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Re: [PATCH] Don't all __access_noerrno with stack protector from __tunables_init [BZ #21744]
On 24/07/2017 10:08, H.J. Lu wrote:
> On Thu, Jul 20, 2017 at 1:20 PM, Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>>
>>
>> On 20/07/2017 10:04, H.J. Lu wrote:
>>> On Thu, Jul 20, 2017 at 5:46 AM, Adhemerval Zanella
>>> <adhemerval.zanella@linaro.org> wrote:
>>>>
>>>> It will fail for architectures that actually define 'err' to something other
>>>> than empty 'do { } while (0)' (for instance sparc and tile). Below it is an
>>>> updated patch:
>>>>
>>>> --
>>>>
>>>> [BZ #21744]
>>>> * elf/dl-tunables.c: Include not-errno.h header.
>>>> * include/unistd.h (__access_noerrno): Remove definition.
>>>> * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise.
>>>> * sysdeps/generic/not-errno.h: New file.
>>>> * sysdeps/unix/sysv/linux/not-errno.h: Likewise.
>>>>
>>>> ---
>>>>
>>>> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
>>>> index 44c160c..231fb8c 100644
>>>> --- a/elf/dl-tunables.c
>>>> +++ b/elf/dl-tunables.c
>>>> @@ -29,6 +29,8 @@
>>>> #define TUNABLES_INTERNAL 1
>>>> #include "dl-tunables.h"
>>>>
>>>> +#include <not-errno.h>
>>>> +
>>>> #if TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring
>>>> # define GLIBC_TUNABLES "GLIBC_TUNABLES"
>>>> #endif
>>>> diff --git a/include/unistd.h b/include/unistd.h
>>>> index 5b2a414..7f1c2cc 100644
>>>> --- a/include/unistd.h
>>>> +++ b/include/unistd.h
>>>> @@ -182,12 +182,5 @@ extern int __getlogin_r_loginuid (char *name, size_t namesize)
>>>> # include <dl-unistd.h>
>>>> # endif
>>>>
>>>> -# if IS_IN (rtld) || !defined SHARED
>>>> -/* __access variant that does not set errno. Used in very early initialization
>>>> - code in libc.a and ld.so. It follows access return semantics (zero for
>>>> - sucess otherwise a value different than 0). */
>>>> -extern __typeof (__access) __access_noerrno attribute_hidden;
>>>> -# endif
>>>> -
>>>> # endif
>>>> #endif
>>>> diff --git a/sysdeps/generic/not-errno.h b/sysdeps/generic/not-errno.h
>>>> new file mode 100644
>>>> index 0000000..2aac095
>>>> --- /dev/null
>>>> +++ b/sysdeps/generic/not-errno.h
>>>> @@ -0,0 +1,19 @@
>>>> +/* Syscall wrapper that do not set errno. Generic version.
>>>> + Copyright (C) 2017 Free Software Foundation, Inc.
>>>> + This file is part of the GNU C Library.
>>>> +
>>>> + 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/>. */
>>>> +
>>>> +extern __typeof (__access) __access_noerrno attribute_hidden;
>>>> diff --git a/sysdeps/unix/sysv/linux/access.c b/sysdeps/unix/sysv/linux/access.c
>>>> index 67e69bd..366b6b6 100644
>>>> --- a/sysdeps/unix/sysv/linux/access.c
>>>> +++ b/sysdeps/unix/sysv/linux/access.c
>>>> @@ -21,21 +21,6 @@
>>>> #include <sysdep-cancel.h>
>>>>
>>>> int
>>>> -__access_noerrno (const char *file, int type)
>>>> -{
>>>> - int res;
>>>> - INTERNAL_SYSCALL_DECL (err);
>>>> -#ifdef __NR_access
>>>> - res = INTERNAL_SYSCALL_CALL (access, err, file, type);
>>>> -#else
>>>> - res = INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, file, type);
>>>> -#endif
>>>> - if (INTERNAL_SYSCALL_ERROR_P (res, err))
>>>> - return INTERNAL_SYSCALL_ERRNO (res, err);
>>>> - return 0;
>>>> -}
>>>> -
>>>> -int
>>>> __access (const char *file, int type)
>>>> {
>>>> #ifdef __NR_access
>>>> diff --git a/sysdeps/unix/sysv/linux/not-errno.h b/sysdeps/unix/sysv/linux/not-errno.h
>>>> new file mode 100644
>>>> index 0000000..888bde0
>>>> --- /dev/null
>>>> +++ b/sysdeps/unix/sysv/linux/not-errno.h
>>>> @@ -0,0 +1,31 @@
>>>> +/* Syscall wrapper that do not set errno. Linux version.
>>>> + Copyright (C) 2017 Free Software Foundation, Inc.
>>>> + This file is part of the GNU C Library.
>>>> +
>>>> + 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/>. */
>>>> +
>>>> +/* This function is used on maybe_enable_malloc_check (elf/dl-tunables.c)
>>>> + and to avoid having to build/use multiple versions if stack protection
>>>> + in enabled it is defined as inline. */
>>>> +static inline int
>>>> +__access_noerrno (const char *pathname, int mode)
>>>> +{
>>>> + INTERNAL_SYSCALL_DECL (err);
>>>> +#ifdef __NR_access
>>>> + return INTERNAL_SYSCALL_CALL (access, err, pathname, mode);
>>>> +#else
>>>> + return INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, file, type);
>>>> +#endif
>>>> +}
>>>> --
>>>> 2.7.4
>>>
>>> LGTM.
>>>
>>> Thanks.
>>>
>>
>> Right, I will commit this shortly if no one opposes it.
>
> Have you checked it in?
>
> Thanks.
>
I am about to in following hours (sorry for the weekend delay).