Valgrind: supressed complaints about uninitialized bytes.

Valgrind complains if we pass uninitialized memory to a syscall:

==36492== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==36492==    at 0x6B5E6A: sendmsg (in /usr/lib/system/libsystem_kernel.dylib)
==36492==    by 0x10004288E: ngx_signal_worker_processes (ngx_process_cycle.c:527)
==36492==    by 0x1000417A7: ngx_master_process_cycle (ngx_process_cycle.c:203)
==36492==    by 0x100001F10: main (nginx.c:410)
==36492==  Address 0x7fff5fbff71c is on thread 1's stack

Even initialization of all members of the structure passed isn't enough, as
there is padding which still remains uninitialized and results in Valgrind
complaint.  Note there is no real problem here as data from uninitialized
memory isn't used.

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 6d94c5034250cf733c459a9ece866a057d54233b..eacca595aea3749eb4e3368d180a4b8ba93e96fc 100644 (file)
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -875,6 +875,8 @@ ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf)
 
     c = r->cache;
 
+    ngx_memzero(h, sizeof(ngx_http_file_cache_header_t));
+
     h->valid_sec = c->valid_sec;
     h->last_modified = c->last_modified;
     h->date = c->date;

diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index dfdfae081c00dbccd2490cb3e8152ff9f34e2132..f937fb66116c65940f00834f53940c1fdf5ee1f3 100644 (file)
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -355,6 +355,8 @@ ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
 
     ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
 
+    ngx_memzero(&ch, sizeof(ngx_channel_t));
+
     ch.command = NGX_CMD_OPEN_CHANNEL;
 
     for (i = 0; i < n; i++) {
@@ -401,6 +403,8 @@ ngx_start_cache_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
                       &ngx_cache_manager_ctx, "cache manager process",
                       respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
 
+    ngx_memzero(&ch, sizeof(ngx_channel_t));
+
     ch.command = NGX_CMD_OPEN_CHANNEL;
     ch.pid = ngx_processes[ngx_process_slot].pid;
     ch.slot = ngx_process_slot;
@@ -460,6 +464,8 @@ ngx_signal_worker_processes(ngx_cycle_t *cycle, int signo)
     ngx_err_t      err;
     ngx_channel_t  ch;
 
+    ngx_memzero(&ch, sizeof(ngx_channel_t));
+
 #if (NGX_BROKEN_SCM_RIGHTS)
 
     ch.command = 0;
@@ -561,6 +567,8 @@ ngx_reap_children(ngx_cycle_t *cycle)
     ngx_channel_t     ch;
     ngx_core_conf_t  *ccf;
 
+    ngx_memzero(&ch, sizeof(ngx_channel_t));
+
     ch.command = NGX_CMD_CLOSE_CHANNEL;
     ch.fd = -1;