linux-kernel - Re: strace, accept(), ERESTARTSYS and EINTR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 05 Jan 2008 20:19:08 +0100
From:	Andreas Schwab <schwab@...e.de>
To:	"Phil Endecott" <phil_wueww_endecott@...zphil.org>
Cc:	"Jiri Slaby" <jirislaby@...il.com>, <linux-kernel@...r.kernel.org>,
	"Frederik Deweerdt" <deweerdt@...e.fr>
Subject: Re: strace, accept(), ERESTARTSYS and EINTR

"Phil Endecott" <phil_wueww_endecott@...zphil.org> writes:

> Andreas Schwab wrote:
>> "Phil Endecott" <phil_wueww_endecott@...zphil.org> writes:
>>
>>> However, there's a lot of code and I know that there are bugs in it.  I
>>> just want to focus on the kernel-related issue that the strace fragment
>>> that I posted brings up:  even if my user code gets completely screwed up
>>> (corrupts its stack, runs out of FDs/VM/threads etc), I don't think that I
>>> should see in the strace output that accept() has returned
>>> ERESTARTSYS.
>>
>> strace always sees the raw return value, before the signal handler is
>> executed and before the check for syscall restart is done.
>
> Yes, but I should see the real final return value in another strace output
> line before I see that thread doing something else.  Correct?

No.  As far as strace is concerned the syscall has finished.  Since it
isn't restarted, you won't see it again in the trace.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@...e.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/