[Bug libc/20647] New: Using current glibc of opensuse Tumbleweed on a Pentium-S leads to an assertion: "maxidx >= 2"

["ralph at gauernet dot de" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=20647

            Bug ID: 20647
           Summary: Using current glibc of opensuse Tumbleweed on a
                    Pentium-S leads to an assertion: "maxidx >= 2"
           Product: glibc
           Version: 2.24
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: ralph at gauernet dot de
                CC: drepper.fsp at gmail dot com
  Target Milestone: ---

Created attachment 9537
  --> https://sourceware.org/bugzilla/attachment.cgi?id=9537&action=edit
proposed patch

The current version of glibc (2.24) used in opensuse Tumbleweed (September
2016) stops every program with an assertion "maxidx >= 2" if it is used on a
Pentium-S.
The Pentium-S reports a "cpuid level" of 1 which is the value that is compared
in this assertion within the function handle_intel in cacheinfo.c
This is probably to prevent errors when inquiring cache features from a cpu
that doesn't support this.
Leaving the assertion as is, prevents the usage of Tumbleweed on these older
cpus.
A possible solution is to return 0 without cache inquiries if maxidx equals 1.
Testing with a glibc 2.24 patched in this way lead to a usable sytem without
any negative effects up to now.

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