linux-serial.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* 4.3 serial driver crashes with console shortly after boot
@ 2015-11-10  0:29 Andi Kleen
  2015-11-10  1:52 ` Peter Hurley
  0 siblings, 1 reply; 8+ messages in thread
From: Andi Kleen @ 2015-11-10  0:29 UTC (permalink / raw)
  To: gregkh, linux-serial, linux-kernel, peter


Hi,

With 4.3 an x86 server is always crashing roughly a minute after boot
in __uart_start/uart_tx_stopped. This is repeatable over multiple boots.

The back trace is
flush_to_ldisc->n_tty_receive_buf2->n_tty_receive_buf_common->
commit_echoes-> uart_flush_chars->uart_start

It seems to follow a bad pointer here 

ffffffff813bbdfa:       f6 80 f4 01 00 00 01    testb  $0x1,0x1f4(%rax)
<---
ffffffff813bbe01:       74 01                   je     ffffffff813bbe04
<__uart_start.isra.1+0x24>

Unfortunately I don't have the contents of RAX which scrolled away,
but since CR2 is 1f4 I suspect it's NUL.

It seems to depend on the order of the console=... arguments on the
kernel command line. With console=tty0 console=ttyS0,115200n8 it
crashes, but when reversing the options it does not crash.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2017-06-23 11:23 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-11-10  0:29 4.3 serial driver crashes with console shortly after boot Andi Kleen
2015-11-10  1:52 ` Peter Hurley
2015-11-10 22:39   ` Andi Kleen
2015-11-10 22:43     ` Andi Kleen
2015-11-10 23:15       ` Peter Hurley
2015-11-11 11:14         ` Peter Hurley
2015-11-11 16:50           ` Andi Kleen
2017-06-23 11:23             ` Jiri Slaby

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).