[Bug gdb/23188] New: Process record does not support instruction 0xc5 (vmovd %esi,%xmm0 / AVX2)

[peter at lekensteyn dot nl]

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

Bug ID: 23188
Summary: Process record does not support instruction 0xc5
(vmovd %esi,%xmm0 / AVX2)
Product: gdb
Version: 8.1
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: gdb
Assignee: unassigned at sourceware dot org
Reporter: peter at lekensteyn dot nl
Target Milestone: ---

Reverse debugging using the "record" command halts when it encounters an
AVX2-related instruction.

(gdb) record full
(gdb) c
Process record does not support instruction 0xc5 at address 0x7fffddca0010.
Process record: failed to record execution log.

0x00007fffddca0010 in __memset_avx2_unaligned_erms () from /usr/lib/libc.so.6
(gdb) x/i $rip
=> 0x7fffddca0010 <__memset_avx2_unaligned_erms>: vmovd %esi,%xmm0


As a workaround, libc can be patched to hide the AVX2 CPU feature, but it is
rather cumbersome to use: https://stackoverflow.com/q/42451492

Affects glibc 2.24, 2.25, 2.27 on Arch Linux and Ubuntu.
CPU: i7-6700HQ

[nathanielmbeaver at gmail dot com]

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

Nathaniel M. Beaver <nathanielmbeaver at gmail dot com> changed:

What |Removed |Added
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CC| |nathanielmbeaver at gmail dot com

--- Comment #1 from Nathaniel M. Beaver <nathanielmbeaver at gmail dot com> ---
Maybe a duplicate of #17346?

https://sourceware.org/bugzilla/show_bug.cgi?id=17346

[peter at lekensteyn dot nl]

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

--- Comment #2 from Peter Wu <peter at lekensteyn dot nl> ---
Not a duplicate, the bug 17346 is about AVX while this one is about AVX2. The
other would be a good starting point for this one I suppose.