From 4d88db53a9977e16cfa9b7315893401ff6eac7ee Mon Sep 17 00:00:00 2001
From: Will Newton <will.newton@gmail.com>
Date: Wed, 24 Nov 2010 12:56:55 -0800
Subject: [PATCH] uml: disable winch irq before freeing handler data
commit 69e83dad5207f8f03c9699e57e1febb114383cb8 upstream.
Disable the winch irq early to make sure we don't take an interrupt part
way through the freeing of the handler data, resulting in a crash on
shutdown:
winch_interrupt : read failed, errno = 9
fd 13 is losing SIGWINCH support
------------[ cut here ]------------
WARNING: at lib/list_debug.c:48 list_del+0xc6/0x100()
list_del corruption, next is LIST_POISON1 (00100100)
082578c8: [<081fd77f>] dump_stack+0x22/0x24
082578e0: [<0807a18a>] warn_slowpath_common+0x5a/0x80
08257908: [<0807a23e>] warn_slowpath_fmt+0x2e/0x30
08257920: [<08172196>] list_del+0xc6/0x100
08257940: [<08060244>] free_winch+0x14/0x80
08257958: [<080606fb>] winch_interrupt+0xdb/0xe0
08257978: [<080a65b5>] handle_IRQ_event+0x35/0xe0
08257998: [<080a8717>] handle_edge_irq+0xb7/0x170
082579bc: [<08059bc4>] do_IRQ+0x34/0x50
082579d4: [<08059e1b>] sigio_handler+0x5b/0x80
082579ec: [<0806a374>] sig_handler_common+0x44/0xb0
08257a68: [<0806a538>] sig_handler+0x38/0x50
08257a78: [<0806a77c>] handle_signal+0x5c/0xa0
08257a9c: [<0806be28>] hard_handler+0x18/0x20
08257aac: [<00c14400>] 0xc14400
Signed-off-by: Will Newton <will.newton@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/um/drivers/line.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 7f7338c90784..1664cce7b0ac 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -727,6 +727,9 @@ struct winch {
static void free_winch(struct winch *winch, int free_irq_ok)
{
+ if (free_irq_ok)
+ free_irq(WINCH_IRQ, winch);
+
list_del(&winch->list);
if (winch->pid != -1)
@@ -735,8 +738,6 @@ static void free_winch(struct winch *winch, int free_irq_ok)
os_close_file(winch->fd);
if (winch->stack != 0)
free_stack(winch->stack, 0);
- if (free_irq_ok)
- free_irq(WINCH_IRQ, winch);
kfree(winch);
}
--
2.34.1