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-rw-r--r--kernel/sys.c50
1 files changed, 32 insertions, 18 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index e219fcfa112d..f8e543f1e38a 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1785,21 +1785,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
struct task_struct *t;
unsigned long flags;
u64 tgutime, tgstime, utime, stime;
- unsigned long maxrss = 0;
+ unsigned long maxrss;
+ struct mm_struct *mm;
struct signal_struct *sig = p->signal;
+ unsigned int seq = 0;
- memset((char *)r, 0, sizeof (*r));
+retry:
+ memset(r, 0, sizeof(*r));
utime = stime = 0;
+ maxrss = 0;
if (who == RUSAGE_THREAD) {
task_cputime_adjusted(current, &utime, &stime);
accumulate_thread_rusage(p, r);
maxrss = sig->maxrss;
- goto out;
+ goto out_thread;
}
- if (!lock_task_sighand(p, &flags))
- return;
+ flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
switch (who) {
case RUSAGE_BOTH:
@@ -1819,9 +1822,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
fallthrough;
case RUSAGE_SELF:
- thread_group_cputime_adjusted(p, &tgutime, &tgstime);
- utime += tgutime;
- stime += tgstime;
r->ru_nvcsw += sig->nvcsw;
r->ru_nivcsw += sig->nivcsw;
r->ru_minflt += sig->min_flt;
@@ -1830,28 +1830,42 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
r->ru_oublock += sig->oublock;
if (maxrss < sig->maxrss)
maxrss = sig->maxrss;
+
+ rcu_read_lock();
__for_each_thread(sig, t)
accumulate_thread_rusage(t, r);
+ rcu_read_unlock();
+
break;
default:
BUG();
}
- unlock_task_sighand(p, &flags);
-out:
- r->ru_utime = ns_to_kernel_old_timeval(utime);
- r->ru_stime = ns_to_kernel_old_timeval(stime);
+ if (need_seqretry(&sig->stats_lock, seq)) {
+ seq = 1;
+ goto retry;
+ }
+ done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
- if (who != RUSAGE_CHILDREN) {
- struct mm_struct *mm = get_task_mm(p);
+ if (who == RUSAGE_CHILDREN)
+ goto out_children;
- if (mm) {
- setmax_mm_hiwater_rss(&maxrss, mm);
- mmput(mm);
- }
+ thread_group_cputime_adjusted(p, &tgutime, &tgstime);
+ utime += tgutime;
+ stime += tgstime;
+
+out_thread:
+ mm = get_task_mm(p);
+ if (mm) {
+ setmax_mm_hiwater_rss(&maxrss, mm);
+ mmput(mm);
}
+
+out_children:
r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
+ r->ru_utime = ns_to_kernel_old_timeval(utime);
+ r->ru_stime = ns_to_kernel_old_timeval(stime);
}
SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)