[SSSD] [PATCHES] Sig handlers cleanups

Lukas Slebodnik lslebodn at redhat.com
Thu Jan 8 10:18:23 UTC 2015


On (08/01/15 11:10), Pavel Reichl wrote:
>
>On 01/08/2015 10:24 AM, Jakub Hrozek wrote:
>>On Mon, Jan 05, 2015 at 06:48:29PM +0100, Pavel Reichl wrote:
>>>On 11/12/2013 11:32 AM, Jakub Hrozek wrote:
>>>>On Tue, Nov 12, 2013 at 11:15:17AM +0100, Sumit Bose wrote:
>>>>>On Tue, Nov 12, 2013 at 10:45:48AM +0100, Jakub Hrozek wrote:
>>>>>>On Tue, Nov 12, 2013 at 10:27:48AM +0100, Sumit Bose wrote:
>>>>>>>On Mon, Nov 11, 2013 at 02:37:39PM -0500, Simo Sorce wrote:
>>>>>>>>On Mon, 2013-11-11 at 17:33 +0100, Sumit Bose wrote:
>>>>>>>>>On Mon, Nov 11, 2013 at 08:56:12AM -0500, Simo Sorce wrote:
>>>>>>>>>>On Mon, 2013-11-11 at 09:20 +0100, Sumit Bose wrote:
>>>>>>>>>>>On Sat, Nov 09, 2013 at 04:26:36PM -0500, Simo Sorce wrote:
>>>>>>>>>>>>While checking if our custom signal handlers properly handle errno, I
>>>>>>>>>>>>stumbled on a few cleanups, they are attached.
>>>>>>>>>>>>
>>>>>>>>>>>>turns out our few signal hanlders are errno safe, and tevent signal
>>>>>>>>>>>>handling function is also fine.
>>>>>>>>>>>>
>>>>>>>>>>>>Simo.
>>>>>>>>>>>>
>>>>>>>>>>>>-- 
>>>>>>>>>>>>Simo Sorce * Red Hat, Inc * New York
>>>>>>>>>>>> From 8244f7619c5042dc45751ce3bbff75f2dbc03e05 Mon Sep 17 00:00:00 2001
>>>>>>>>>>>>From: Simo Sorce <simo at redhat.com>
>>>>>>>>>>>>Date: Sat, 9 Nov 2013 16:11:04 -0500
>>>>>>>>>>>>Subject: [PATCH 2/3] Signals: Remove empty sig_hup
>>>>>>>>>>>>
>>>>>>>>>>>>SIGHUP handling is simply not implemented, so just block the signal instead of
>>>>>>>>>>>it is, see te_server_hup() and the usage is documented in the sssd man
>>>>>>>>>>>page.
>>>>>>>>>>>
>>>>>>>>>>>>using a fake handler.
>>>>>>>>>>Ok does it mean I need to remove the part where I block the signal ?
>>>>>>>>>no, but you have to unblock it in server_setup() and if it is harmless
>>>>>>>>>to unblock a signal twice I would unblock it in monitor_process_init()
>>>>>>>>>before calling tevent_add_signal() as well.
>>>>>>>>>
>>>>>>>>>>Do you have any other comment ?
>>>>>>>>>no, but I still need to test them.
>>>>>>>>>
>>>>>>>>>>The sig_hup(int sig) function *was* useless ? Or is it there as a place
>>>>>>>>>>holder until te_server_hup() takes over ?
>>>>>>>>>no, I think the common patter here is to block everything in
>>>>>>>>>setup_signals() and then unblock the signal when the related
>>>>>>>>>tevent_add_signal() is called.
>>>>>>>>Ok after looking more carefully at how we setup the tevent handlers for
>>>>>>>>SIGHUP I just reverted the part of the patch that would block the
>>>>>>>>signal, it makes no sense to block it just to revert the action a few
>>>>>>>>microseconds later.
>>>>>>>>
>>>>>>>>New patch 0002 attached.
>>>>>>>Thank you. With this patch SSSD receives and handles all documented
>>>>>>>signals.
>>>>>>>
>>>>>>>ACK
>>>>>>>
>>>>>>>While testing I came across an oddness which we might want to fix. The
>>>>>>>sssd_be processes can receive SIGUSR1 individually and go offline. But
>>>>>>>the SIGUSR2 is not handled by sssd_be directly but only by the monitor
>>>>>>>which then send a reset offline request to all backends. Shall sssd_be
>>>>>>>handle SIGUSR2 as well?
>>>>>>>
>>>>>>>bye,
>>>>>>>Sumit
>>>>>>Which patches should be pushed? #1 and #3 from the original mail and #2
>>>>>>from the follow up?
>>>>>yes
>>>>>
>>>>>bye,
>>>>>Sumit
>>>>OK, pushed those three to master.
>>>Hello, I'm having some troubles compiling SSSD 1-11 when Samba 4.1.14-1 is
>>>installed.
>>>These problem seem to be solved when patch 'Signals: Remove unused
>>>functions' is applied.
>>>Can we push it to 1-11 branch?
>>I don't have a problem with pushing a patch that removes unused static
>>functions, although Samba really shouldn't export non-namespaced
>>functions.
>>
>>Is that another manifestation of:
>>     https://bugzilla.samba.org/show_bug.cgi?id=11033
>>?
>I think the root of the problem is same - samba provides in its public
>headers (ndr.h includes samba_util.h) declarations of its functions (void
>(*CatchChild(void))(int);  void (*CatchChildLeaveStatus(void))(int);)  which
>conflicts with SSSD function's (void CatchChild(void); void
>CatchChildLeaveStatus(void);)
>
Actually, our file src/util/signal.c was copied from samba code.
@see header of that file. So we should have used prefixed version as well.

LS



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