Hi Samuel, Samuel Thibault <samuel.thiba...@gnu.org> skribis:
> About the backtrace: > >>>>>> user space <<<<< > 0x1000(bfffff24,0,0,1160b,0) > 0x11627(bfffff9c,0,0,0,2) > 0x11bb() > > That is quite surprising actually: in my ld.so there is nothing useful > at 0x1000. Perhaps you can check what 0x11627 is all about? Sure: --8<---------------cut here---------------start------------->8--- $ addr2line -e /gnu/store/m8afvcgwmrfhvjpd7b0xllk8vv5isd6j-glibc-cross-i586-pc-gnu-2.33/lib/ld.so.1 0x1000 0x11627 0x11bb ??:0 /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/glibc-2.33/elf/dl-misc.c:333 :? --8<---------------cut here---------------end--------------->8--- That’s ‘_dl_fatal_printf’ calling ‘_exit’; it’s trying to tell us something. I’ll try and rebuild the system with the debugging patches at <https://lists.gnu.org/archive/html/bug-hurd/2011-11/msg00038.html>, to get early ld.so output, for lack of a better solution… >> Program Header: >> LOAD off 0x00000000 vaddr 0x00000000 paddr 0x00000000 align 2**12 >> filesz 0x00000dd8 memsz 0x00000dd8 flags r-- > > We don't have this section in the Debian glibc. It'd probably be useful > to know what this is about. Address 0 is for the ‘_begin’ symbol, passed by -Wl,-defsym: --8<---------------cut here---------------start------------->8--- i586-pc-gnu-gcc -nostdlib -nostartfiles -r -o /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/librtld.os '-Wl,-(' /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/dl-allobjs.os /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/rtld-libc.a -lgcc '-Wl,-)' \ -Wl,-Map,/tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/librtld.os.map i586-pc-gnu-gcc -nostdlib -nostartfiles -shared -o /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/ld.so.new \ -Wl,-z,combreloc -Wl,-z,relro -Wl,--hash-style=both -Wl,-z,defs \ /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/librtld.os -Wl,--version-script=/tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/ld.map \ -Wl,-soname=ld.so.1 \ -Wl,-defsym=_begin=0 i586-pc-gnu-readelf -s /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/ld.so.new \ | gawk '($7 ~ /^UND(|EF)$/ && $1 != "0:" && $4 != "REGISTER") { print; p=1 } END { exit p != 0 }' mv -f /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/ld.so.new /tmp/guix-build-glibc-cross-i586-pc-gnu-2.33.drv-0/build/elf/ld.so --8<---------------cut here---------------end--------------->8--- And indeed: --8<---------------cut here---------------start------------->8--- $ objdump -t /gnu/store/m8afvcgwmrfhvjpd7b0xllk8vv5isd6j-glibc-cross-i586-pc-gnu-2.33/lib/ld.so.1|grep _begin 00000000 l *ABS* 00000000 _begin --8<---------------cut here---------------end--------------->8--- That ‘-Wl,-defsym=_begin=0’ flag was removed in glibc commit 6f043e0ee7e477f50a44024ed0cb579d5e3f511d (April 2022). On darnassus it’s different but then it’s Debian’s glibc 2.35, natively built, so I don’t what conclusions can be drawn: --8<---------------cut here---------------start------------->8--- ludo@darnassus:~$ /lib/ld.so.1 --version ld.so (Debian GLIBC 2.35-1) stable release version 2.35. Copyright (C) 2022 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. ludo@darnassus:~$ objdump -x /lib/ld.so.1 |head -40 /lib/ld.so.1: file format elf32-i386 /lib/ld.so.1 architecture: i386, flags 0x00000150: HAS_SYMS, DYNAMIC, D_PAGED start address 0x0001cc40 Program Header: LOAD off 0x00000000 vaddr 0x00000000 paddr 0x00000000 align 2**12 filesz 0x00038494 memsz 0x00038494 flags r-x LOAD off 0x00038c00 vaddr 0x00039c00 paddr 0x00039c00 align 2**12 filesz 0x00001ca8 memsz 0x00001e34 flags rw- DYNAMIC off 0x00039f24 vaddr 0x0003af24 paddr 0x0003af24 align 2**2 filesz 0x000000b8 memsz 0x000000b8 flags rw- NOTE off 0x00000114 vaddr 0x00000114 paddr 0x00000114 align 2**2 filesz 0x00000024 memsz 0x00000024 flags r-- --8<---------------cut here---------------end--------------->8--- Thanks for your feedback! Ludo’.
