view src/event/ngx_event_posted.h @ 4964:2464ccebdb52

Upstream: fixed SIGSEGV with the "if" directive. Configuration like location / { set $true 1; if ($true) { proxy_pass http://backend; } if ($true) { # nothing } } resulted in segmentation fault due to NULL pointer dereference as the upstream configuration wasn't initialized in an implicit location created by the last if(), but the r->content_handler was set due to first if(). Instead of committing a suicide by dereferencing a NULL pointer, return 500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better fix would be to avoid such cases by fixing the "if" directive handling, but it's out of scope of this patch. Prodded by Piotr Sikora.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 13 Dec 2012 16:05:59 +0000
parents d620f497c50f
children 3377f9459e99
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_POSTED_H_INCLUDED_
#define _NGX_EVENT_POSTED_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


#if (NGX_THREADS)
extern ngx_mutex_t  *ngx_posted_events_mutex;
#endif


#define ngx_locked_post_event(ev, queue)                                      \
                                                                              \
    if (ev->prev == NULL) {                                                   \
        ev->next = (ngx_event_t *) *queue;                                    \
        ev->prev = (ngx_event_t **) queue;                                    \
        *queue = ev;                                                          \
                                                                              \
        if (ev->next) {                                                       \
            ev->next->prev = &ev->next;                                       \
        }                                                                     \
                                                                              \
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0, "post event %p", ev);  \
                                                                              \
    } else  {                                                                 \
        ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0,                        \
                       "update posted event %p", ev);                         \
    }


#define ngx_post_event(ev, queue)                                             \
                                                                              \
    ngx_mutex_lock(ngx_posted_events_mutex);                                  \
    ngx_locked_post_event(ev, queue);                                         \
    ngx_mutex_unlock(ngx_posted_events_mutex);


#define ngx_delete_posted_event(ev)                                           \
                                                                              \
    *(ev->prev) = ev->next;                                                   \
                                                                              \
    if (ev->next) {                                                           \
        ev->next->prev = ev->prev;                                            \
    }                                                                         \
                                                                              \
    ev->prev = NULL;                                                          \
    ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0,                            \
                   "delete posted event %p", ev);



void ngx_event_process_posted(ngx_cycle_t *cycle,
    ngx_thread_volatile ngx_event_t **posted);
void ngx_wakeup_worker_thread(ngx_cycle_t *cycle);

#if (NGX_THREADS)
ngx_int_t ngx_event_thread_process_posted(ngx_cycle_t *cycle);
#endif


extern ngx_thread_volatile ngx_event_t  *ngx_posted_accept_events;
extern ngx_thread_volatile ngx_event_t  *ngx_posted_events;


#endif /* _NGX_EVENT_POSTED_H_INCLUDED_ */