li
From: Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
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.
Quoted 8 lines
Cc Peter Zijlstra <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Miao Xie <[email protected]>
Cc Kees Cook <[email protected]>
Signed-off-by Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
Acked-by Kees Cook <[email protected]>
[ lizf: slightly modified subject and changelog ]
Signed-off-by Zefan Li <[email protected]>

Quoted 2 lines

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.

Signature · 1 line

tejun

Tetsuo Handa

2014-09-24 14:09 UTC #9 lore raw

Quoted 2 lines · Tejun Heo

Quoted 2 lines
Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr fixed.

s/happend/happened/

Quoted 2 lines

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

Tejun Heo

maintainer

2014-09-24 14:32 UTC #10 lore raw

Quoted 4 lines · Tetsuo Handa

Quoted 2 lines · Tejun Heo
Quoted 2 lines
Applied 1-3 to cgroup/for-3.17-fixes w/ the typo spotted by davidr fixed.

Quoted 8 lines

s/happend/happened/
Quoted 2 lines
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':

Quoted 1 line

Quoted 1 line
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;

Signature · 1 line

tejun

Zefan Li

author

2014-09-25 01:42 UTC #11 lore raw

In reply to Tejun Heo

Quoted 19 lines · Tejun Heo

Quoted 18 lines · Tejun Heo
Quoted 16 lines · Zefan Li
From: Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
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 <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Miao Xie <[email protected]>
Cc Kees Cook <[email protected]>
Signed-off-by Tetsuo Handa <penguin-kernel-JPay3/[email protected]>
Acked-by Kees Cook <[email protected]>
[ lizf: slightly modified subject and changelog ]
Signed-off-by Zefan Li <[email protected]>

Quoted 5 lines

Quoted 2 lines
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...