SUMMARY
***
unhandled amd64-linux syscall: 441

I received this warning message when running the commands below.
I ran the same command on a couple C programs after receiving the warning,
and they all output the same message show below. 
The warning states that there is an unhandled amd64-linux syscall, specifying 441. 
I'm not very inclined when it comes to hardware, but I am on an intel cpu, so I'm 
curious as to why there would be an amd syscall. 

The programs that I ran the command on were  compiled with the c89, c99, gcc, and clang compilers.
All of the programs output the same warning message shown below.
***

STEPS TO REPRODUCE
1. valgrind --tool=cachegrind ls -l ./<program> (cmd source: https://courses.cs.washington.edu/courses/cse326/05wi/valgrind-doc/cg_main.html)

I get the following output after running the command: 

$ valgrind --tool=cachegrind ls -l ./<program>
WARNING: unhandled amd64-linux syscall: 441
You may be able to write your own handler.
Read the file README_MISSING_SYSCALL_OR_IOCTL.
Nevertheless we consider this a bug.  Please report
it at http://valgrind.org/support/bug_reports.html.

EXPECTED OUTCOME:
something along the lines of:
==31751== I   refs:      27,742,716
==31751== I1  misses:           276
==31751== L2  misses:           275
==31751== I1  miss rate:        0.0%
==31751== L2i miss rate:        0.0%
==31751== 
==31751== D   refs:      15,430,290  (10,955,517 rd + 4,474,773 wr)
==31751== D1  misses:        41,185  (    21,905 rd +    19,280 wr)
==31751== L2  misses:        23,085  (     3,987 rd +    19,098 wr)
==31751== D1  miss rate:        0.2% (       0.1%   +       0.4%)
==31751== L2d miss rate:        0.1% (       0.0%   +       0.4%)
==31751== 
==31751== L2 misses:         23,360  (     4,262 rd +    19,098 wr)
==31751== L2 miss rate:         0.0% (       0.0%   +       0.4%)


SOFTWARE/OS VERSIONS
clang: 15.0.7
gcc: 13.1.1
archlinux: 6.3.9