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

Ben Hutchings
2017-10-09T13:55:20Z

From: Zefan Li <lizefan@huawei.com>

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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/'\