Re: port binary dumping core on recent head in poudriere [tmpfs corruptions involving blocks of zeros that should not be all zeros]

I think @kib has found the source of the problem.  I've attached an 
attempt to fix it.

On 11/26/24 09:52, Mark Millard wrote:
> On Nov 26, 2024, at 05:38, Konstantin Belousov <kib@freebsd.org> wrote:
>
>> On Tue, Nov 26, 2024 at 01:58:19PM +0100, Dimitry Andric wrote:
>>> On 26 Nov 2024, at 13:32, Dimitry Andric <dim@FreeBSD.org> wrote:
>>>> On 26 Nov 2024, at 11:19, Dag-Erling Smørgrav <des@FreeBSD.org> wrote:
>>>>> Mark Millard <marklmi@yahoo.com> writes:
>>>>>>  From inside a bulk -i where I did a manual make command
>>>>>> after it built and installed libsass.so.1.0.0 . The
>>>>>> manual make produced a /wrkdirs/ :
>>>>>> [...]
>>>>>> So the original creation looks okay. But . . .
>>>>>> [...]
>>>>>> So: The later, staged copy is a bad copy. Both are in the
>>>>>> tmpfs. So copying to the staging area makes a corrupted
>>>>>> copy inside the same tmpfs. After that, further copies of
>>>>>> staging's bad copy can be expected to be messed up.
>>>>> This and the fact that it happens on 14 and 15 but not on 13 strongly
>>>>> suggests an issue wth `copy_file_range(2)`, since `install(1)` in 14 and
>>>>> 15 (but not in 13) now uses `copy_file_range(2)` if at all possible.
>>>>>
>>>>> My educated guess is that hole detection doesn't work reliably for files
>>>>> that have had holes filled while memory-mapped, so `copy_file_range(2)`
>>>>> thinks there is a hole where there isn't one and skips some of the data
>>>>> when `install(1)` uses it to copy the library from `${WRKSRC}` to
>>>>> `${STAGEDIR}`.  This may or may not be specific to tmpfs.
>>>>>
>>>>> You may want to try applying the attached patch to your FreeBSD 14 and
>>>>> 15 jails.  It prevents `cp(1)` and `install(1)` from trying to use
>>>>> `copy_file_range(2)`.
>>>> Yes, tmpfs is indeed the culprit (or at least involved). I have had USE_TMPFS=localbase in my poudriere.conf for a long time, since otherwise my build machine would run out of memory very quickly, so I didn't encounter any issues.
>>>>
>>>> Now I changed it to USE_TMPFS=yes, rebuilt only textproc/libsass and textproc/sassc, and then after reinstalling those packages:
>>>>
>>>> $ /usr/local/bin/sassc
>>>> Segmentation fault
>>> And after applying Dag-Erling's patch to disable copy_file_range for cp and install, it works correctly again.
>> So indeed there might be an issue in tmpfs seeking for data.  Could you try
>> the following?
>>
>> commit f4b848946a131dab260b44eab2cfabceb82bee0c
>> Author: Konstantin Belousov <kib@FreeBSD.org>
>> Date:   Tue Nov 26 15:34:56 2024 +0200
>>
>>     tmpfs: do not skip pages searching for data
>>
>>     If the iterator finds invalid page at the requested pindex in
>>     swap_pager_seek_data(), the current code only looks at the swap blocks
>>     to search for data.  This is not correct, valid pages may appear at the
>>     higher indexes still.
>>
>> diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
>> index db925f4ae7f6..390b2c10d680 100644
>> --- a/sys/vm/swap_pager.c
>> +++ b/sys/vm/swap_pager.c
>> @@ -2503,12 +2503,9 @@ swap_pager_seek_data(vm_object_t object, vm_pindex_t pindex)
>> 	VM_OBJECT_ASSERT_RLOCKED(object);
>> 	vm_page_iter_init(&pages, object);
>> 	m = vm_page_iter_lookup_ge(&pages, pindex);
>> -	if (m != NULL) {
>> -		if (!vm_page_any_valid(m))
>> -			m = NULL;
>> -		else if (pages.index == pindex)
>> -			return (pages.index);
>> -	}
>> +	if (m != NULL && pages.index == pindex)
>> +		return (pages.index);
>> +
>> 	swblk_iter_init_only(&blks, object);
>> 	swap_index = swap_pager_iter_find_least(&blks, pindex);
>> 	if (swap_index == pindex)
> Not sufficient, unfortunately . . .
>
> I patched what I've been running and rebooted into:
>
> # uname -apKU
> FreeBSD 7950X3D-ZFS 15.0-CURRENT FreeBSD 15.0-CURRENT #152 main-n273696-43e045c1733d-dirty: Tue Nov 26 07:21:27 PST 2024     root@7950X3D-ZFS:/usr/obj/BUILDs/main-amd64-nodbg-clang/usr/main-src/amd64.amd64/sys/GENERIC-NODBG amd64 amd64 1500027 1500027
>
> Note: 43e045c1733d is from 2024-Nov-18 .
>
> I then built libsass :
>
> [00:00:02] [01] [00:00:00] Building   textproc/libsass | libsass-3.6.6
> [00:00:20] [01] [00:00:18] Finished   textproc/libsass | libsass-3.6.6: Success ending TMPFS: 3.42 GiB
>
> I then installed it, resulting in:
>
> # pkg info libsass
> libsass-3.6.6
> Name           : libsass
> Version        : 3.6.6
> Installed on   : Tue Nov 26 07:33:15 2024 PST
> Origin         : textproc/libsass
> Architecture   : FreeBSD:15:amd64
> Prefix         : /usr/local
> Categories     : textproc
> Licenses       : MIT
> Maintainer     : nivit@FreeBSD.org
> WWW            : https://sass-lang.com/libsass
> Comment        : C/C++ implementation of a Sass compiler
> Shared Libs provided:
> libsass.so.1
> Annotations    :
> FreeBSD_version: 1500027
> build_timestamp: 2024-11-26T15:32:33+0000
> built_by       : poudriere-git-3.4.99.20240811
> . . .
>
> libsass.so.1.0.0 still has .got.plt starting with (this time):
>
>   2bed60 00000000 00000000 00000000 00000000  ................
>   2bed70 00000000 00000000 00000000 00000000  ................
>   2bed80 00000000 00000000 00000000 00000000  ................
>   2bed90 00000000 00000000 00000000 00000000  ................
> . . .
>   2bffc0 00000000 00000000 00000000 00000000  ................
>   2bffd0 00000000 00000000 00000000 00000000  ................
>   2bffe0 00000000 00000000 00000000 00000000  ................
>   2bfff0 00000000 00000000 00000000 00000000  ................
>   2c0000 96cb2a00 00000000 a6cb2a00 00000000  ..*.......*.....
>   2c0010 b6cb2a00 00000000 c6cb2a00 00000000  ..*.......*.....
>   2c0020 d6cb2a00 00000000 e6cb2a00 00000000  ..*.......*.....
>   2c0030 f6cb2a00 00000000 06cc2a00 00000000  ..*.......*.....
> . . .
>
> And still results in:
>
> # sassc
> Segmentation fault (core dumped)
>
>
>
> ===
> Mark Millard
> marklmi at yahoo.com
>