Commit c1fdac47 authored by Yann Ylavic's avatar Yann Ylavic
Browse files

Merge r1783849 from trunk: 

MPMs unix: Place signals handlers and helpers out of DSOs to avoid
a possible crash if a signal is caught during (graceful) restart.
PR 60487.

Reviewedby: ylavic, wrowe, icing


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1797368 13f79535-47bb-0310-9956-ffa450edef68
parent 06974b86

CHANGES

+4 −0
Original line number Diff line number Diff line
@@ -2,6 +2,10 @@ 


Changes with Apache 2.4.26



  *) MPMs unix: Place signals handlers and helpers out of DSOs to avoid

     a possible crash if a signal is caught during (graceful) restart.

     PR 60487.  [Yann Ylavic]



  *) core: Deprecate ap_get_basic_auth_pw() and add

     ap_get_basic_auth_components().

     [Emmanuel Dreyfus <manu netbsd.org>, Jacob Champion, Eric Covener]

STATUS

+0 −7
Original line number Diff line number Diff line
@@ -120,13 +120,6 @@ RELEASE SHOWSTOPPERS: 
PATCHES ACCEPTED TO BACKPORT FROM TRUNK:

  [ start all new proposals below, under PATCHES PROPOSED. ]



  *) MPMs unix: Place signals handlers and helpers out of DSOs to avoid a

     possible crash if a signal is caught during (graceful) restart. PR 60487.

     trunk patch: http://svn.apache.org/r1783849

     2.4.x patch: svn merge -c 1783849 ^/httpd/httpd/trunk .

                  (trunk works, modulo CHANGES)

     +1: ylavic, wrowe, icing



PATCHES PROPOSED TO BACKPORT FROM TRUNK:

  [ New proposals should be added at the end of the list ]

os/unix/unixd.c

+149 −0
Original line number Diff line number Diff line
@@ -434,6 +434,155 @@ 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;

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));

        retained_data->mpm_state = AP_MPMQ_STARTING;

    }

    return retained_data;

}



static void sig_term(int sig)

{

    retained_data->mpm_state = AP_MPMQ_STOPPING;

    if (retained_data->shutdown_pending

            && (retained_data->is_ungraceful

                || sig == AP_SIG_GRACEFUL_STOP)) {

        /* Already handled */

        return;

    }



    retained_data->shutdown_pending = 1;

    if (sig != AP_SIG_GRACEFUL_STOP) {

        retained_data->is_ungraceful = 1;

    }

}



static void sig_restart(int sig)

{

    retained_data->mpm_state = AP_MPMQ_STOPPING;

    if (retained_data->restart_pending

            && (retained_data->is_ungraceful

                || sig == AP_SIG_GRACEFUL)) {

        /* Already handled */

        return;

    }



    retained_data->restart_pending = 1;

    if (sig != AP_SIG_GRACEFUL) {

        retained_data->is_ungraceful = 1;

    }

}



static apr_status_t unset_signals(void *unused)

{

    retained_data->shutdown_pending = retained_data->restart_pending = 0;

    retained_data->was_graceful = !retained_data->is_ungraceful;

    retained_data->is_ungraceful = 0;



    return APR_SUCCESS;

}



AP_DECLARE(void) ap_unixd_mpm_set_signals(apr_pool_t *pconf, int one_process)

{

#ifndef NO_USE_SIGACTION

    struct sigaction sa;

#endif



    /* Signals' handlers depend on retained data */

    (void)ap_unixd_mpm_get_retained_data();



#ifndef NO_USE_SIGACTION

    memset(&sa, 0, sizeof sa);

    sigemptyset(&sa.sa_mask);



#ifdef SIGPIPE

    sa.sa_handler = SIG_IGN;

    if (sigaction(SIGPIPE, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00269)

                     "sigaction(SIGPIPE)");

#endif

#ifdef SIGXCPU

    sa.sa_handler = SIG_DFL;

    if (sigaction(SIGXCPU, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00267)

                     "sigaction(SIGXCPU)");

#endif

#ifdef SIGXFSZ

    /* For systems following the LFS standard, ignoring SIGXFSZ allows

     * a write() beyond the 2GB limit to fail gracefully with E2BIG

     * rather than terminate the process. */

    sa.sa_handler = SIG_IGN;

    if (sigaction(SIGXFSZ, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00268)

                     "sigaction(SIGXFSZ)");

#endif



    sa.sa_handler = sig_term;

    if (sigaction(SIGTERM, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00264)

                     "sigaction(SIGTERM)");

#ifdef SIGINT

    if (sigaction(SIGINT, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00266)

                     "sigaction(SIGINT)");

#endif

#ifdef AP_SIG_GRACEFUL_STOP

    if (sigaction(AP_SIG_GRACEFUL_STOP, &sa, NULL) < 0)

        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00265)

                     "sigaction(" AP_SIG_GRACEFUL_STOP_STRING ")");

#endif



    /* Don't catch restart signals in ONE_PROCESS mode :) */

    if (!one_process) {

        sa.sa_handler = sig_restart;

        if (sigaction(SIGHUP, &sa, NULL) < 0)

            ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00270)

                         "sigaction(SIGHUP)");

        if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0)

            ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00271)

                         "sigaction(" AP_SIG_GRACEFUL_STRING ")");

    }



#else  /* NO_USE_SIGACTION */



#ifdef SIGPIPE

    apr_signal(SIGPIPE, SIG_IGN);

#endif /* SIGPIPE */

#ifdef SIGXCPU

    apr_signal(SIGXCPU, SIG_DFL);

#endif /* SIGXCPU */

#ifdef SIGXFSZ

    apr_signal(SIGXFSZ, SIG_IGN);

#endif /* SIGXFSZ */



    apr_signal(SIGTERM, sig_term);

#ifdef AP_SIG_GRACEFUL_STOP

    apr_signal(AP_SIG_GRACEFUL_STOP, sig_term);

#endif /* AP_SIG_GRACEFUL_STOP */



    if (!one_process) {

        /* Don't restart in ONE_PROCESS mode :) */

#ifdef SIGHUP

        apr_signal(SIGHUP, sig_restart);

#endif /* SIGHUP */

#ifdef AP_SIG_GRACEFUL

        apr_signal(AP_SIG_GRACEFUL, sig_restart);

#endif /* AP_SIG_GRACEFUL */

    }



#endif /* NO_USE_SIGACTION */



    apr_pool_cleanup_register(pconf, NULL, unset_signals,

                              apr_pool_cleanup_null);

}





#ifdef _OSD_POSIX



#include "apr_lib.h"

os/unix/unixd.h

+25 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 


#include "httpd.h"

#include "http_config.h"

#include "scoreboard.h"

#include "ap_listen.h"

#ifdef HAVE_SYS_TIME_H

#include <sys/time.h>
@@ -109,6 +110,30 @@ AP_DECLARE(apr_status_t) ap_unixd_accept(void **accepted, ap_listen_rec *lr, apr 
#define ap_os_killpg(x, y)      (kill (-(x), (y)))

#endif /* HAVE_KILLPG */



typedef struct {

    void            *baton;  /* MPM's */



    /* volatile because they're updated from signals' handlers */

    int volatile    mpm_state;

    int volatile    shutdown_pending;

    int volatile    restart_pending;

    int volatile    is_ungraceful;



    ap_generation_t my_generation;

    int             module_loads;

    int             was_graceful;



    /*

     * Current number of listeners buckets and maximum reached across

     * restarts (to size retained data according to dynamic num_buckets,

     * eg. idle_spawn_rate).

     */

    int num_buckets, max_buckets;

} ap_unixd_mpm_retained_data;



AP_DECLARE(ap_unixd_mpm_retained_data *) ap_unixd_mpm_get_retained_data(void);

AP_DECLARE(void) ap_unixd_mpm_set_signals(apr_pool_t *pconf, int once_process);



#ifdef __cplusplus

}

#endif

server/mpm/event/event.c

+69 −211

File changed.

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