[PATCH 6.1 62/71] getrusage: add the "signal_struct *sig" local variable

[Sasha Levin]

From: Oleg Nesterov <oleg@xxxxxxxxxx>

[ Upstream commit c7ac8231ace9b07306d0299969e42073b189c70a ]

No functional changes, cleanup/preparation.

Link: https://lkml.kernel.org/r/20230909172554.GA20441@xxxxxxxxxx
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Stable-dep-of: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/sys.c | 37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index c85e1abf7b7c7..177155ba50cd3 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1779,6 +1779,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
 	unsigned long flags;
 	u64 tgutime, tgstime, utime, stime;
 	unsigned long maxrss = 0;
+	struct signal_struct *sig = p->signal;
 
 	memset((char *)r, 0, sizeof (*r));
 	utime = stime = 0;
@@ -1786,7 +1787,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
 	if (who == RUSAGE_THREAD) {
 		task_cputime_adjusted(current, &utime, &stime);
 		accumulate_thread_rusage(p, r);
-		maxrss = p->signal->maxrss;
+		maxrss = sig->maxrss;
 		goto out;
 	}
 
@@ -1796,15 +1797,15 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
 	switch (who) {
 	case RUSAGE_BOTH:
 	case RUSAGE_CHILDREN:
-		utime = p->signal->cutime;
-		stime = p->signal->cstime;
-		r->ru_nvcsw = p->signal->cnvcsw;
-		r->ru_nivcsw = p->signal->cnivcsw;
-		r->ru_minflt = p->signal->cmin_flt;
-		r->ru_majflt = p->signal->cmaj_flt;
-		r->ru_inblock = p->signal->cinblock;
-		r->ru_oublock = p->signal->coublock;
-		maxrss = p->signal->cmaxrss;
+		utime = sig->cutime;
+		stime = sig->cstime;
+		r->ru_nvcsw = sig->cnvcsw;
+		r->ru_nivcsw = sig->cnivcsw;
+		r->ru_minflt = sig->cmin_flt;
+		r->ru_majflt = sig->cmaj_flt;
+		r->ru_inblock = sig->cinblock;
+		r->ru_oublock = sig->coublock;
+		maxrss = sig->cmaxrss;
 
 		if (who == RUSAGE_CHILDREN)
 			break;
@@ -1814,14 +1815,14 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
 		thread_group_cputime_adjusted(p, &tgutime, &tgstime);
 		utime += tgutime;
 		stime += tgstime;
-		r->ru_nvcsw += p->signal->nvcsw;
-		r->ru_nivcsw += p->signal->nivcsw;
-		r->ru_minflt += p->signal->min_flt;
-		r->ru_majflt += p->signal->maj_flt;
-		r->ru_inblock += p->signal->inblock;
-		r->ru_oublock += p->signal->oublock;
-		if (maxrss < p->signal->maxrss)
-			maxrss = p->signal->maxrss;
+		r->ru_nvcsw += sig->nvcsw;
+		r->ru_nivcsw += sig->nivcsw;
+		r->ru_minflt += sig->min_flt;
+		r->ru_majflt += sig->maj_flt;
+		r->ru_inblock += sig->inblock;
+		r->ru_oublock += sig->oublock;
+		if (maxrss < sig->maxrss)
+			maxrss = sig->maxrss;
 		t = p;
 		do {
 			accumulate_thread_rusage(t, r);
-- 
2.43.0