sched: add macros to define bitops for task atomic flags

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@kernel.org>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[lizf: Backported to 3.4:
 - adjust context
 - remove no_new_priv code
 - add atomic_flags to struct task_struct]

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8cd5cb80223c762a58634e5cb50dd76822d6e29d..b85b71963e883b7686efe1c9e37fad4677da9e97 100644 (file)
--- 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 cf7b12fee573174c8aaf00ee75aa9d21c056d61d..246e4f6bc2adffe2ee08e4913838842157243973 100755 (executable)
--- 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/'