From: fengchengwen <fengchengwen@huawei.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
Isaac Boukris <iboukris@gmail.com>,
Thomas Monjalon <thomas@monjalon.net>
Cc: <dev@dpdk.org>,
"haijie1@huawei.com >> Jie Hai" <haijie1@huawei.com>,
<huangdengdui@huawei.com>
Subject: Re: Use of strtok() in dpdk code
Date: Tue, 22 Oct 2024 14:51:39 +0800 [thread overview]
Message-ID: <282a31cf-7ccd-4de3-99b9-687287b20e24@huawei.com> (raw)
In-Reply-To: <20241021180820.48c7bffd@hermes.local>
On 2024/10/22 9:08, Stephen Hemminger wrote:
> On Mon, 21 Oct 2024 21:30:02 +0300
> Isaac Boukris <iboukris@gmail.com> wrote:
>
>> Hello,
>>
>> I was debugging a crash resulting from strtok() returning NULL
>> unexpectedly (string still had tokens and delimiters), and the only
>> explanation I could come up with was that strtok is thread-unsafe and
>> another thread could have been calling it at the same time, and so I
>> changed it to use strtok_r().
>>
>> That said, the only other possible use of strtok() that I could find
>> was in the dpdk code (telemetry), which brings me to my question,
>> should we consider changing all occurrences to strtok_r() or am I
>> missing something? there seem to be quite some in non-initialization
>> code.
>>
>> Thanks!
>
>
> Most of the uses are in tests and other single threaded code.
> In general, simpler just to use strtok_r everywhere and not worry about it.
> Similar to not using sprintf() and instead using snprintf().
I'm afraid I can't agree.
DPDK is just a SDK, it's not an application (although DPDK provided simple examples).
Many code will developped based on DPDK, we can't predict how it was implemented.
So there maybe a DPDK thread and a application thread both invoke strtok().
From this point of view, I hope that DPDK solves some of the reentrant problems of
such C functions (e.g. strtok()\strerror()).
Actually, we've try to solve before, but unfortunately it wasn't merged.
1\ strtok(): https://inbox.dpdk.org/dev/20231114110006.91148-1-haijie1@huawei.com/T/#u
2\ strerror(): https://inbox.dpdk.org/dev/20231114123552.398072-1-huangdengdui@huawei.com/T/#u
>
> Some code scanners like codeql also flag this.
next prev parent reply other threads:[~2024-10-22 6:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-21 18:30 Isaac Boukris
2024-10-22 1:08 ` Stephen Hemminger
2024-10-22 6:51 ` fengchengwen [this message]
2024-10-22 12:27 ` Isaac Boukris
2024-10-22 15:25 ` Stephen Hemminger
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