public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: "Yann Droneaud" <ydroneaud@opteya.com>
To: "Adhemerval Zanella" <adhemerval.zanella@linaro.org>,
	libc-alpha@sourceware.org
Subject: Re: [PATCH] malloc: Do not clobber errno on __getrandom_nocancel (BZ#29624)
Date: Thu, 29 Sep 2022 17:46:39 +0000	[thread overview]
Message-ID: <eb0bc7d58352ae813ad2c41d6270e303258f54e4@opteya.com> (raw)
In-Reply-To: <20220929164510.3454281-1-adhemerval.zanella@linaro.org>

Hi,

29 septembre 2022 à 18:45 "Adhemerval Zanella via Libc-alpha" a écrit:

> Use INTERNAL_SYSCALL_CALL instead of INLINE_SYSCALL_CALL. This
> requires emulate the semantic for hurd call (so __arc4random_buf
> uses the fallback).
> 
> Checked on x86_64-linux-gnu.
> ---
>  stdlib/arc4random.c | 4 ++--
>  sysdeps/mach/hurd/not-cancel.h | 11 +++++++++--
>  sysdeps/unix/sysv/linux/not-cancel.h | 2 +-
>  3 files changed, 12 insertions(+), 5 deletions(-)

[...] 

> diff --git a/sysdeps/mach/hurd/not-cancel.h b/sysdeps/mach/hurd/not-cancel.h
> index ae58b734e3..f2cb9b60ba 100644
> --- a/sysdeps/mach/hurd/not-cancel.h
> +++ b/sysdeps/mach/hurd/not-cancel.h
> @@ -75,8 +76,14 @@ __typeof (__fcntl) __fcntl_nocancel;
>  #define __fcntl64_nocancel(...) \
>  __fcntl_nocancel (__VA_ARGS__)
>  
> -#define __getrandom_nocancel(buf, size, flags) \
> - __getrandom (buf, size, flags)
> +static inline int
> +__getrandom_nocancel (void *buf, size_t buflen, unsigned int flags)
> +{
> + int save_errno = errno;
> + int r = __getrandom (buf, buflen, flags);
> + __set_errno (save_errno);
> + return r == -1 ? -save_errno : r;
> +}
>  

I don't get why the saved errno value is returned.


Regards.

-- 
Yann Droneaud
OPTEYA

  parent reply	other threads:[~2022-09-29 17:46 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-29 16:45 Adhemerval Zanella
2022-09-29 17:31 ` Andreas Schwab
2022-09-29 17:46 ` Yann Droneaud [this message]
2022-09-29 17:49   ` Adhemerval Zanella Netto
2022-09-29 17:52 ` Wilco Dijkstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=eb0bc7d58352ae813ad2c41d6270e303258f54e4@opteya.com \
    --to=ydroneaud@opteya.com \
    --cc=adhemerval.zanella@linaro.org \
    --cc=libc-alpha@sourceware.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).