quoted

--- interrupt: c00

Code: f821ff91 2f890000 409e0034 7c0802a6 3c62fff0 39200001 3d420177 3863e310 992ad6db f8010080 4b209899 60000000 <0fe00000> e8010080 7c0803a6 2f9f0000 
---[ end trace 0000000000000000 ]—

This warning is seen while running test that was added by
following commit:

commit 3bf7009251f0f41cdd0188ab7b3879df81810703
    tracing/selftests: Add test to test the trace_marker

This adds the user space selftest that triggered this warning, but it is
not the cause of it. Could you run this test against kernel builds before
this commit. Does this test cause this to trigger on older versions of the
kernel?

Running the mentioned test against an older kernel does not trigger this
warning.

# uname -r
6.7.0
#
#  ./ftracetest test.d/00basic/trace_marker.tc
=== Ftrace unit tests ===
[1] Basic tests on writing to trace_marker [PASS]
[2] (instance)  Basic tests on writing to trace_marker [PASS]


# of passed:  2
# of failed:  0
# of unresolved:  0
# of untested:  0
# of unsupported:  0
# of xfailed:  0
# of undefined(test bug):  0
#

I used this setup to again run bisect between 6.7.0 and 6.8-rc1.
Bisect points to following patch 

commit 8ec90be7f15fac42992ea821be929d3b06cd0fd9
    tracing: Allow for max buffer data size trace_marker writes


— Sachin