From 48f6a7a511ef8823fdff39afee0320092d43a8a0 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Mon, 11 Mar 2013 13:12:45 +0400 Subject: posix-timers: Introduce /proc/PID/timers file Currently kernel doesn't provide any API for getting info about what posix timers are configured by processes. It's implied, that a process which configured some timers, knows what it did. However, for external tools it's impossible to get this information. In particular, this is critical for checkpoint-restore project to have this info. Introduce a per-pid proc file with information about posix timers. Since these timers are shared between threads, this file is present on tgid level only, no such thing in tid subdirs. The file format is expected to be the "/proc//smaps"-like, i.e. each timer will occupy seveal lines to allow for future extending. Each new timer entry starts with the ID: line which is added by this patch. Signed-off-by: Pavel Emelyanov Cc: Peter Zijlstra Cc: Michael Kerrisk Cc: Matthew Helsley Link: http://lkml.kernel.org/r/513DA00D.6070009@parallels.com Signed-off-by: Thomas Gleixner --- fs/proc/base.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) (limited to 'fs/proc') diff --git a/fs/proc/base.c b/fs/proc/base.c index 69078c7cef1f..01def9f8aa74 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -86,6 +86,7 @@ #include #include #include +#include #ifdef CONFIG_HARDWALL #include #endif @@ -2013,6 +2014,85 @@ static const struct file_operations proc_map_files_operations = { .llseek = default_llseek, }; +struct timers_private { + struct pid *pid; + struct task_struct *task; + struct sighand_struct *sighand; + unsigned long flags; +}; + +static void *timers_start(struct seq_file *m, loff_t *pos) +{ + struct timers_private *tp = m->private; + + tp->task = get_pid_task(tp->pid, PIDTYPE_PID); + if (!tp->task) + return ERR_PTR(-ESRCH); + + tp->sighand = lock_task_sighand(tp->task, &tp->flags); + if (!tp->sighand) + return ERR_PTR(-ESRCH); + + return seq_list_start(&tp->task->signal->posix_timers, *pos); +} + +static void *timers_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct timers_private *tp = m->private; + return seq_list_next(v, &tp->task->signal->posix_timers, pos); +} + +static void timers_stop(struct seq_file *m, void *v) +{ + struct timers_private *tp = m->private; + + if (tp->sighand) { + unlock_task_sighand(tp->task, &tp->flags); + tp->sighand = NULL; + } + + if (tp->task) { + put_task_struct(tp->task); + tp->task = NULL; + } +} + +static int show_timer(struct seq_file *m, void *v) +{ + struct k_itimer *timer; + + timer = list_entry((struct list_head *)v, struct k_itimer, list); + seq_printf(m, "ID: %d\n", timer->it_id); + + return 0; +} + +static const struct seq_operations proc_timers_seq_ops = { + .start = timers_start, + .next = timers_next, + .stop = timers_stop, + .show = show_timer, +}; + +static int proc_timers_open(struct inode *inode, struct file *file) +{ + struct timers_private *tp; + + tp = __seq_open_private(file, &proc_timers_seq_ops, + sizeof(struct timers_private)); + if (!tp) + return -ENOMEM; + + tp->pid = proc_pid(inode); + return 0; +} + +static const struct file_operations proc_timers_operations = { + .open = proc_timers_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; #endif /* CONFIG_CHECKPOINT_RESTORE */ static struct dentry *proc_pident_instantiate(struct inode *dir, @@ -2583,6 +2663,9 @@ static const struct pid_entry tgid_base_stuff[] = { REG("gid_map", S_IRUGO|S_IWUSR, proc_gid_map_operations), REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), #endif +#ifdef CONFIG_CHECKPOINT_RESTORE + REG("timers", S_IRUGO, proc_timers_operations), +#endif }; static int proc_tgid_base_readdir(struct file * filp, -- cgit v1.2.3 From 57b8015e07a70301e9ec9f324db1a8b73b5a1e2b Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Mon, 11 Mar 2013 13:13:08 +0400 Subject: posix-timers: Show sigevent info in proc file Previous patch added proc file to list posix timers created by task. Expand the information provided in this file by adding info about notification method, with which timers were created. I.e. after the "ID:" line there go 1. "signal:" line, that shows signal number and sigval bits; 2. "notify:" line, that shows the timer notification method. Thus the timer entry would looke like this: ID: 123 signal: 14/0000000000b005d0 notify: signal/pid.732 This information is enough to understand how timer_create() was called for each particular timer. Signed-off-by: Pavel Emelyanov Cc: Peter Zijlstra Cc: Michael Kerrisk Cc: Matthew Helsley Link: http://lkml.kernel.org/r/513DA024.80404@parallels.com Signed-off-by: Thomas Gleixner --- fs/proc/base.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'fs/proc') diff --git a/fs/proc/base.c b/fs/proc/base.c index 01def9f8aa74..a19308604145 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2018,6 +2018,7 @@ struct timers_private { struct pid *pid; struct task_struct *task; struct sighand_struct *sighand; + struct pid_namespace *ns; unsigned long flags; }; @@ -2060,9 +2061,24 @@ static void timers_stop(struct seq_file *m, void *v) static int show_timer(struct seq_file *m, void *v) { struct k_itimer *timer; + struct timers_private *tp = m->private; + int notify; + static char *nstr[] = { + [SIGEV_SIGNAL] = "signal", + [SIGEV_NONE] = "none", + [SIGEV_THREAD] = "thread", + }; timer = list_entry((struct list_head *)v, struct k_itimer, list); + notify = timer->it_sigev_notify; + seq_printf(m, "ID: %d\n", timer->it_id); + seq_printf(m, "signal: %d/%p\n", timer->sigq->info.si_signo, + timer->sigq->info.si_value.sival_ptr); + seq_printf(m, "notify: %s/%s.%d\n", + nstr[notify & ~SIGEV_THREAD_ID], + (notify & SIGEV_THREAD_ID) ? "tid" : "pid", + pid_nr_ns(timer->it_pid, tp->ns)); return 0; } @@ -2084,6 +2100,7 @@ static int proc_timers_open(struct inode *inode, struct file *file) return -ENOMEM; tp->pid = proc_pid(inode); + tp->ns = inode->i_sb->s_fs_info; return 0; } -- cgit v1.2.3