Bug 920345 – app-editors/xemacs-21.5.35 fails to compile on sparc: update-elc-2 crashes with SIGBUS

• Status: CONFIRMED
• Product: Gentoo Linux

[Description matoro 2023-12-20 02:30:16 UTC]

build.log and emerge --info in attachment.  Working on backtrace/UBSAN run.

Reproducible: Always

[Comment 1 matoro 2023-12-20 02:30:53 UTC]

Created attachment 880020 [details]
build.log and emerge --info

[Comment 2 matoro 2023-12-20 02:58:08 UTC]

(gdb) bt full
#0  0x000000000027c86c in pdump_reloc_one (data=0xdb5fd4 <dumped_data+6942356>, delta=7438336, desc=0x6f9070 <coding_system_description>)
    at dumper.c:1100
        ptr = 6847584
        desc1 = 0x6f9070 <coding_system_description>
        rdata = 0xdb5fe4 <dumped_data+6942372>
        pos = 0
#1  0x0000000000280204 in pdump_load_finish () at dumper.c:1897
        reloc = 0xe7b720 <dumped_data+7751136>
        rt = {desc = 0x6f9070 <coding_system_description>, count = 592}
        i = 71
        p = 0xe7b720 <dumped_data+7751136> ""
        delta = 7438336
        count = 2
        header = 0x718000 <dumped_data+3776>
#2  0x0000000000280aa8 in pdump_load (argv0=0x7feffc77617 "./xemacs") at dumper.c:2194
        exe_path = 0x0
        w = 0x0
        dir = 0x658257ea <error: Cannot access memory at address 0x658257ea>
        p = 0x16dcc4dc <error: Cannot access memory at address 0x16dcc4dc>
#3  0x0000000000231f64 in xemacs_21_5_b35_sparc64_unknown_linux (argc=10, argv=0x7feffc773b8, unused_envp=0x0, restart=0) at emacs.c:1345
        inhibit_early_packages_save = 1
        inhibit_autoloads_save = 1
        inhibit_all_packages_save = 1
        vanilla_inhibiting_save = 1
        debug_paths_save = 0
        inhibit_site_lisp_save = 0
        inhibit_site_modules_save = 0
        stack_bottom_variable = 0 '\000'
        skip_args = 4
        load_me = 8791794346289
#4  0x0000000000234018 in main (argc=10, argv=0x7feffc773b8, unused_envp=0x7feffc77410) at emacs.c:3135
        vol_argc = 10
        vol_argv = 0x7feffc773b8
        restarted = 0
(gdb) l
1095            case XD_OPAQUE_DATA_PTR:
1096            case XD_ASCII_STRING:
1097            case XD_BLOCK_PTR:
1098            case XD_LO_LINK:
1099              {
1100                EMACS_INT ptr = *(EMACS_INT *)rdata;
1101                if (ptr)
1102                  *(EMACS_INT *)rdata = ptr+delta;
1103                break;
1104              }

[Comment 3 matoro 2023-12-20 03:02:04 UTC]

UBSAN picks this up but it also picks up a million other UB instances all over the place apparently.

make[2]: Leaving directory '/var/tmp/portage/app-editors/xemacs-21.5.35/work/xemacs-21.5.35/src'
./xemacs -no-packages -no-configured-paths -batch -no-autoloads -l update-elc-2.el -f batch-update-elc-2 ../lisp
dumper.c:1100:16: runtime error: load of misaligned address 0x00001137501c for type 'long int', which requires 8 byte alignment
0x00001137501c: note: pointer points here
  00 00 00 00 e0 7e 68 00  00 00 00 00 78 6b 4f 00  00 00 00 00 70 70 1a 00  00 00 00 00 50 70 1a 00
              ^

[Comment 4 matoro 2023-12-20 03:03:19 UTC]

Created attachment 880022 [details]
terrible UBSAN run from hell

[Comment 5 Mats Lidell 2023-12-21 15:21:23 UTC]

Thanks for the report. Upstream has been contacted and is looking into this.