From: Paul Eggert <eggert@cs.ucla.edu>
To: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>,
Alejandro Colomar <alx.manpages@gmail.com>,
linux-man@vger.kernel.org
Cc: Alejandro Colomar <alx@kernel.org>,
libc-alpha@sourceware.org,
Wilco Dijkstra <Wilco.Dijkstra@arm.com>,
"G. Branden Robinson" <g.branden.robinson@gmail.com>
Subject: Re: [PATCH] bind.2, mount_setattr.2, openat2.2, perf_event_open.2, pidfd_send_signal.2, recvmmsg.2, seccomp_unotify.2, select_tut.2, sendmmsg.2, set_thread_area.2, sysctl.2, bzero.3, getaddrinfo.3, getaddrinfo_a.3, getutent.3, mbrtowc.3, mbsinit.3, rtime.3, rtnetlink.3, strptime.3, NULL.3const, size_t.3type, void.3type, aio.7, netlink.7, unix.7: Prefer bzero(3) over memset(3)
Date: Thu, 5 Jan 2023 12:55:51 -0800 [thread overview]
Message-ID: <18377873-00df-84fa-a9e9-5d1207e4ea52@cs.ucla.edu> (raw)
In-Reply-To: <2e3e0b30-0fdd-cf17-fa84-a241d2169745@linaro.org>
On 2023-01-05 12:48, Adhemerval Zanella Netto via Libc-alpha wrote:
>
>
> On 05/01/23 16:37, Alejandro Colomar via Libc-alpha wrote:
>> bzero(3) is simpler to use, and can avoid silly mistakes that are hard
>> to spot. memset(3), while it is necessary in a few very-specific cases,
>> should be avoided when the memory is to be zeroed.
>>
>> POSIX and ISO can say otherwise, but it doesn't make any sense to
>> recommend using memset(3) over bzero(3).
>
> bzero is deprecated by POSIX.1-2001, removed by POSIX.1-2008, and on glibc
> implementation now calls memset (previously some architecture added ifunc
> redirection to optimized bzero to avoid the extra function call, it was
> removed from all architectures).
>
> Also, GCC for some time also replaces bzero with memset so there is no gain
> in actually call bzero (check glibc commit 9403b71ae97e3f1a91c796ddcbb4e6f044434734).
In addition, gcc -Wall warns if you mistakenly pass 0 as memset's 3rd
arg, which undercuts the argument that bzero avoids silly mistakes.
next prev parent reply other threads:[~2023-01-05 20:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-05 19:37 Alejandro Colomar
2023-01-05 20:48 ` Adhemerval Zanella Netto
2023-01-05 20:55 ` Paul Eggert [this message]
2023-01-05 21:12 ` [PATCH] bind.2, mount_setattr.2, openat2.2, perf_event_open.2, pidfd_send_signal.2, recvmmsg.2, seccomp_unotify.2, select_tut.2, sendmmsg.2, set_thread_area.2, sysctl.2, bzero.3, getaddrinfo.3, getaddrinfo_a.3, getutent.3, mbrtowc.3, mbsinit.3, rti Wilco Dijkstra
2023-01-05 21:33 ` Alejandro Colomar
2023-01-05 23:30 ` Wilco Dijkstra
2023-01-05 21:42 ` [PATCH] bind.2, mount_setattr.2, openat2.2, perf_event_open.2, pidfd_send_signal.2, recvmmsg.2, seccomp_unotify.2, select_tut.2, sendmmsg.2, set_thread_area.2, sysctl.2, bzero.3, getaddrinfo.3, getaddrinfo_a.3, getutent.3, mbrtowc.3, mbsinit.3, rtime.3, rtnetlink.3, strptime.3, NULL.3const, size_t.3type, void.3type, aio.7, netlink.7, unix.7: Prefer bzero(3) over memset(3) Alejandro Colomar
2023-01-06 10:55 ` Christian Brauner
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