Bug 30807 - Process record does not support instruction 0x62 (AVX512)
Summary: Process record does not support instruction 0x62 (AVX512)
Status: NEW
Alias: None
Product: gdb
Classification: Unclassified
Component: gdb (show other bugs)
Version: HEAD
: P2 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2023-08-29 14:34 UTC by Simon Marchi
Modified: 2023-08-29 17:44 UTC (History)
0 users

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Description Simon Marchi 2023-08-29 14:34:00 UTC
This is basically the same as this:

https://sourceware.org/bugzilla/show_bug.cgi?id=23188

... but for AVX512.  I'm seeing this when running gdb.reverse/step-precsave.exp on a CPU with AVX512 support (AMD EPYC 9634) on Debian 12 (bookworm):

      continue^M
      Continuing.^M
      Process record does not support instruction bound.^M
      Process record does not support instruction 0x62 at address 0x7ffff7f49b40.^M
      Process record: failed to record execution log.^M
      ^M
      Program stopped.^M
      0x00007ffff7f49b40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6^M
      (gdb) FAIL: gdb.reverse/step-precsave.exp: run to end of main
Comment 1 Sourceware Commits 2023-08-29 17:44:28 UTC
The master branch has been updated by Simon Marchi <simark@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4fd1ba162ed6f197169d2af29f4230d7a89e2636

commit 4fd1ba162ed6f197169d2af29f4230d7a89e2636
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Tue Aug 29 12:19:02 2023 -0400

    gdb/testsuite: recognize one more unsupported instruction in gdb.reverse/step-precsave.exp
    
    When running this test on a processor that supports AVX512 (AMD EPYC
    9634) on Debian 12 bookwork (system compiler is gcc 12.2.0), I see:
    
        continue^M
        Continuing.^M
        Process record does not support instruction bound.^M
        Process record does not support instruction 0x62 at address 0x7ffff7f49b40.^M
        Process record: failed to record execution log.^M
        ^M
        Program stopped.^M
        0x00007ffff7f49b40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6^M
        (gdb) FAIL: gdb.reverse/step-precsave.exp: run to end of main
    
    The instruction at this address is:
    
       0x00007ffff7f49b40:  62 e2 7d 48 7a c6   vpbroadcastb %esi,%zmm16
    
    This seems like an AVX512 instruction (given the use of zmm16).  Match
    this byte value in order to produce a KFAIL.
    
    Change-Id: I1d20357fa538ba60b9c537160acf511a37d751ee
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30807
    Approved-By: Tom Tromey <tom@tromey.com>