[PATCH 2/2] xen/common: Use enhanced ASSERT_ALLOC_CONTEXT in xmalloc()

[Henry Wang <Henry.Wang@xxxxxxx>]

xmalloc() will use a pool for allocation smaller than a page.
The pool is extended only when there are no more space. At which
point, alloc_xenheap_pages() is called to add more memory.

xmalloc() must be protected by ASSERT_ALLOC_CONTEXT. It should not
rely on pool expanding to trigger the ASSERT_ALLOC_CONTEXT in
alloc_xenheap_pages(). Hence, this commit moves the definition of
ASSERT_ALLOC_CONTEXT to header and uses the ASSERT_ALLOC_CONTEXT
to replace the original assertion in xmalloc().

Reported-by: Wei Chen <Wei.Chen@xxxxxxx>
Suggested-by: Julien Grall <jgrall@xxxxxxxxxx>
Signed-off-by: Henry Wang <Henry.Wang@xxxxxxx>
Change-Id: Ia463d2241e80e8a78d7dbb5b2318694d3ca5ed67
---
 xen/common/page_alloc.c   | 7 -------
 xen/common/xmalloc_tlsf.c | 2 +-
 xen/include/xen/irq.h     | 7 +++++++
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index e866e0d864..ea59cd1a4a 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -162,13 +162,6 @@
 static char __initdata opt_badpage[100] = "";
 string_param("badpage", opt_badpage);
 
-/*
- * Heap allocations may need TLB flushes which may require IRQs to be
- * enabled (except when only 1 PCPU is online).
- */
-#define ASSERT_ALLOC_CONTEXT() \
-    ASSERT(!in_irq() && (local_irq_is_enabled() || num_online_cpus() <= 1))
-
 /*
  * no-bootscrub -> Free pages are not zeroed during boot.
  */
diff --git a/xen/common/xmalloc_tlsf.c b/xen/common/xmalloc_tlsf.c
index d2ad909502..b8f838ae74 100644
--- a/xen/common/xmalloc_tlsf.c
+++ b/xen/common/xmalloc_tlsf.c
@@ -594,7 +594,7 @@ void *_xmalloc(unsigned long size, unsigned long align)
 {
     void *p = NULL;
 
-    ASSERT(!in_irq());
+    ASSERT_ALLOC_CONTEXT();
 
     if ( !size )
         return ZERO_BLOCK_PTR;
diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h
index d8beadd16b..300625e56d 100644
--- a/xen/include/xen/irq.h
+++ b/xen/include/xen/irq.h
@@ -10,6 +10,13 @@
 #include <asm/hardirq.h>
 #include <public/event_channel.h>
 
+/*
+ * Heap allocations may need TLB flushes which may require IRQs to be
+ * enabled (except when only 1 PCPU is online).
+ */
+#define ASSERT_ALLOC_CONTEXT() \
+    ASSERT(!in_irq() && (local_irq_is_enabled() || num_online_cpus() <= 1))
+
 struct irqaction {
     void (*handler)(int, void *, struct cpu_user_regs *);
     const char *name;
-- 
2.25.1