On Fri, Nov 01, 2019 at 10:22:14AM +0100, Aurelien Jarno wrote: >On 2019-10-30 00:17, Steve McIntyre wrote: >> Source: glibc >> Version: 2.28-10 >> Severity: important >> >> Hi folks, >> >> It looks like my old Arm ABI detection patch for ld.so is causing >> problems for people using LLVM. I've been contacted by a developer, >> referring to a mailing list thread: >> >> https://lists.llvm.org/pipermail/llvm-dev/2019-October/135993.html >> >> It looks like the LLVM version of strip is more aggressive than the >> GNU binutils version, and this is causing problems - it's stripping >> the .ARM.attributes data and that's causing problems with our extra >> checks for the Tag_ABI_VFP_args setting. Whether that's a valid thing >> to do or not is an argument for another day, I think... However, >> checking with the bzip2 binaries that the reporter provided I can see >> that they have the right ABI flag in the ELF header but we're still >> running the extra ABI check: >> >> (sid-armhf)steve@mjolnir:~/abi$ LD_PRELOAD=./libbz2.so.all ./bzip2 >> ERROR: ld.so: object './libbz2.so.all' from LD_PRELOAD cannot be preloaded >> (cannot open shared object file): ignored. >> bzip2: I won't write compressed data to a terminal. >> bzip2: For help, type: `bzip2 --help'. >> >> (sid-armhf)steve@mjolnir:~/abi$ readelf -a libbz2.so.all | grep "^ Flags" >> Flags: 0x5000400, Version5 EABI, hard-float ABI >> >> I think this is wrong, and I can't think of why I didn't find this >> earlier when I was working in this area. :-/ >> >> So: I think we have two sensible options: >> >> 1. I find time now to fix up ld.so to only do the extra check here if >> we think it's needed >> >> OR >> >> 2. Just remove the patch for extra check here - it was always the plan >> that this would go away after a while once people were unlikely to >> still be running binaries from the pre ELF-header toolchains. >> >> Checking history, I can see that the binutils changes for those ELF >> header changes landed in Debian back in Nov 2012. (Wow, time >> flies!). Given that, I'd now be strongly in favour of just dropping the >> patch in >> >> debian/patches/arm/unsubmitted-ldso-abi-check.diff >> >> as it's now safely obsolete. What do others think? > >Given this patch is not needed anymore, I also thing it's the way to do. >It caused us issue in the past, so i'll be very happy to see it going >away.
ACK. I did want to keep it around for a while for safety, and that period is clearly done. Thanks for your help with this! -- Steve McIntyre, Cambridge, UK. st...@einval.com You raise the blade, you make the change... You re-arrange me 'til I'm sane...