Bug#1050589: gcc-13: [x32] -fbuiltin-strchr miscompiles
Dixi quod…
>Package: gcc-13
>Version: 13.2.0-1
This is a regression against gcc-12 (= 12.3.0-8); if I install that
and export CC='diet -Os gcc-12' it works.
>./mksh -c 'x=q; x=${ echo a; typeset e=2; return 3; echo x$e;}; echo .$x.'
In case this is relevant: that codepath uses setjmp/longjmp quite a bit,
and builds for glibc, musl or klibc don’t trigger this, so it’s probably
a combination of several things. Using dietlibc/amd64 is also fine, and
dietlibc-wise, they are good as identical: differ only in start.S and
syscall numbers, and a few sections in header files.
bye,
//mirabilos
--
you introduced a merge commit│ % g rebase -i HEAD^^
sorry, no idea and rebasing just fscked │ Segmentation
should have cloned into a clean repo │ fault (core dumped)
if I rebase that now, it's really ugh │ wuahh
Bug#1050589: gcc-13: [x32] -fbuiltin-strchr miscompiles
Package: gcc-13
Version: 13.2.0-1
Severity: normal
X-Debbugs-Cc: t...@mirbsd.de
I've got miscompiles of mksh with gcc-13 on x32 with dietlibc.
I could reproduce this in a chroot by doing…
export CC='diet -Os gcc'
export CFLAGS='-g -Wformat -Werror=format-security -Wall -Wextra'
export CPPFLAGS='-Wdate-time -D_FORTIFY_SOURCE=2 -DMKSH_BUILDMEAT'
sh Build.sh -r -j
./mksh -c 'x=q; x=${ echo a; typeset e=2; return 3; echo x$e;}; echo .$x.'
… in an mksh source tree. (Output is “..” but “.a.” was expected.)
Adding -fno-builtin-strchr to CFLAGS makes the problem go away.
This is as far as I could reduce this; more would involve diving
into the gcc internals.
-- System Information:
Debian Release: trixie/sid
APT prefers unreleased
APT policy: (500, 'unreleased'), (500, 'unstable')
Architecture: x32 (x86_64)
Kernel: Linux 5.10.0-23-amd64 (SMP w/4 CPU threads)
Kernel taint flags: TAINT_FIRMWARE_WORKAROUND
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C),
LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: unable to detect
Versions of packages gcc-13 depends on:
ii binutils 2.41-4
ii cpp-13 13.2.0-1
ii gcc-13-base13.2.0-1
ii libc6 2.37-7
ii libcc1-0 13.2.0-1
ii libgcc-13-dev 13.2.0-1
ii libgcc-s1 13.2.0-1
ii libgmp10 2:6.3.0+dfsg-2
ii libisl23 0.26-3
ii libmpc31.3.1-1
ii libmpfr6 4.2.0-1
ii libstdc++6 13.2.0-1
ii libzstd1 1.5.5+dfsg2-1
ii zlib1g 1:1.2.13.dfsg-3
Versions of packages gcc-13 recommends:
ii libc6-dev 2.37-7
Versions of packages gcc-13 suggests:
pn gcc-13-doc
pn gcc-13-locales
pn gcc-13-multilib
-- no debconf information
