From: Mathieu Desnoyers via lttng-dev <lttng-dev@lists.lttng.org>
To: Benjamin Marzinski <bmarzins@redhat.com>,
lttng-dev@lists.lttng.org,
Michael Jeanson <mjeanson@efficios.com>
Subject: Re: [lttng-dev] [PATCH urcu] fix: handle EINTR correctly in get_cpu_mask_from_sysfs
Date: Thu, 2 May 2024 09:54:55 -0400 [thread overview]
Message-ID: <2a7f6659-4332-47ed-adbf-45e88915ac6b@efficios.com> (raw)
In-Reply-To: <20240501234242.2395659-1-bmarzins@redhat.com>
On 2024-05-01 19:42, Benjamin Marzinski via lttng-dev wrote:
> If the read() in get_cpu_mask_from_sysfs() fails with EINTR, the code is
> supposed to retry, but the while loop condition has (bytes_read > 0),
> which is false when read() fails with EINTR. The result is that the code
> exits the loop, having only read part of the string.
>
> Use (bytes_read != 0) in the while loop condition instead, since the
> (bytes_read < 0) case is already handled in the loop.
Thanks for the fix ! It is indeed the right thing to do.
I would like to integrate this fix into the librseq and libside
projects as well though, but I notice the the copy in liburcu
is LGPLv2.1 whereas the copy in librseq and libside are
MIT.
Michael, should we first relicense the liburcu src/compat-smp.h
implementation to MIT so it matches the license of the copies
in librseq and libside ?
Thanks,
Mathieu
>
> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
> ---
> src/compat-smp.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/compat-smp.h b/src/compat-smp.h
> index 31fa979..075a332 100644
> --- a/src/compat-smp.h
> +++ b/src/compat-smp.h
> @@ -164,7 +164,7 @@ static inline int get_cpu_mask_from_sysfs(char *buf, size_t max_bytes, const cha
>
> total_bytes_read += bytes_read;
> assert(total_bytes_read <= max_bytes);
> - } while (max_bytes > total_bytes_read && bytes_read > 0);
> + } while (max_bytes > total_bytes_read && bytes_read != 0);
>
> /*
> * Make sure the mask read is a null terminated string.
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
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next prev parent reply other threads:[~2024-05-02 13:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-01 23:42 [lttng-dev] [PATCH urcu] fix: handle EINTR correctly in get_cpu_mask_from_sysfs Benjamin Marzinski via lttng-dev
2024-05-02 13:54 ` Mathieu Desnoyers via lttng-dev [this message]
2024-05-02 14:32 ` Michael Jeanson via lttng-dev
2024-05-02 14:34 ` Mathieu Desnoyers via lttng-dev
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