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#
# This file and its contents are supplied under the terms of the
# Common Development and Distribution License ("CDDL"), version 1.0.
# You may only use this file in accordance with the terms of version
# 1.0 of the CDDL.
#
# A full copy of the text of the CDDL should have accompanied this
# source. A copy of the CDDL is also available via the Internet at
# http://www.illumos.org/license/CDDL.
#
#
# Copyright (c) 2017, Joyent, Inc. All rights reserved.
#
#
# This test attempts to reproduce a three-way deadlock between mod_lock,
# dtrace_lock and P_PR_LOCK that is induced by shmsys having to go through
# mod_hold_stub.
#
if [ $# != 1 ]; then
echo expected one argument: '<'dtrace-path'>'
exit 2
fi
dtrace=$1
DIR=/var/tmp/dtest.$$
mkdir $DIR
cd $DIR
cat > prov.d <<EOF
provider test_prov {
probe ripraf();
};
EOF
$dtrace -h -s prov.d
if [ $? -ne 0 ]; then
print -u2 "failed to generate header file"
exit 1
fi
cat > test.c <<EOF
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <stdlib.h>
#include "prov.h"
void
main(int argc)
{
void *addr;
int shmid;
if (argc > 1) {
TEST_PROV_RIPRAF();
exit(0);
}
shmid = shmget(IPC_PRIVATE, sizeof (int), IPC_CREAT | 0666);
if (shmid == -1) {
perror("shmget: ");
exit(1);
}
if ((addr = shmat(shmid, NULL, 0)) == (void *)-1) {
perror("shmat: ");
exit(1);
}
printf("%p\n", addr);
for (;;) {
TEST_PROV_RIPRAF();
sleep(1);
}
}
EOF
gcc -m32 -c test.c
if [ $? -ne 0 ]; then
print -u2 "failed to compile test.c"
exit 1
fi
$dtrace -G -32 -s prov.d test.o
if [ $? -ne 0 ]; then
print -u2 "failed to create DOF"
exit 1
fi
gcc -m32 -o test test.o prov.o
if [ $? -ne 0 ]; then
print -u2 "failed to link final executable"
exit 1
fi
#
# Kick off the victim program.
#
./test &
victim=$!
#
# Kick off a shell that will do nothing but read our victim's /proc map
#
( while true ; do read foo < /proc/$victim/map ; done ) &
stubby=$!
#
# Kick off a shell that will do nothing but instrument (and de-instrument)
# the victim
#
( while true; do \
$dtrace -q -P test_prov$victim -n BEGIN'{exit(0)}' > /dev/null ; done ) &
inst=$!
#
# Finally, kick off a shell that will cause lots of provider registration and
# (importantly) de-registration
#
( while true; do ./test foo ; done) &
reg=$!
echo $DIR
echo victim: $victim
echo stubby: $stubby
echo inst: $inst
echo reg: $reg
sleep 120
kill $reg
sleep 1
kill $inst
sleep 1
kill $stubby
sleep 1
kill $victim
#
# If we're deadlocked, this DTrace enabling won't work (if we even make it this
# far, which seems unlikely). In the spirit of the deadlock, we denote our
# success by emiting a classic Faulknerism.
#
raf="Maybe you're not so worthless!"
dtrace -qn BEGIN"{printf(\"$raf\"); exit(0)}"
cd /
/usr/bin/rm -rf $DIR
exit 0
|
