Core: fix misallocation at ngx_crypt_apr1 (ticket #412). Found by using auth_basic.t from mdounin nginx-tests under valgrind. ==10470== Invalid write of size 1 ==10470== at 0x43603D: ngx_crypt_to64 (ngx_crypt.c:168) ==10470== by 0x43648E: ngx_crypt (ngx_crypt.c:153) ==10470== by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297) ==10470== by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240) ==10470== by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121) ==10470== by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895) ==10470== by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878) ==10470== by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852) ==10470== by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283) ==10470== by 0x456A91: ngx_http_process_request_line (ngx_http_request.c:964) ==10470== by 0x457097: ngx_http_wait_request_handler (ngx_http_request.c:486) ==10470== by 0x4411EE: ngx_epoll_process_events (ngx_epoll_module.c:691) ==10470== Address 0x5866fab is 0 bytes after a block of size 27 alloc'd ==10470== at 0x4A074CD: malloc (vg_replace_malloc.c:236) ==10470== by 0x43B251: ngx_alloc (ngx_alloc.c:22) ==10470== by 0x421B0D: ngx_malloc (ngx_palloc.c:119) ==10470== by 0x421B65: ngx_pnalloc (ngx_palloc.c:147) ==10470== by 0x436368: ngx_crypt (ngx_crypt.c:140) ==10470== by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297) ==10470== by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240) ==10470== by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121) ==10470== by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895) ==10470== by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878) ==10470== by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852) ==10470== by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283) ==10470==

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


void
ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin)
{

#if (NGX_HAVE_ATOMIC_OPS)

    ngx_uint_t  i, n;

    for ( ;; ) {

        if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
            return;
        }

        if (ngx_ncpu > 1) {

            for (n = 1; n < spin; n <<= 1) {

                for (i = 0; i < n; i++) {
                    ngx_cpu_pause();
                }

                if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
                    return;
                }
            }
        }

        ngx_sched_yield();
    }

#else

#if (NGX_THREADS)

#error ngx_spinlock() or ngx_atomic_cmp_set() are not defined !

#endif

#endif

}