linux-kernel - [PATCH 3/7] pid: use the CONST_CAST macro instead to write to const task

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

Message-Id: <d7307cfb4bac25729cb42764668d5e9ac037e502.1390495874.git.rgb@redhat.com>
Date:	Thu, 23 Jan 2014 14:32:36 -0500
From:	Richard Guy Briggs <rgb@...hat.com>
To:	linux-audit@...hat.com, linux-kernel@...r.kernel.org
Cc:	Richard Guy Briggs <rgb@...hat.com>, eparis@...hat.com,
	sgrubb@...hat.com, akpm@...ux-foundation.org, peterz@...radead.org,
	oleg@...hat.com
Subject: [PATCH 3/7] pid: use the CONST_CAST macro instead to write to const task_struct::pid

The CONST_CAST macro is a cleaner and more reliable way to write to the const
task_struct::pid.

Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Signed-off-by: Richard Guy Briggs <rgb@...hat.com>
---
 fs/exec.c     |    4 +---
 kernel/fork.c |    5 +----
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index a6b585e..1d2369d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -906,8 +906,6 @@ static int de_thread(struct task_struct *tsk)
 	 */
 	if (!thread_group_leader(tsk)) {
 		struct task_struct *leader = tsk->group_leader;
-		/* tast_struct::pid is const pid_t, hence the ugly cast */
-		pid_t *pid_p = (pid_t*)&(tsk->pid);
 
 		sig->notify_count = -1;	/* for exit_notify() */
 		for (;;) {
@@ -950,7 +948,7 @@ static int de_thread(struct task_struct *tsk)
 		 * Note: The old leader also uses this pid until release_task
 		 *       is called.  Odd but simple and correct.
 		 */
-		*pid_p = leader->pid;
+		CONST_CAST(pid_t, tsk->pid) = leader->pid;
 		change_pid(tsk, PIDTYPE_PID, task_pid(leader));
 		transfer_pid(leader, tsk, PIDTYPE_PGID);
 		transfer_pid(leader, tsk, PIDTYPE_SID);
diff --git a/kernel/fork.c b/kernel/fork.c
index 296e564..207c543 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1135,7 +1135,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 {
 	int retval;
 	struct task_struct *p;
-	pid_t *pid_p;
 
 	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
 		return ERR_PTR(-EINVAL);
@@ -1391,9 +1390,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 	/* ok, now we should be set up.. */
 
-	/* tast_struct::pid is const pid_t, hence the ugly cast */
-	pid_p = (pid_t*)&(p->pid);
-	*pid_p = pid_nr(pid);
+	CONST_CAST(pid_t, p->pid) = pid_nr(pid);
 	if (clone_flags & CLONE_THREAD) {
 		p->exit_signal = -1;
 		p->group_leader = current->group_leader;
-- 
1.7.1

--
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/