* [PATCH] ia64: Pin controlling tty for unaligned fault message
@ 2014-10-16 19:10 Peter Hurley
2014-10-16 19:12 ` Peter Hurley
0 siblings, 1 reply; 2+ messages in thread
From: Peter Hurley @ 2014-10-16 19:10 UTC (permalink / raw)
To: Tony Luck, Fenghua Yu
Cc: Greg Kroah-Hartman, linux-ia64, linux-kernel, Peter Hurley
Prevent destruction of the controlling tty before tty_write_message()
can determine if the tty is safe to use.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
arch/ia64/kernel/unaligned.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c
index 622772b..e7ae608 100644
--- a/arch/ia64/kernel/unaligned.c
+++ b/arch/ia64/kernel/unaligned.c
@@ -1336,8 +1336,11 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs)
* Don't call tty_write_message() if we're in the kernel; we might
* be holding locks...
*/
- if (user_mode(regs))
- tty_write_message(current->signal->tty, buf);
+ if (user_mode(regs)) {
+ struct tty_struct *tty = get_current_tty();
+ tty_write_message(tty, buf);
+ tty_kref_put(tty);
+ }
buf[len-1] = '\0'; /* drop '\r' */
/* watch for command names containing %s */
printk(KERN_WARNING "%s", buf);
--
2.1.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] ia64: Pin controlling tty for unaligned fault message
2014-10-16 19:10 [PATCH] ia64: Pin controlling tty for unaligned fault message Peter Hurley
@ 2014-10-16 19:12 ` Peter Hurley
0 siblings, 0 replies; 2+ messages in thread
From: Peter Hurley @ 2014-10-16 19:12 UTC (permalink / raw)
To: Tony Luck, Fenghua Yu; +Cc: Greg Kroah-Hartman, linux-ia64, linux-kernel
On 10/16/2014 03:10 PM, Peter Hurley wrote:
> Prevent destruction of the controlling tty before tty_write_message()
> can determine if the tty is safe to use.
This does not make tty_write_message() bulletproof from concurrent
teardown, but that's on my todo list.
> Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
> ---
> arch/ia64/kernel/unaligned.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c
> index 622772b..e7ae608 100644
> --- a/arch/ia64/kernel/unaligned.c
> +++ b/arch/ia64/kernel/unaligned.c
> @@ -1336,8 +1336,11 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs)
> * Don't call tty_write_message() if we're in the kernel; we might
> * be holding locks...
> */
> - if (user_mode(regs))
> - tty_write_message(current->signal->tty, buf);
> + if (user_mode(regs)) {
> + struct tty_struct *tty = get_current_tty();
> + tty_write_message(tty, buf);
> + tty_kref_put(tty);
> + }
> buf[len-1] = '\0'; /* drop '\r' */
> /* watch for command names containing %s */
> printk(KERN_WARNING "%s", buf);
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2014-10-16 19:12 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-10-16 19:10 [PATCH] ia64: Pin controlling tty for unaligned fault message Peter Hurley
2014-10-16 19:12 ` Peter Hurley
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox