Bug#842796: libc recently more aggressive about pthread locks in stable ?

[Adrian Bunk]

On Sun, Nov 06, 2016 at 05:41:34PM -0200, Henrique de Moraes Holschuh wrote:
> On Sun, 06 Nov 2016, Ben Hutchings wrote:
> > It's worth noting that TSX is broken in 'Haswell' processors and is
> > supposed to be disabled via a microcode update.  I don't know whether
> > glibc avoids using it on these processors if the microcode update is
> > not applied.  (Linux doesn't appear to hide the feature flags.)
> 
> It does avoid it.  For glibc libpthreads, Debian has blacklisted Intel
> TSX use [in libpthreads] on all of Haswell and much of Broadwell.
> 
> But anything else *will* attempt to use it, people query cpuid directly
> for these things.  You need a hypervisor that filters cpuid().

All users who are using intel-microcode from non-free instead of running 
outdated microcode with known errata should be OK here?

Running outdated microcode is a bad idea, and noone is making 
Debian-specific workarounds for all the other CPU errata.

cu
Adrian

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