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] [day] [month] [year] [list]
Date:	Fri, 22 Jan 2010 23:00:15 +0100 (CET)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Ivan Novick <novickivan@...il.com>
cc:	linux-kernel@...r.kernel.org
Subject: Re: sys_rt_sigreturn calling sys_futex?

On Fri, 22 Jan 2010, Ivan Novick wrote:
> Hello,
> 
> I have a userspace app that I profiled using SystemTap.
> 
> It says there are frequent calls to sys_futex which come from sys_rt_sigreturn.
> 
> It is true, that my app has many signal handler calls due to
> frequently set timers in the code.
> 
> I had a look at the source for my kernel: Suse: linux-2.6.27.39-0.3
> but I don't see any calls to futex from inside sys_rt_sigreturn.
> 
> Do you know if sys_rt_sigreturn is somehow calling sys_futex?

Well, it is not calling sys_futex, it is resuming the sys_futex
syscall which was interrupted by the signal. When the signal handler
returns it returns to the system call automatically.
 
Thanks,

	tglx
--
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/

Powered by blists - more mailing lists