This patch is a fix for memory issues with
pcre-jit, see upstream bug report at
https://github.com/varnishcache/varnish-cache/issues/2817

The patch is based on upstream commits
a3129a5340566d17192de8058a9c1dbb051a7039
683b7cbe8cde1dde8f9e516a354b82430f1d318e
1226e77f9501c56976635c714c99d84f417aa5d2


diff -Naur a/bin/varnishd/cache/cache_panic.c b/bin/varnishd/cache/cache_panic.c
--- a/bin/varnishd/cache/cache_panic.c	2018-10-24 11:29:10.000000000 +0200
+++ b/bin/varnishd/cache/cache_panic.c	2019-03-07 16:27:16.592441674 +0100
@@ -601,6 +601,33 @@
 	VSB_indent(vsb, -2);
 }
 
+#ifdef HAVE_PTHREAD_GETATTR_NP
+static void
+pan_threadattr(struct vsb *vsb)
+{
+	pthread_attr_t attr[1];
+	size_t sz;
+	void *addr;
+
+	if (pthread_getattr_np(pthread_self(), attr) != 0)
+		return;
+
+	VSB_cat(vsb, "pthread.attr = {\n");
+	VSB_indent(vsb, 2);
+
+	if (pthread_attr_getguardsize(attr, &sz) == 0)
+		VSB_printf(vsb, "guard = %zu,\n", sz);
+	if (pthread_attr_getstack(attr, &addr, &sz) == 0) {
+		VSB_printf(vsb, "stack_bottom = %p,\n", addr);
+		VSB_printf(vsb, "stack_top = %p,\n", (char *)addr + sz);
+		VSB_printf(vsb, "stack_size = %zu,\n", sz);
+	}
+	VSB_indent(vsb, -2);
+	VSB_cat(vsb, "}\n");
+	(void) pthread_attr_destroy(attr);
+}
+#endif
+
 /*--------------------------------------------------------------------*/
 
 static void __attribute__((__noreturn__))
@@ -673,6 +700,10 @@
 	if (q != NULL)
 		VSB_printf(pan_vsb, "thread = (%s)\n", q);
 
+#ifdef HAVE_PTHREAD_GETATTR_NP
+	pan_threadattr(pan_vsb);
+#endif
+
 	if (!FEATURE(FEATURE_SHORT_PANIC)) {
 		req = THR_GetRequest();
 		VSB_cat(pan_vsb, "thr.");
diff -Naur a/bin/varnishd/mgt/mgt_param.c b/bin/varnishd/mgt/mgt_param.c
--- a/bin/varnishd/mgt/mgt_param.c	2018-10-24 11:29:10.000000000 +0200
+++ b/bin/varnishd/mgt/mgt_param.c	2019-03-07 16:27:16.594441699 +0100
@@ -494,6 +494,8 @@
 
 	MCF_TcpParams();
 
+	def = 56 * 1024;
+
 	if (sizeof(void *) < 8) {		/*lint !e506 !e774  */
 		/*
 		 * Adjust default parameters for 32 bit systems to conserve
@@ -505,20 +507,16 @@
 		MCF_ParamConf(MCF_DEFAULT, "http_req_size", "12k");
 		MCF_ParamConf(MCF_DEFAULT, "gzip_buffer", "4k");
 		MCF_ParamConf(MCF_MAXIMUM, "vsl_space", "1G");
+		def = 48 * 1024;
 	}
 
-#if !defined(HAVE_ACCEPT_FILTERS) || defined(__linux)
-	MCF_ParamConf(MCF_DEFAULT, "accept_filter", "off");
-#endif
-
 	low = sysconf(_SC_THREAD_STACK_MIN);
 	MCF_ParamConf(MCF_MINIMUM, "thread_pool_stack", "%jdb", (intmax_t)low);
 
 #if defined(__SANITIZER) || __has_feature(address_sanitizer)
 	def = 92 * 1024;
-#else
-	def = 48 * 1024;
 #endif
+
 	if (def < low)
 		def = low;
 	MCF_ParamConf(MCF_DEFAULT, "thread_pool_stack", "%jdb", (intmax_t)def);
@@ -529,6 +527,10 @@
 
 	MCF_ParamConf(MCF_MAXIMUM, "thread_pools", "%d", MAX_THREAD_POOLS);
 
+#if !defined(HAVE_ACCEPT_FILTERS) || defined(__linux)
+	MCF_ParamConf(MCF_DEFAULT, "accept_filter", "off");
+#endif
+
 	VCLS_AddFunc(mgt_cls, MCF_AUTH, cli_params);
 
 	vsb = VSB_new_auto();
diff -Naur a/configure.ac b/configure.ac
--- a/configure.ac	2018-10-26 13:22:45.000000000 +0200
+++ b/configure.ac	2019-03-07 16:27:16.592441674 +0100
@@ -239,6 +239,7 @@
 AC_CHECK_FUNCS([pthread_set_name_np])
 AC_CHECK_FUNCS([pthread_setname_np])
 AC_CHECK_FUNCS([pthread_mutex_isowned_np])
+AC_CHECK_FUNCS([pthread_getattr_np])
 LIBS="${save_LIBS}"
 
 # Support for visibility attribute