linux-kernel - [ 37/94] swap: dont do discard if no discard option added

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: <20120527010428.972090489@linuxfoundation.org>
Date:	Sun, 27 May 2012 10:05:00 +0900
From:	Greg KH <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Shaohua Li <shli@...ionio.com>,
	Holger Kiehl <Holger.Kiehl@....de>,
	Hugh Dickins <hughd@...gle.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	William Dauchy <wdauchy@...il.com>
Subject: [ 37/94] swap: dont do discard if no discard option added

3.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shaohua Li <shli@...nel.org>

commit 052b1987faca3606109d88d96bce124851f7c4c2 upstream.

When swapon() was not passed the SWAP_FLAG_DISCARD option, sys_swapon()
will still perform a discard operation.  This can cause problems if
discard is slow or buggy.

Reverse the order of the check so that a discard operation is performed
only if the sys_swapon() caller is attempting to enable discard.

Signed-off-by: Shaohua Li <shli@...ionio.com>
Reported-by: Holger Kiehl <Holger.Kiehl@....de>
Tested-by: Holger Kiehl <Holger.Kiehl@....de>
Cc: Hugh Dickins <hughd@...gle.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: William Dauchy <wdauchy@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 mm/swapfile.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2103,7 +2103,7 @@ SYSCALL_DEFINE2(swapon, const char __use
 			p->flags |= SWP_SOLIDSTATE;
 			p->cluster_next = 1 + (random32() % p->highest_bit);
 		}
-		if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD))
+		if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
 			p->flags |= SWP_DISCARDABLE;
 	}
 


--
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/