From: "Xueming(Steven) Li" <xuemingl@mellanox.com>
To: Olivier Matz <olivier.matz@6wind.com>
Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2] lib/cmdline: init CLI parsing memory
Date: Thu, 18 Jan 2018 04:29:59 +0000 [thread overview]
Message-ID: <VI1PR05MB1678497BEC4648EB45B1E300ACE80@VI1PR05MB1678.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20180116124549.32w7g5jmhl633m2v@platinum>
> -----Original Message-----
> From: Olivier Matz [mailto:olivier.matz@6wind.com]
> Sent: Tuesday, January 16, 2018 8:46 PM
> To: Xueming(Steven) Li <xuemingl@mellanox.com>
> Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>; dev@dpdk.org
> Subject: Re: [PATCH v2] lib/cmdline: init CLI parsing memory
>
> Hi Xueming,
>
> Sorry for the late response.
>
> On Tue, Dec 26, 2017 at 12:57:41PM +0000, Xueming(Steven) Li wrote:
> > HI Olivier,
> >
> > By reading p1 comments carefully, looks like the pointer to result
> > buffer issue not resolved by result copy. How about this:
> >
> > @@ -263,6 +263,7 @@
> > #ifdef RTE_LIBRTE_CMDLINE_DEBUG
> > char debug_buf[BUFSIZ];
> > #endif
> > + char *result_buf = result.buf;
> >
> > if (!cl || !buf)
> > return CMDLINE_PARSE_BAD_ARGS;
> > @@ -312,16 +313,13 @@
> > debug_printf("INST %d\n", inst_num);
> >
> > /* fully parsed */
> > - tok = match_inst(inst, buf, 0, tmp_result.buf,
> > - sizeof(tmp_result.buf));
> > + tok = match_inst(inst, buf, 0, result_buf, sizeof(result.buf));
>
> If we don't use tmp_result, it is maybe better to also replace
> sizeof(result.buf) by CMDLINE_PARSE_RESULT_BUFSIZE
Thanks, would like to send out new version soon
>
> >
> > if (tok > 0) /* we matched at least one token */
> > err = CMDLINE_PARSE_BAD_ARGS;
> >
> > else if (!tok) {
> > debug_printf("INST fully parsed\n");
> > - memcpy(&result, &tmp_result,
> > - sizeof(result));
> > /* skip spaces */
> > while (isblank2(*curbuf)) {
> > curbuf++;
> > @@ -332,6 +330,7 @@
> > if (!f) {
> > memcpy(&f, &inst->f, sizeof(f));
> > memcpy(&data, &inst->data, sizeof(data));
> > + result_buf = tmp_result.buf;
> > }
> > else {
> > /* more than 1 inst matches */
> >
>
>
> I guess the issue you are talking about is the one described in
> "cmdline: fix dynamic tokens parsing" in my previous description?
>
> I think this patch is ok, and is probably better than the initial
> suggestion, because it avoids to copy the buffer. However, I don't
> understand why the previous patch was wrong, can you detail?
Let me quote your last email:
" When using dynamic tokens, the result buffer contains pointers
to some location inside the result buffer. When the content of
the temporary buffer is copied in the final one, these pointers
still point to the temporary buffer."
If pointer exist in buffer, the new copy still pint to the old copy
which very probably being changed.
>
> Thanks
> Olivier
next prev parent reply other threads:[~2018-01-18 4:30 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-15 15:54 [dpdk-dev] [PATCH] lib/cmdline: init parse result memeory Xueming Li
2017-12-07 14:48 ` Olivier MATZ
2017-12-07 15:05 ` Xueming(Steven) Li
2017-12-07 15:35 ` Xueming(Steven) Li
2017-12-07 17:13 ` Adrien Mazarguil
2017-12-08 7:02 ` [dpdk-dev] [PATCH v1] lib/cmdline: init parse result memory Xueming Li
2017-12-08 12:27 ` Adrien Mazarguil
2017-12-08 13:51 ` Olivier MATZ
2017-12-08 14:50 ` Xueming(Steven) Li
2017-12-08 15:04 ` Adrien Mazarguil
2017-12-08 15:26 ` Olivier MATZ
2017-12-09 15:39 ` [dpdk-dev] [PATCH v2] lib/cmdline: init CLI parsing memory Xueming Li
2017-12-14 15:35 ` Olivier MATZ
2017-12-18 10:51 ` Adrien Mazarguil
2017-12-18 13:44 ` Xueming(Steven) Li
2017-12-26 12:57 ` Xueming(Steven) Li
2018-01-16 12:45 ` Olivier Matz
2018-01-18 4:29 ` Xueming(Steven) Li [this message]
2018-01-19 9:07 ` Olivier Matz
2018-01-19 18:18 ` Xueming(Steven) Li
2018-01-19 18:16 ` [dpdk-dev] [PATCH v3] cmdline: fix dynamic tokens parsing Xueming Li
2018-01-22 13:13 ` Olivier Matz
2018-01-25 22:14 ` [dpdk-dev] [dpdk-stable] " Thomas Monjalon
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