Re: [PATCH v9 37/39] kselftest/arm64: Add GCS signal tests

Mark Brown [off-list ref] writes:

Do some testing of the signal handling for GCS, checking that a GCS
frame has the expected information in it and that the expected signals
are delivered with invalid operations.

Reviewed-by: Thiago Jung Bauermann <redacted>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/.gitignore    |  1 +
 .../selftests/arm64/signal/test_signals_utils.h    | 10 +++
 .../arm64/signal/testcases/gcs_exception_fault.c   | 62 +++++++++++++++
 .../selftests/arm64/signal/testcases/gcs_frame.c   | 88 ++++++++++++++++++++++
 .../arm64/signal/testcases/gcs_write_fault.c       | 67 ++++++++++++++++
 5 files changed, 228 insertions(+)

The gcs_write_fault test fails for me, even without THP:

$ sudo ./run_kselftest.sh -t arm64:gcs_write_fault
TAP version 13
1..1
# timeout set to 45
# selftests: arm64: gcs_write_fault
# # GCS write fault :: Normal writes to a GCS segfault
# Registered handlers for all signals.
# Detected MINSTKSIGSZ:4720
# Required Features: [ GCS ] supported
# Incompatible Features: [] absent
# Testcase initialized.
# Read value 0x0
# SIG_OK -- SP:0xFFFFCF1292D0  si_addr@:0xffffba645000  si_code:10  token@:(nil)  offset:-281473808879616
# si_code != SEGV_ACCERR...test is probably broken!
# -- RX UNEXPECTED SIGNAL: 6 code -6 address 0xf76
# ==>> completed. FAIL(0)
not ok 1 selftests: arm64: gcs_write_fault # exit=1

It also generates an "INVALID GCS" line in dmesg.

-- 
Thiago