From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: [PATCH 2/4] devmem: fix kmem write bug on memory holes Date: Fri, 22 Jan 2010 12:59:16 +0800 Message-ID: <20100122051517.415742055@intel.com> References: <20100122045914.993668874@intel.com> Cc: Greg Kroah-Hartman , Andi Kleen , Benjamin Herrenschmidt , Christoph Lameter , Ingo Molnar , Tejun Heo , Nick Piggin , KAMEZAWA Hiroyuki , , Wu Fengguang To: Andrew Morton Return-path: Cc: LKML cc: Linux Memory Management List , Content-Disposition: inline; filename=vwrite-fix.patch Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org write_kmem() used to assume vwrite() always return the full buffer length. However now vwrite() could return 0 to indicate memory hole. This creates a bug that "buf" is not advanced accordingly. Fix it to simply ignore the return value, hence the memory hole. CC: Andi Kleen CC: Benjamin Herrenschmidt CC: Christoph Lameter CC: Ingo Molnar CC: Tejun Heo CC: Nick Piggin CC: KAMEZAWA Hiroyuki CC: Signed-off-by: Wu Fengguang --- drivers/char/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-mm.orig/drivers/char/mem.c 2010-01-11 10:32:32.000000000 +0800 +++ linux-mm/drivers/char/mem.c 2010-01-11 10:32:34.000000000 +0800 @@ -555,7 +555,7 @@ static ssize_t write_kmem(struct file * err = -EFAULT; break; } - sz = vwrite(kbuf, (char *)p, sz); + vwrite(kbuf, (char *)p, sz); count -= sz; buf += sz; virtr += sz; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org