Bug 27446 - Do not unconditionally enable x86 ISA level
Summary: Do not unconditionally enable x86 ISA level
Status: RESOLVED DUPLICATE of bug 27318
Alias: None
Product: glibc
Classification: Unclassified
Component: build (show other bugs)
Version: 2.33
: P2 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-02-20 12:55 UTC by Jan Engelhardt
Modified: 2021-03-01 14:54 UTC (History)
1 user (show)

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Description Jan Engelhardt 2021-02-20 12:55:06 UTC 
» uname -m
i686
» gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i586-suse-linux/10/lto-wrapper
Target: i586-suse-linux
...
» ld -v
GNU ld (GNU Binutils; openSUSE Tumbleweed) 2.35.1.20201112-1


glibc» ../configure CFLAGS="-O2" --prefix=/usr --host=i586-linux-gnu && make
...
checking for linker x86 ISA level support... yes
...


glibc» readelf -aW csu/abi-note.o | grep PROP
  GNU                  0x0000000c       NT_GNU_PROPERTY_TYPE_0        Properties: <procesor-specific type 0xc0008002 data: 01 00 00 00 >

The presence of this property propagates to a fully-built glibc, which in turn propagates to all programs subsequently built with such glibc.

libc.so.6 becomes unloadable, as e.g. reported on
https://lists.opensuse.org/archives/list/factory@lists.opensuse.org/thread/GTPAXHRFLUGFGFMQULYWHHEZJS67CB4Z/

It is my understanding that ISA_LEVEL was specified for the x86_64 psABI only, so it should not even be emitted on ix86.
Comment 1 Andreas Schwab 2021-03-01 14:54:05 UTC 
dup

*** This bug has been marked as a duplicate of bug 27318 ***