9 May
2019
9 May
'19
9:10 p.m.
On Thu, May 9, 2019 at 11:34 AM Max Filippov <jcmvbkbc(a)gmail.com> wrote:
I've tried to run uclibc-ng tests on xtensa in a
buildroot-built rootfs
and found misc/tst-preadvwritev failing with the following message:
first buffer from first preadv different than expected
Digging deeper into it I've found that the test is built with the following
definition in the command line: -D_FILE_OFFSET_BITS=64,
due to the following line in the uclibc-ng-test.mk:
UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)"
but uclibc-ng itself does not have -D_FILE_OFFSET_BITS=64,
because of the following definition in the uclibc-ng.mk:
UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)"
uclibc-ng defaults to 32-bit off_t type then.
I'm not sure what's broken here, buildroot or uclibc-ng. Ideas?
Ok, I see something definitely strange in the uclibc-ng:
ublibc-ng does not honor -D_FILE_OFFSET_BITS=64
when it's passed to it in the make command, because
the following fragment of the include/features.h that defines
__USE_FILE_OFFSET64 based on the value of
_FILE_OFFSET_BITS
#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
# define __USE_FILE_OFFSET64 1
#endif
is neutralized by the following fragment at the end of the same file:
#ifdef _LIBC
# undef _FILE_OFFSET_BITS
# undef __USE_FILE_OFFSET64
# include <libc-internal.h>
#endif
--
Thanks.
-- Max
10 May
10 May
1:31 p.m.
New subject: uclibc-ng built with wrong _FILE_OFFSET_BITS
If that can be of any help, this test seems to PASS on armv7 arch:
https://uclibc-ng-ci.sionneau.net:8443/job/uclibc-ng-multiarch/arch=armv7/1…
However this bugs reproduces for mips32r6 :
https://uclibc-ng-ci.sionneau.net:8443/job/uclibc-ng-multiarch/19/arch=mips…
Also, I can confirm I am able to reproduce the issue with
buildroot+uclibc-ng by building the qemu_xtensa_lx60_defconfig buildroot
config
And then by booting it with qemu following this readme:
https://github.com/buildroot/buildroot/tree/master/board/qemu/xtensa-lx60
On 5/9/19 11:10 PM, Max Filippov wrote:
On Thu, May 9, 2019 at 11:34 AM Max Filippov
<jcmvbkbc(a)gmail.com> wrote:
I've tried to run uclibc-ng tests on xtensa
in a buildroot-built rootfs
and found misc/tst-preadvwritev failing with the following message:
first buffer from first preadv different than expected
Digging deeper into it I've found that the test is built with the following
definition in the command line: -D_FILE_OFFSET_BITS=64,
due to the following line in the uclibc-ng-test.mk:
UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)"
but uclibc-ng itself does not have -D_FILE_OFFSET_BITS=64,
because of the following definition in the uclibc-ng.mk:
UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)"
uclibc-ng defaults to 32-bit off_t type then.
I'm not sure what's broken here, buildroot or uclibc-ng. Ideas?
Ok, I see
something definitely strange in the uclibc-ng:
ublibc-ng does not honor -D_FILE_OFFSET_BITS=64
when it's passed to it in the make command, because
the following fragment of the include/features.h that defines
__USE_FILE_OFFSET64 based on the value of
_FILE_OFFSET_BITS
#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
# define __USE_FILE_OFFSET64 1
#endif
is neutralized by the following fragment at the end of the same file:
#ifdef _LIBC
# undef _FILE_OFFSET_BITS
# undef __USE_FILE_OFFSET64
# include <libc-internal.h>
#endif
--
Thanks.
-- Max
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2:08 p.m.
New subject: uclibc-ng built with wrong _FILE_OFFSET_BITS
On Fri, May 10, 2019 at 6:32 AM Yann Sionneau <ysionneau(a)kalray.eu> wrote:
If that can be of any help, this test seems to PASS on armv7 arch:
https://uclibc-ng-ci.sionneau.net:8443/job/uclibc-ng-multiarch/arch=armv7/1…
However this bugs reproduces for mips32r6 :
https://uclibc-ng-ci.sionneau.net:8443/job/uclibc-ng-multiarch/19/arch=mips…
Also, I can confirm I am able to reproduce the issue with
buildroot+uclibc-ng by building the qemu_xtensa_lx60_defconfig buildroot
config
Thanks for the confirmation.
I've spent some more time on this issue and I hope have got a better
understanding of it. So:
- uclibc-ng itself is not meant to be compiled differently with
-D_FILE_OFFSET_BITS=64
and without it. It is meant to provide both LFS and non-LFS function versions,
like ftruncate and ftruncate64.
- the library user on the other hand gets different set of
declarations depending
on the presence of -D_FILE_OFFSET_BITS=64, that results in a call to different
functions.
- however this is not the case for preadv/pwritev: there's only one
definition for
each of these functions. When libc is built these functions assume 32-bit
off_t, but when the user code is built, off_t size is selected by the
_FILE_OFFSET_BITS resulting in declaration that does not match definition.
I guess the right way to fix it is using __off64_t in declarations and
definitions
of both preadv/pwritev. With this change the test passes on xtensa.
--
Thanks.
-- Max
2023
days inactive
2024
days old
2 comments
2 participants
participants (2)
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Max Filippov -
Yann Sionneau