linux-kernel - [PATCH] check_for_tasks: read_lock(tasklist

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20150910130750.GA20055@redhat.com>
Date:	Thu, 10 Sep 2015 15:07:50 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Cc:	Kirill Tkhai <ktkhai@...allels.com>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] check_for_tasks: read_lock(tasklist_lock) doesn't need to
	disable irqs

check_for_tasks() doesn't need to disable irqs, recursive read_lock()
from interrupt is fine.

While at it, s/do_each_thread/for_each_process_thread/.

Signed-off-by: Oleg Nesterov <oleg@...hat.com>
---
 kernel/cpu.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 94bbe46..24551f2 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -302,8 +302,8 @@ static inline void check_for_tasks(int dead_cpu)
 {
 	struct task_struct *g, *p;
 
-	read_lock_irq(&tasklist_lock);
-	do_each_thread(g, p) {
+	read_lock(&tasklist_lock);
+	for_each_process_thread(g, p) {
 		if (!p->on_rq)
 			continue;
 		/*
@@ -318,8 +318,8 @@ static inline void check_for_tasks(int dead_cpu)
 
 		pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n",
 			p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags);
-	} while_each_thread(g, p);
-	read_unlock_irq(&tasklist_lock);
+	}
+	read_unlock(&tasklist_lock);
 }
 
 struct take_cpu_down_param {
-- 
1.5.5.1


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/