monero/external/unbound/testcode/lock_verify.c

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2014-10-05 21:44:31 +00:00
/*
* testcode/lock_verify.c - verifier program for lock traces, checks order.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file checks the lock traces generated by checklock.c.
* Checks if locks are consistently locked in the same order.
* If not, this can lead to deadlock if threads execute the different
* ordering at the same time.
*
*/
#include "config.h"
#include "util/log.h"
#include "util/rbtree.h"
#include "util/locks.h"
#include "util/fptr_wlist.h"
/* --- data structures --- */
struct lock_ref;
/** keep track of lock id in lock-verify application
* Also defined in smallapp/worker_cb.c for fptr_wlist encapsulation
* breakage (the security tests break encapsulation for this test app) */
struct order_id {
/** the thread id that created it */
int thr;
/** the instance number of creation */
int instance;
};
/** a lock */
struct order_lock {
/** rbnode in all tree */
rbnode_t node;
/** lock id */
struct order_id id;
/** the creation file */
char* create_file;
/** creation line */
int create_line;
/** set of all locks that are smaller than this one (locked earlier) */
rbtree_t* smaller;
/** during depthfirstsearch, this is a linked list of the stack
* of locks. points to the next lock bigger than this one. */
struct lock_ref* dfs_next;
/** if lock has been visited (all smaller locks have been compared to
* this lock), only need to compare this with all unvisited(bigger)
* locks */
int visited;
};
/** reference to a lock in a rbtree set */
struct lock_ref {
/** rbnode, key is an order_id ptr */
rbnode_t node;
/** the lock referenced */
struct order_lock* lock;
/** why is this ref */
char* file;
/** line number */
int line;
};
/** count of errors detected */
static int errors_detected = 0;
/** verbose? */
static int verb = 0;
/** print program usage help */
static void
usage()
{
printf("lock_verify <trace files>\n");
}
/** read header entry.
* @param in: file to read header of.
* @return: False if it does not belong to the rest. */
static int
read_header(FILE* in)
{
time_t t;
pid_t p;
int thrno;
static int have_values = 0;
static time_t the_time;
static pid_t the_pid;
static int threads[256];
if(fread(&t, sizeof(t), 1, in) != 1 ||
fread(&thrno, sizeof(thrno), 1, in) != 1 ||
fread(&p, sizeof(p), 1, in) != 1) {
fatal_exit("fread failed");
}
/* check these values are sorta OK */
if(!have_values) {
the_time = t;
the_pid = p;
memset(threads, 0, 256*sizeof(int));
if(thrno >= 256) {
fatal_exit("Thread number too big. %d", thrno);
}
threads[thrno] = 1;
have_values = 1;
printf(" trace %d from pid %u on %s", thrno,
(unsigned)p, ctime(&t));
} else {
if(the_pid != p) {
printf(" has pid %u, not %u. Skipped.\n",
(unsigned)p, (unsigned)the_pid);
return 0;
}
if(threads[thrno])
fatal_exit("same threadno in two files");
threads[thrno] = 1;
if( abs((int)(the_time - t)) > 3600)
fatal_exit("input files from different times: %u %u",
(unsigned)the_time, (unsigned)t);
printf(" trace of thread %u:%d\n", (unsigned)p, thrno);
}
return 1;
}
/** max length of strings: filenames and function names. */
#define STRMAX 1024
/** read a string from file, false on error */
static int readup_str(char** str, FILE* in)
{
char buf[STRMAX];
int len = 0;
int c;
/* ends in zero */
while( (c = fgetc(in)) != 0) {
if(c == EOF)
fatal_exit("eof in readstr, file too short");
buf[len++] = c;
if(len == STRMAX) {
fatal_exit("string too long, bad file format");
}
}
buf[len] = 0;
*str = strdup(buf);
return 1;
}
/** read creation entry */
static void read_create(rbtree_t* all, FILE* in)
{
struct order_lock* o = calloc(1, sizeof(struct order_lock));
if(!o) fatal_exit("malloc failure");
if(fread(&o->id.thr, sizeof(int), 1, in) != 1 ||
fread(&o->id.instance, sizeof(int), 1, in) != 1 ||
!readup_str(&o->create_file, in) ||
fread(&o->create_line, sizeof(int), 1, in) != 1)
fatal_exit("fread failed");
o->smaller = rbtree_create(order_lock_cmp);
o->node.key = &o->id;
if(!rbtree_insert(all, &o->node)) {
/* already inserted */
struct order_lock* a = (struct order_lock*)rbtree_search(all,
&o->id);
log_assert(a);
a->create_file = o->create_file;
a->create_line = o->create_line;
free(o->smaller);
free(o);
o = a;
}
if(verb) printf("read create %u %u %s %d\n",
(unsigned)o->id.thr, (unsigned)o->id.instance,
o->create_file, o->create_line);
}
/** insert lock entry (empty) into list */
static struct order_lock*
insert_lock(rbtree_t* all, struct order_id* id)
{
struct order_lock* o = calloc(1, sizeof(struct order_lock));
if(!o) fatal_exit("malloc failure");
o->smaller = rbtree_create(order_lock_cmp);
o->id = *id;
o->node.key = &o->id;
if(!rbtree_insert(all, &o->node))
fatal_exit("insert fail should not happen");
return o;
}
/** read lock entry */
static void read_lock(rbtree_t* all, FILE* in, int val)
{
struct order_id prev_id, now_id;
struct lock_ref* ref;
struct order_lock* prev, *now;
ref = (struct lock_ref*)calloc(1, sizeof(struct lock_ref));
if(!ref) fatal_exit("malloc failure");
prev_id.thr = val;
if(fread(&prev_id.instance, sizeof(int), 1, in) != 1 ||
fread(&now_id.thr, sizeof(int), 1, in) != 1 ||
fread(&now_id.instance, sizeof(int), 1, in) != 1 ||
!readup_str(&ref->file, in) ||
fread(&ref->line, sizeof(int), 1, in) != 1)
fatal_exit("fread failed");
if(verb) printf("read lock %u %u %u %u %s %d\n",
(unsigned)prev_id.thr, (unsigned)prev_id.instance,
(unsigned)now_id.thr, (unsigned)now_id.instance,
ref->file, ref->line);
/* find the two locks involved */
prev = (struct order_lock*)rbtree_search(all, &prev_id);
now = (struct order_lock*)rbtree_search(all, &now_id);
/* if not there - insert 'em */
if(!prev) prev = insert_lock(all, &prev_id);
if(!now) now = insert_lock(all, &now_id);
ref->lock = prev;
ref->node.key = &prev->id;
if(!rbtree_insert(now->smaller, &ref->node)) {
free(ref->file);
free(ref);
}
}
/** read input file */
static void readinput(rbtree_t* all, char* file)
{
FILE *in = fopen(file, "r");
int fst;
if(!in) {
perror(file);
exit(1);
}
printf("file %s", file);
if(!read_header(in)) {
fclose(in);
return;
}
while(fread(&fst, sizeof(fst), 1, in) == 1) {
if(fst == -1)
read_create(all, in);
else read_lock(all, in, fst);
}
fclose(in);
}
/** print cycle message */
static void found_cycle(struct lock_ref* visit, int level)
{
struct lock_ref* p;
int i = 0;
errors_detected++;
printf("Found inconsistent locking order of length %d\n", level);
printf("for lock %d %d created %s %d\n",
visit->lock->id.thr, visit->lock->id.instance,
visit->lock->create_file, visit->lock->create_line);
printf("sequence is:\n");
p = visit;
while(p) {
struct order_lock* next =
p->lock->dfs_next?p->lock->dfs_next->lock:visit->lock;
printf("[%d] is locked at line %s %d before lock %d %d\n",
i, p->file, p->line, next->id.thr, next->id.instance);
printf("[%d] lock %d %d is created at %s %d\n",
i, next->id.thr, next->id.instance,
next->create_file, next->create_line);
i++;
p = p->lock->dfs_next;
if(p && p->lock == visit->lock)
break;
}
}
/** Detect cycle by comparing visited now with all (unvisited) bigger nodes */
static int detect_cycle(struct lock_ref* visit, struct lock_ref* from)
{
struct lock_ref* p = from;
while(p) {
if(p->lock == visit->lock)
return 1;
p = p->lock->dfs_next;
}
return 0;
}
/** recursive function to depth first search for cycles.
* @param visit: the lock visited at this step.
* its dfs_next pointer gives the visited lock up in recursion.
* same as lookfor at level 0.
* @param level: depth of recursion. 0 is start.
* @param from: search for matches from unvisited node upwards.
*/
static void search_cycle(struct lock_ref* visit, int level,
struct lock_ref* from)
{
struct lock_ref* ref;
/* check for cycle */
if(detect_cycle(visit, from) && level != 0) {
found_cycle(visit, level);
fatal_exit("found lock order cycle");
}
/* recurse */
if(!visit->lock->visited)
from = visit;
if(verb > 1) fprintf(stderr, "[%d] visit lock %u %u %s %d\n", level,
(unsigned)visit->lock->id.thr,
(unsigned)visit->lock->id.instance,
visit->lock->create_file, visit->lock->create_line);
RBTREE_FOR(ref, struct lock_ref*, visit->lock->smaller) {
ref->lock->dfs_next = visit;
search_cycle(ref, level+1, from);
}
visit->lock->visited = 1;
}
/** Check ordering of one lock */
static void check_order_lock(struct order_lock* lock)
{
struct lock_ref start;
if(lock->visited) return;
start.node.key = &lock->id;
start.lock = lock;
start.file = lock->create_file;
start.line = lock->create_line;
if(!lock->create_file)
log_err("lock %u %u does not have create info",
(unsigned)lock->id.thr, (unsigned)lock->id.instance);
/* depth first search to find cycle with this lock at head */
lock->dfs_next = NULL;
search_cycle(&start, 0, &start);
}
/** Check ordering of locks */
static void check_order(rbtree_t* all_locks)
{
/* check each lock */
struct order_lock* lock;
int i=0;
RBTREE_FOR(lock, struct order_lock*, all_locks) {
if(verb)
printf("[%d/%d] Checking lock %d %d %s %d\n",
i, (int)all_locks->count,
lock->id.thr, lock->id.instance,
lock->create_file, lock->create_line);
else if (i % ((all_locks->count/75)<1?1:all_locks->count/75)
== 0)
fprintf(stderr, ".");
i++;
check_order_lock(lock);
}
fprintf(stderr, "\n");
}
/** main program to verify all traces passed */
int
main(int argc, char* argv[])
{
rbtree_t* all_locks;
int i;
time_t starttime = time(NULL);
#ifdef USE_THREAD_DEBUG
/* do not overwrite the ublocktrace files with the ones generated
* by this program (i.e. when the log code creates a lock) */
check_locking_order = 0;
#endif
if(argc <= 1) {
usage();
return 1;
}
log_init(NULL, 0, NULL);
log_ident_set("lock-verify");
/* init */
all_locks = rbtree_create(order_lock_cmp);
errors_detected = 0;
/* read the input files */
for(i=1; i<argc; i++) {
readinput(all_locks, argv[i]);
}
/* check ordering */
check_order(all_locks);
/* do not free a thing, OS will do it */
printf("checked %d locks in %d seconds with %d errors.\n",
(int)all_locks->count, (int)(time(NULL)-starttime),
errors_detected);
if(errors_detected) return 1;
return 0;
}