linux-kernel - [PATCH -mm 2/2] mm, vmalloc: Check VM_UNINITIALIZED flag in s_show instead of show_numa

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 for Android: free password hash cracker in your pocket

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

Date:	Sat, 08 Jun 2013 16:44:54 +0800
From:	Zhang Yanfei <zhangyanfei.yes@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Joonsoo Kim <iamjoonsoo.kim@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Linux MM <linux-mm@...ck.org>
Subject: [PATCH -mm 2/2] mm, vmalloc: Check VM_UNINITIALIZED flag in s_show
 instead of show_numa_info

From: Zhang Yanfei <zhangyanfei@...fujitsu.com>

We should check the VM_UNITIALIZED flag in s_show(). If this
flag is set, that said, the vm_struct is not fully initialized.
So it is unnecessary to try to show the information contained
in vm_struct.

We checked this flag in show_numa_info(), but I think it's better
to check it earlier.

Signed-off-by: Zhang Yanfei <zhangyanfei@...fujitsu.com>
---
 mm/vmalloc.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index fe41a4f..722268b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2591,11 +2591,6 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 		if (!counters)
 			return;
 
-		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
-		smp_rmb();
-		if (v->flags & VM_UNINITIALIZED)
-			return;
-
 		memset(counters, 0, nr_node_ids * sizeof(unsigned int));
 
 		for (nr = 0; nr < v->nr_pages; nr++)
@@ -2624,6 +2619,11 @@ static int s_show(struct seq_file *m, void *p)
 
 	v = va->vm;
 
+	/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+	smp_rmb();
+	if (v->flags & VM_UNINITIALIZED)
+		return 0;
+
 	seq_printf(m, "0x%pK-0x%pK %7ld",
 		v->addr, v->addr + v->size, v->size);
 
-- 
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/