From: Yann Ylavic Date: Wed, 10 Jan 2018 21:48:04 +0000 (+0000) Subject: Merge r1809881, r1809973, r1809976, r1812075 from trunk: X-Git-Tag: 2.4.30~175 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9efbcd940a959dd80b572aaa5bef04d2d09336f7;p=apache Merge r1809881, r1809973, r1809976, r1812075 from trunk: core: deregister all hooks before leaving pconf, otherwise some late cleanup or function call (e.g. ap_log) may use one while DSOs are unloaded. See PR 61558 (double/second fault). core, MPMs unix: follow up to r1809881. Deregister all hooks first (in pre_cleanup), by doing it last we could still have had them run when DSOs were unloaded. Likewise, avoid double faults when handling fatal signals by restoring the default handler before pconf is cleared (we can't ap_log_error there). Finally, we need to ignore sig_term/restart (do nothing) when the main process is exiting (i.e. ap_pglobal is destroyed), since retained_data are freed. Aimed to fix all faults in PR 61558. MPMs unix: follow up to r1809881 and r1809973. unset_signals() is called when ap_pglobal is destroyed too. Follow up to r1809881: CHANGES entry. Submitted by: ylavic Reviewed by: ylavic, jim, covener git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1820794 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/CHANGES b/CHANGES index d99d07bb99..1d528ea7eb 100644 --- a/CHANGES +++ b/CHANGES @@ -1,6 +1,9 @@ -*- coding: utf-8 -*- Changes with Apache 2.4.30 + *) core: A signal received while stopping could have crashed the main + process. PR 61558. [Yann Ylavic] + *) mod_ssl: support for mod_md added. [Stefan Eissing] *) mod_proxy_html: process parsed comments immediately. diff --git a/os/unix/unixd.c b/os/unix/unixd.c index 07a9bef754..7f71d1a642 100644 --- a/os/unix/unixd.c +++ b/os/unix/unixd.c @@ -437,11 +437,19 @@ AP_DECLARE(apr_status_t) ap_unixd_accept(void **accepted, ap_listen_rec *lr, /* Unixes MPMs' */ static ap_unixd_mpm_retained_data *retained_data = NULL; +static apr_status_t retained_data_cleanup(void *unused) +{ + (void)unused; + retained_data = NULL; + return APR_SUCCESS; +} + AP_DECLARE(ap_unixd_mpm_retained_data *) ap_unixd_mpm_get_retained_data() { if (!retained_data) { retained_data = ap_retained_data_create("ap_unixd_mpm_retained_data", sizeof(*retained_data)); + apr_pool_pre_cleanup_register(ap_pglobal, NULL, retained_data_cleanup); retained_data->mpm_state = AP_MPMQ_STARTING; } return retained_data; @@ -449,6 +457,10 @@ AP_DECLARE(ap_unixd_mpm_retained_data *) ap_unixd_mpm_get_retained_data() static void sig_term(int sig) { + if (!retained_data) { + /* Main process (ap_pglobal) is dying */ + return; + } retained_data->mpm_state = AP_MPMQ_STOPPING; if (retained_data->shutdown_pending && (retained_data->is_ungraceful @@ -465,6 +477,10 @@ static void sig_term(int sig) static void sig_restart(int sig) { + if (!retained_data) { + /* Main process (ap_pglobal) is dying */ + return; + } retained_data->mpm_state = AP_MPMQ_STOPPING; if (retained_data->restart_pending && (retained_data->is_ungraceful @@ -481,6 +497,10 @@ static void sig_restart(int sig) static apr_status_t unset_signals(void *unused) { + if (!retained_data) { + /* Main process (ap_pglobal) is dying */ + return APR_SUCCESS; + } retained_data->shutdown_pending = retained_data->restart_pending = 0; retained_data->was_graceful = !retained_data->is_ungraceful; retained_data->is_ungraceful = 0; @@ -494,6 +514,10 @@ AP_DECLARE(void) ap_unixd_mpm_set_signals(apr_pool_t *pconf, int one_process) struct sigaction sa; #endif + if (!one_process) { + ap_fatal_signal_setup(ap_server_conf, pconf); + } + /* Signals' handlers depend on retained data */ (void)ap_unixd_mpm_get_retained_data(); diff --git a/server/main.c b/server/main.c index ec0ea68d9b..3a4b1a6254 100644 --- a/server/main.c +++ b/server/main.c @@ -273,6 +273,30 @@ static int abort_on_oom(int retcode) return retcode; /* unreachable, hopefully. */ } +/* Deregister all hooks when clearing pconf (pre_cleanup). + * TODO: have a hook to deregister and run them from here? + * ap_clear_auth_internal() is already a candidate. + */ +static apr_status_t deregister_all_hooks(void *unused) +{ + (void)unused; + ap_clear_auth_internal(); + apr_hook_deregister_all(); + return APR_SUCCESS; +} + +static void reset_process_pconf(process_rec *process) +{ + if (process->pconf) { + apr_pool_clear(process->pconf); + } + else { + apr_pool_create(&process->pconf, process->pool); + apr_pool_tag(process->pconf, "pconf"); + } + apr_pool_pre_cleanup_register(process->pconf, NULL, deregister_all_hooks); +} + static process_rec *init_process(int *argc, const char * const * *argv) { process_rec *process; @@ -317,8 +341,9 @@ static process_rec *init_process(int *argc, const char * const * *argv) process = apr_palloc(cntx, sizeof(process_rec)); process->pool = cntx; - apr_pool_create(&process->pconf, process->pool); - apr_pool_tag(process->pconf, "pconf"); + process->pconf = NULL; + reset_process_pconf(process); + process->argc = *argc; process->argv = *argv; process->short_name = apr_filepath_name_get((*argv)[0]); @@ -721,9 +746,7 @@ int main(int argc, const char * const argv[]) do { ap_main_state = AP_SQ_MS_DESTROY_CONFIG; - apr_hook_deregister_all(); - apr_pool_clear(pconf); - ap_clear_auth_internal(); + reset_process_pconf(process); ap_main_state = AP_SQ_MS_CREATE_CONFIG; ap_config_generation++; diff --git a/server/mpm/event/event.c b/server/mpm/event/event.c index bd3ad3c998..2efde3982d 100644 --- a/server/mpm/event/event.c +++ b/server/mpm/event/event.c @@ -2878,9 +2878,6 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) ap_scoreboard_image->global->running_generation = retained->mpm->my_generation; } - if (!one_process) { - ap_fatal_signal_setup(ap_server_conf, pconf); - } ap_unixd_mpm_set_signals(pconf, one_process); /* Don't thrash since num_buckets depends on the diff --git a/server/mpm/prefork/prefork.c b/server/mpm/prefork/prefork.c index a386a757ff..3fb328467d 100644 --- a/server/mpm/prefork/prefork.c +++ b/server/mpm/prefork/prefork.c @@ -863,9 +863,6 @@ static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) ap_scoreboard_image->global->running_generation = retained->mpm->my_generation; } - if (!one_process) { - ap_fatal_signal_setup(ap_server_conf, pconf); - } ap_unixd_mpm_set_signals(pconf, one_process); if (one_process) { diff --git a/server/mpm/worker/worker.c b/server/mpm/worker/worker.c index d2147bf5d9..776ae7fc2d 100644 --- a/server/mpm/worker/worker.c +++ b/server/mpm/worker/worker.c @@ -1671,9 +1671,6 @@ static int worker_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) ap_scoreboard_image->global->running_generation = retained->mpm->my_generation; } - if (!one_process) { - ap_fatal_signal_setup(ap_server_conf, pconf); - } ap_unixd_mpm_set_signals(pconf, one_process); /* Don't thrash since num_buckets depends on the diff --git a/server/mpm_unix.c b/server/mpm_unix.c index 2f3d20e4df..1800f5dabf 100644 --- a/server/mpm_unix.c +++ b/server/mpm_unix.c @@ -1009,6 +1009,33 @@ AP_DECLARE(apr_status_t) ap_fatal_signal_child_setup(server_rec *s) return APR_SUCCESS; } +/* We can't call sig_coredump (ap_log_error) once pconf is destroyed, so + * avoid double faults by restoring each default signal handler on cleanup. + */ +static apr_status_t fatal_signal_cleanup(void *unused) +{ + (void)unused; + + apr_signal(SIGSEGV, SIG_DFL); +#ifdef SIGBUS + apr_signal(SIGBUS, SIG_DFL); +#endif /* SIGBUS */ +#ifdef SIGABORT + apr_signal(SIGABORT, SIG_DFL); +#endif /* SIGABORT */ +#ifdef SIGABRT + apr_signal(SIGABRT, SIG_DFL); +#endif /* SIGABRT */ +#ifdef SIGILL + apr_signal(SIGILL, SIG_DFL); +#endif /* SIGILL */ +#ifdef SIGFPE + apr_signal(SIGFPE, SIG_DFL); +#endif /* SIGFPE */ + + return APR_SUCCESS; +} + AP_DECLARE(apr_status_t) ap_fatal_signal_setup(server_rec *s, apr_pool_t *in_pconf) { @@ -1071,6 +1098,8 @@ AP_DECLARE(apr_status_t) ap_fatal_signal_setup(server_rec *s, pconf = in_pconf; parent_pid = my_pid = getpid(); + apr_pool_cleanup_register(pconf, NULL, fatal_signal_cleanup, + fatal_signal_cleanup); return APR_SUCCESS; }