From: Alexander Stein <alexander.stein@systec-electronic.com>
To: linux-rt-users@vger.kernel.org
Subject: Triggering BUG on SIGSEGV signaling
Date: Tue, 24 Nov 2015 12:09:12 +0100 [thread overview]
Message-ID: <2830783.CAkrTrFBlp@ws-stein> (raw)
On our system (i.MX35 based, so ARMv6) is running a v3.10.47-rt50 kernel, I get the following output from serial console when the application tries to dereference a NULL pointer:
> BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
> in_atomic(): 0, irqs_disabled(): 128, pid: 648, name: plccore-imx35-h
> CPU: 0 PID: 648 Comm: plccore-imx35-h Tainted: G O 3.10.47-rt50 #1
> [<c001367c>] (unwind_backtrace+0x0/0x130) from [<c0011e50>] (show_stack+0x10/0x14)
> [<c0011e50>] (show_stack+0x10/0x14) from [<c03b0738>] (rt_spin_lock+0x18/0x2c)
> [<c03b0738>] (rt_spin_lock+0x18/0x2c) from [<c002fd44>] (do_force_sig_info+0x20/0xd8)
> [<c002fd44>] (do_force_sig_info+0x20/0xd8) from [<c0017dac>] (__do_user_fault+0x98/0xd8)
> [<c0017dac>] (__do_user_fault+0x98/0xd8) from [<c0018144>] (do_bad_area+0x6c/0x88)
> [<c0018144>] (do_bad_area+0x6c/0x88) from [<c00181cc>] (do_translation_fault+0x6c/0xa8)
> [<c00181cc>] (do_translation_fault+0x6c/0xa8) from [<c0008344>] (do_DataAbort+0x34/0x9c)
> [<c0008344>] (do_DataAbort+0x34/0x9c) from [<c000e914>] (__dabt_usr+0x34/0x40)
> Exception stack(0xc5c91fb0 to 0xc5c91ff8)
> 1fa0: efcdefcd 00000001 00000001 00084690
> 1fc0: 00000010 00000000 00000000 00000003 014dd2c4 00000002 00000000 000000ff
> 1fe0: 0c8a7b41 be8c9b58 000219a8 000219c8 60000010 ffffffff
Reading the backtrace it seems that might_sleep() in rt_spin_lock_fastlock() raises this dump. The interrupts are apparently disabled.
Following the code path it seems to me, that (at lease in this case) ARCH_RT_DELAYS_SIGNAL_SEND must be supported on ARM too which AFAICS is for sending signals while being in_atomic.
Any comments on this? I wonder what makes this so special it didn't came up yet.
Best regards,
Alexander
--
Dipl.-Inf. Alexander Stein
SYS TEC electronic GmbH
alexander.stein@systec-electronic.com
Legal and Commercial Address:
Am Windrad 2
08468 Heinsdorfergrund
Germany
Office: +49 (0) 3765 38600-0
Fax: +49 (0) 3765 38600-4100
Managing Directors:
Director Technology/CEO: Dipl.-Phys. Siegmar Schmidt;
Director Commercial Affairs/COO: Dipl. Ing. (FH) Armin von Collrepp
Commercial Registry:
Amtsgericht Chemnitz, HRB 28082; USt.-Id Nr. DE150534010
next reply other threads:[~2015-11-24 11:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-24 11:09 Alexander Stein [this message]
2015-11-26 12:10 ` Triggering BUG on SIGSEGV signaling Alexander Stein
2015-12-11 17:32 ` Sebastian Andrzej Siewior
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2830783.CAkrTrFBlp@ws-stein \
--to=alexander.stein@systec-electronic.com \
--cc=linux-rt-users@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.