Re: set_labels_identifiers_target -fsanitize=undefined error

[Sam James]

Sam James <sam@gentoo.org> writes:

> John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> writes:
>
>> Hi Gavin!
>>
>> On Sat, 2023-11-04 at 11:00 +0000, Gavin Smith wrote:
>>> The line in question is:
>>> 
>>>   memcpy (targets, list_of_labels, labels_number * sizeof(LABEL));
>>> 
>>> - again, the second argument of memcpy.
>>> 
>>> However, main/targets.c was only introduced after Texinfo 7.1 so
>>> this is not the original problem.
>>
>> I'll provide a backtrace as well as the commit that introduced the regression
>> on SPARC within the next days. Need to set up two new SPARC servers next week
>> first.
>>
>
> OK, I tried this out on sparc with Gavin's fix on master, and got...
>
> export UBSAN_OPTIONS=print_stacktrace=1:halt_on_error=1
> ./autogen.sh;  ./configure PERL_EXT_CFLAGS="-O2 -ggdb3
> -fsanitize=undefined" CFLAGS="-O2 -ggdb3 -fsanitize=undefined"   ; make
> -j$(nproc) ; make check -j$(nproc)
>
> parsetexi/tree.c:77:11: runtime error: member access within misaligned 
> address 0x0100010e9744 for type 'struct ELEMENT', which requires 8 byte 
> alignment
> 0x0100010e9744: note: pointer points here
>   00 00 01 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  
> 00 00 00 00 00 00 00 00
>               ^
>     #0 0xfff8000102fc12ec in new_element parsetexi/tree.c:77
>     #1 0xfff8000102fc12ec in new_element parsetexi/tree.c:77
>     #2 0xfff8000102fabee4 in setup_document_root_and_before_node_section 
> parsetexi/parser.c:521
>     #3 0xfff8000102fbc584 in parse_texi_document parsetexi/parser.c:532
>     #4 0xfff8000102f84338 in parse_file parsetexi/api.c:231
>     #5 0xfff8000102f73f28 in XS_Texinfo__Parser_parse_file 
> parsetexi/Parsetexi.c:239
>     #6 0xfff80001004563bc  (/usr/lib64/libperl.so.5.38+0x1563bc)
>     #7 0xfff800010044ae64 in Perl_runops_standard 
> (/usr/lib64/libperl.so.5.38+0x14ae64)
>     #8 0xfff800010037a2b4 in perl_run (/usr/lib64/libperl.so.5.38+0x7a2b4)
>     #9 0x10000000d10 in main (/usr/bin/perl+0xd10)
>     #10 0xfff800010092a894 in __libc_start_call_main 
> ../sysdeps/nptl/libc_start_call_main.h:58
>     #11 0xfff800010092a99c in __libc_start_main_impl 
> /usr/src/debug/sys-libs/glibc-2.37-r3/glibc-2.37/csu/libc-start.c:360
>     #12 0x10000000d74 in _start (/usr/bin/perl+0xd74)
>
> The test suite logs have loads of the same violation with ELEMENT, so I
> suspect this is the root problem (before I built the perl modules with
> PERL_EXT_CFLAGS with UBSAN, I got the Bus Error originally reported.)
>
> I have not tried to reproduce the alignment problem on amd64 with 
> PERL_EXT_CFLAGS.
>

Also, Gavin (and Adrian), you're both welcome to have access to the
sparc machine I'm using here.

>> Adrian