memblock: Add debug markers at the end of the array

Since we allocate one more than needed, why not do a bit of sanity checking here to ensure we don't walk past the end of the array ? Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

memblock: Add debug markers at the end of the array
Since we allocate one more than needed, why not do a bit of sanity checking here to ensure we don't walk past the end of the array ? Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Benjamin Herrenschmidt
1 parent bf23c51f1f
Showing 1 changed file with 11 additions and 0 deletions Side-by-side Diff
mm/memblock.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/bitops.h>
+#include <linux/poison.h>
 #include <linux/memblock.h>
  
 struct memblock memblock;
@@ -112,6 +113,10 @@
 	memblock.reserved.regions	= memblock_reserved_init_regions;
 	memblock.reserved.max	= INIT_MEMBLOCK_REGIONS;
  
+	/* Write a marker in the unused last array entry */
+	memblock.memory.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
+	memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
+
 	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
 	 * This simplifies the memblock_add() code below...
 	 */
@@ -130,6 +135,12 @@
 void __init memblock_analyze(void)
 {
 	int i;
+
+	/* Check marker in the unused last array entry */
+	WARN_ON(memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS].base
+		!= (phys_addr_t)RED_INACTIVE);
+	WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base
+		!= (phys_addr_t)RED_INACTIVE);
  
 	memblock.memory_size = 0;
...	...	@@ -13,6 +13,7 @@
13	13	#include <linux/kernel.h>
14	14	#include <linux/init.h>
15	15	#include <linux/bitops.h>
	16	+#include <linux/poison.h>
16	17	#include <linux/memblock.h>
17	18
18	19	struct memblock memblock;
...	...	@@ -112,6 +113,10 @@
112	113	memblock.reserved.regions = memblock_reserved_init_regions;
113	114	memblock.reserved.max = INIT_MEMBLOCK_REGIONS;
114	115
	116	+ /* Write a marker in the unused last array entry */
	117	+ memblock.memory.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
	118	+ memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
	119	+
115	120	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
116	121	* This simplifies the memblock_add() code below...
117	122	*/
...	...	@@ -130,6 +135,12 @@
130	135	void __init memblock_analyze(void)
131	136	{
132	137	int i;
	138	+
	139	+ /* Check marker in the unused last array entry */
	140	+ WARN_ON(memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS].base
	141	+ != (phys_addr_t)RED_INACTIVE);
	142	+ WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base
	143	+ != (phys_addr_t)RED_INACTIVE);
133	144
134	145	memblock.memory_size = 0;
135	146