torture: Drop trailing ^M from console output

Console logs can sometimes have trailing control-M characters, which the
forward-progress evaluation code in kvm-recheck-rcu.sh passes through
to the user output. Which does not cause a technical problem, but which
can look ugly. This commit therefore strips the control-M characters.

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

rcutorture: Combine n_max_cbs from all kthreads in a callback flood

With the addition of multiple callback-flood kthreads, the maximum number
of callbacks from any one of those kthreads is reported in the rcutorture
run summary. This commit changes this to report the sum of each kthread's
maximum number of callbacks in a given callback-flooding episode.

Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

torture: Fix grace-period rate output

The kvm-again.sh script relies on shell comments added to the qemu-cmd
file, but this means that code extracting values from the QEMU command in
this file must grep out those commment. Which kvm-recheck-rcu.sh failed
to do, which destroyed its grace-period-per-second calculation. This
commit therefore adds the needed "grep -v '^#'" to kvm-recheck-rcu.sh.

Fixes: 315957cad445 ("torture: Prepare for splitting qemu execution from kvm-test-1-run.sh")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

rcutorture: Make kvm-recheck-rcu.sh handle truncated lines

System hangs or killed rcutorture guest OSes can result in truncated
"Reader Pipe:" lines, which can in turn result in false-positive
reader-batch near-miss warnings. This commit therefore adjusts the
reader-batch checks to account for possible line truncation.

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

rcutorture: Add worst-case call_rcu() forward-progress results

This commit adds the worst-case results from any call_rcu()
forward-progress tests to the rcutorture test-summary output.

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

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>

rcutorture: Make kvm-find-errors.sh find close calls

Although warnings about close calls are printed by kvm-recheck.sh,
kvm-find-errors.sh currently ignores them. This could easily result
in someone failing to investigate close calls, so this commit makes
them visible to kvm-find-errors.sh.

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

rcutorture: Abbreviate kvm.sh summary lines

With the addition of the end-of-test state, it is not uncommon for the
kvm.sh summary lines to overflow 80 characters. This commit therefore
applies abbreviations in order to make the line fit into 80 characters
with high probability.

And yes, I did make heavy use of punched cards back in the day, so 80
columns it is for my xterms! ;-)

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

rcutorture: Print end-of-test state in kvm.sh summary

This commit adds the end-of-test test, if present in the console output,
to the kvm.sh test summary that is printed by kvm-recheck.sh. Note that
this only applies to rcutorture console output.

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

rcutorture: Simplify functions.sh include path

Inclusions of 'functions.sh' from 'kvm-test-1-run.sh' and
'kvm-recheck*.sh' use its absolute path. Because the directory containing
'functions.sh' is already in PATH, the full path is unnecessary. This
commit therefore simplifies the inclusions to use the short relative path.

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

rcutorture/kvm-recheck-*: Improve result directory readability check

The kvm-recheck-(lock|rcu|rcuperf).sh scripts check whether the
user-specified results directory exists. If not, it prints out error
message that says the specified directory is unreadable. To make the
message more precise, this commit adds a readability check.

Fixes: 2193e1604eac ("rcutorture: Abstract kvm-recheck.sh")

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

rcutorture: Issue warnings on close calls due to Reader Batch blows

Normal rcutorture checking overestimates grace periods somewhat due to
the fact that there is a delay from a grace-period request until the
start of the corresponding grace period and another delay from the end
of that grace period to notification of the requestor. This means that
rcutorture's detection of RCU bugs is less sensitive than it might be.

It turns out that rcutorture also checks the underlying grace-period
"completed" counter (displayed in Reader Batch output), which in theory
allows rcutorture to do exact checks. In practice, memory misordering
(by both compiler and CPU) can result in false positives. However,
experience on x86 shows that these false positives are quite rare,
occurring less than one time per 1,000 hours of testing. This commit
therefore does the exact checking, giving a warning if any Reader Batch
blows happen, and flagging an error if they happen more often than
once every three hours in long tests.

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: Better summary diagnostics for build failures

The reaction of kvm-recheck.sh is obscure at best, and easy to miss
completely. This commit therefore prints "BUG: Build failed" in the
summary at the end of a run. This commit also adds the line of dashes
in cases where performance info is not available, and also avoids
printing nonsense diagnostics in cases where some of the normal test
output is not available. In addition, this commit saves off the .config
file even when the build fails.

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

rcutorture: Abstract kvm-recheck.sh

This commit creates a plug-in to allow kvm-recheck.sh to process
non-rcutorture console output.

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