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Re: [PATCH] __readlink_chk: Assume HAVE_INLINED_SYSCALLS
On 20/08/2018 13:53, Florian Weimer wrote:
> On 08/20/2018 06:21 PM, Adhemerval Zanella wrote:
>>
>>
>> On 20/08/2018 13:18, Adhemerval Zanella wrote:
>>>
>>>
>>> On 20/08/2018 11:40, Florian Weimer wrote:
>>>> HAVE_INLINED_SYSCALLS is always defined on Linux.
>>>>
>>>> 2018-08-20 Florian Weimer <fweimer@redhat.com>
>>>>
>>>> * sysdeps/unix/sysv/linux/generic/readlink_chk.c: Remove
>>>> HAVE_INLINED_SYSCALLS conditionals
>>>
>>> LGTM.
>>
>> In fact, do we really need to have a duplicated Linux implementation
>> for this micro-optimization? Couldn't we just use default debug
>> one and call '__readlink' instead?
>
> Like this?
>
LGTM, thanks.
> Thanks,
> Florian
>
> readlink_chk.patch
>
>
> Subject: [PATCH] __readlink_chk: Remove micro-optimization
> To: libc-alpha@sourceware.org
>
> 2018-08-20 Florian Weimer <fweimer@redhat.com>
>
> * debug/readlink_chk.c (__readlink_chk): Always call __readlink.
> * sysdeps/unix/sysv/linux/generic/readlink_chk.c: Remove file.
>
> diff --git a/debug/readlink_chk.c b/debug/readlink_chk.c
> index c44d1d8c37..e3204004d2 100644
> --- a/debug/readlink_chk.c
> +++ b/debug/readlink_chk.c
> @@ -29,9 +29,5 @@ __readlink_chk (const char *path, void *buf, size_t len, size_t buflen)
> if (len > buflen)
> __chk_fail ();
>
> -#ifdef HAVE_INLINED_SYSCALLS
> - return INLINE_SYSCALL (readlink, 3, path, buf, len);
> -#else
> return __readlink (path, buf, len);
> -#endif
> }
> diff --git a/sysdeps/unix/sysv/linux/generic/readlink_chk.c b/sysdeps/unix/sysv/linux/generic/readlink_chk.c
> deleted file mode 100644
> index 52d1f5b522..0000000000
> --- a/sysdeps/unix/sysv/linux/generic/readlink_chk.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -/* Copyright (C) 2011-2018 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> - Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library. If not, see
> - <http://www.gnu.org/licenses/>. */
> -
> -#include <unistd.h>
> -#include <fcntl.h>
> -#include <sys/param.h>
> -# include <errno.h>
> -# include <sysdep.h>
> -
> -
> -ssize_t
> -__readlink_chk (const char *path, void *buf, size_t len, size_t buflen)
> -{
> - if (len > buflen)
> - __chk_fail ();
> -
> - return INLINE_SYSCALL_CALL (readlinkat, AT_FDCWD, path, buf, len);
> -}
>