From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Will Deacon <will.deacon@arm.com>
Cc: "Wang, Yalin" <Yalin.Wang@sonymobile.com>,
'richard -rw- weinberger' <richard.weinberger@gmail.com>,
"'linux-arch@vger.kernel.org'" <linux-arch@vger.kernel.org>,
"'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
"'linux-arm-kernel@lists.infradead.org'"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: A bug about system call on ARM
Date: Mon, 3 Jun 2013 11:18:09 +0100 [thread overview]
Message-ID: <20130603101809.GK18614@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20130530114112.GH7483@mudshark.cambridge.arm.com>
On Thu, May 30, 2013 at 12:41:12PM +0100, Will Deacon wrote:
> +#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
> + /*
> + * We may have faulted trying to load the SWI instruction due to
> + * concurrent page aging on another CPU. In this case, return
> + * back to the swi instruction and fault the page back.
> + */
> +9001:
> + sub lr, lr, #4
> + str lr, [sp, #S_PC]
> + b ret_fast_syscall
> +#endif
The comment is wrong. If we get here, it means that the fault from
trying to loading the instruction can't be fixed up. Arguably, that
should result in a SIGSEGV being sent immediately, but we'll get to
that when we then try to re-load the instruction.
What it means is that the page we were trying to execute has been
unmapped beneath us.
BTW, I notice that the kernel oops was never posted to the list, so it's
impossible for other people following this thread to see what the real
problem is...
next prev parent reply other threads:[~2013-06-03 10:18 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-29 6:52 A bug about system call on ARM Wang, Yalin
2013-05-29 7:34 ` richard -rw- weinberger
2013-05-29 7:37 ` Wang, Yalin
2013-05-29 8:24 ` Wang, Yalin
2013-05-29 8:46 ` richard -rw- weinberger
2013-05-29 9:48 ` Will Deacon
2013-05-29 9:50 ` Wang, Yalin
2013-05-30 1:41 ` Wang, Yalin
2013-05-30 9:09 ` Will Deacon
2013-05-30 11:41 ` Will Deacon
2013-05-30 11:41 ` Will Deacon
2013-05-31 2:56 ` Wang, Yalin
2013-05-31 8:46 ` Will Deacon
2013-05-31 11:02 ` Wang, Yalin
2013-05-31 11:13 ` Will Deacon
2013-05-31 11:30 ` Wang, Yalin
2013-06-03 5:25 ` Wang, Yalin
2013-06-03 9:54 ` Will Deacon
2013-06-03 9:58 ` Wang, Yalin
2013-06-04 5:33 ` Wang, Yalin
2013-06-04 8:48 ` Will Deacon
2013-06-04 8:48 ` Will Deacon
2013-06-04 9:30 ` Wang, Yalin
2013-06-04 11:27 ` Will Deacon
2013-06-14 6:53 ` Wang, Yalin
2013-05-31 16:48 ` Nicolas Pitre
2013-05-31 16:52 ` Will Deacon
2013-05-31 3:54 ` Nicolas Pitre
2013-05-31 3:54 ` Nicolas Pitre
2013-05-31 8:45 ` Will Deacon
2013-06-03 10:18 ` Russell King - ARM Linux [this message]
2013-06-03 10:27 ` Will Deacon
2013-06-03 10:45 ` Russell King - ARM Linux
2013-06-03 12:39 ` Will Deacon
2013-05-29 8:54 ` Mikael Pettersson
2013-05-29 8:54 ` Mikael Pettersson
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