* [PATCH] skip testing time before epoch on mips
@ 2021-03-10 3:31 Chen Li
0 siblings, 0 replies; 5+ messages in thread
From: Chen Li @ 2021-03-10 3:31 UTC (permalink / raw)
To: gcc-patches, libstdc++
When execute libstdc++ testcases on mips, I notice that last_write_time
alawys failed, and the failed VERIFY is "VERIFY(
approx_equal(last_write_time(f.path), time) );" where testing time before
than epoch.
Below is the minimal case:
```
// gcc a.c
int main()
{
struct timespec times[2] = {{1, UTIME_OMIT}, {-1201, 985000000}};
utimensat(AT_FDCWD, "test", times, 0);
}
```
$ touch test && gcc a.c && ./a.out && stat test
File: test
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: 805h/2053d Inode: 1056841 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1000/ deepin) Gid: ( 1000/ deepin)
Access: 2021-03-08 13:52:55.966354501 +0800
Modify: 2106-02-07 14:08:15.985000000 +0800
Change: 2021-03-08 13:52:56.907782193 +0800
Birth: -
Undoubtedly, mtime's type is unsigned somewhere on mips.
After debuging kernel, it turns out that mtime is always -1201 in
ext4_setattr, cp_new_stat, newlstat and etc, so the problem should not
occur in kernel space.
go back to user space via copy_to_user, I finally found mips used
"unsigned int st_mtime_sec;" in struct kernel_stat, which is used to
receive -1201 from kernel.
Maybe sparc also suffers from this problem, but I have no machine to
verify.
---
.../testsuite/27_io/filesystem/operations/last_write_time.cc | 2 ++
.../experimental/filesystem/operations/last_write_time.cc | 2 ++
2 files changed, 4 insertions(+)
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
index 6ae64c482b6..72272d4e781 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
@@ -200,11 +200,13 @@ test02()
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
+ #ifndef __mips__
// A time before than the epoch
time -= chrono::milliseconds(1000 * 60 * 20 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #endif
}
int
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
index 536ab1f28f6..6fb490a6bc3 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
@@ -165,11 +165,13 @@ test02()
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #ifndef __mips__
ec = bad_ec;
time -= chrono::milliseconds(1000 * 60 * 10 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #endif
}
int
--
2.30.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] skip testing time before epoch on mips
2021-03-08 10:57 ` Jonathan Wakely
@ 2021-03-08 11:15 ` YunQiang Su
0 siblings, 0 replies; 5+ messages in thread
From: YunQiang Su @ 2021-03-08 11:15 UTC (permalink / raw)
To: Jonathan Wakely; +Cc: Chen Li, libstdc++, gcc-patches
Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> 于2021年3月8日周一 下午6:57写道：
>
> On 08/03/21 14:35 +0800, Chen Li wrote:
> >
> >When execute libstdc++ testcases on mips, I notice that last_write_time
> >alawys failed, and the failed VERIFY is "VERIFY(
> >approx_equal(last_write_time(f.path), time) );" where testing time before
> >than epoch.
> >
> >Below is the minimal case:
> >
> >```
> >// gcc a.c
> >int main()
> >{
> > struct timespec times[2] = {{1, UTIME_OMIT}, {-1201, 985000000}};
> > utimensat(AT_FDCWD, "test", times, 0);
> >
> >}
> >```
> >
> >$ touch test && gcc a.c && ./a.out && stat test
> > File: test
> > Size: 0 Blocks: 0 IO Block: 4096 regular empty file
> >Device: 805h/2053d Inode: 1056841 Links: 1
> >Access: (0644/-rw-r--r--) Uid: ( 1000/ deepin) Gid: ( 1000/ deepin)
> >Access: 2021-03-08 13:52:55.966354501 +0800
> >Modify: 2106-02-07 14:08:15.985000000 +0800
> >Change: 2021-03-08 13:52:56.907782193 +0800
> > Birth: -
> >
> >Undoubtedly, mtime's type is unsigned somewhere on mips.
> >
> >After debuging kernel, it turns out that mtime is always -1201 in
> >ext4_setattr, cp_new_stat, newlstat and etc, so the problem should not
> >occur in kernel space.
> >
> >go back to user space via copy_to_user, I finally found mips used
> >"unsigned int st_mtime_sec;" in struct kernel_stat, which is used to
> >receive -1201 from kernel.
>
> I can't reproduce this on a mips64 machine:
>
> jwakely@erpro8-fsf2:~$ uname -a
> Linux erpro8-fsf2 4.1.4 #1 SMP PREEMPT Mon Aug 3 14:22:54 PDT 2015 mips64 GNU/Linux
> jwakely@erpro8-fsf2:~$ apt list libc6
> Listing... Done
> libc6/oldstable,now 2.19-18+deb8u10 mipsel [installed]
it is mips32, not mips64. Here mips64 we mean userland, not the kernel.
> jwakely@erpro8-fsf2:~$ touch test && ./a.out && TZ= stat test
> File: ‘test’
> Size: 0 Blocks: 0 IO Block: 131072 regular empty file
> Device: 21h/33d Inode: 36596524 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 1049/ jwakely) Gid: ( 1049/ jwakely)
> Access: 2021-03-08 10:52:06.855991946 +0000
> Modify: 1969-12-31 23:39:59.985000000 +0000
> Change: 2021-03-08 10:52:06.859992051 +0000
> Birth: -
>
> This is an ext4 filesystem.
>
> Do I need to compile a 64-bit executable?
>
Yes. you need 64bit userland.
> In any case, shouldn't this be fixed in glibc to return EINVAL instead
> of setting a bogus time? That would make the std::filesystem library
> report an error.
>
Since kernel has introduced statx(2), so we can use statx to implemente stat(3).
>
> >Maybe sparc also suffers from this problem, but I have no machine to
> >verify.
>
> Your test case works correctly for me on sparc-linux (both 32-bit and
> 64-bit on ext4 and xfs filesystems):
>
> $ uname -a
> Linux gcc202 5.10.0-4-sparc64-smp #1 SMP Debian 5.10.19-1 (2021-03-02) sparc64 GNU/Linux
> $ apt list libc6
> Listing... Done
> libc6/unstable,now 2.31-4 sparc64 [installed]
> $ ./a.out
> $ TZ= stat test
> File: test
> Size: 0 Blocks: 0 IO Block: 8192 regular empty file
> Device: fd01h/64769d Inode: 657291843 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 1049/ jwakely) Gid: ( 1049/ jwakely)
> Access: 2021-03-08 10:25:43.593819539 +0000
> Modify: 1969-12-31 23:39:59.985000000 +0000
> Change: 2021-03-08 10:34:13.711287778 +0000
> Birth: 2021-03-08 10:24:27.106598699 +0000
>
--
YunQiang Su
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] skip testing time before epoch on mips
2021-03-08 6:35 Chen Li
2021-03-08 6:41 ` YunQiang Su
@ 2021-03-08 10:57 ` Jonathan Wakely
2021-03-08 11:15 ` YunQiang Su
1 sibling, 1 reply; 5+ messages in thread
From: Jonathan Wakely @ 2021-03-08 10:57 UTC (permalink / raw)
To: Chen Li; +Cc: gcc-patches, libstdc++
On 08/03/21 14:35 +0800, Chen Li wrote:
>
>When execute libstdc++ testcases on mips, I notice that last_write_time
>alawys failed, and the failed VERIFY is "VERIFY(
>approx_equal(last_write_time(f.path), time) );" where testing time before
>than epoch.
>
>Below is the minimal case:
>
>```
>// gcc a.c
>int main()
>{
> struct timespec times[2] = {{1, UTIME_OMIT}, {-1201, 985000000}};
> utimensat(AT_FDCWD, "test", times, 0);
>
>}
>```
>
>$ touch test && gcc a.c && ./a.out && stat test
> File: test
> Size: 0 Blocks: 0 IO Block: 4096 regular empty file
>Device: 805h/2053d Inode: 1056841 Links: 1
>Access: (0644/-rw-r--r--) Uid: ( 1000/ deepin) Gid: ( 1000/ deepin)
>Access: 2021-03-08 13:52:55.966354501 +0800
>Modify: 2106-02-07 14:08:15.985000000 +0800
>Change: 2021-03-08 13:52:56.907782193 +0800
> Birth: -
>
>Undoubtedly, mtime's type is unsigned somewhere on mips.
>
>After debuging kernel, it turns out that mtime is always -1201 in
>ext4_setattr, cp_new_stat, newlstat and etc, so the problem should not
>occur in kernel space.
>
>go back to user space via copy_to_user, I finally found mips used
>"unsigned int st_mtime_sec;" in struct kernel_stat, which is used to
>receive -1201 from kernel.
I can't reproduce this on a mips64 machine:
jwakely@erpro8-fsf2:~$ uname -a
Linux erpro8-fsf2 4.1.4 #1 SMP PREEMPT Mon Aug 3 14:22:54 PDT 2015 mips64 GNU/Linux
jwakely@erpro8-fsf2:~$ apt list libc6
Listing... Done
libc6/oldstable,now 2.19-18+deb8u10 mipsel [installed]
jwakely@erpro8-fsf2:~$ touch test && ./a.out && TZ= stat test
File: ‘test’
Size: 0 Blocks: 0 IO Block: 131072 regular empty file
Device: 21h/33d Inode: 36596524 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1049/ jwakely) Gid: ( 1049/ jwakely)
Access: 2021-03-08 10:52:06.855991946 +0000
Modify: 1969-12-31 23:39:59.985000000 +0000
Change: 2021-03-08 10:52:06.859992051 +0000
Birth: -
This is an ext4 filesystem.
Do I need to compile a 64-bit executable?
In any case, shouldn't this be fixed in glibc to return EINVAL instead
of setting a bogus time? That would make the std::filesystem library
report an error.
>Maybe sparc also suffers from this problem, but I have no machine to
>verify.
Your test case works correctly for me on sparc-linux (both 32-bit and
64-bit on ext4 and xfs filesystems):
$ uname -a
Linux gcc202 5.10.0-4-sparc64-smp #1 SMP Debian 5.10.19-1 (2021-03-02) sparc64 GNU/Linux
$ apt list libc6
Listing... Done
libc6/unstable,now 2.31-4 sparc64 [installed]
$ ./a.out
$ TZ= stat test
File: test
Size: 0 Blocks: 0 IO Block: 8192 regular empty file
Device: fd01h/64769d Inode: 657291843 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1049/ jwakely) Gid: ( 1049/ jwakely)
Access: 2021-03-08 10:25:43.593819539 +0000
Modify: 1969-12-31 23:39:59.985000000 +0000
Change: 2021-03-08 10:34:13.711287778 +0000
Birth: 2021-03-08 10:24:27.106598699 +0000
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] skip testing time before epoch on mips
2021-03-08 6:35 Chen Li
@ 2021-03-08 6:41 ` YunQiang Su
2021-03-08 10:57 ` Jonathan Wakely
1 sibling, 0 replies; 5+ messages in thread
From: YunQiang Su @ 2021-03-08 6:41 UTC (permalink / raw)
To: Chen Li; +Cc: gcc-patches, libstdc++
Chen Li <chenli@uniontech.com> 于2021年3月8日周一 下午2:35写道：
>
>
> When execute libstdc++ testcases on mips, I notice that last_write_time
> alawys failed, and the failed VERIFY is "VERIFY(
> approx_equal(last_write_time(f.path), time) );" where testing time before
> than epoch.
>
> Below is the minimal case:
>
> ```
> // gcc a.c
> int main()
> {
> struct timespec times[2] = {{1, UTIME_OMIT}, {-1201, 985000000}};
> utimensat(AT_FDCWD, "test", times, 0);
>
> }
> ```
>
> $ touch test && gcc a.c && ./a.out && stat test
> File: test
> Size: 0 Blocks: 0 IO Block: 4096 regular empty file
> Device: 805h/2053d Inode: 1056841 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 1000/ deepin) Gid: ( 1000/ deepin)
> Access: 2021-03-08 13:52:55.966354501 +0800
> Modify: 2106-02-07 14:08:15.985000000 +0800
> Change: 2021-03-08 13:52:56.907782193 +0800
> Birth: -
>
> Undoubtedly, mtime's type is unsigned somewhere on mips.
>
It only has this problem on mips64.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983769
> After debuging kernel, it turns out that mtime is always -1201 in
> ext4_setattr, cp_new_stat, newlstat and etc, so the problem should not
> occur in kernel space.
>
> go back to user space via copy_to_user, I finally found mips used
> "unsigned int st_mtime_sec;" in struct kernel_stat, which is used to
> receive -1201 from kernel.
>
> Maybe sparc also suffers from this problem, but I have no machine to
> verify.
> ---
> .../testsuite/27_io/filesystem/operations/last_write_time.cc | 2 ++
> .../experimental/filesystem/operations/last_write_time.cc | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
> index 6ae64c482b6..72272d4e781 100644
> --- a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
> +++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
> @@ -200,11 +200,13 @@ test02()
> VERIFY( approx_equal(last_write_time(f.path), time) );
>
> ec = bad_ec;
> + #ifndef __mips__
> // A time before than the epoch
> time -= chrono::milliseconds(1000 * 60 * 20 + 15);
> last_write_time(f.path, time, ec);
> VERIFY( !ec );
> VERIFY( approx_equal(last_write_time(f.path), time) );
> + #endif
> }
>
> int
> diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
> index 536ab1f28f6..6fb490a6bc3 100644
> --- a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
> +++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
> @@ -165,11 +165,13 @@ test02()
> VERIFY( !ec );
> VERIFY( approx_equal(last_write_time(f.path), time) );
>
> + #ifndef __mips__
> ec = bad_ec;
> time -= chrono::milliseconds(1000 * 60 * 10 + 15);
> last_write_time(f.path, time, ec);
> VERIFY( !ec );
> VERIFY( approx_equal(last_write_time(f.path), time) );
> + #endif
> }
>
> int
> --
> 2.30.0
>
>
>
--
YunQiang Su
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] skip testing time before epoch on mips
@ 2021-03-08 6:35 Chen Li
2021-03-08 6:41 ` YunQiang Su
2021-03-08 10:57 ` Jonathan Wakely
0 siblings, 2 replies; 5+ messages in thread
From: Chen Li @ 2021-03-08 6:35 UTC (permalink / raw)
To: gcc-patches, libstdc++
When execute libstdc++ testcases on mips, I notice that last_write_time
alawys failed, and the failed VERIFY is "VERIFY(
approx_equal(last_write_time(f.path), time) );" where testing time before
than epoch.
Below is the minimal case:
```
// gcc a.c
int main()
{
struct timespec times[2] = {{1, UTIME_OMIT}, {-1201, 985000000}};
utimensat(AT_FDCWD, "test", times, 0);
}
```
$ touch test && gcc a.c && ./a.out && stat test
File: test
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: 805h/2053d Inode: 1056841 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1000/ deepin) Gid: ( 1000/ deepin)
Access: 2021-03-08 13:52:55.966354501 +0800
Modify: 2106-02-07 14:08:15.985000000 +0800
Change: 2021-03-08 13:52:56.907782193 +0800
Birth: -
Undoubtedly, mtime's type is unsigned somewhere on mips.
After debuging kernel, it turns out that mtime is always -1201 in
ext4_setattr, cp_new_stat, newlstat and etc, so the problem should not
occur in kernel space.
go back to user space via copy_to_user, I finally found mips used
"unsigned int st_mtime_sec;" in struct kernel_stat, which is used to
receive -1201 from kernel.
Maybe sparc also suffers from this problem, but I have no machine to
verify.
---
.../testsuite/27_io/filesystem/operations/last_write_time.cc | 2 ++
.../experimental/filesystem/operations/last_write_time.cc | 2 ++
2 files changed, 4 insertions(+)
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
index 6ae64c482b6..72272d4e781 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/last_write_time.cc
@@ -200,11 +200,13 @@ test02()
VERIFY( approx_equal(last_write_time(f.path), time) );
ec = bad_ec;
+ #ifndef __mips__
// A time before than the epoch
time -= chrono::milliseconds(1000 * 60 * 20 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #endif
}
int
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
index 536ab1f28f6..6fb490a6bc3 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
@@ -165,11 +165,13 @@ test02()
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #ifndef __mips__
ec = bad_ec;
time -= chrono::milliseconds(1000 * 60 * 10 + 15);
last_write_time(f.path, time, ec);
VERIFY( !ec );
VERIFY( approx_equal(last_write_time(f.path), time) );
+ #endif
}
int
--
2.30.0
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-03-10 3:31 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2021-03-10 3:31 [PATCH] skip testing time before epoch on mips Chen Li
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2021-03-08 6:35 Chen Li
2021-03-08 6:41 ` YunQiang Su
2021-03-08 10:57 ` Jonathan Wakely
2021-03-08 11:15 ` YunQiang Su
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