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Diffstat (limited to 'fs/proc/array.c')
-rw-r--r--fs/proc/array.c88
1 files changed, 48 insertions, 40 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 0b615d62a15..25e917fb473 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -162,7 +162,7 @@ static inline char * task_state(struct task_struct *p, char *buffer)
int g;
struct fdtable *fdt = NULL;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
buffer += sprintf(buffer,
"State:\t%s\n"
"SleepAVG:\t%lu%%\n"
@@ -174,14 +174,13 @@ static inline char * task_state(struct task_struct *p, char *buffer)
"Gid:\t%d\t%d\t%d\t%d\n",
get_task_state(p),
(p->sleep_avg/1024)*100/(1020000000/1024),
- p->tgid,
- p->pid, pid_alive(p) ? p->group_leader->real_parent->tgid : 0,
- pid_alive(p) && p->ptrace ? p->parent->pid : 0,
+ p->tgid, p->pid,
+ pid_alive(p) ? rcu_dereference(p->real_parent)->tgid : 0,
+ pid_alive(p) && p->ptrace ? rcu_dereference(p->parent)->pid : 0,
p->uid, p->euid, p->suid, p->fsuid,
p->gid, p->egid, p->sgid, p->fsgid);
- read_unlock(&tasklist_lock);
+
task_lock(p);
- rcu_read_lock();
if (p->files)
fdt = files_fdtable(p->files);
buffer += sprintf(buffer,
@@ -244,6 +243,7 @@ static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
static inline char * task_sig(struct task_struct *p, char *buffer)
{
+ unsigned long flags;
sigset_t pending, shpending, blocked, ignored, caught;
int num_threads = 0;
unsigned long qsize = 0;
@@ -255,10 +255,8 @@ static inline char * task_sig(struct task_struct *p, char *buffer)
sigemptyset(&ignored);
sigemptyset(&caught);
- /* Gather all the data with the appropriate locks held */
- read_lock(&tasklist_lock);
- if (p->sighand) {
- spin_lock_irq(&p->sighand->siglock);
+ rcu_read_lock();
+ if (lock_task_sighand(p, &flags)) {
pending = p->pending.signal;
shpending = p->signal->shared_pending.signal;
blocked = p->blocked;
@@ -266,9 +264,9 @@ static inline char * task_sig(struct task_struct *p, char *buffer)
num_threads = atomic_read(&p->signal->count);
qsize = atomic_read(&p->user->sigpending);
qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
- spin_unlock_irq(&p->sighand->siglock);
+ unlock_task_sighand(p, &flags);
}
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
buffer += sprintf(buffer, "Threads:\t%d\n", num_threads);
buffer += sprintf(buffer, "SigQ:\t%lu/%lu\n", qsize, qlim);
@@ -322,7 +320,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
sigset_t sigign, sigcatch;
char state;
int res;
- pid_t ppid, pgid = -1, sid = -1;
+ pid_t ppid = 0, pgid = -1, sid = -1;
int num_threads = 0;
struct mm_struct *mm;
unsigned long long start_time;
@@ -330,8 +328,8 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
unsigned long min_flt = 0, maj_flt = 0;
cputime_t cutime, cstime, utime, stime;
unsigned long rsslim = 0;
- struct task_struct *t;
char tcomm[sizeof(task->comm)];
+ unsigned long flags;
state = *get_task_state(task);
vsize = eip = esp = 0;
@@ -347,15 +345,35 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
sigemptyset(&sigign);
sigemptyset(&sigcatch);
cutime = cstime = utime = stime = cputime_zero;
- read_lock(&tasklist_lock);
- if (task->sighand) {
- spin_lock_irq(&task->sighand->siglock);
- num_threads = atomic_read(&task->signal->count);
+
+ mutex_lock(&tty_mutex);
+ rcu_read_lock();
+ if (lock_task_sighand(task, &flags)) {
+ struct signal_struct *sig = task->signal;
+ struct tty_struct *tty = sig->tty;
+
+ if (tty) {
+ /*
+ * sig->tty is not stable, but tty_mutex
+ * protects us from release_dev(tty)
+ */
+ barrier();
+ tty_pgrp = tty->pgrp;
+ tty_nr = new_encode_dev(tty_devnum(tty));
+ }
+
+ num_threads = atomic_read(&sig->count);
collect_sigign_sigcatch(task, &sigign, &sigcatch);
+ cmin_flt = sig->cmin_flt;
+ cmaj_flt = sig->cmaj_flt;
+ cutime = sig->cutime;
+ cstime = sig->cstime;
+ rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;
+
/* add up live thread stats at the group level */
if (whole) {
- t = task;
+ struct task_struct *t = task;
do {
min_flt += t->min_flt;
maj_flt += t->maj_flt;
@@ -363,31 +381,21 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
stime = cputime_add(stime, t->stime);
t = next_thread(t);
} while (t != task);
- }
- spin_unlock_irq(&task->sighand->siglock);
- }
- if (task->signal) {
- if (task->signal->tty) {
- tty_pgrp = task->signal->tty->pgrp;
- tty_nr = new_encode_dev(tty_devnum(task->signal->tty));
+ min_flt += sig->min_flt;
+ maj_flt += sig->maj_flt;
+ utime = cputime_add(utime, sig->utime);
+ stime = cputime_add(stime, sig->stime);
}
+
+ sid = sig->session;
pgid = process_group(task);
- sid = task->signal->session;
- cmin_flt = task->signal->cmin_flt;
- cmaj_flt = task->signal->cmaj_flt;
- cutime = task->signal->cutime;
- cstime = task->signal->cstime;
- rsslim = task->signal->rlim[RLIMIT_RSS].rlim_cur;
- if (whole) {
- min_flt += task->signal->min_flt;
- maj_flt += task->signal->maj_flt;
- utime = cputime_add(utime, task->signal->utime);
- stime = cputime_add(stime, task->signal->stime);
- }
+ ppid = rcu_dereference(task->real_parent)->tgid;
+
+ unlock_task_sighand(task, &flags);
}
- ppid = pid_alive(task) ? task->group_leader->real_parent->tgid : 0;
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
+ mutex_unlock(&tty_mutex);
if (!whole || num_threads<2)
wchan = get_wchan(task);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-16 17:19:32 +0000