Mercurial > hg > nginx
view src/os/unix/ngx_darwin_sendfile_chain.c @ 8106:8852f39311de
Fixed segfault when switching off master process during upgrade.
Binary upgrades are not supported without master process, but it is,
however, possible, that nginx running with master process is asked
to upgrade binary, and the configuration file as available on disk
at this time includes "master_process off;".
If this happens, listening sockets inherited from the previous binary
will have ls[i].previous set. But the old cycle on initial process
startup, including startup after binary upgrade, is destroyed by
ngx_init_cycle() once configuration parsing is complete. As a result,
an attempt to dereference ls[i].previous in ngx_event_process_init()
accesses already freed memory.
Fix is to avoid looking into ls[i].previous if the old cycle is already
freed.
With this change it is also no longer needed to clear ls[i].previous in
worker processes, so the relevant code was removed.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 23 Nov 2022 23:48:53 +0300 |
parents | 7cc2d3a96ea3 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> /* * It seems that Darwin 9.4 (Mac OS X 1.5) sendfile() has the same * old bug as early FreeBSD sendfile() syscall: * http://bugs.freebsd.org/33771 * * Besides sendfile() has another bug: if one calls sendfile() * with both a header and a trailer, then sendfile() ignores a file part * at all and sends only the header and the trailer together. * For this reason we send a trailer only if there is no a header. * * Although sendfile() allows to pass a header or a trailer, * it may send the header or the trailer and a part of the file * in different packets. And FreeBSD workaround (TCP_NOPUSH option) * does not help. */ ngx_chain_t * ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc; off_t send, prev_send, sent; off_t file_size; ssize_t n; ngx_uint_t eintr; ngx_err_t err; ngx_buf_t *file; ngx_event_t *wev; ngx_chain_t *cl; ngx_iovec_t header, trailer; struct sf_hdtr hdtr; struct iovec headers[NGX_IOVS_PREALLOCATE]; struct iovec trailers[NGX_IOVS_PREALLOCATE]; wev = c->write; if (!wev->ready) { return in; } #if (NGX_HAVE_KQUEUE) if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) { (void) ngx_connection_error(c, wev->kq_errno, "kevent() reported about an closed connection"); wev->error = 1; return NGX_CHAIN_ERROR; } #endif /* the maximum limit size is the maximum size_t value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) { limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize; } send = 0; header.iovs = headers; header.nalloc = NGX_IOVS_PREALLOCATE; trailer.iovs = trailers; trailer.nalloc = NGX_IOVS_PREALLOCATE; for ( ;; ) { eintr = 0; prev_send = send; /* create the header iovec and coalesce the neighbouring bufs */ cl = ngx_output_chain_to_iovec(&header, in, limit - send, c->log); if (cl == NGX_CHAIN_ERROR) { return NGX_CHAIN_ERROR; } send += header.size; if (cl && cl->buf->in_file && send < limit) { file = cl->buf; /* coalesce the neighbouring file bufs */ file_size = ngx_chain_coalesce_file(&cl, limit - send); send += file_size; if (header.count == 0 && send < limit) { /* * create the trailer iovec and coalesce the neighbouring bufs */ cl = ngx_output_chain_to_iovec(&trailer, cl, limit - send, c->log); if (cl == NGX_CHAIN_ERROR) { return NGX_CHAIN_ERROR; } send += trailer.size; } else { trailer.count = 0; } /* * sendfile() returns EINVAL if sf_hdtr's count is 0, * but corresponding pointer is not NULL */ hdtr.headers = header.count ? header.iovs : NULL; hdtr.hdr_cnt = header.count; hdtr.trailers = trailer.count ? trailer.iovs : NULL; hdtr.trl_cnt = trailer.count; sent = header.size + file_size; ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: @%O %O h:%uz", file->file_pos, sent, header.size); rc = sendfile(file->file->fd, c->fd, file->file_pos, &sent, &hdtr, 0); if (rc == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; (void) ngx_connection_error(c, err, "sendfile() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err, "sendfile() sent only %O bytes", sent); } if (rc == 0 && sent == 0) { /* * if rc and sent equal to zero, then someone * has truncated the file, so the offset became beyond * the end of the file */ ngx_log_error(NGX_LOG_ALERT, c->log, 0, "sendfile() reported that \"%s\" was truncated", file->file->name.data); return NGX_CHAIN_ERROR; } ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: %d, @%O %O:%O", rc, file->file_pos, sent, file_size + header.size); } else { n = ngx_writev(c, &header); if (n == NGX_ERROR) { return NGX_CHAIN_ERROR; } sent = (n == NGX_AGAIN) ? 0 : n; } c->sent += sent; in = ngx_chain_update_sent(in, sent); if (eintr) { send = prev_send + sent; continue; } if (send - prev_send != sent) { wev->ready = 0; return in; } if (send >= limit || in == NULL) { return in; } } }