linux-kernel - [PATCH] ptrace: don't take tasklist to get/set ->last

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]

Date:	Thu, 28 May 2009 10:21:13 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Roland McGrath <roland@...hat.com>, linux-kernel@...r.kernel.org
Subject: [PATCH] ptrace: don't take tasklist to get/set ->last_siginfo

Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock. Perhaps it makes sense to make a singler helper
with "bool rw" argument.

Signed-off-by: Oleg Nesterov <oleg@...hat.com>

--- PTRACE/kernel/ptrace.c~SIGINFO	2009-05-28 10:03:01.000000000 +0200
+++ PTRACE/kernel/ptrace.c	2009-05-28 10:06:59.000000000 +0200
@@ -463,37 +463,33 @@ static int ptrace_setoptions
 
 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
 {
+	unsigned long flags;
 	int error = -ESRCH;
 
-	read_lock(&tasklist_lock);
-	if (likely(child->sighand != NULL)) {
+	if (lock_task_sighand(child, &flags)) {
 		error = -EINVAL;
-		spin_lock_irq(&child->sighand->siglock);
 		if (likely(child->last_siginfo != NULL)) {
 			*info = *child->last_siginfo;
 			error = 0;
 		}
-		spin_unlock_irq(&child->sighand->siglock);
+		unlock_task_sighand(child, &flags);
 	}
-	read_unlock(&tasklist_lock);
 	return error;
 }
 
 static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
 {
+	unsigned long flags;
 	int error = -ESRCH;
 
-	read_lock(&tasklist_lock);
-	if (likely(child->sighand != NULL)) {
+	if (lock_task_sighand(child, &flags)) {
 		error = -EINVAL;
-		spin_lock_irq(&child->sighand->siglock);
 		if (likely(child->last_siginfo != NULL)) {
 			*child->last_siginfo = *info;
 			error = 0;
 		}
-		spin_unlock_irq(&child->sighand->siglock);
+		unlock_task_sighand(child, &flags);
 	}
-	read_unlock(&tasklist_lock);
 	return error;
 }
 

--
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/