Fix thread syncronization problems

CMakeLists.txt

@@ -529,7 +529,7 @@ if (MSVC)
 endif()
 
 if (${CMAKE_C_COMPILER_ID} STREQUAL "GNU" OR ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
-	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pipe -W -Wall -Wnonnull -Wshadow -Wformat -Wundef -Wno-unused-parameter -Wmissing-prototypes -Wno-unknown-pragmas -Wno-int-conversion -Werror=implicit-function-declaration -D_GNU_SOURCE -std=c99")
+	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pipe -W -Wall -Wnonnull -Wshadow -Wformat -Wundef -Wno-unused-parameter -Wmissing-prototypes -Wno-unknown-pragmas -Wno-int-conversion -Werror=implicit-function-declaration -D_GNU_SOURCE -DRBT_IMPLICIT_LOCKING=1 -std=c99")
 	add_link_options(-Wl,-z,now)
 endif()
 if(${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")

src/OVAL/probes/SEAP/seap-command.c

@@ -205,7 +205,7 @@ static SEXP_t *__SEAP_cmd_sync_handler (SEXP_t *res, void *arg)
         h->args = res;
         (void) pthread_mutex_lock (&h->mtx);
         h->signaled = 1;
-        (void) pthread_cond_signal (&h->cond);
+        (void) pthread_cond_broadcast (&h->cond);
         (void) pthread_mutex_unlock (&h->mtx);
 
         return (NULL);
@@ -322,9 +322,6 @@ SEXP_t *SEAP_cmd_exec (SEAP_CTX_t    *ctx,
                         h.args = NULL;
                         h.signaled = 0;
 
-                        if (pthread_mutex_lock (&(h.mtx)) != 0)
-                                abort ();
-
                         rec = SEAP_cmdrec_new ();
                         rec->code = cmdptr->id;
                         rec->func = &__SEAP_cmd_sync_handler;
@@ -377,8 +374,6 @@ SEXP_t *SEAP_cmd_exec (SEAP_CTX_t    *ctx,
                                   timeout.tv_nsec = 0;
                                 */
                                 for (;;) {
-                                        pthread_mutex_unlock(&h.mtx);
-
                                         if (SEAP_packet_recv(ctx, sd, &packet_rcv) != 0) {
                                                 dD("FAIL: ctx=%p, sd=%d, errno=%u, %s.", ctx, sd, errno, strerror(errno));
 						SEAP_packet_free(packet);
@@ -407,21 +402,23 @@ SEXP_t *SEAP_cmd_exec (SEAP_CTX_t    *ctx,
                                         }
 
                                         /* Morbo: THIS IS NOT HOW SYCHNRONIZATION WORKS! */
-                                        if (h.signaled)
+                                        if (h.signaled) {
+						h.signaled = 0;
                                                 break;
+					}
                                 }
                         } else {
                                 /*
                                  * Someone else does receiving of events for us.
                                  * Just wait for the condition to be signaled.
                                  */
-                                if (pthread_cond_wait(&h.cond, &h.mtx) != 0) {
-                                        /*
-                                         * Fatal error - don't know how to handle
-                                         * this so let's just call abort()...
-                                         */
-                                        abort();
-                                }
+				pthread_mutex_lock(&h.mtx);
+				while (!h.signaled) {
+					pthread_cond_wait(&h.cond, &h.mtx);
+				}
+				// This might not be needed, but still
+				h.signaled = 0;
+				pthread_mutex_unlock(&h.mtx);
                         }
 
                         dD("cond return: h.args=%p", h.args);
@@ -436,7 +433,6 @@ SEXP_t *SEAP_cmd_exec (SEAP_CTX_t    *ctx,
                         /*
                          * SEAP_cmdtbl_del(dsc->cmd_w_table, rec);
                          */
-                        pthread_mutex_unlock (&(h.mtx));
                         pthread_cond_destroy (&(h.cond));
                         pthread_mutex_destroy (&(h.mtx));
                         SEAP_packet_free(packet);

src/OVAL/probes/SEAP/seap-packet.c

@@ -206,9 +206,14 @@ static int SEAP_packet_sexp2msg (SEXP_t *sexp_msg, SEAP_msg_t *seap_msg)
         _A(attr_i >= (SEXP_list_length (sexp_msg) - 4)/2);
 
         seap_msg->attrs_cnt = attr_i;
-        void *new_attrs = realloc(seap_msg->attrs, sizeof(SEAP_attr_t) * seap_msg->attrs_cnt);
-        if (new_attrs != NULL || seap_msg->attrs_cnt == 0)
+        if (seap_msg->attrs_cnt == 0) {
+                free(seap_msg->attrs);
+                seap_msg->attrs = NULL;
+        } else {
+                void *new_attrs = realloc(seap_msg->attrs, sizeof(SEAP_attr_t) * seap_msg->attrs_cnt);
                 seap_msg->attrs = new_attrs;
+        }
+
         seap_msg->sexp = SEXP_list_last (sexp_msg);
 
         return (0);

src/OVAL/probes/probe/icache.c

@@ -201,7 +201,7 @@ const char* thread_name = "icache_worker";
 	pair = &pair_mem;
         dD("icache worker ready");
 
-        switch (errno = pthread_barrier_wait(&OSCAP_GSYM(th_barrier)))
+        switch (errno = pthread_barrier_wait(cache->th_barrier))
         {
         case 0:
         case PTHREAD_BARRIER_SERIAL_THREAD:
@@ -309,7 +309,7 @@ const char* thread_name = "icache_worker";
         return (NULL);
 }
 
-probe_icache_t *probe_icache_new(void)
+probe_icache_t *probe_icache_new(pthread_barrier_t *th_barrier)
 {
         probe_icache_t *cache = malloc(sizeof(probe_icache_t));
         cache->tree = rbt_i64_new();
@@ -323,6 +323,7 @@ probe_icache_t *probe_icache_new(void)
         cache->queue_end = 0;
         cache->queue_cnt = 0;
         cache->queue_max = PROBE_IQUEUE_CAPACITY;
+        cache->th_barrier = th_barrier;
 
         if (pthread_cond_init(&cache->queue_notempty, NULL) != 0) {
                 dE("Can't initialize icache queue condition variable (notempty): %u, %s",

src/OVAL/probes/probe/icache.h

@@ -25,6 +25,7 @@
 #include <stddef.h>
 #include <sexp.h>
 #include "../SEAP/generic/rbt/rbt.h"
+#include "common/compat_pthread_barrier.h"
 
 #ifndef PROBE_IQUEUE_CAPACITY
 #define PROBE_IQUEUE_CAPACITY 1024
@@ -41,6 +42,7 @@ typedef struct {
 typedef struct {
         rbt_t    *tree; /* XXX: rewrite to extensible or linear hashing */
         pthread_t thid;
+        pthread_barrier_t *th_barrier;
 
         pthread_mutex_t queue_mutex;
         pthread_cond_t  queue_notempty;
@@ -58,7 +60,7 @@ typedef struct {
         uint16_t  count;
 } probe_citem_t;
 
-probe_icache_t *probe_icache_new(void);
+probe_icache_t *probe_icache_new(pthread_barrier_t *th_barrier);
 int probe_icache_add(probe_icache_t *cache, SEXP_t *cobj, SEXP_t *item);
 int probe_icache_nop(probe_icache_t *cache);
 void probe_icache_free(probe_icache_t *cache);

src/OVAL/probes/probe/input_handler.c

@@ -85,7 +85,7 @@ void *probe_input_handler(void *arg)
 
 	pthread_cleanup_push(pthread_attr_cleanup_handler, (void *)&pth_attr);
 
-        switch (errno = pthread_barrier_wait(&OSCAP_GSYM(th_barrier)))
+        switch (errno = pthread_barrier_wait(probe->th_barrier))
         {
         case 0:
         case PTHREAD_BARRIER_SERIAL_THREAD:

src/OVAL/probes/probe/probe.h

@@ -66,6 +66,7 @@ typedef struct {
 
 	pthread_t th_input;
 	pthread_t th_signal;
+	pthread_barrier_t *th_barrier;
 
         rbt_t    *workers;
         uint32_t  max_threads;
@@ -105,6 +106,4 @@ typedef enum {
 	PROBE_OFFLINE_ALL = 0x0f
 } probe_offline_flags;
 
-extern pthread_barrier_t OSCAP_GSYM(th_barrier);
-
 #endif /* PROBE_H */

src/OVAL/probes/probe/probe_main.c

@@ -71,8 +71,6 @@ bool   OSCAP_GSYM(varref_handling)    = true;
 char **OSCAP_GSYM(no_varref_ents)     = NULL;
 size_t OSCAP_GSYM(no_varref_ents_cnt) = 0;
 
-pthread_barrier_t OSCAP_GSYM(th_barrier);
-
 extern probe_ncache_t *OSCAP_GSYM(ncache);
 
 static int probe_optecmp(char **a, char **b)
@@ -191,8 +189,10 @@ void *probe_common_main(void *arg)
 
 	dD("probe_common_main started");
 
+	pthread_barrier_t barrier;
+
 	const unsigned thread_count = 2; // input and icache threads
-	if ((errno = pthread_barrier_init(&OSCAP_GSYM(th_barrier), NULL, thread_count)) != 0) {
+	if ((errno = pthread_barrier_init(&barrier, NULL, thread_count)) != 0) {
 		fail(errno, "pthread_barrier_init", __LINE__ - 6);
 	}
 
@@ -218,9 +218,10 @@ void *probe_common_main(void *arg)
 	 * Initialize result & name caching
 	 */
 	probe.rcache = probe_rcache_new();
-	probe.icache = probe_icache_new();
+	probe.icache = probe_icache_new(&barrier);
 	probe_ncache_clear(OSCAP_GSYM(ncache));
 	probe.ncache = OSCAP_GSYM(ncache);
+	probe.th_barrier = &barrier;
 
 	/*
 	 * Initialize probe option handlers
@@ -266,5 +267,7 @@ void *probe_common_main(void *arg)
 
 	pthread_cleanup_pop(1);
 
+	pthread_barrier_destroy(&barrier);
+
 	return NULL;
 }

src/OVAL/probes/probe/worker.c

@@ -72,6 +72,13 @@ static void preload_libraries_before_chroot()
 	pthread_join(t, NULL);
 }
 
+static void pthread_pair_cleanup_handler(void *arg)
+{
+	probe_pwpair_t *pair = (probe_pwpair_t *)arg;
+	dW("Probe worker thread finished unxpectedly, trying to avoid deadlock now...");
+	SEAP_replyerr(pair->probe->SEAP_ctx, pair->probe->sd, pair->pth->msg, -100);
+}
+
 void *probe_worker_runfn(void *arg)
 {
 	dD("probe_worker_runfn has started");
@@ -88,6 +95,8 @@ void *probe_worker_runfn(void *arg)
 # endif
 #endif
 	dD("handling SEAP message ID %u", pair->pth->sid);
+	pthread_cleanup_push(pthread_pair_cleanup_handler, (void *)pair);
+
 	//
 	probe_ret = -1;
 	probe_res = pair->pth->msg_handler(pair->probe, pair->pth->msg, &probe_ret);
@@ -172,6 +181,8 @@ void *probe_worker_runfn(void *arg)
 	free(pair);
 	pthread_detach(pthread_self());
 
+	pthread_cleanup_pop(0);
+
 	dD("probe_worker_runfn has finished");
 	return (NULL);
 }

src/common/oscap_pcre.c

@@ -106,7 +106,6 @@ oscap_pcre_t *oscap_pcre_compile(const char *pattern, oscap_pcre_options_t optio
 	int errno;
 	PCRE2_SIZE erroffset2;
 	res->re_ctx = NULL;
-	dD("pcre2_compile_8: patt=%s", pattern);
 	res->re = pcre2_compile_8((PCRE2_SPTR)pattern, PCRE2_ZERO_TERMINATED, _oscap_pcre_opts_to_pcre(options), &errno, &erroffset2, NULL);
 	if (res->re == NULL) {
 		PCRE2_UCHAR8 errmsg[PCRE2_ERR_BUF_SIZE];
@@ -139,13 +138,9 @@ int oscap_pcre_exec(const oscap_pcre_t *opcre, const char *subject,
 	// The ovecsize is multiplied by 3 in the code for compatibility with PCRE1
 	int ovecsize2 = ovecsize/3;
 	pcre2_match_data_8 *mdata = pcre2_match_data_create_8(ovecsize2, NULL);
-	dD("pcre2_match_8: subj=%s", subject);
 	rc = pcre2_match_8(opcre->re, (PCRE2_SPTR8)subject, length, startoffset, _oscap_pcre_opts_to_pcre(options), mdata, opcre->re_ctx);
-	dD("pcre2_match_8: rc=%d, ", rc);
 	if (rc > PCRE2_ERROR_NOMATCH) {
 		PCRE2_SIZE *ovecp = pcre2_get_ovector_pointer_8(mdata);
-		uint32_t ovecp_count = pcre2_get_ovector_count_8(mdata);
-		dD("pcre2_match_8: pcre2_get_ovector_count_8=%d", ovecp_count);
 		for (int i = 0; i < rc; i++) {
 			if (i < ovecsize2) {
 				ovector[i*2] = ovecp[i*2];