Commit 60eb4507 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'lkmm-scripting.2023.04.07a' of...

Merge tag 'lkmm-scripting.2023.04.07a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull Linux Kernel Memory Model scripting updates from Paul McKenney:
 "This improves litmus-test documentation and improves the ability to do
  before/after tests on the https://github.com/paulmckrcu/litmus repo"

* tag 'lkmm-scripting.2023.04.07a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (32 commits)
  tools/memory-model: Remove out-of-date SRCU documentation
  tools/memory-model: Document LKMM test procedure
  tools/memory-model: Use "grep -E" instead of "egrep"
  tools/memory-model: Use "-unroll 0" to keep --hw runs finite
  tools/memory-model: Make judgelitmus.sh handle scripted Result: tag
  tools/memory-model: Add data-race capabilities to judgelitmus.sh
  tools/memory-model: Add checktheselitmus.sh to run specified litmus tests
  tools/memory-model: Repair parseargs.sh header comment
  tools/memory-model:  Add "--" to parseargs.sh for additional arguments
  tools/memory-model: Make history-check scripts use mselect7
  tools/memory-model: Make checkghlitmus.sh use mselect7
  tools/memory-model: Fix scripting --jobs argument
  tools/memory-model: Implement --hw support for checkghlitmus.sh
  tools/memory-model: Add -v flag to jingle7 runs
  tools/memory-model: Make runlitmus.sh check for jingle errors
  tools/memory-model: Allow herd to deduce CPU type
  tools/memory-model: Keep assembly-language litmus tests
  tools/memory-model: Move from .AArch64.litmus.out to .litmus.AArch.out
  tools/memory-model: Make runlitmus.sh generate .litmus.out for --hw
  tools/memory-model: Split runlitmus.sh out of checklitmus.sh
  ...
parents 40603735 cc4a2981
C DCL-broken
(*
* Result: Sometimes
*
* This litmus test demonstrates more than just locking is required to
* correctly implement double-checked locking.
*)
{
int flag;
int data;
}
P0(int *flag, int *data, spinlock_t *lck)
{
int r0;
int r1;
int r2;
r0 = READ_ONCE(*flag);
if (r0 == 0) {
spin_lock(lck);
r1 = READ_ONCE(*flag);
if (r1 == 0) {
WRITE_ONCE(*data, 1);
WRITE_ONCE(*flag, 1);
}
spin_unlock(lck);
}
r2 = READ_ONCE(*data);
}
P1(int *flag, int *data, spinlock_t *lck)
{
int r0;
int r1;
int r2;
r0 = READ_ONCE(*flag);
if (r0 == 0) {
spin_lock(lck);
r1 = READ_ONCE(*flag);
if (r1 == 0) {
WRITE_ONCE(*data, 1);
WRITE_ONCE(*flag, 1);
}
spin_unlock(lck);
}
r2 = READ_ONCE(*data);
}
locations [flag;data;0:r0;0:r1;1:r0;1:r1]
exists (0:r2=0 \/ 1:r2=0)
C DCL-fixed
(*
* Result: Never
*
* This litmus test demonstrates that double-checked locking can be
* reliable given proper use of smp_load_acquire() and smp_store_release()
* in addition to the locking.
*)
{
int flag;
int data;
}
P0(int *flag, int *data, spinlock_t *lck)
{
int r0;
int r1;
int r2;
r0 = smp_load_acquire(flag);
if (r0 == 0) {
spin_lock(lck);
r1 = READ_ONCE(*flag);
if (r1 == 0) {
WRITE_ONCE(*data, 1);
smp_store_release(flag, 1);
}
spin_unlock(lck);
}
r2 = READ_ONCE(*data);
}
P1(int *flag, int *data, spinlock_t *lck)
{
int r0;
int r1;
int r2;
r0 = smp_load_acquire(flag);
if (r0 == 0) {
spin_lock(lck);
r1 = READ_ONCE(*flag);
if (r1 == 0) {
WRITE_ONCE(*data, 1);
smp_store_release(flag, 1);
}
spin_unlock(lck);
}
r2 = READ_ONCE(*data);
}
locations [flag;data;0:r0;0:r1;1:r0;1:r1]
exists (0:r2=0 \/ 1:r2=0)
C RM-broken
(*
* Result: DEADLOCK
*
* This litmus test demonstrates that the old "roach motel" approach
* to locking, where code can be freely moved into critical sections,
* cannot be used in the Linux kernel.
*)
{
int x;
atomic_t y;
}
P0(int *x, atomic_t *y, spinlock_t *lck)
{
int r2;
spin_lock(lck);
r2 = atomic_inc_return(y);
WRITE_ONCE(*x, 1);
spin_unlock(lck);
}
P1(int *x, atomic_t *y, spinlock_t *lck)
{
int r0;
int r1;
int r2;
spin_lock(lck);
r0 = READ_ONCE(*x);
r1 = READ_ONCE(*x);
r2 = atomic_inc_return(y);
spin_unlock(lck);
}
locations [x;0:r2;1:r0;1:r1;1:r2]
filter (1:r0=0 /\ 1:r1=1)
exists (1:r2=1)
C RM-fixed
(*
* Result: Never
*
* This litmus test demonstrates that the old "roach motel" approach
* to locking, where code can be freely moved into critical sections,
* cannot be used in the Linux kernel.
*)
{
int x;
atomic_t y;
}
P0(int *x, atomic_t *y, spinlock_t *lck)
{
int r2;
spin_lock(lck);
r2 = atomic_inc_return(y);
WRITE_ONCE(*x, 1);
spin_unlock(lck);
}
P1(int *x, atomic_t *y, spinlock_t *lck)
{
int r0;
int r1;
int r2;
r0 = READ_ONCE(*x);
r1 = READ_ONCE(*x);
spin_lock(lck);
r2 = atomic_inc_return(y);
spin_unlock(lck);
}
locations [x;0:r2;1:r0;1:r1;1:r2]
filter (1:r0=0 /\ 1:r1=1)
exists (1:r2=1)
......@@ -1028,32 +1028,7 @@ Limitations of the Linux-kernel memory model (LKMM) include:
additional call_rcu() process to the site of the
emulated rcu-barrier().
e. Although sleepable RCU (SRCU) is now modeled, there
are some subtle differences between its semantics and
those in the Linux kernel. For example, the kernel
might interpret the following sequence as two partially
overlapping SRCU read-side critical sections:
1 r1 = srcu_read_lock(&my_srcu);
2 do_something_1();
3 r2 = srcu_read_lock(&my_srcu);
4 do_something_2();
5 srcu_read_unlock(&my_srcu, r1);
6 do_something_3();
7 srcu_read_unlock(&my_srcu, r2);
In contrast, LKMM will interpret this as a nested pair of
SRCU read-side critical sections, with the outer critical
section spanning lines 1-7 and the inner critical section
spanning lines 3-5.
This difference would be more of a concern had anyone
identified a reasonable use case for partially overlapping
SRCU read-side critical sections. For more information
on the trickiness of such overlapping, please see:
https://paulmck.livejournal.com/40593.html
f. Reader-writer locking is not modeled. It can be
e. Reader-writer locking is not modeled. It can be
emulated in litmus tests using atomic read-modify-write
operations.
......
Locking
=======
Locking is well-known and the common use cases are straightforward: Any
CPU holding a given lock sees any changes previously seen or made by any
CPU before it previously released that same lock. This last sentence
is the only part of this document that most developers will need to read.
However, developers who would like to also access lock-protected shared
variables outside of their corresponding locks should continue reading.
Locking and Prior Accesses
--------------------------
The basic rule of locking is worth repeating:
Any CPU holding a given lock sees any changes previously seen
or made by any CPU before it previously released that same lock.
Note that this statement is a bit stronger than "Any CPU holding a
given lock sees all changes made by any CPU during the time that CPU was
previously holding this same lock". For example, consider the following
pair of code fragments:
/* See MP+polocks.litmus. */
void CPU0(void)
{
WRITE_ONCE(x, 1);
spin_lock(&mylock);
WRITE_ONCE(y, 1);
spin_unlock(&mylock);
}
void CPU1(void)
{
spin_lock(&mylock);
r0 = READ_ONCE(y);
spin_unlock(&mylock);
r1 = READ_ONCE(x);
}
The basic rule guarantees that if CPU0() acquires mylock before CPU1(),
then both r0 and r1 must be set to the value 1. This also has the
consequence that if the final value of r0 is equal to 1, then the final
value of r1 must also be equal to 1. In contrast, the weaker rule would
say nothing about the final value of r1.
Locking and Subsequent Accesses
-------------------------------
The converse to the basic rule also holds: Any CPU holding a given
lock will not see any changes that will be made by any CPU after it
subsequently acquires this same lock. This converse statement is
illustrated by the following litmus test:
/* See MP+porevlocks.litmus. */
void CPU0(void)
{
r0 = READ_ONCE(y);
spin_lock(&mylock);
r1 = READ_ONCE(x);
spin_unlock(&mylock);
}
void CPU1(void)
{
spin_lock(&mylock);
WRITE_ONCE(x, 1);
spin_unlock(&mylock);
WRITE_ONCE(y, 1);
}
This converse to the basic rule guarantees that if CPU0() acquires
mylock before CPU1(), then both r0 and r1 must be set to the value 0.
This also has the consequence that if the final value of r1 is equal
to 0, then the final value of r0 must also be equal to 0. In contrast,
the weaker rule would say nothing about the final value of r0.
These examples show only a single pair of CPUs, but the effects of the
locking basic rule extend across multiple acquisitions of a given lock
across multiple CPUs.
Double-Checked Locking
----------------------
It is well known that more than just a lock is required to make
double-checked locking work correctly, This litmus test illustrates
one incorrect approach:
/* See Documentation/litmus-tests/locking/DCL-broken.litmus. */
void CPU0(void)
{
r0 = READ_ONCE(flag);
if (r0 == 0) {
spin_lock(&lck);
r1 = READ_ONCE(flag);
if (r1 == 0) {
WRITE_ONCE(data, 1);
WRITE_ONCE(flag, 1);
}
spin_unlock(&lck);
}
r2 = READ_ONCE(data);
}
/* CPU1() is the exactly the same as CPU0(). */
There are two problems. First, there is no ordering between the first
READ_ONCE() of "flag" and the READ_ONCE() of "data". Second, there is
no ordering between the two WRITE_ONCE() calls. It should therefore be
no surprise that "r2" can be zero, and a quick herd7 run confirms this.
One way to fix this is to use smp_load_acquire() and smp_store_release()
as shown in this corrected version:
/* See Documentation/litmus-tests/locking/DCL-fixed.litmus. */
void CPU0(void)
{
r0 = smp_load_acquire(&flag);
if (r0 == 0) {
spin_lock(&lck);
r1 = READ_ONCE(flag);
if (r1 == 0) {
WRITE_ONCE(data, 1);
smp_store_release(&flag, 1);
}
spin_unlock(&lck);
}
r2 = READ_ONCE(data);
}
/* CPU1() is the exactly the same as CPU0(). */
The smp_load_acquire() guarantees that its load from "flags" will
be ordered before the READ_ONCE() from data, thus solving the first
problem. The smp_store_release() guarantees that its store will be
ordered after the WRITE_ONCE() to "data", solving the second problem.
The smp_store_release() pairs with the smp_load_acquire(), thus ensuring
that the ordering provided by each actually takes effect. Again, a
quick herd7 run confirms this.
In short, if you access a lock-protected variable without holding the
corresponding lock, you will need to provide additional ordering, in
this case, via the smp_load_acquire() and the smp_store_release().
Ordering Provided by a Lock to CPUs Not Holding That Lock
---------------------------------------------------------
It is not necessarily the case that accesses ordered by locking will be
seen as ordered by CPUs not holding that lock. Consider this example:
/* See Z6.0+pooncelock+pooncelock+pombonce.litmus. */
void CPU0(void)
{
spin_lock(&mylock);
WRITE_ONCE(x, 1);
WRITE_ONCE(y, 1);
spin_unlock(&mylock);
}
void CPU1(void)
{
spin_lock(&mylock);
r0 = READ_ONCE(y);
WRITE_ONCE(z, 1);
spin_unlock(&mylock);
}
void CPU2(void)
{
WRITE_ONCE(z, 2);
smp_mb();
r1 = READ_ONCE(x);
}
Counter-intuitive though it might be, it is quite possible to have
the final value of r0 be 1, the final value of z be 2, and the final
value of r1 be 0. The reason for this surprising outcome is that CPU2()
never acquired the lock, and thus did not fully benefit from the lock's
ordering properties.
Ordering can be extended to CPUs not holding the lock by careful use
of smp_mb__after_spinlock():
/* See Z6.0+pooncelock+poonceLock+pombonce.litmus. */
void CPU0(void)
{
spin_lock(&mylock);
WRITE_ONCE(x, 1);
WRITE_ONCE(y, 1);
spin_unlock(&mylock);
}
void CPU1(void)
{
spin_lock(&mylock);
smp_mb__after_spinlock();
r0 = READ_ONCE(y);
WRITE_ONCE(z, 1);
spin_unlock(&mylock);
}
void CPU2(void)
{
WRITE_ONCE(z, 2);
smp_mb();
r1 = READ_ONCE(x);
}
This addition of smp_mb__after_spinlock() strengthens the lock
acquisition sufficiently to rule out the counter-intuitive outcome.
In other words, the addition of the smp_mb__after_spinlock() prohibits
the counter-intuitive result where the final value of r0 is 1, the final
value of z is 2, and the final value of r1 is 0.
No Roach-Motel Locking!
-----------------------
This example requires familiarity with the herd7 "filter" clause, so
please read up on that topic in litmus-tests.txt.
It is tempting to allow memory-reference instructions to be pulled
into a critical section, but this cannot be allowed in the general case.
For example, consider a spin loop preceding a lock-based critical section.
Now, herd7 does not model spin loops, but we can emulate one with two
loads, with a "filter" clause to constrain the first to return the
initial value and the second to return the updated value, as shown below:
/* See Documentation/litmus-tests/locking/RM-fixed.litmus. */
void CPU0(void)
{
spin_lock(&lck);
r2 = atomic_inc_return(&y);
WRITE_ONCE(x, 1);
spin_unlock(&lck);
}
void CPU1(void)
{
r0 = READ_ONCE(x);
r1 = READ_ONCE(x);
spin_lock(&lck);
r2 = atomic_inc_return(&y);
spin_unlock(&lck);
}
filter (1:r0=0 /\ 1:r1=1)
exists (1:r2=1)
The variable "x" is the control variable for the emulated spin loop.
CPU0() sets it to "1" while holding the lock, and CPU1() emulates the
spin loop by reading it twice, first into "1:r0" (which should get the
initial value "0") and then into "1:r1" (which should get the updated
value "1").
The "filter" clause takes this into account, constraining "1:r0" to
equal "0" and "1:r1" to equal 1.
Then the "exists" clause checks to see if CPU1() acquired its lock first,
which should not happen given the filter clause because CPU0() updates
"x" while holding the lock. And herd7 confirms this.
But suppose that the compiler was permitted to reorder the spin loop
into CPU1()'s critical section, like this:
/* See Documentation/litmus-tests/locking/RM-broken.litmus. */
void CPU0(void)
{
int r2;
spin_lock(&lck);
r2 = atomic_inc_return(&y);
WRITE_ONCE(x, 1);
spin_unlock(&lck);
}
void CPU1(void)
{
spin_lock(&lck);
r0 = READ_ONCE(x);
r1 = READ_ONCE(x);
r2 = atomic_inc_return(&y);
spin_unlock(&lck);
}
filter (1:r0=0 /\ 1:r1=1)
exists (1:r2=1)
If "1:r0" is equal to "0", "1:r1" can never equal "1" because CPU0()
cannot update "x" while CPU1() holds the lock. And herd7 confirms this,
showing zero executions matching the "filter" criteria.
And this is why Linux-kernel lock and unlock primitives must prevent
code from entering critical sections. It is not sufficient to only
prevent code from leaving them.
# SPDX-License-Identifier: GPL-2.0-only
*.litmus.out
*.litmus.*
......@@ -27,6 +27,14 @@ checklitmushist.sh
checklitmus.sh
Check a single litmus test against its "Result:" expected result.
Not intended to for manual use.
checktheselitmus.sh
Check the specified list of litmus tests against their "Result:"
expected results. This takes optional parseargs.sh arguments,
followed by "--" followed by pathnames starting from the current
directory.
cmplitmushist.sh
......@@ -43,10 +51,10 @@ initlitmushist.sh
judgelitmus.sh
Given a .litmus file and its .litmus.out herd7 output, check the
.litmus.out file against the .litmus file's "Result:" comment to
judge whether the test ran correctly. Not normally run manually,
provided instead for use by other scripts.
Given a .litmus file and its herd7 output, check the output file
against the .litmus file's "Result:" comment to judge whether
the test ran correctly. Not normally run manually, provided
instead for use by other scripts.
newlitmushist.sh
......@@ -68,3 +76,35 @@ runlitmushist.sh
README
This file
Testing a change to LKMM might go as follows:
# Populate expected results without that change, and
# runs for about an hour on an 8-CPU x86 system:
scripts/initlitmushist.sh --timeout 10m --procs 10
# Incorporate the change:
git am -s -3 /path/to/patch # Or whatever it takes.
# Test the new version of LKMM as follows...
# Runs in seconds, good smoke test:
scripts/checkalllitmus.sh
# Compares results to those produced by initlitmushist.sh,
# and runs for about an hour on an 8-CPU x86 system:
scripts/checklitmushist.sh --timeout 10m --procs 10
# Checks results against Result tags, runs in minutes:
scripts/checkghlitmus.sh --timeout 10m --procs 10
The checkghlitmus.sh should not report errors in cases where the
checklitmushist.sh script did not also report a change. However,
this check is nevertheless valuable because it can find errors in the
original version of LKMM. Note however, that given the above procedure,
an error in the original LKMM version that is fixed by the patch will
be reported both as a mismatch by checklitmushist.sh and as an error
by checkghlitmus.sh. One exception to this rule of thumb is when the
test fails completely on the original version of LKMM and passes on the
new version. In this case, checklitmushist.sh will report a mismatch
and checkghlitmus.sh will report success. This happens when the change
to LKMM introduces a new primitive for which litmus tests already existed.
#!/bin/sh
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+
#
# Run herd7 tests on all .litmus files in the litmus-tests directory
......@@ -8,6 +8,11 @@
# "^^^". It also outputs verification results to a file whose name is
# that of the specified litmus test, but with ".out" appended.
#
# If the --hw argument is specified, this script translates the .litmus
# C-language file to the specified type of assembly and verifies that.
# But in this case, litmus tests using complex synchronization (such as
# locking, RCU, and SRCU) are cheerfully ignored.
#
# Usage:
# checkalllitmus.sh
#
......@@ -17,7 +22,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
. scripts/parseargs.sh
......@@ -30,29 +35,23 @@ else
exit 255
fi
# Create any new directories that have appeared in the github litmus
# repo since the last run.
# Create any new directories that have appeared in the litmus-tests
# directory since the last run.
if test "$LKMM_DESTDIR" != "."
then
find $litmusdir -type d -print |
( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
fi
# Find the checklitmus script. If it is not where we expect it, then
# assume that the caller has the PATH environment variable set
# appropriately.
if test -x scripts/checklitmus.sh
then
clscript=scripts/checklitmus.sh
else
clscript=checklitmus.sh
fi
# Run the script on all the litmus tests in the specified directory
ret=0
for i in $litmusdir/*.litmus
do
if ! $clscript $i
if test -n "$LKMM_HW_MAP_FILE" && ! scripts/simpletest.sh $i
then
continue
fi
if ! scripts/checklitmus.sh $i
then
ret=1
fi
......
......@@ -10,6 +10,7 @@
# parseargs.sh scripts for arguments.
. scripts/parseargs.sh
. scripts/hwfnseg.sh
T=/tmp/checkghlitmus.sh.$$
trap 'rm -rf $T' 0
......@@ -32,19 +33,19 @@ then
( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
fi
# Create a list of the C-language litmus tests previously run.
( cd $LKMM_DESTDIR; find litmus -name '*.litmus.out' -print ) |
sed -e 's/\.out$//' |
xargs -r egrep -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' |
# Create a list of the specified litmus tests previously run.
( cd $LKMM_DESTDIR; find litmus -name "*.litmus${hwfnseg}.out" -print ) |
sed -e "s/${hwfnseg}"'\.out$//' |
xargs -r grep -E -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' |
xargs -r grep -L "^P${LKMM_PROCS}"> $T/list-C-already
# Create a list of C-language litmus tests with "Result:" commands and
# no more than the specified number of processes.
find litmus -name '*.litmus' -exec grep -l -m 1 "^C " {} \; > $T/list-C
xargs < $T/list-C -r egrep -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' > $T/list-C-result
find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C
xargs < $T/list-C -r grep -E -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' > $T/list-C-result
xargs < $T/list-C-result -r grep -L "^P${LKMM_PROCS}" > $T/list-C-result-short
# Form list of tests without corresponding .litmus.out files
# Form list of tests without corresponding .out files
sort $T/list-C-already $T/list-C-result-short | uniq -u > $T/list-C-needed
# Run any needed tests.
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Run a herd7 test and invokes judgelitmus.sh to check the result against
# a "Result:" comment within the litmus test. It also outputs verification
# results to a file whose name is that of the specified litmus test, but
# with ".out" appended.
# Invokes runlitmus.sh and judgelitmus.sh on its arguments to run the
# specified litmus test and pass judgment on the results.
#
# Usage:
# checklitmus.sh file.litmus
......@@ -15,20 +13,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
litmus=$1
herdoptions=${LKMM_HERD_OPTIONS--conf linux-kernel.cfg}
if test -f "$litmus" -a -r "$litmus"
then
:
else
echo ' --- ' error: \"$litmus\" is not a readable file
exit 255
fi
echo Herd options: $herdoptions > $LKMM_DESTDIR/$litmus.out
/usr/bin/time $LKMM_TIMEOUT_CMD herd7 $herdoptions $litmus >> $LKMM_DESTDIR/$litmus.out 2>&1
scripts/judgelitmus.sh $litmus
scripts/runlitmus.sh $1
scripts/judgelitmus.sh $1
......@@ -12,7 +12,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
. scripts/parseargs.sh
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Invokes checklitmus.sh on its arguments to run the specified litmus
# test and pass judgment on the results.
#
# Usage:
# checktheselitmus.sh -- [ file1.litmus [ file2.litmus ... ] ]
#
# Run this in the directory containing the memory model, specifying the
# pathname of the litmus test to check. The usual parseargs.sh arguments
# can be specified prior to the "--".
#
# This script is intended for use with pathnames that start from the
# tools/memory-model directory. If some of the pathnames instead start at
# the root directory, they all must do so and the "--destdir /" parseargs.sh
# argument must be specified prior to the "--". Alternatively, some other
# "--destdir" argument can be supplied as long as the needed subdirectories
# are populated.
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
. scripts/parseargs.sh
ret=0
for i in "$@"
do
if scripts/checklitmus.sh $i
then
:
else
ret=1
fi
done
if test "$ret" -ne 0
then
echo " ^^^ VERIFICATION MISMATCHES" 1>&2
else
echo All litmus tests verified as was expected. 1>&2
fi
exit $ret
......@@ -12,12 +12,49 @@ trap 'rm -rf $T' 0
mkdir $T
# comparetest oldpath newpath
badmacnam=0
timedout=0
perfect=0
obsline=0
noobsline=0
obsresult=0
badcompare=0
comparetest () {
if grep -q ': Unknown macro ' $1 || grep -q ': Unknown macro ' $2
then
if grep -q ': Unknown macro ' $1
then
badname=`grep ': Unknown macro ' $1 |
sed -e 's/^.*: Unknown macro //' |
sed -e 's/ (User error).*$//'`
echo 'Current LKMM version does not know "'$badname'"' $1
fi
if grep -q ': Unknown macro ' $2
then
badname=`grep ': Unknown macro ' $2 |
sed -e 's/^.*: Unknown macro //' |
sed -e 's/ (User error).*$//'`
echo 'Current LKMM version does not know "'$badname'"' $2
fi
badmacnam=`expr "$badmacnam" + 1`
return 0
elif grep -q '^Command exited with non-zero status 124' $1 ||
grep -q '^Command exited with non-zero status 124' $2
then
if grep -q '^Command exited with non-zero status 124' $1 &&
grep -q '^Command exited with non-zero status 124' $2
then
echo Both runs timed out: $2
elif grep -q '^Command exited with non-zero status 124' $1
then
echo Old run timed out: $2
elif grep -q '^Command exited with non-zero status 124' $2
then
echo New run timed out: $2
fi
timedout=`expr "$timedout" + 1`
return 0
fi
grep -v 'maxresident)k\|minor)pagefaults\|^Time' $1 > $T/oldout
grep -v 'maxresident)k\|minor)pagefaults\|^Time' $2 > $T/newout
if cmp -s $T/oldout $T/newout && grep -q '^Observation' $1
......@@ -38,7 +75,7 @@ comparetest () {
return 0
fi
else
echo Missing Observation line "(e.g., herd7 timeout)": $2
echo Missing Observation line "(e.g., syntax error)": $2
noobsline=`expr "$noobsline" + 1`
return 0
fi
......@@ -72,12 +109,20 @@ then
fi
if test "$noobsline" -ne 0
then
echo Missing Observation line "(e.g., herd7 timeout)": $noobsline 1>&2
echo Missing Observation line "(e.g., syntax error)": $noobsline 1>&2
fi
if test "$obsresult" -ne 0
then
echo Matching Observation Always/Sometimes/Never result: $obsresult 1>&2
fi
if test "$timedout" -ne 0
then
echo "!!!" Timed out: $timedout 1>&2
fi
if test "$badmacnam" -ne 0
then
echo "!!!" Unknown primitive: $badmacnam 1>&2
fi
if test "$badcompare" -ne 0
then
echo "!!!" Result changed: $badcompare 1>&2
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Generate the hardware extension to the litmus-test filename, or the
# empty string if this is an LKMM run. The extension is placed in
# the shell variable hwfnseg.
#
# Usage:
# . hwfnseg.sh
#
# Copyright IBM Corporation, 2019
#
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
if test -z "$LKMM_HW_MAP_FILE"
then
hwfnseg=
else
hwfnseg=".$LKMM_HW_MAP_FILE"
fi
......@@ -60,7 +60,7 @@ fi
# Create a list of the C-language litmus tests with no more than the
# specified number of processes (per the --procs argument).
find litmus -name '*.litmus' -exec grep -l -m 1 "^C " {} \; > $T/list-C
find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C
xargs < $T/list-C -r grep -L "^P${LKMM_PROCS}" > $T/list-C-short
scripts/runlitmushist.sh < $T/list-C-short
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Given a .litmus test and the corresponding .litmus.out file, check
# the .litmus.out file against the "Result:" comment to judge whether
# the test ran correctly.
# Given a .litmus test and the corresponding litmus output file, check
# the .litmus.out file against the "Result:" comment to judge whether the
# test ran correctly. If the --hw argument is omitted, check against the
# LKMM output, which is assumed to be in file.litmus.out. If either a
# "DATARACE" marker in the "Result:" comment or a "Flag data-race" marker
# in the LKMM output is present, the other must also be as well, at least
# for litmus tests having a "Result:" comment. In this case, a failure of
# the Always/Sometimes/Never portion of the "Result:" prediction will be
# noted, but forgiven.
#
# If the --hw argument is provided, this is assumed to be a hardware
# test, and the output is assumed to be in file.litmus.HW.out, where
# "HW" is the --hw argument. In addition, non-Sometimes verification
# results will be noted, but forgiven. Furthermore, if there is no
# "Result:" comment but there is an LKMM .litmus.out file, the observation
# in that file will be used to judge the assembly-language verification.
#
# Usage:
# judgelitmus.sh file.litmus
......@@ -13,7 +26,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
litmus=$1
......@@ -24,55 +37,120 @@ else
echo ' --- ' error: \"$litmus\" is not a readable file
exit 255
fi
if test -f "$LKMM_DESTDIR/$litmus".out -a -r "$LKMM_DESTDIR/$litmus".out
if test -z "$LKMM_HW_MAP_FILE"
then
litmusout=$litmus.out
lkmmout=
else
litmusout="`echo $litmus |
sed -e 's/\.litmus$/.litmus.'${LKMM_HW_MAP_FILE}'/'`.out"
lkmmout=$litmus.out
fi
if test -f "$LKMM_DESTDIR/$litmusout" -a -r "$LKMM_DESTDIR/$litmusout"
then
:
else
echo ' --- ' error: \"$LKMM_DESTDIR/$litmus\".out is not a readable file
echo ' --- ' error: \"$LKMM_DESTDIR/$litmusout is not a readable file
exit 255
fi
if grep -q '^ \* Result: ' $litmus
if grep -q '^Flag data-race$' "$LKMM_DESTDIR/$litmusout"
then
outcome=`grep -m 1 '^ \* Result: ' $litmus | awk '{ print $3 }'`
datarace_modeled=1
fi
if grep -q '^[( ]\* Result: ' $litmus
then
outcome=`grep -m 1 '^[( ]\* Result: ' $litmus | awk '{ print $3 }'`
if grep -m1 '^[( ]\* Result: .* DATARACE' $litmus
then
datarace_predicted=1
fi
if test -n "$datarace_predicted" -a -z "$datarace_modeled" -a -z "$LKMM_HW_MAP_FILE"
then
echo '!!! Predicted data race not modeled' $litmus
exit 252
elif test -z "$datarace_predicted" -a -n "$datarace_modeled"
then
# Note that hardware models currently don't model data races
echo '!!! Unexpected data race modeled' $litmus
exit 253
fi
elif test -n "$LKMM_HW_MAP_FILE" && grep -q '^Observation' $LKMM_DESTDIR/$lkmmout > /dev/null 2>&1
then
outcome=`grep -m 1 '^Observation ' $LKMM_DESTDIR/$lkmmout | awk '{ print $3 }'`
else
outcome=specified
fi
grep '^Observation' $LKMM_DESTDIR/$litmus.out
if grep -q '^Observation' $LKMM_DESTDIR/$litmus.out
grep '^Observation' $LKMM_DESTDIR/$litmusout
if grep -q '^Observation' $LKMM_DESTDIR/$litmusout
then
:
elif grep ': Unknown macro ' $LKMM_DESTDIR/$litmusout
then
badname=`grep ': Unknown macro ' $LKMM_DESTDIR/$litmusout |
sed -e 's/^.*: Unknown macro //' |
sed -e 's/ (User error).*$//'`
badmsg=' !!! Current LKMM version does not know "'$badname'"'" $litmus"
echo $badmsg
if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
then
echo ' !!! '$badmsg >> $LKMM_DESTDIR/$litmusout 2>&1
fi
exit 254
elif grep '^Command exited with non-zero status 124' $LKMM_DESTDIR/$litmusout
then
echo ' !!! Timeout' $litmus
if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
then
echo ' !!! Timeout' >> $LKMM_DESTDIR/$litmusout 2>&1
fi
exit 124
else
echo ' !!! Verification error' $litmus
if ! grep -q '!!!' $LKMM_DESTDIR/$litmus.out
if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
then
echo ' !!! Verification error' >> $LKMM_DESTDIR/$litmus.out 2>&1
echo ' !!! Verification error' >> $LKMM_DESTDIR/$litmusout 2>&1
fi
exit 255
fi
if test "$outcome" = DEADLOCK
then
if grep '^Observation' $LKMM_DESTDIR/$litmus.out | grep -q 'Never 0 0$'
if grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q 'Never 0 0$'
then
ret=0
else
echo " !!! Unexpected non-$outcome verification" $litmus
if ! grep -q '!!!' $LKMM_DESTDIR/$litmus.out
if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
then
echo " !!! Unexpected non-$outcome verification" >> $LKMM_DESTDIR/$litmus.out 2>&1
echo " !!! Unexpected non-$outcome verification" >> $LKMM_DESTDIR/$litmusout 2>&1
fi
ret=1
fi
elif grep '^Observation' $LKMM_DESTDIR/$litmus.out | grep -q $outcome || test "$outcome" = Maybe
elif grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q 'Never 0 0$'
then
echo " !!! Unexpected non-$outcome deadlock" $litmus
if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
then
echo " !!! Unexpected non-$outcome deadlock" $litmus >> $LKMM_DESTDIR/$litmusout 2>&1
fi
ret=1
elif grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q $outcome || test "$outcome" = Maybe
then
ret=0
else
echo " !!! Unexpected non-$outcome verification" $litmus
if ! grep -q '!!!' $LKMM_DESTDIR/$litmus.out
if test \( -n "$LKMM_HW_MAP_FILE" -a "$outcome" = Sometimes \) -o -n "$datarace_modeled"
then
echo " !!! Unexpected non-$outcome verification" >> $LKMM_DESTDIR/$litmus.out 2>&1
fi
flag="--- Forgiven"
ret=0
else
flag="!!! Unexpected"
ret=1
fi
echo " $flag non-$outcome verification" $litmus
if ! grep -qe "$flag" $LKMM_DESTDIR/$litmusout
then
echo " $flag non-$outcome verification" >> $LKMM_DESTDIR/$litmusout 2>&1
fi
fi
tail -2 $LKMM_DESTDIR/$litmus.out | head -1
tail -2 $LKMM_DESTDIR/$litmusout | head -1
exit $ret
......@@ -12,7 +12,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
. scripts/parseargs.sh
......@@ -43,7 +43,7 @@ fi
# Form full list of litmus tests with no more than the specified
# number of processes (per the --procs argument).
find litmus -name '*.litmus' -exec grep -l -m 1 "^C " {} \; > $T/list-C-all
find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C-all
xargs < $T/list-C-all -r grep -L "^P${LKMM_PROCS}" > $T/list-C-short
# Form list of new tests. Note: This does not handle litmus-test deletion!
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# the corresponding .litmus.out file, and does not judge the result.
# Parse arguments common to the various scripts.
#
# . scripts/parseargs.sh
#
......@@ -9,7 +9,7 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
T=/tmp/parseargs.sh.$$
mkdir $T
......@@ -27,6 +27,7 @@ initparam () {
initparam LKMM_DESTDIR "."
initparam LKMM_HERD_OPTIONS "-conf linux-kernel.cfg"
initparam LKMM_HW_MAP_FILE ""
initparam LKMM_JOBS `getconf _NPROCESSORS_ONLN`
initparam LKMM_PROCS "3"
initparam LKMM_TIMEOUT "1m"
......@@ -37,10 +38,11 @@ usagehelp () {
echo "Usage $scriptname [ arguments ]"
echo " --destdir path (place for .litmus.out, default by .litmus)"
echo " --herdopts -conf linux-kernel.cfg ..."
echo " --hw AArch64"
echo " --jobs N (number of jobs, default one per CPU)"
echo " --procs N (litmus tests with at most this many processes)"
echo " --timeout N (herd7 timeout (e.g., 10s, 1m, 2hr, 1d, '')"
echo "Defaults: --destdir '$LKMM_DESTDIR_DEF' --herdopts '$LKMM_HERD_OPTIONS_DEF' --jobs '$LKMM_JOBS_DEF' --procs '$LKMM_PROCS_DEF' --timeout '$LKMM_TIMEOUT_DEF'"
echo "Defaults: --destdir '$LKMM_DESTDIR_DEF' --herdopts '$LKMM_HERD_OPTIONS_DEF' --hw '$LKMM_HW_MAP_FILE' --jobs '$LKMM_JOBS_DEF' --procs '$LKMM_PROCS_DEF' --timeout '$LKMM_TIMEOUT_DEF'"
exit 1
}
......@@ -81,7 +83,7 @@ do
echo "Cannot create directory --destdir '$LKMM_DESTDIR'"
usage
fi
if test -d "$LKMM_DESTDIR" -a -w "$LKMM_DESTDIR" -a -x "$LKMM_DESTDIR"
if test -d "$LKMM_DESTDIR" -a -x "$LKMM_DESTDIR"
then
:
else
......@@ -95,6 +97,11 @@ do
LKMM_HERD_OPTIONS="$2"
shift
;;
--hw)
checkarg --hw "(.map file architecture name)" "$#" "$2" '^[A-Za-z0-9_-]\+' '^--'
LKMM_HW_MAP_FILE="$2"
shift
;;
-j[1-9]*)
njobs="`echo $1 | sed -e 's/^-j//'`"
trailchars="`echo $njobs | sed -e 's/[0-9]\+\(.*\)$/\1/'`"
......@@ -106,7 +113,7 @@ do
LKMM_JOBS="`echo $njobs | sed -e 's/^\([0-9]\+\).*$/\1/'`"
;;
--jobs|--job|-j)
checkarg --jobs "(number)" "$#" "$2" '^[1-9][0-9]\+$' '^--'
checkarg --jobs "(number)" "$#" "$2" '^[1-9][0-9]*$' '^--'
LKMM_JOBS="$2"
shift
;;
......@@ -120,6 +127,10 @@ do
LKMM_TIMEOUT="$2"
shift
;;
--)
shift
break
;;
*)
echo Unknown argument $1
usage
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Without the -hw argument, runs a herd7 test and outputs verification
# results to a file whose name is that of the specified litmus test,
# but with ".out" appended.
#
# If the --hw argument is specified, this script translates the .litmus
# C-language file to the specified type of assembly and verifies that.
# But in this case, litmus tests using complex synchronization (such as
# locking, RCU, and SRCU) are cheerfully ignored.
#
# Either way, return the status of the herd7 command.
#
# Usage:
# runlitmus.sh file.litmus
#
# Run this in the directory containing the memory model, specifying the
# pathname of the litmus test to check. The caller is expected to have
# properly set up the LKMM environment variables.
#
# Copyright IBM Corporation, 2019
#
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
litmus=$1
if test -f "$litmus" -a -r "$litmus"
then
:
else
echo ' !!! ' error: \"$litmus\" is not a readable file
exit 255
fi
if test -z "$LKMM_HW_MAP_FILE" -o ! -e $LKMM_DESTDIR/$litmus.out
then
# LKMM run
herdoptions=${LKMM_HERD_OPTIONS--conf linux-kernel.cfg}
echo Herd options: $herdoptions > $LKMM_DESTDIR/$litmus.out
/usr/bin/time $LKMM_TIMEOUT_CMD herd7 $herdoptions $litmus >> $LKMM_DESTDIR/$litmus.out 2>&1
ret=$?
if test -z "$LKMM_HW_MAP_FILE"
then
exit $ret
fi
echo " --- " Automatically generated LKMM output for '"'--hw $LKMM_HW_MAP_FILE'"' run
fi
# Hardware run
T=/tmp/checklitmushw.sh.$$
trap 'rm -rf $T' 0 2
mkdir $T
# Generate filenames
mapfile="Linux2${LKMM_HW_MAP_FILE}.map"
themefile="$T/${LKMM_HW_MAP_FILE}.theme"
herdoptions="-model $LKMM_HW_CAT_FILE"
hwlitmus=`echo $litmus | sed -e 's/\.litmus$/.litmus.'${LKMM_HW_MAP_FILE}'/'`
hwlitmusfile=`echo $hwlitmus | sed -e 's,^.*/,,'`
# Don't run on litmus tests with complex synchronization
if ! scripts/simpletest.sh $litmus
then
echo ' --- ' error: \"$litmus\" contains locking, RCU, or SRCU
exit 254
fi
# Generate the assembly code and run herd7 on it.
gen_theme7 -n 10 -map $mapfile -call Linux.call > $themefile
jingle7 -v -theme $themefile $litmus > $LKMM_DESTDIR/$hwlitmus 2> $T/$hwlitmusfile.jingle7.out
if grep -q "Generated 0 tests" $T/$hwlitmusfile.jingle7.out
then
echo ' !!! ' jingle7 failed, errors in $hwlitmus.err
cp $T/$hwlitmusfile.jingle7.out $LKMM_DESTDIR/$hwlitmus.err
exit 253
fi
/usr/bin/time $LKMM_TIMEOUT_CMD herd7 -unroll 0 $LKMM_DESTDIR/$hwlitmus > $LKMM_DESTDIR/$hwlitmus.out 2>&1
exit $?
......@@ -13,7 +13,9 @@
#
# Copyright IBM Corporation, 2018
#
# Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
. scripts/hwfnseg.sh
T=/tmp/runlitmushist.sh.$$
trap 'rm -rf $T' 0
......@@ -30,15 +32,12 @@ fi
# Prefixes for per-CPU scripts
for ((i=0;i<$LKMM_JOBS;i++))
do
echo dir="$LKMM_DESTDIR" > $T/$i.sh
echo T=$T >> $T/$i.sh
echo herdoptions=\"$LKMM_HERD_OPTIONS\" >> $T/$i.sh
cat << '___EOF___' >> $T/$i.sh
runtest () {
echo ' ... ' /usr/bin/time $LKMM_TIMEOUT_CMD herd7 $herdoptions $1 '>' $dir/$1.out '2>&1'
if /usr/bin/time $LKMM_TIMEOUT_CMD herd7 $herdoptions $1 > $dir/$1.out 2>&1
if scripts/runlitmus.sh $1
then
if ! grep -q '^Observation ' $dir/$1.out
if ! grep -q '^Observation ' $LKMM_DESTDIR/$1$2.out
then
echo ' !!! Herd failed, no Observation:' $1
fi
......@@ -47,11 +46,17 @@ do
if test "$exitcode" -eq 124
then
exitmsg="timed out"
elif test "$exitcode" -eq 253
then
exitmsg=
else
exitmsg="failed, exit code $exitcode"
fi
if test -n "$exitmsg"
then
echo ' !!! Herd' ${exitmsg}: $1
fi
fi
}
___EOF___
done
......@@ -59,11 +64,13 @@ done
awk -v q="'" -v b='\\' '
{
print "echo `grep " q "^P[0-9]" b "+(" q " " $0 " | tail -1 | sed -e " q "s/^P" b "([0-9]" b "+" b ")(.*$/" b "1/" q "` " $0
}' | bash |
sort -k1n |
awk -v ncpu=$LKMM_JOBS -v t=$T '
}' | sh | sort -k1n |
awk -v dq='"' -v hwfnseg="$hwfnseg" -v ncpu="$LKMM_JOBS" -v t="$T" '
{
print "runtest " $2 >> t "/" NR % ncpu ".sh";
print "if test -z " dq hwfnseg dq " || scripts/simpletest.sh " dq $2 dq
print "then"
print "\techo runtest " dq $2 dq " " hwfnseg " >> " t "/" NR % ncpu ".sh";
print "fi"
}
END {
......
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0+
#
# Give zero status if this is a simple test and non-zero otherwise.
# Simple tests do not contain locking, RCU, or SRCU.
#
# Usage:
# simpletest.sh file.litmus
#
# Copyright IBM Corporation, 2019
#
# Author: Paul E. McKenney <paulmck@linux.ibm.com>
litmus=$1
if test -f "$litmus" -a -r "$litmus"
then
:
else
echo ' --- ' error: \"$litmus\" is not a readable file
exit 255
fi
exclude="^[[:space:]]*\("
exclude="${exclude}spin_lock(\|spin_unlock(\|spin_trylock(\|spin_is_locked("
exclude="${exclude}\|rcu_read_lock(\|rcu_read_unlock("
exclude="${exclude}\|synchronize_rcu(\|synchronize_rcu_expedited("
exclude="${exclude}\|srcu_read_lock(\|srcu_read_unlock("
exclude="${exclude}\|synchronize_srcu(\|synchronize_srcu_expedited("
exclude="${exclude}\)"
if grep -q $exclude $litmus
then
exit 255
fi
exit 0
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment