[PATCH 3.16 190/192] sched: add macros to define bitops for task atomic flags

[Ben Hutchings]

3.16.49-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Zefan Li <lizefan@xxxxxxxxxx>

commit e0e5070b20e01f0321f97db4e4e174f3f6b49e50 upstream.

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: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Miao Xie <miaox@xxxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 include/linux/sched.h | 21 ++++++++++++---------
 scripts/tags.sh       |  6 ++++++
 2 files changed, 18 insertions(+), 9 deletions(-)

--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1981,15 +1981,18 @@ static inline void memalloc_noio_restore
 /* 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);
-}
+#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); }
 
-static inline void task_set_no_new_privs(struct task_struct *p)
-{
-	set_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
-}
+TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
+TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
 
 /*
  * task->jobctl flags
--- 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/'	\
@@ -259,6 +262,9 @@ 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/'\