+ __kill_pgrp_info-simplify-the-calculation-of-return-value.patch added to mm-nonmm-unstable branch

+ __kill_pgrp_info-simplify-the-calculation-of-return-value.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: __kill_pgrp_info: simplify the calculation of return value
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     __kill_pgrp_info-simplify-the-calculation-of-return-value.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/__kill_pgrp_info-simplify-the-calculation-of-return-value.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Oleg Nesterov <oleg@redhat.com>
Subject: __kill_pgrp_info: simplify the calculation of return value
Date: Wed, 23 Aug 2023 19:14:55 +0200

No need to calculate/check the "success" variable, we can kill it and update
retval in the main loop unless it is zero.

Link: https://lkml.kernel.org/r/20230823171455.GA12188@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/signal.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

--- a/kernel/signal.c~__kill_pgrp_info-simplify-the-calculation-of-return-value
+++ a/kernel/signal.c
@@ -1471,16 +1471,21 @@ int group_send_sig_info(int sig, struct
 int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp)
 {
 	struct task_struct *p = NULL;
-	int retval, success;
+	int ret = -ESRCH;
 
-	success = 0;
-	retval = -ESRCH;
 	do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
 		int err = group_send_sig_info(sig, info, p, PIDTYPE_PGID);
-		success |= !err;
-		retval = err;
+		/*
+		 * If group_send_sig_info() succeeds at least once ret
+		 * becomes 0 and after that the code below has no effect.
+		 * Otherwise we return the last err or -ESRCH if this
+		 * process group is empty.
+		 */
+		if (ret)
+			ret = err;
 	} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
-	return success ? 0 : retval;
+
+	return ret;
 }
 
 int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid)
_

Patches currently in -mm which might be from oleg@redhat.com are

change-thread_group_empty-to-use-task_struct-thread_node.patch
kill-task_struct-thread_group.patch
__kill_pgrp_info-simplify-the-calculation-of-return-value.patch