main/varnish: fix stack overflow

ref #4938

1 files changed, 44 insertions, 0 deletions

diff --git a/main/varnish/fix-stack-overflow.patch b/main/varnish/fix-stack-overflow.patch
new file mode 100644
index 0000000000..67677b3306
--- /dev/null
+++ b/main/varnish/fix-stack-overflow.patch
@@ -0,0 +1,44 @@
+From bc0b56b8703e7e02af745af28bc6fff48ab806ba Mon Sep 17 00:00:00 2001
+From: Natanael Copa <ncopa@alpinelinux.org>
+Date: Wed, 2 Mar 2016 10:46:49 +0100
+Subject: [PATCH] fix stack overflow in epoll waiter
+
+musl libc has a default thread stack of 80k. avoid overflow the stack by
+allocating the epol_event array on heap instead of stack.
+---
+ bin/varnishd/waiter/cache_waiter_epoll.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/bin/varnishd/waiter/cache_waiter_epoll.c b/bin/varnishd/waiter/cache_waiter_epoll.c
+index f50ae46..65719e5 100644
+--- a/bin/varnishd/waiter/cache_waiter_epoll.c
++++ b/bin/varnishd/waiter/cache_waiter_epoll.c
+@@ -71,7 +71,7 @@ struct vwe {
+ static void *
+ vwe_thread(void *priv)
+ {
+-	struct epoll_event ev[NEEV], *ep;
++	struct epoll_event *ev, *ep;
+ 	struct waited *wp;
+ 	struct waiter *w;
+ 	double now, then;
+@@ -83,6 +83,8 @@ vwe_thread(void *priv)
+ 	w = vwe->waiter;
+ 	CHECK_OBJ_NOTNULL(w, WAITER_MAGIC);
+ 	THR_SetName("cache-epoll");
++	ev = malloc(NEEV * sizeof(struct epoll_event));
++	assert(ev != NULL);
+ 
+ 	now = VTIM_real();
+ 	while (1) {
+@@ -146,6 +148,7 @@ vwe_thread(void *priv)
+ 	AZ(close(vwe->pipe[0]));
+ 	AZ(close(vwe->pipe[1]));
+ 	AZ(close(vwe->epfd));
++	free(ev);
+ 	return (NULL);
+ }
+ 
+-- 
+2.7.2
+