kmemleak: Remove some of the kmemleak false positives

There are allocations for which the main pointer cannot be found but they are not memory leaks. This patch fixes some of them. For more information on false positives, see Documentation/kmemleak.txt. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kmemleak: Remove some of the kmemleak false positives
There are allocations for which the main pointer cannot be found but they are not memory leaks. This patch fixes some of them. For more information on false positives, see Documentation/kmemleak.txt. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Catalin Marinas
1 parent 4f2294b6dc
Showing 3 changed files with 18 additions and 0 deletions Side-by-side Diff
drivers/char/vt.c
fs/block_dev.c
include/linux/percpu.h
@@ -104,6 +104,7 @@
 #include <linux/io.h>
 #include <asm/system.h>
 #include <linux/uaccess.h>
+#include <linux/kmemleak.h>
  
 #define MAX_NR_CON_DRIVER 16
  
@@ -2880,6 +2881,12 @@
 	 */
 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
 		vc_cons[currcons].d = vc = alloc_bootmem(sizeof(struct vc_data));
+		/*
+		 * Kmemleak does not track the memory allocated via
+		 * alloc_bootmem() but this block contains pointers to
+		 * other blocks allocated via kmalloc.
+		 */
+		kmemleak_alloc(vc, sizeof(struct vc_data), 1, GFP_ATOMIC);
 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 		visual_init(vc, currcons, 1);
 		vc->vc_screenbuf = (unsigned short *)alloc_bootmem(vc->vc_screenbuf_size);
@@ -25,6 +25,7 @@
 #include <linux/uio.h>
 #include <linux/namei.h>
 #include <linux/log2.h>
+#include <linux/kmemleak.h>
 #include <asm/uaccess.h>
 #include "internal.h"
  
@@ -492,6 +493,11 @@
 	bd_mnt = kern_mount(&bd_type);
 	if (IS_ERR(bd_mnt))
 		panic("Cannot create bdev pseudo-fs");
+	/*
+	 * This vfsmount structure is only used to obtain the
+	 * blockdev_superblock, so tell kmemleak not to report it.
+	 */
+	kmemleak_not_leak(bd_mnt);
 	blockdev_superblock = bd_mnt->mnt_sb;	/* For writeback */
 }
  
@@ -86,7 +86,12 @@
 	void *ptrs[1];
 };
  
+/* pointer disguising messes up the kmemleak objects tracking */
+#ifndef CONFIG_DEBUG_KMEMLEAK
 #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
+#else
+#define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
+#endif
  
 #define per_cpu_ptr(ptr, cpu)						\
 ({									\
...	...	@@ -104,6 +104,7 @@
104	104	#include <linux/io.h>
105	105	#include <asm/system.h>
106	106	#include <linux/uaccess.h>
	107	+#include <linux/kmemleak.h>
107	108
108	109	#define MAX_NR_CON_DRIVER 16
109	110
...	...	@@ -2880,6 +2881,12 @@
2880	2881	*/
2881	2882	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
2882	2883	vc_cons[currcons].d = vc = alloc_bootmem(sizeof(struct vc_data));
	2884	+ /*
	2885	+ * Kmemleak does not track the memory allocated via
	2886	+ * alloc_bootmem() but this block contains pointers to
	2887	+ * other blocks allocated via kmalloc.
	2888	+ */
	2889	+ kmemleak_alloc(vc, sizeof(struct vc_data), 1, GFP_ATOMIC);
2883	2890	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
2884	2891	visual_init(vc, currcons, 1);
2885	2892	vc->vc_screenbuf = (unsigned short *)alloc_bootmem(vc->vc_screenbuf_size);
...	...	@@ -25,6 +25,7 @@
25	25	#include <linux/uio.h>
26	26	#include <linux/namei.h>
27	27	#include <linux/log2.h>
	28	+#include <linux/kmemleak.h>
28	29	#include <asm/uaccess.h>
29	30	#include "internal.h"
30	31
...	...	@@ -492,6 +493,11 @@
492	493	bd_mnt = kern_mount(&bd_type);
493	494	if (IS_ERR(bd_mnt))
494	495	panic("Cannot create bdev pseudo-fs");
	496	+ /*
	497	+ * This vfsmount structure is only used to obtain the
	498	+ * blockdev_superblock, so tell kmemleak not to report it.
	499	+ */
	500	+ kmemleak_not_leak(bd_mnt);
495	501	blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
496	502	}
497	503
...	...	@@ -86,7 +86,12 @@
86	86	void *ptrs[1];
87	87	};
88	88
	89	+/* pointer disguising messes up the kmemleak objects tracking */
	90	+#ifndef CONFIG_DEBUG_KMEMLEAK
89	91	#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
	92	+#else
	93	+#define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
	94	+#endif
90	95
91	96	#define per_cpu_ptr(ptr, cpu) \
92	97	({ \