From: "Jan Beulich" <JBeulich@suse.com>
To: Wei Liu <wei.liu2@citrix.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
Paulina Szubarczyk <paulinaszubarczyk@gmail.com>,
Ian Jackson <ian.jackson@eu.citrix.com>,
Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH] libxl: fix an error path that uses uninitialised rc in libxl_set_memory_target
Date: Wed, 22 Jun 2016 09:20:57 -0600 [thread overview]
Message-ID: <576AC8F902000078000F7BDB@prv-mh.provo.novell.com> (raw)
In-Reply-To: <20160622135934.GF1790@citrix.com>
>>> On 22.06.16 at 15:59, <wei.liu2@citrix.com> wrote:
> On Wed, Jun 22, 2016 at 07:53:56AM -0600, Jan Beulich wrote:
>> >>> On 22.06.16 at 15:47, <wei.liu2@citrix.com> wrote:
>> > On Wed, Jun 22, 2016 at 06:58:28AM -0600, Jan Beulich wrote:
>> >> >>> On 12.06.16 at 16:09, <wei.liu2@citrix.com> wrote:
>> >> > --- a/tools/libxl/libxl.c
>> >> > +++ b/tools/libxl/libxl.c
>> >> > @@ -4927,10 +4927,12 @@ retry_transaction:
>> >> >
>> >> > target = libxl__xs_read(gc, t, GCSPRINTF("%s/memory/target",
> dompath));
>> >> > if (!target && !domid) {
>> >> > - if (!xs_transaction_end(ctx->xsh, t, 1))
>> >> > + if (!xs_transaction_end(ctx->xsh, t, 1)) {
>> >> > + rc = ERROR_FAIL;
>> >>
>> >> I'm sorry for noticing this only now - is ERROR_FAIL the right thing
>> >> to use here, considering how things worked before the change that
>> >> introduced the issue getting fixed here? I had intentionally decided
>> >> to use ERROR_INVAL in the patch variant I did submit (as at that
>> >> time I wasn't yet aware of the other fix floating around already).
>> >>
>> >
>> > When I wrote this patch, I thought the return value should be tied to
>> > xs_transaction_end.
>>
>> xs_transaction_end() returning zero means success afaict.
>>
>
> /* End a transaction.
> * If abandon is true, transaction is discarded instead of committed.
> * Returns false on failure: if errno == EAGAIN, you have to restart
> * transaction.
> */
> bool xs_transaction_end(struct xs_handle *h, xs_transaction_t t,
> bool abort);
>
> I think you misread.
Indeed, I got mislead by "goto out_no_transaction". Yet that
doesn't change the discussion of the error - originally this didn't
return -1 here, but +1 (i.e. reflecting the surrounding if(), not
the inner one).
Jan
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next prev parent reply other threads:[~2016-06-22 15:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-12 14:09 [PATCH] libxl: fix an error path that uses uninitialised rc in libxl_set_memory_target Wei Liu
2016-06-20 13:32 ` Ian Jackson
2016-06-22 12:58 ` Jan Beulich
2016-06-22 13:47 ` Wei Liu
2016-06-22 13:53 ` Jan Beulich
2016-06-22 13:59 ` Wei Liu
2016-06-22 15:20 ` Jan Beulich [this message]
2016-06-22 15:29 ` Wei Liu
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