From: Florian Weimer <fweimer@redhat.com>
To: Luca Boccassi <luca.boccassi@gmail.com>
Cc: Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>,
Adhemerval Zanella <adhemerval.zanella@linaro.org>
Subject: Re: [PATCH v2 3/3] linux: Add pidfd_getpid
Date: Tue, 02 May 2023 19:13:44 +0200 [thread overview]
Message-ID: <87mt2mslkn.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <CAMw=ZnSgpRzJNu3PWR7nZfzNjFwQYStb3FjpKQ2r4_GEXJy=fw@mail.gmail.com> (Luca Boccassi's message of "Tue, 2 May 2023 17:19:26 +0100")
* Luca Boccassi:
> On Tue, 2 May 2023 at 17:07, Florian Weimer <fweimer@redhat.com> wrote:
>>
>> * Adhemerval Zanella via Libc-alpha:
>> > diff --git a/sysdeps/unix/sysv/linux/pidfd_getpid.c b/sysdeps/unix/sysv/linux/pidfd_getpid.c
>> > new file mode 100644
>> > index 0000000000..d0c7987791
>> > --- /dev/null
>> > +++ b/sysdeps/unix/sysv/linux/pidfd_getpid.c
>> > @@ -0,0 +1,94 @@
>>
>> > +static bool
>> > +parse_fdinfo (const char *l, void *arg)
>> > +{
>> > + enum { fieldlen = sizeof ("Pid:") - 1 };
>> > + if (strncmp (l, "Pid:", fieldlen) != 0)
>> > + return true;
>> > +
>> > + l += fieldlen;
>> > +
>> > + char *endp;
>> > + long int n = strtol (l, &endp, 10);
>> > + if (l == endp || n > INT_MAX)
>> > + return true;
>>
>> Should this use strtoul? Otherwise I'm not sure the overflow check will
>> work on 32-bit.
>>
>> Rest of the implementation looks okay, but the kernel should really
>> provide an ioctl or similar for this.
>
> This can be -1 when the process is gone, and it is important to get
> that distinction (with certainty) to tell the caller ESRCH. We need
> this distinction in callers.
That shouldn't be a problem, strotul processes leading signs, too. The
entire error checking is a bit dubious because it doesn't check much,
considering strtol's general flexibility.
Thanks,
Florian
next prev parent reply other threads:[~2023-05-02 17:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-20 14:20 [PATCH v2 0/3] Add pidfd_spawn, pidfd_spawnp, pidfd_fork, and pidfd_getpid Adhemerval Zanella
2023-04-20 14:20 ` [PATCH v2 1/3] posix: Add pidfd_spawn and pidfd_spawnp (BZ# 30349) Adhemerval Zanella
2023-04-20 14:20 ` [PATCH v2 2/3] posix: Add pidfd_fork Adhemerval Zanella
2023-04-20 14:20 ` [PATCH v2 3/3] linux: Add pidfd_getpid Adhemerval Zanella
2023-04-20 14:24 ` Luca Boccassi
2023-05-02 16:07 ` Florian Weimer
2023-05-02 16:19 ` Luca Boccassi
2023-05-02 17:13 ` Florian Weimer [this message]
2023-05-15 17:39 ` Adhemerval Zanella Netto
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