[PATCH 3.4 63/91] sched: add macros to define bitops for task atomic flags

From: lizf
Date: Thu Nov 27 2014 - 03:58:37 EST


From: Zefan Li <lizefan@xxxxxxxxxx>

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

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


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>
[lizf: Backported to 3.4:
- adjust context
- remove no_new_priv code
- add atomic_flags to struct task_struct]
---
include/linux/sched.h | 13 +++++++++++++
scripts/tags.sh | 10 ++++++++--
2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8cd5cb8..b85b719 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1359,6 +1359,7 @@ struct task_struct {
/* IRQ handler threads */
unsigned irq_thread:1;
#endif
+ unsigned long atomic_flags; /* Flags needing atomic access. */

pid_t pid;
pid_t tgid;
@@ -1866,6 +1867,18 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
#define used_math() tsk_used_math(current)

+/* Per-process 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->jobctl flags
*/
diff --git a/scripts/tags.sh b/scripts/tags.sh
index cf7b12f..246e4f6 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -153,7 +153,10 @@ exuberant()
--regex-c++='/CLEARPAGEFLAG_NOOP\(([^,)]*).*/ClearPage\1/' \
--regex-c++='/__CLEARPAGEFLAG_NOOP\(([^,)]*).*/__ClearPage\1/' \
--regex-c++='/TESTCLEARFLAG_FALSE\(([^,)]*).*/TestClearPage\1/' \
- --regex-c++='/__TESTCLEARFLAG_FALSE\(([^,)]*).*/__TestClearPage\1/'
+ --regex-c++='/__TESTCLEARFLAG_FALSE\(([^,)]*).*/__TestClearPage\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/'

all_kconfigs | xargs $1 -a \
--langdef=kconfig --language-force=kconfig \
@@ -195,7 +198,10 @@ emacs()
--regex='/CLEARPAGEFLAG_NOOP\(([^,)]*).*/ClearPage\1/' \
--regex='/__CLEARPAGEFLAG_NOOP\(([^,)]*).*/__ClearPage\1/' \
--regex='/TESTCLEARFLAG_FALSE\(([^,)]*).*/TestClearPage\1/' \
- --regex='/__TESTCLEARFLAG_FALSE\(([^,)]*).*/__TestClearPage\1/'
+ --regex='/__TESTCLEARFLAG_FALSE\(([^,)]*).*/__TestClearPage\1/'\
+ --regex='/TASK_PFA_TEST\([^,]*,\s*([^)]*)\)/task_\1/' \
+ --regex='/TASK_PFA_SET\([^,]*,\s*([^)]*)\)/task_set_\1/' \
+ --regex='/TASK_PFA_CLEAR\([^,]*,\s*([^)]*)\)/task_clear_\1/'

all_kconfigs | xargs $1 -a \
--regex='/^[ \t]*\(\(menu\)*config\)[ \t]+\([a-zA-Z0-9_]+\)/\3/'
--
1.9.1

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