From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Wed, 24 May 2017 23:08:45 +0000 (-0400)
Subject: Alloc a pooled object for the stack, so we can use mutable frame extensions without... 
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10d8d8f8cd34fc74890977c8b5daaf779925ba55;p=thirdparty%2Ffreeradius-server.git

Alloc a pooled object for the stack, so we can use mutable frame extensions without leaking request pool memory
---

diff --git a/src/include/interpreter.h b/src/include/interpreter.h
index fb87483e302..fbc25e65eac 100644
--- a/src/include/interpreter.h
+++ b/src/include/interpreter.h
@@ -218,6 +218,12 @@ typedef struct {
 	unlang_t		*found;
 } unlang_stack_entry_redundant_t;
 
+typedef union {
+	unlang_stack_entry_modcall_t	modcall;	//!< State for a modcall.
+	unlang_stack_entry_foreach_t	foreach;	//!< Foreach iterator state.
+	unlang_stack_entry_redundant_t	redundant;	//!< Redundant section state.
+} unlang_stack_entry_t;
+
 /** Our interpreter stack, as distinct from the C stack
  *
  * We don't call the modules recursively.  Instead we iterate over a list of #unlang_t and
diff --git a/src/main/request.c b/src/main/request.c
index 863b9533cae..d593e3fd498 100644
--- a/src/main/request.c
+++ b/src/main/request.c
@@ -110,7 +110,26 @@ REQUEST *request_alloc(TALLOC_CTX *ctx)
 
 	request->module = NULL;
 	request->component = "<core>";
+
+#ifdef HAVE_TALLOC_POOLED_OBJECT
+	/*
+	 *	If we have talloc_pooled_object allocate the
+	 *	stack as a combined chunk/pool, with memory
+	 *	to hold at mutable data for at least a quarter
+	 *	of the maximum number of stack frames.
+	 *
+	 *	Having a dedicated pool for mutable stack data
+	 *	means we don't have memory fragmentations issues
+	 *	as we would if request were used as the pool.
+	 *
+	 *	This number is pretty arbitrary, but it seems
+	 *	like too low level to make into a tuneable.
+	 */
+	request->stack = talloc_pooled_object(request, unlang_stack_t, UNLANG_STACK_MAX / 4,
+					      sizeof(unlang_stack_entry_t));
+#else
 	request->stack = talloc_zero(request, unlang_stack_t);
+#endif
 	request->heap_id = -1;
 
 	request->state_ctx = talloc_init("session-state");