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 <[email protected]>
---
arch/um/drivers/line.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 5f12fef..050e4dd 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);
}
--
1.7.0.4
On Sat, Nov 13, 2010 at 05:45:19PM +0000, Will Newton wrote:
>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 <[email protected]>
Acked-by: WANG Cong <[email protected]>
Cc Andrew Morton.
>---
> arch/um/drivers/line.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
>diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
>index 5f12fef..050e4dd 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);
> }
>
>--
>1.7.0.4
>From 439d75478f6981ff1b829d711bcce3603f5a9786 Mon Sep 17 00:00:00 2001
>From: Will Newton <[email protected]>
>Date: Sat, 13 Nov 2010 17:12:33 +0000
>Subject: [PATCH 2/2] uml: Disable winch irq before freeing handler data.
>
>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 <[email protected]>
>---
> arch/um/drivers/line.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
>diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
>index 5f12fef..050e4dd 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);
> }
>
>--
>1.7.0.4
>
--
Live like a child, think like the god.