5 files changed, 110 insertions, 162 deletions

diff --git a/arch/arm/oprofile/Makefile b/arch/arm/oprofile/Makefile
index 8ffb523e6c7..6a94e54848f 100644
--- a/arch/arm/oprofile/Makefile
+++ b/arch/arm/oprofile/Makefile
@@ -6,6 +6,6 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
 		oprofilefs.o oprofile_stats.o \
 		timer_int.o )
 
-oprofile-y				:= $(DRIVER_OBJS) init.o backtrace.o
-oprofile-$(CONFIG_CPU_XSCALE)		+= common.o op_model_xscale.o
+oprofile-y				:= $(DRIVER_OBJS) common.o backtrace.o
+oprofile-$(CONFIG_CPU_XSCALE)		+= op_model_xscale.o
 
diff --git a/arch/arm/oprofile/backtrace.c b/arch/arm/oprofile/backtrace.c
index df35c452a8b..7c22c12618c 100644
--- a/arch/arm/oprofile/backtrace.c
+++ b/arch/arm/oprofile/backtrace.c
@@ -49,42 +49,22 @@ static struct frame_tail* kernel_backtrace(struct frame_tail *tail)
 
 static struct frame_tail* user_backtrace(struct frame_tail *tail)
 {
-	struct frame_tail buftail;
+	struct frame_tail buftail[2];
 
-	/* hardware pte might not be valid due to dirty/accessed bit emulation
-	 * so we use copy_from_user and benefit from exception fixups */
-	if (copy_from_user(&buftail, tail, sizeof(struct frame_tail)))
+	/* Also check accessibility of one struct frame_tail beyond */
+	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+		return NULL;
+	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
 		return NULL;
 
-	oprofile_add_trace(buftail.lr);
+	oprofile_add_trace(buftail[0].lr);
 
 	/* frame pointers should strictly progress back up the stack
 	 * (towards higher addresses) */
-	if (tail >= buftail.fp)
+	if (tail >= buftail[0].fp)
 		return NULL;
 
-	return buftail.fp-1;
-}
-
-/* Compare two addresses and see if they're on the same page */
-#define CMP_ADDR_EQUAL(x,y,offset) ((((unsigned long) x) >> PAGE_SHIFT) \
-	== ((((unsigned long) y) + offset) >> PAGE_SHIFT))
-
-/* check that the page(s) containing the frame tail are present */
-static int pages_present(struct frame_tail *tail)
-{
-	struct mm_struct * mm = current->mm;
-
-	if (!check_user_page_readable(mm, (unsigned long)tail))
-		return 0;
-
-	if (CMP_ADDR_EQUAL(tail, tail, 8))
-		return 1;
-
-	if (!check_user_page_readable(mm, ((unsigned long)tail) + 8))
-		return 0;
-
-	return 1;
+	return buftail[0].fp-1;
 }
 
 /*
@@ -118,7 +98,6 @@ static int valid_kernel_stack(struct frame_tail *tail, struct pt_regs *regs)
 void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
 {
 	struct frame_tail *tail;
-	unsigned long last_address = 0;
 
 	tail = ((struct frame_tail *) regs->ARM_fp) - 1;
 
@@ -132,13 +111,6 @@ void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
 		return;
 	}
 
-	while (depth-- && tail && !((unsigned long) tail & 3)) {
-		if ((!CMP_ADDR_EQUAL(last_address, tail, 0)
-			|| !CMP_ADDR_EQUAL(last_address, tail, 8))
-				&& !pages_present(tail))
-			return;
-		last_address = (unsigned long) tail;
+	while (depth-- && tail && !((unsigned long) tail & 3))
 		tail = user_backtrace(tail);
-	}
 }
-
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index e57dde88289..1415930ceee 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -10,74 +10,23 @@
 #include <linux/init.h>
 #include <linux/oprofile.h>
 #include <linux/errno.h>
-#include <asm/semaphore.h>
 #include <linux/sysdev.h>
+#include <asm/semaphore.h>
 
 #include "op_counter.h"
 #include "op_arm_model.h"
 
-static struct op_arm_model_spec *pmu_model;
-static int pmu_enabled;
-static struct semaphore pmu_sem;
-
-static int pmu_start(void);
-static int pmu_setup(void);
-static void pmu_stop(void);
-static int pmu_create_files(struct super_block *, struct dentry *);
-
-#ifdef CONFIG_PM
-static int pmu_suspend(struct sys_device *dev, pm_message_t state)
-{
-	if (pmu_enabled)
-		pmu_stop();
-	return 0;
-}
-
-static int pmu_resume(struct sys_device *dev)
-{
-	if (pmu_enabled)
-		pmu_start();
-	return 0;
-}
-
-static struct sysdev_class oprofile_sysclass = {
-	set_kset_name("oprofile"),
-	.resume		= pmu_resume,
-	.suspend	= pmu_suspend,
-};
-
-static struct sys_device device_oprofile = {
-	.id		= 0,
-	.cls		= &oprofile_sysclass,
-};
-
-static int __init init_driverfs(void)
-{
-	int ret;
-
-	if (!(ret = sysdev_class_register(&oprofile_sysclass)))
-		ret = sysdev_register(&device_oprofile);
-
-	return ret;
-}
-
-static void  exit_driverfs(void)
-{
-	sysdev_unregister(&device_oprofile);
-	sysdev_class_unregister(&oprofile_sysclass);
-}
-#else
-#define init_driverfs()	do { } while (0)
-#define exit_driverfs() do { } while (0)
-#endif /* CONFIG_PM */
+static struct op_arm_model_spec *op_arm_model;
+static int op_arm_enabled;
+static struct semaphore op_arm_sem;
 
 struct op_counter_config counter_config[OP_MAX_COUNTER];
 
-static int pmu_create_files(struct super_block *sb, struct dentry *root)
+static int op_arm_create_files(struct super_block *sb, struct dentry *root)
 {
 	unsigned int i;
 
-	for (i = 0; i < pmu_model->num_counters; i++) {
+	for (i = 0; i < op_arm_model->num_counters; i++) {
 		struct dentry *dir;
 		char buf[2];
 
@@ -94,63 +43,123 @@ static int pmu_create_files(struct super_block *sb, struct dentry *root)
 	return 0;
 }
 
-static int pmu_setup(void)
+static int op_arm_setup(void)
 {
 	int ret;
 
 	spin_lock(&oprofilefs_lock);
-	ret = pmu_model->setup_ctrs();
+	ret = op_arm_model->setup_ctrs();
 	spin_unlock(&oprofilefs_lock);
 	return ret;
 }
 
-static int pmu_start(void)
+static int op_arm_start(void)
 {
 	int ret = -EBUSY;
 
-	down(&pmu_sem);
-	if (!pmu_enabled) {
-		ret = pmu_model->start();
-		pmu_enabled = !ret;
+	down(&op_arm_sem);
+	if (!op_arm_enabled) {
+		ret = op_arm_model->start();
+		op_arm_enabled = !ret;
 	}
-	up(&pmu_sem);
+	up(&op_arm_sem);
 	return ret;
 }
 
-static void pmu_stop(void)
+static void op_arm_stop(void)
+{
+	down(&op_arm_sem);
+	if (op_arm_enabled)
+		op_arm_model->stop();
+	op_arm_enabled = 0;
+	up(&op_arm_sem);
+}
+
+#ifdef CONFIG_PM
+static int op_arm_suspend(struct sys_device *dev, pm_message_t state)
 {
-	down(&pmu_sem);
-	if (pmu_enabled)
-		pmu_model->stop();
-	pmu_enabled = 0;
-	up(&pmu_sem);
+	down(&op_arm_sem);
+	if (op_arm_enabled)
+		op_arm_model->stop();
+	up(&op_arm_sem);
+	return 0;
 }
 
-int __init pmu_init(struct oprofile_operations *ops, struct op_arm_model_spec *spec)
+static int op_arm_resume(struct sys_device *dev)
 {
-	init_MUTEX(&pmu_sem);
+	down(&op_arm_sem);
+	if (op_arm_enabled && op_arm_model->start())
+		op_arm_enabled = 0;
+	up(&op_arm_sem);
+	return 0;
+}
+
+static struct sysdev_class oprofile_sysclass = {
+	set_kset_name("oprofile"),
+	.resume		= op_arm_resume,
+	.suspend	= op_arm_suspend,
+};
 
-	if (spec->init() < 0)
-		return -ENODEV;
+static struct sys_device device_oprofile = {
+	.id		= 0,
+	.cls		= &oprofile_sysclass,
+};
 
-	pmu_model = spec;
-	init_driverfs();
-	ops->create_files = pmu_create_files;
-	ops->setup = pmu_setup;
-	ops->shutdown = pmu_stop;
-	ops->start = pmu_start;
-	ops->stop = pmu_stop;
-	ops->cpu_type = pmu_model->name;
-	printk(KERN_INFO "oprofile: using %s PMU\n", spec->name);
+static int __init init_driverfs(void)
+{
+	int ret;
 
-	return 0;
+	if (!(ret = sysdev_class_register(&oprofile_sysclass)))
+		ret = sysdev_register(&device_oprofile);
+
+	return ret;
+}
+
+static void  exit_driverfs(void)
+{
+	sysdev_unregister(&device_oprofile);
+	sysdev_class_unregister(&oprofile_sysclass);
+}
+#else
+#define init_driverfs()	do { } while (0)
+#define exit_driverfs() do { } while (0)
+#endif /* CONFIG_PM */
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+	struct op_arm_model_spec *spec = NULL;
+	int ret = -ENODEV;
+
+#ifdef CONFIG_CPU_XSCALE
+	spec = &op_xscale_spec;
+#endif
+
+	if (spec) {
+		init_MUTEX(&op_arm_sem);
+
+		if (spec->init() < 0)
+			return -ENODEV;
+
+		op_arm_model = spec;
+		init_driverfs();
+		ops->create_files = op_arm_create_files;
+		ops->setup = op_arm_setup;
+		ops->shutdown = op_arm_stop;
+		ops->start = op_arm_start;
+		ops->stop = op_arm_stop;
+		ops->cpu_type = op_arm_model->name;
+		ops->backtrace = arm_backtrace;
+		printk(KERN_INFO "oprofile: using %s\n", spec->name);
+	}
+
+	return ret;
 }
 
-void pmu_exit(void)
+void oprofile_arch_exit(void)
 {
-	if (pmu_model) {
+	if (op_arm_model) {
 		exit_driverfs();
-		pmu_model = NULL;
+		op_arm_model = NULL;
 	}
 }
 
diff --git a/arch/arm/oprofile/init.c b/arch/arm/oprofile/init.c
deleted file mode 100644
index d315a3a86c8..00000000000
--- a/arch/arm/oprofile/init.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/**
- * @file init.c
- *
- * @remark Copyright 2004 Oprofile Authors
- * @remark Read the file COPYING
- *
- * @author Zwane Mwaikambo
- */
-
-#include <linux/oprofile.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include "op_arm_model.h"
-
-int __init oprofile_arch_init(struct oprofile_operations *ops)
-{
-	int ret = -ENODEV;
-
-#ifdef CONFIG_CPU_XSCALE
-	ret = pmu_init(ops, &op_xscale_spec);
-#endif
-
-	ops->backtrace = arm_backtrace;
-
-	return ret;
-}
-
-void oprofile_arch_exit(void)
-{
-#ifdef CONFIG_CPU_XSCALE
-	pmu_exit();
-#endif
-}
diff --git a/arch/arm/oprofile/op_arm_model.h b/arch/arm/oprofile/op_arm_model.h
index 2148d07484b..38c6ad15854 100644
--- a/arch/arm/oprofile/op_arm_model.h
+++ b/arch/arm/oprofile/op_arm_model.h
@@ -26,6 +26,6 @@ extern struct op_arm_model_spec op_xscale_spec;
 
 extern void arm_backtrace(struct pt_regs * const regs, unsigned int depth);
 
-extern int __init pmu_init(struct oprofile_operations *ops, struct op_arm_model_spec *spec);
-extern void pmu_exit(void);
+extern int __init op_arm_init(struct oprofile_operations *ops, struct op_arm_model_spec *spec);
+extern void op_arm_exit(void);
 #endif /* OP_ARM_MODEL_H */