svn commit: r220526 - head/sys/kern

[Attilio Rao]

2011/4/15 Kostik Belousov <kostikbel at gmail.com>:
> On Thu, Apr 14, 2011 at 05:13:28PM -0400, John Baldwin wrote:
>> On Sunday, April 10, 2011 1:07:03 pm Konstantin Belousov wrote:
>> > Author: kib
>> > Date: Sun Apr 10 17:07:02 2011
>> > New Revision: 220526
>> > URL: http://svn.freebsd.org/changeset/base/220526
>> >
>> > Log:
>> >   Some callers of proc_reparent() already have the parent process locked.
>> >   Detect the situation and avoid process lock recursion.
>> >
>> >   Reported by:      Fabian Keil <freebsd-listen fabiankeil de>
>> >
>> > Modified:
>> >   head/sys/kern/kern_exit.c
>>
>> Can we instead assert it is always held and fix callers that don't?  Using
>> locked variables is messy and I'd rather avoid it when possible.  We already
>> require the caller to hold other locks for this operation.
>>
> I agree that this is ugly, and proper fix probably would be something else.
> E.g. struct proc could grow another field that holds a pointer to the ucred
> it is accounted for, and locked with some global lock.

As you already hold allproc_lock the process can't be distructed, then
as I already pointed out to Tomasz, it should alright to just bump the
refcount for cred and pass down, I guess.

Attilio


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