21 Oct
2023
21 Oct
'23
3:06 p.m.
Hi Waldemar,
This is due to statx structure being defined in statx.h
statx.h being included in sys/stat.h conditionally to
__UCLIBC_HAVE_STATX__ being defined. Which is not, for mips arch.
defining __UCLIBC_HAVE_STATX__ in
libc/sysdeps/linux/mips/bits/uClibc_arch_features.h does the job and
everything compiles OK.
BUT, I'm not sure if this is the best way of fixing things...
I am wondering why we use this __UCLIBC_HAVE_STATX__ macro in the libc
instead of testing the existence of the syscall in the kernel like for
every other syscall by doing `#if defined(__NR_statx)` ?
Or maybe __UCLIBC_HAVE_STATX__ means something else? Maybe it means we
want to expose a real statx() function wrapper to userspace?
If this is the case, that would mean fstatat.c would need to include
directly bits/statx.h instead of sys/stat.h BUT it's explicitly forbidden:
```
#ifndef _SYS_STAT_H
# error Never include <bits/statx.h> directly, include <sys/stat.h> instead.
#endif
```
So... I'm a bit hesitant here on what's the correct thing to do.
Any thoughts on the list?
Regards,
Yann
Le 21/10/2023 à 07:50, Waldemar Brodkorb a écrit :
Hi Yann,
it seems I haven't tested this series good enough.
It breaks mips64n32 build with following error:
libc/sysdeps/linux/common/fstatat.c: In function 'fstatat':
libc/sysdeps/linux/common/fstatat.c:41:22: error: storage size of 'tmp' isn't
known
41 | struct statx tmp;
| ^~~
In file included from ./include/sys/syscall.h:33,
from libc/sysdeps/linux/common/fstatat.c:9:
./include/bits/syscalls.h:290:48: warning: cast from pointer to integer of different size
[-Wpointer-to-int-cast]
290 | register ARG_TYPE __a1 __asm__("$5") = (ARG_TYPE) arg2;
\
| ^
./include/bits/syscalls.h:49:9: note: in expansion of macro 'internal_syscall5'
49 | internal_syscall##nr (, "li\t$2, %2\t\t\t# " #name
"\n\t", \
| ^~~~~~~~~~~~~~~~
./include/bits/syscalls.h:24:24: note: in expansion of macro 'INTERNAL_SYSCALL'
24 | long result_var = INTERNAL_SYSCALL(name, err, nr, args); \
| ^~~~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:43:15: note: in expansion of macro
'INLINE_SYSCALL'
43 | ret = INLINE_SYSCALL(statx, 5, fd, file, flag,
| ^~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:44:30: error: 'STATX_BASIC_STATS' undeclared
(first use in this function)
44 | STATX_BASIC_STATS, &tmp);
| ^~~~~~~~~~~~~~~~~
./include/bits/syscalls.h:292:59: note: in definition of macro
'internal_syscall5'
292 | register ARG_TYPE __a3 __asm__("$7") = (ARG_TYPE) arg4;
\
| ^~~~
./include/bits/syscalls.h:24:24: note: in expansion of macro 'INTERNAL_SYSCALL'
24 | long result_var = INTERNAL_SYSCALL(name, err, nr, args); \
| ^~~~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:43:15: note: in expansion of macro
'INLINE_SYSCALL'
43 | ret = INLINE_SYSCALL(statx, 5, fd, file, flag,
| ^~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:44:30: note: each undeclared identifier is reported
only once for each function it appears in
44 | STATX_BASIC_STATS, &tmp);
| ^~~~~~~~~~~~~~~~~
./include/bits/syscalls.h:292:59: note: in definition of macro
'internal_syscall5'
292 | register ARG_TYPE __a3 __asm__("$7") = (ARG_TYPE) arg4;
\
| ^~~~
./include/bits/syscalls.h:24:24: note: in expansion of macro 'INTERNAL_SYSCALL'
24 | long result_var = INTERNAL_SYSCALL(name, err, nr, args); \
| ^~~~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:43:15: note: in expansion of macro
'INLINE_SYSCALL'
43 | ret = INLINE_SYSCALL(statx, 5, fd, file, flag,
| ^~~~~~~~~~~~~~
libc/sysdeps/linux/common/fstatat.c:41:22: warning: unused variable 'tmp'
[-Wunused-variable]
41 | struct statx tmp;
| ^~~
gmake[6]: *** [Makerules:369: libc/sysdeps/linux/common/fstatat.os] Error 1
Any idea?
It is with uClibc-ng current git.
Thanks in advance
Waldemar
yann(a)sionneau.net wrote,
> From: Yann Sionneau <ysionneau(a)kalray.eu>
>
> Define fstatat64 as a wrapper of statx if the kernel does not support fstatat64
syscall
> This is the case for non-legacy architectures that don't define
__ARCH_WANT_NEW_STAT
> in their linux arch/xxx/include/asm/unistd.h
>
> Signed-off-by: Yann Sionneau <ysionneau(a)kalray.eu>
>
> ---
> libc/sysdeps/linux/common/fstatat64.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/libc/sysdeps/linux/common/fstatat64.c
b/libc/sysdeps/linux/common/fstatat64.c
> index 711521a6a..836ed4114 100644
> --- a/libc/sysdeps/linux/common/fstatat64.c
> +++ b/libc/sysdeps/linux/common/fstatat64.c
> @@ -43,5 +43,28 @@ int fstatat64(int fd, const char *file, struct stat64 *buf, int
flag)
> }
> libc_hidden_def(fstatat64)
> #else
> +
> +#if defined(__NR_statx) && defined(__UCLIBC_HAVE_STATX__)
> +# include <sys/stat.h>
> +# include <statx_cp.h>
> +# include <fcntl.h> // for AT_NO_AUTOMOUNT
> +
> +int fstatat64(int fd, const char *file, struct stat64 *buf, int flag)
> +{
> + struct statx tmp;
> +
> + int r = INLINE_SYSCALL(statx, 5, fd, file, AT_NO_AUTOMOUNT | flag,
> + STATX_BASIC_STATS, &tmp);
> +
> + if (r != 0)
> + return r;
> +
> + __cp_stat_statx ((struct stat *)buf, &tmp);
> +
> + return 0;
> +}
> +libc_hidden_def(fstatat64)
> +#endif
> +
> /* should add emulation with fstat64() and /proc/self/fd/ ... */
> #endif
> --
> 2.42.0
>
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