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.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index dfdfae081..f937fb661 100644
--- 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;