Merge branch 'oprofile/urgent' into HEAD

Robert Richter
2 parents 5f307491f3 a0e3e70243
Showing 2 changed files Side-by-side Diff
arch/x86/oprofile/backtrace.c
arch/x86/oprofile/nmi_int.c
@@ -11,10 +11,12 @@
 #include <linux/oprofile.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/compat.h>
+#include <linux/highmem.h>
+
 #include <asm/ptrace.h>
 #include <asm/uaccess.h>
 #include <asm/stacktrace.h>
-#include <linux/compat.h>
  
 static int backtrace_stack(void *data, char *name)
 {
  
  
  
  
@@ -36,18 +38,54 @@
 	.walk_stack	= print_context_stack,
 };
  
+/* from arch/x86/kernel/cpu/perf_event.c: */
+
+/*
+ * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
+ */
+static unsigned long
+copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
+{
+	unsigned long offset, addr = (unsigned long)from;
+	unsigned long size, len = 0;
+	struct page *page;
+	void *map;
+	int ret;
+
+	do {
+		ret = __get_user_pages_fast(addr, 1, 0, &page);
+		if (!ret)
+			break;
+
+		offset = addr & (PAGE_SIZE - 1);
+		size = min(PAGE_SIZE - offset, n - len);
+
+		map = kmap_atomic(page);
+		memcpy(to, map+offset, size);
+		kunmap_atomic(map);
+		put_page(page);
+
+		len  += size;
+		to   += size;
+		addr += size;
+
+	} while (len < n);
+
+	return len;
+}
+
 #ifdef CONFIG_COMPAT
 static struct stack_frame_ia32 *
 dump_user_backtrace_32(struct stack_frame_ia32 *head)
 {
+	/* Also check accessibility of one struct frame_head beyond: */
 	struct stack_frame_ia32 bufhead[2];
 	struct stack_frame_ia32 *fp;
+	unsigned long bytes;
  
-	/* Also check accessibility of one struct frame_head beyond */
-	if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
+	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+	if (bytes != sizeof(bufhead))
 		return NULL;
-	if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
-		return NULL;
  
 	fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
  
  
  
@@ -87,12 +125,12 @@
  
 static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
 {
+	/* Also check accessibility of one struct frame_head beyond: */
 	struct stack_frame bufhead[2];
+	unsigned long bytes;
  
-	/* Also check accessibility of one struct stack_frame beyond */
-	if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
-		return NULL;
-	if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
+	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+	if (bytes != sizeof(bufhead))
 		return NULL;
  
 	oprofile_add_trace(bufhead[0].return_address);
@@ -112,8 +112,10 @@
 static int nmi_start(void)
 {
 	get_online_cpus();
-	on_each_cpu(nmi_cpu_start, NULL, 1);
 	ctr_running = 1;
+	/* make ctr_running visible to the nmi handler: */
+	smp_mb();
+	on_each_cpu(nmi_cpu_start, NULL, 1);
 	put_online_cpus();
 	return 0;
 }
  
  
@@ -504,15 +506,18 @@
  
 	nmi_enabled = 0;
 	ctr_running = 0;
-	barrier();
+	/* make variables visible to the nmi handler: */
+	smp_mb();
 	err = register_die_notifier(&profile_exceptions_nb);
 	if (err)
 		goto fail;
  
 	get_online_cpus();
 	register_cpu_notifier(&oprofile_cpu_nb);
-	on_each_cpu(nmi_cpu_setup, NULL, 1);
 	nmi_enabled = 1;
+	/* make nmi_enabled visible to the nmi handler: */
+	smp_mb();
+	on_each_cpu(nmi_cpu_setup, NULL, 1);
 	put_online_cpus();
  
 	return 0;
@@ -531,7 +536,8 @@
 	nmi_enabled = 0;
 	ctr_running = 0;
 	put_online_cpus();
-	barrier();
+	/* make variables visible to the nmi handler: */
+	smp_mb();
 	unregister_die_notifier(&profile_exceptions_nb);
 	msrs = &get_cpu_var(cpu_msrs);
 	model->shutdown(msrs);
...	...	@@ -11,10 +11,12 @@
11	11	#include <linux/oprofile.h>
12	12	#include <linux/sched.h>
13	13	#include <linux/mm.h>
	14	+#include <linux/compat.h>
	15	+#include <linux/highmem.h>
	16	+
14	17	#include <asm/ptrace.h>
15	18	#include <asm/uaccess.h>
16	19	#include <asm/stacktrace.h>
17		-#include <linux/compat.h>
18	20
19	21	static int backtrace_stack(void data, char name)
20	22	{
21	23
22	24
23	25
24	26
...	...	@@ -36,18 +38,54 @@
36	38	.walk_stack = print_context_stack,
37	39	};
38	40
	41	+/* from arch/x86/kernel/cpu/perf_event.c: */
	42	+
	43	+/*
	44	+ * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
	45	+ */
	46	+static unsigned long
	47	+copy_from_user_nmi(void to, const void __user from, unsigned long n)
	48	+{
	49	+ unsigned long offset, addr = (unsigned long)from;
	50	+ unsigned long size, len = 0;
	51	+ struct page *page;
	52	+ void *map;
	53	+ int ret;
	54	+
	55	+ do {
	56	+ ret = __get_user_pages_fast(addr, 1, 0, &page);
	57	+ if (!ret)
	58	+ break;
	59	+
	60	+ offset = addr & (PAGE_SIZE - 1);
	61	+ size = min(PAGE_SIZE - offset, n - len);
	62	+
	63	+ map = kmap_atomic(page);
	64	+ memcpy(to, map+offset, size);
	65	+ kunmap_atomic(map);
	66	+ put_page(page);
	67	+
	68	+ len += size;
	69	+ to += size;
	70	+ addr += size;
	71	+
	72	+ } while (len < n);
	73	+
	74	+ return len;
	75	+}
	76	+
39	77	#ifdef CONFIG_COMPAT
40	78	static struct stack_frame_ia32 *
41	79	dump_user_backtrace_32(struct stack_frame_ia32 *head)
42	80	{
	81	+ /* Also check accessibility of one struct frame_head beyond: */
43	82	struct stack_frame_ia32 bufhead[2];
44	83	struct stack_frame_ia32 *fp;
	84	+ unsigned long bytes;
45	85
46		- /* Also check accessibility of one struct frame_head beyond */
47		- if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
	86	+ bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
	87	+ if (bytes != sizeof(bufhead))
48	88	return NULL;
49		- if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
50		- return NULL;
51	89
52	90	fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
53	91
54	92
55	93
...	...	@@ -87,12 +125,12 @@
87	125
88	126	static struct stack_frame dump_user_backtrace(struct stack_frame head)
89	127	{
	128	+ /* Also check accessibility of one struct frame_head beyond: */
90	129	struct stack_frame bufhead[2];
	130	+ unsigned long bytes;
91	131
92		- /* Also check accessibility of one struct stack_frame beyond */
93		- if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
94		- return NULL;
95		- if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
	132	+ bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
	133	+ if (bytes != sizeof(bufhead))
96	134	return NULL;
97	135
98	136	oprofile_add_trace(bufhead[0].return_address);
...	...	@@ -112,8 +112,10 @@
112	112	static int nmi_start(void)
113	113	{
114	114	get_online_cpus();
115		- on_each_cpu(nmi_cpu_start, NULL, 1);
116	115	ctr_running = 1;
	116	+ /* make ctr_running visible to the nmi handler: */
	117	+ smp_mb();
	118	+ on_each_cpu(nmi_cpu_start, NULL, 1);
117	119	put_online_cpus();
118	120	return 0;
119	121	}
120	122
121	123
...	...	@@ -504,15 +506,18 @@
504	506
505	507	nmi_enabled = 0;
506	508	ctr_running = 0;
507		- barrier();
	509	+ /* make variables visible to the nmi handler: */
	510	+ smp_mb();
508	511	err = register_die_notifier(&profile_exceptions_nb);
509	512	if (err)
510	513	goto fail;
511	514
512	515	get_online_cpus();
513	516	register_cpu_notifier(&oprofile_cpu_nb);
514		- on_each_cpu(nmi_cpu_setup, NULL, 1);
515	517	nmi_enabled = 1;
	518	+ /* make nmi_enabled visible to the nmi handler: */
	519	+ smp_mb();
	520	+ on_each_cpu(nmi_cpu_setup, NULL, 1);
516	521	put_online_cpus();
517	522
518	523	return 0;
...	...	@@ -531,7 +536,8 @@
531	536	nmi_enabled = 0;
532	537	ctr_running = 0;
533	538	put_online_cpus();
534		- barrier();
	539	+ /* make variables visible to the nmi handler: */
	540	+ smp_mb();
535	541	unregister_die_notifier(&profile_exceptions_nb);
536	542	msrs = &get_cpu_var(cpu_msrs);
537	543	model->shutdown(msrs);