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Request exclusive access when crashing via fatal()

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When loading the configuration fails, there might be already other tasks
running and calling OpenSSL library functions.  The OpenSSL on_exit
handler is called when exiting the main process and there's a timing
race between the on_exit function that destroys OpenSSL allocated
resources (threads, locks, ...) and other tasks accessing the very same
resources leading to a crash in the system threading library. Therefore,
the fatal() function needs to request exlusive access to the task
manager to finish the already running tasks and exit only when no other
tasks are running.
This commit is contained in:
Ondřej Surý
2019-11-22 11:39:57 +01:00
parent bc66044246
commit ca4b4bf421
1 changed files with 14 additions and 5 deletions
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19
bin/named/server.c
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@@ -201,8 +201,8 @@
#define CHECKFATAL(op, msg) \
do { result = (op); \
if (result != ISC_R_SUCCESS) \
fatal(msg, result); \
if (result != ISC_R_SUCCESS) \
fatal(server, msg, result); \
} while (0) \
/*%
@@ -431,7 +431,8 @@ const char *empty_zones[] = {
};
ISC_PLATFORM_NORETURN_PRE static void
fatal(const char *msg, isc_result_t result) ISC_PLATFORM_NORETURN_POST;
fatal(named_server_t *server,const char *msg, isc_result_t result)
ISC_PLATFORM_NORETURN_POST;
static void
named_server_reload(isc_task_t *task, isc_event_t *event);
@@ -9805,7 +9806,7 @@ named_server_create(isc_mem_t *mctx, named_server_t **serverp) {
named_server_t *server = isc_mem_get(mctx, sizeof(*server));
if (server == NULL)
fatal("allocating server object", ISC_R_NOMEMORY);
fatal(server, "allocating server object", ISC_R_NOMEMORY);
server->mctx = mctx;
server->task = NULL;
@@ -10016,7 +10017,15 @@ named_server_destroy(named_server_t **serverp) {
}
static void
fatal(const char *msg, isc_result_t result) {
fatal(named_server_t *server, const char *msg, isc_result_t result) {
if (server != NULL) {
/*
* Prevent races between the OpenSSL on_exit registered
* function and any other OpenSSL calls from other tasks
* by requesting exclusive access to the task manager.
*/
(void)isc_task_beginexclusive(server->task);
}
isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
NAMED_LOGMODULE_SERVER, ISC_LOG_CRITICAL,
"%s: %s", msg, isc_result_totext(result));