Hi, On 2022-10-14 11:58, Adam D. Barratt wrote: > Control: tags -1 + confirmed > > On Sat, 2022-10-08 at 11:30 +0200, Aurelien Jarno wrote: > > The glibc/2.31-13+deb11u4 update introduced a regression (bug > > #1019855) on some early Intel Haswell processors which expose the > > AVX2 instructions, but lack the BMI2 instructions. On such systems > > the memchr and strlen related functions fails with SIGILL, rendering > > them unusable. > > > > The issue is that some of the backported commits to fix the overflow > > bugs in the AVX2 implementation of wmemchr and wcslen that went in > > the upstream 2.31 branch, started to use BMI2 instructions in > > addition to the AVX2 instructions, without checking for the > > availability of those instructions. This was done in another commit > > that hasn't been backported. > > > > It happens that a microcode update for the affected CPUs (either > > through the BIOS/firmware or from a package) fixes this, so it went > > barely noticed up to now, especially given other distributions > > usually install firmware updates by default. > > > > [ Impact ] > > While the number of affected systems is probably small, this bug > > makes them unusable. > [...] > > Given the severity of the bug, it might be a good idea to release it > > through stable-updates. > > Please go ahead.
Thanks for the review, I have just uploaded it. Regards Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net
