selftests: rcutorture: Use "grep -E" instead of "egrep"

The latest version of grep is deprecating the egrep command, so that
its output contains warnings as follows:

egrep: warning: egrep is obsolescent; using grep -E

Fix this using "grep -E" instead.

sed -i "s/egrep/grep -E/g" `grep egrep -rwl tools/testing/selftests/rcutorture`

Here are the steps to install the latest grep:

wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz
tar xf grep-3.8.tar.gz
cd grep-3.8 && ./configure && make
sudo make install
export PATH=/usr/local/bin:$PATH

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: make kvm-find-errors.sh check for compressed vmlinux files

Under some conditions, a given run's vmlinux file will be compressed,
so that it is named vmlinux.xz rather than vmlinux. in such cases,
kvm-find-errors.sh will complain about the nonexistence of vmlinux.
This commit therefore causes kvm-find-errors.sh to check for vmlinux.xz
as well as for vmlinux.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Skip vmlinux check for kvm-again.sh runs

The kvm-again.sh script reruns an previously built set of kernels, so
the vmlinux files are associated with that previous run, not this on.
This results in kvm-find_errors.sh reporting spurious failed-build errors.
This commit therefore omits the vmlinux check for kvm-again.sh runs.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Make kvm-find-errors.sh notice missing vmlinux file

Currently, an obtuse compiler diagnostic can fool kvm-find-errors.sh
into believing that the build was successful. This commit therefore
adds a check for a missing vmlinux file. Note that in the case of
repeated torture-test scenarios ("--configs '2*TREE01'"), the vmlinux
file will only be present in the first directory, that is, in TREE01
but not TREE01.2.

Link: https://lore.kernel.org/lkml/36bd91e4-8eda-5677-7fde-40295932a640@molgen.mpg.de/
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Make kvm-find-errors.sh report link-time undefined symbols

This commit makes kvm-find-errors.sh check for and report undefined
symbols that are detected at link time.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Make kvm-find-errors.sh account for kvm-remote.sh

Currently, kvm-find-errors.sh assumes that if "--buildonly" appears in
the log file, then the run did builds but ran no kernels. This breaks
with kvm-remote.sh, which uses kvm.sh to do a build, then kvm-again.sh
to run the kernels built on remote systems. This commit therefore adds
a check for a kvm-remote.sh run.

While in the area, this commit checks for "--build-only" as well as
"--build-only".

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Simplify exit-code plumbing for kvm-recheck.sh and kvm-find-errors.sh

This commit simplifies exit-code plumbing. It makes kvm-recheck.sh return
the value 1 for a build error and 2 for a runtime error. It also makes
kvm-find-errors.sh avoid checking runtime files for --build-only runs.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Make kvm.sh return failure upon build failure

The kvm.sh script uses kvm-find-errors.sh to evaluate whether or not
a build failed. Unfortunately, kvm-find-errors.sh returns success if
there are no failed runs (including when there are no runs at all) even if
there are build failures. This commit therefore makes kvm-find-errors.sh
return failure in response to build failures.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

rcutorture: Make kvm-find-errors.sh abort on bad directory

Currently, kvm-find-errors.sh gives a usage prompt when given a bad
directory, but then soldiers on, giving a series of confusing error
messages. This commit therefore prints an error message and exits when
given a bad directory, hopefully reducing confusion.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit status

This commit causes both kvm-find-errors.sh and kvm-recheck.sh to provide
an exit status based on whether or not errors were located. In the
case of kvm-recheck.sh, this will be the error status of the last run.
This change allows these commands to be used in scripting and Makefiles
to automatically report failed rcutorture runs.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

tools/.../rcutorture: Convert to SPDX license identifier

Replace the license boiler plate with a SPDX license identifier.
While in the area, update an email address and add copyright notices.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

torture: Make kvm-find-errors.sh find build warnings

Currently, kvm-find-errors.sh looks only for build errors ("error:"),
so this commit makes it also locate build warnings ("warning:").

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Nicholas Piggin <npiggin@gmail.com>

torture: Add a script to edit output from failed runs

This commit adds a script that allows viewing the build and/or
console output from failed rcutorture, locktorture, or rcuperf runs.
This replaces a time-honored but inefficient manual procedure that uses
cut and paste.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Nicholas Piggin <npiggin@gmail.com>