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: Use mktemp instead of guessing at unique names

This commit drags the rcutorture scripting kicking and screaming into the
twenty-first century by making use of the BSD-derived mktemp command to
create temporary files and directories. In happy contrast to many of its
ill-behaved predecessors, mktemp seems to actually work reasonably reliably!

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

torture: Correctly fetch number of CPUs for non-English languages

Grepping for "CPU" on lscpu output isn't always successful, depending
on the local language setting. As a result, the build can be aborted
early with:

"make: the '-j' option requires a positive integer argument"

This commit therefore uses the human-language-independent approach
available via the getconf command, both in kvm-build.sh and in
kvm-remote.sh.

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

torture: Make the build machine control N in "make -jN"

Given remote rcutorture runs, it is quite possible that the build system
will have fewer CPUs than the system(s) running the actual test scenarios.
In such cases, using the number of CPUs on the test systems can overload
the build system, slowing down the build or, worse, OOMing the build
system. This commit therefore uses the build system's CPU count to set
N in "make -jN", and by tradition sets "N" to double the CPU count.

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

torture: Add a stop-run capability

When bisecting RCU issues, it is often the case that the first error in
an unsuccessful run will happen quickly, but that a successful run must
go on for some time in order to obtain a sufficiently low false-negative
error rate. In many cases, a bisection requires multiple concurrent
runs, in which case the first failure in any run indicates failure,
pure and simple. In such cases, it would speed things up greatly if
the first failure terminated all runs.

This commit therefore adds scripting that checks for a file named "STOP"
in the top-level results directory, terminating the run when it appears.
Note that in-progress builds will continue until completion, but future
builds and all runs will be cut short.

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

torture: Run kernel build in source directory

For historical reasons, rcutorture places its build products in a
tools/testing/selftests/rcutorture/b1 directory using the O= kbuild
command-line argument. However, doing this requires that the source
directory be pristine: Not just "make clean" pristine, but instead "make
mrproper" (or, equivalently, "make distclean") pristine. Therefore,
rcutorture executes a "make mrproper" before each build. Unfortunately,
"make mrproper" has the side effect of removing pretty much everything,
including tags files and cscope databases, which can be inconvenient
to people whose workflow centers around a single source tree.

This commit therefore makes rcutorture do the build directly in the
source directory, removing the need for "make mrproper". This works
because all needed build products are moved to their proper place in the
"res" directory immediately after the build completes, so that multiple
rcutorture kernels can still run concurrently.

Reported-by: Peter Zijlstra <peterz@infradead.org>
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: Use a single build directory for torture scenarios

The torture scripting currently builds each kernel from a set of parallel
runs in its own build directory. This can waste quite a bit of space when
running large numbers of concurrent scenarios, and pointlessly given that
the builds are run sequentially (albeit with a largish -j number passed to
"make"). This commit therefore places all build-command output in the
results directory, then does all builds in a single "b1" build directory.

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

rcutorture/kvm-build.sh: Skip build directory check

Check for build-directory existence and write permissions are provided in
both 'kvm-test-1-run.sh' an 'kvm-build.sh'. Because the 'kvm-build.sh'
is dependent on 'kvm-test-1-run.sh' ('kvm-build.sh' uses variables that
defined from its caller.), these checks are unnecessarily duplicated.
This commit therefore removes the check in from the 'kvm-build.sh' script.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

torture: Provide TMPDIR environment variable to specify tmpdir

Both rcutorture and locktorture currently place temporary files in /tmp,
in keeping with decades-long tradition. However, sometimes it is useful
to specify an alternative temporary directory, for example, for space
or performance reasons. This commit therefore causes the torture-test
scripting to use the path specified in the TMPDIR environment variable,
or to fall back to traditional /tmp if this variable is not set.

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

torture: Add --kconfig argument to kvm.sh

Currently, testing a variant of an existing scenario requires editing
that scenario's file or creating a new scenario file. This is messy
and error prone with respect to changes to scenarios.

This commit therefore adds a --kconfig argument to kvm.sh, so that
'--kconfig "CONFIG_RCU_TRACE=y CONFIG_RCU_EQS_DEBUG=n" will override those
two Kconfig options. In addition, there is now clear precedence:
the config fragment overrides CFcommon, and the --kconfig argument
overrides both.

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

rcutorture: Correctly handle CONFIG_RCU_TORTURE_TEST_* options

The rcutorture scripting handles the CONFIG_*_TORTURE_TEST Kconfig
options specially, and therefore greps them out of the Kconfig-fragment
files. Unfortunately, a poor choice of grep pattern means that the
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP, CONFIG_RCU_TORTURE_TEST_SLOW_INIT,
and CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT Kconfig options are also grepped
out, preventing rcutorture from using them. This commit therefore fixes
the offending grep pattern to focus only on the CONFIG_*_TORTURE_TEST
Kconfig options.

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

rcutorture: Set executable bit and drop bash from Usage

This commit sets the executable bit on test scripts config2frag.sh
and kvm.sh. Since #!/bin/bash is set in all the scripts, this commit
also drops it from all usage lines because the scripts can now all be
invoked directly.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

rcutorture: Use bash shell for all the test scripts

Some of the scripts encode a default /bin/sh shell. On systems which use
dash as default shell, these scripts fail as they are bash scripts. I
encountered this while testing the sprintf() changes on a Debian system
where dash is the default shell.

This commit changes all such uses to use bash explicitly.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

torture: Make config-fragment filtering RCU-independent

The torture tests need to set specific values for their respective
Kconfig options (e.g., CONFIG_LOCK_TORTURE_TEST), and must therefore
filter any conflicting definitions from the Kconfig fragment
file. Unfortunately, the code in kvm-build.sh was looking only for
CONFIG_RCU_TORTURE_TEST. This commit therefore handles the general case
of CONFIG_[A-Z]*_TORTURE_TEST.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

torture: Rename RCU_KMAKE_ARG to TORTURE_KMAKE_ARG

This commit makes the torture scripts a bit more RCU-independent by
changing RCU_KMAKE_ARG to TORTURE_KMAKE_ARG. It also removes the
unnecessary export command.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

torture: Rename RCU_INITRD to TORTURE_INITRD

This commit makes the torture scripts a bit more RCU-independent.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

rcutorture: Stop tracking FSF's postal address

All of the rcutorture scripts has the usual GPL header, which contains
a long-obsolete postal address for FSF. To avoid the need to track the
FSF office's movements, this commit substitutes the URL where GPL may
be found.

Reported-by: Greg KH <gregkh@linuxfoundation.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

rcutorture: Add --kmake-arg argument to kvm.sh

This commit adds the --kmake-arg to kvm.sh, which allows passing in
things like "V=1" to see the build commands, as well as enabling the
CROSS_COMPILE= make macro used for cross-building.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>

rcutorture: Add --no-initrd argument to kvm.sh

This commit adds the --no-initrd argument to kvm.sh, which permits
initrd to be contained in a root partition specified by the --bootargs
argument. Without --no-initrd, the kernel build expects an initrd
directory in the same rcutorture directory that contains bin and configs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>

rcutorture: Add KVM-based test framework

This commit adds the test framework that I used to test RCU under KVM.
This consists of a group of scripts and Kconfig fragments.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>