From 483d7142396f0d8b8f8748a4069b71c13ca662e5 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Fri, 5 Feb 2010 15:02:13 -0500 Subject: [PATCH] devmem: fix kmem write bug on memory holes commit c85e9a97c4102ce2e83112da850d838cfab5ab13 upstream devmem: fix kmem write bug on memory holes [ cebbert@redhat.com : backport to 2.6.32 ] 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. Signed-off-by: Wu Fengguang 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: Andrew Morton Signed-off-by: Linus Torvalds Cc: Chuck Ebbert Signed-off-by: Greg Kroah-Hartman --- drivers/char/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 96b2586d2bec..aef3fb42150e 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -593,7 +593,7 @@ static ssize_t write_kmem(struct file * file, const char __user * buf, break; } } - len = vwrite(kbuf, (char *)p, len); + vwrite(kbuf, (char *)p, len); count -= len; buf += len; virtr += len; -- 2.39.2