From: Oleg Nesterov Date: Mon, 7 Apr 2014 22:38:46 +0000 (-0700) Subject: wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide EXIT_TRACE from user-space X-Git-Tag: accepted/tizen/common/20141203.182822~260^2~61 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ad86622b478eaafdc25b74237df82b10fce6326d;p=platform%2Fkernel%2Flinux-arm64.git wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide EXIT_TRACE from user-space get_task_state() uses the most significant bit to report the state to user-space, this means that EXIT_ZOMBIE->EXIT_TRACE->EXIT_DEAD transition can be noticed via /proc as Z -> X -> Z change. Note that this was possible even before EXIT_TRACE was introduced. This is not really bad but imho it make sense to hide EXIT_TRACE from user-space completely. So the patch simply swaps EXIT_ZOMBIE and EXIT_DEAD, this way EXIT_TRACE will be seen as EXIT_ZOMBIE by user-space. Signed-off-by: Oleg Nesterov Cc: Jan Kratochvil Cc: Michal Schmidt Cc: Al Viro Cc: Lennart Poettering Cc: Roland McGrath Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/proc/array.c b/fs/proc/array.c index 656e401..64db2bc 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -138,8 +138,8 @@ static const char * const task_state_array[] = { "D (disk sleep)", /* 2 */ "T (stopped)", /* 4 */ "t (tracing stop)", /* 8 */ - "Z (zombie)", /* 16 */ - "X (dead)", /* 32 */ + "X (dead)", /* 16 */ + "Z (zombie)", /* 32 */ }; static inline const char *get_task_state(struct task_struct *tsk) diff --git a/include/linux/sched.h b/include/linux/sched.h index 7781de5..075b305 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -210,8 +210,8 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); #define __TASK_STOPPED 4 #define __TASK_TRACED 8 /* in tsk->exit_state */ -#define EXIT_ZOMBIE 16 -#define EXIT_DEAD 32 +#define EXIT_DEAD 16 +#define EXIT_ZOMBIE 32 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) /* in tsk->state again */ #define TASK_DEAD 64