From: Florian Weimer <fw@deneb.enyo.de>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Florian Weimer <fweimer@redhat.com>, libc-alpha@sourceware.org
Subject: Re: [PATCH v2 1/5] mips: Do not malloc on getdents64 fallback
Date: Tue, 08 Oct 2019 19:59:00 -0000 [thread overview]
Message-ID: <87sgo3uhy8.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <23bef2c5-def2-19bb-950f-70d2b4c43ba0@linaro.org> (Adhemerval Zanella's message of "Tue, 8 Oct 2019 16:52:36 -0300")
* Adhemerval Zanella:
>>> + memcpy (DP_MEMBER (dp, struct dirent64, d_reclen), &new_reclen,
>>> + sizeof ((struct dirent64){0}.d_reclen));
>>
>> That looks wrong. DP_MEMBER (dp, struct dirent64, d_reclen) is a
>> temporary object, so the outer memcpy is dead.
>
> Sigh, indeed. I changed to:
>
> memcpy (((char *)(dp) + offsetof (struct dirent64, d_reclen)),
> &new_reclen, sizeof ((struct dirent64){0}.d_reclen));
sizeof ((struct dirent64){0}.d_reclen) could just be
sizeof (new_reclen). After all, this only works if they are the same.
I guess -fno-strict-aliasing looks more attractive now. 8-/
You probably should write ((char *) dp) instead of (char *)(dp) if you
want to make the operator precedence explicit, or at least drop the
parentheses around dp. (I think the cast binds tighter than the +,
but I can't really remember. I tend to write the paranetheses.)
next prev parent reply other threads:[~2019-10-08 19:59 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-31 18:31 Adhemerval Zanella
2019-07-31 18:31 ` [PATCH v2 3/5] posix: Optimize stack Linux posix_spawn Adhemerval Zanella
2019-08-28 14:09 ` Adhemerval Zanella
2019-10-07 17:50 ` Adhemerval Zanella
2019-07-31 18:31 ` [PATCH v2 2/5] posix: Add posix_spawn_file_actions_closefrom Adhemerval Zanella
2019-08-28 14:09 ` Adhemerval Zanella
2019-08-28 17:22 ` Joseph Myers
2019-08-28 21:03 ` Adhemerval Zanella
2019-07-31 18:31 ` [PATCH 4/5] linux: Optimize posix_spawn spurious sigaction calls Adhemerval Zanella
2019-08-28 14:09 ` Adhemerval Zanella
2019-08-29 8:38 ` Florian Weimer
2019-08-29 11:26 ` Adhemerval Zanella
2019-08-30 10:07 ` Florian Weimer
2019-08-30 13:05 ` Adhemerval Zanella
2019-09-02 13:14 ` Florian Weimer
2019-09-02 19:47 ` Adhemerval Zanella
2019-10-07 17:51 ` Adhemerval Zanella
2019-10-07 18:25 ` Christian Brauner
2019-10-07 18:32 ` Florian Weimer
2019-10-07 21:08 ` Christian Brauner
2019-10-07 18:35 ` Adhemerval Zanella
2019-10-07 18:40 ` Florian Weimer
2019-10-07 19:20 ` Adhemerval Zanella
2019-10-09 9:37 ` Florian Weimer
2019-10-09 10:25 ` Christian Brauner
2019-10-09 12:17 ` Adhemerval Zanella
2019-10-09 19:16 ` Florian Weimer
2019-10-07 21:00 ` Joseph Myers
2019-10-07 18:41 ` Florian Weimer
2019-07-31 18:31 ` [PATCH v2 5/5] posix: Use posix_spawn for wordexp Adhemerval Zanella
2019-08-28 14:10 ` Adhemerval Zanella
2019-10-07 17:51 ` Adhemerval Zanella
2019-10-07 19:33 ` Florian Weimer
2019-10-07 21:04 ` Carlos O'Donell
2019-10-08 9:58 ` Florian Weimer
2019-10-08 17:41 ` Adhemerval Zanella
2019-10-09 9:11 ` Florian Weimer
2019-10-09 12:18 ` Adhemerval Zanella
2019-08-28 14:09 ` [PATCH v2 1/5] mips: Do not malloc on getdents64 fallback Adhemerval Zanella
2019-08-28 14:35 ` Andreas Schwab
2019-08-28 17:01 ` Adhemerval Zanella
2019-08-28 14:42 ` Florian Weimer
2019-08-28 21:02 ` Adhemerval Zanella
2019-08-28 21:23 ` Florian Weimer
2019-08-29 11:04 ` Adhemerval Zanella
2019-08-30 9:53 ` Florian Weimer
2019-08-30 12:53 ` Adhemerval Zanella
2019-09-02 12:59 ` Florian Weimer
2019-09-02 17:38 ` Adhemerval Zanella
2019-10-07 17:49 ` Adhemerval Zanella
2019-10-07 18:29 ` Florian Weimer
2019-10-08 17:38 ` Adhemerval Zanella
2019-10-08 18:52 ` Florian Weimer
2019-10-08 19:52 ` Adhemerval Zanella
2019-10-08 19:59 ` Florian Weimer [this message]
2019-10-09 13:02 ` Adhemerval Zanella
2020-11-02 19:51 ` Joseph Myers
2020-11-02 22:10 ` Adhemerval Zanella
2020-11-03 10:27 ` Florian Weimer
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