selftests/powerpc: add const qualification where possible

Various char * parameters in the common powerpc selftest APIs can be
const.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230817-powerpc-selftest-misc-v1-2-a84cc1ef78b2@linux.ibm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191

Based on 1 normalized pattern(s):

licensed under gplv2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 99 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170027.163048684@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/powerpc: Add a signal fuzzer selftest

This is a new selftest that raises SIGUSR1 signals and handles it in a
set of different ways, trying to create different scenario for testing
purpose.

This test works raising a signal and calling sigreturn interleaved
with TM operations, as starting, suspending and terminating a
transaction. The test depends on random numbers, and, based on them,
it sets different TM states.

Other than that, the test fills out the user context struct that is
passed to the sigreturn system call with random data, in order to make
sure that the signal handler syscall can handle different and invalid
states properly.

This selftest has command line parameters to control what kind of
tests the user wants to run, as for example, if a transaction should
be started prior to signal being raised, or, after the signal being
raised and before the sigreturn. If no parameter is given, the default
is enabling all options.

This test does not check if the user context is being read and set
properly by the kernel. Its purpose, at this time, is basically
guaranteeing that the kernel does not crash on invalid scenarios.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftests/powerpc: Kill child processes on SIGINT

There are some powerpc selftests, as tm/tm-unavailable, that run for a long
period (>120 seconds), and if it is interrupted, as pressing CRTL-C
(SIGINT), the foreground process (harness) dies but the child process and
threads continue to execute (with PPID = 1 now) in background.

In this case, you'd think the whole test exited, but there are remaining
threads and processes being executed in background. Sometimes these
zombies processes are doing annoying things, as consuming the whole CPU or
dumping things to STDOUT.

This patch fixes this problem by attaching an empty signal handler to
SIGINT in the harness process. This handler will interrupt (EINTR) the
parent process waitpid() call, letting the code to follow through the
normal flow, which will kill all the processes in the child process group.

This patch also fixes a typo.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftest/powerpc: Fix false failures for skipped tests

Tests under alignment subdirectory are skipped when executed on previous
generation hardware, but harness still marks them as failed.

test: test_copy_unaligned
tags: git_version:unknown
[SKIP] Test skipped on line 26
skip: test_copy_unaligned
selftests: copy_unaligned [FAIL]

The MAGIC_SKIP_RETURN_VALUE value assigned to rc variable is retained till
the program exit which causes the test to be marked as failed.

This patch resets the value before returning to the main() routine.
With this patch the test o/p is as follows:

test: test_copy_unaligned
tags: git_version:unknown
[SKIP] Test skipped on line 26
skip: test_copy_unaligned
selftests: copy_unaligned [PASS]

Signed-off-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftests/powerpc: Allow tests to extend their kill timeout

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftests/powerpc: Move get_auxv_entry() into utils.c

This doesn't really belong in harness.c, it's a helper function. So move
it into utils.c.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftests/powerpc: Move get_auxv_entry() to harness.c

Move get_auxv_entry() from pmu/lib.c up to harness.c in order to make
it available to other tests.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

selftests/powerpc: Add support for skipping tests

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

selftests/powerpc: Put the test in a separate process group

Allows us to kill the test and any children it has spawned.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

selftests: Add support files for powerpc tests

This commit adds support code used by upcoming powerpc tests.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>