[PATCH v2 3/9] ia64: Pin controlling tty for unaligned fault message

From: Peter Hurley
Date: Sun Jan 10 2016 - 23:38:24 EST


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@xxxxxxxxxxxxxxxxxx>
---
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);
--
2.7.0