---

yaml
---
r: 76072
b: refs/heads/master
c: 13b54a5
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6ea6dd93c9454cc9521134f907bc970d09f460e4
+refs/heads/master: 13b54a50525a9685065684e1e11258d27dd27bdf

trunk/arch/avr32/kernel/Makefile

@@ -6,7 +6,7 @@ extra-y				:= head.o vmlinux.lds
 
 obj-$(CONFIG_SUBARCH_AVR32B)	+= entry-avr32b.o
 obj-y				+= syscall_table.o syscall-stubs.o irq.o
-obj-y				+= setup.o traps.o semaphore.o ptrace.o
+obj-y				+= setup.o traps.o semaphore.o ocd.o ptrace.o
 obj-y				+= signal.o sys_avr32.o process.o time.o
 obj-y				+= init_task.o switch_to.o cpu.o
 obj-$(CONFIG_MODULES)		+= module.o avr32_ksyms.o

trunk/arch/avr32/kernel/kprobes.c

@@ -48,6 +48,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
 	pr_debug("arming kprobe at %p\n", p->addr);
+	ocd_enable(NULL);
 	*p->addr = BREAKPOINT_INSTRUCTION;
 	flush_icache_range((unsigned long)p->addr,
 			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
@@ -56,6 +57,7 @@ void __kprobes arch_arm_kprobe(struct kprobe *p)
 void __kprobes arch_disarm_kprobe(struct kprobe *p)
 {
 	pr_debug("disarming kprobe at %p\n", p->addr);
+	ocd_disable(NULL);
 	*p->addr = p->opcode;
 	flush_icache_range((unsigned long)p->addr,
 			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
@@ -260,9 +262,6 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
 
 int __init arch_init_kprobes(void)
 {
-	printk("KPROBES: Enabling monitor mode (MM|DBE)...\n");
-	ocd_write(DC, (1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT));
-
 	/* TODO: Register kretprobe trampoline */
 	return 0;
 }

trunk/arch/avr32/kernel/ocd.c

@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+
+#include <asm/ocd.h>
+
+static long ocd_count;
+static spinlock_t ocd_lock;
+
+/**
+ * ocd_enable - enable on-chip debugging
+ * @child: task to be debugged
+ *
+ * If @child is non-NULL, ocd_enable() first checks if debugging has
+ * already been enabled for @child, and if it has, does nothing.
+ *
+ * If @child is NULL (e.g. when debugging the kernel), or debugging
+ * has not already been enabled for it, ocd_enable() increments the
+ * reference count and enables the debugging hardware.
+ */
+void ocd_enable(struct task_struct *child)
+{
+	u32 dc;
+
+	if (child)
+		pr_debug("ocd_enable: child=%s [%u]\n",
+				child->comm, child->pid);
+	else
+		pr_debug("ocd_enable (no child)\n");
+
+	if (!child || !test_and_set_tsk_thread_flag(child, TIF_DEBUG)) {
+		spin_lock(&ocd_lock);
+		ocd_count++;
+		dc = ocd_read(DC);
+		dc |= (1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT);
+		ocd_write(DC, dc);
+		spin_unlock(&ocd_lock);
+	}
+}
+
+/**
+ * ocd_disable - disable on-chip debugging
+ * @child: task that was being debugged, but isn't anymore
+ *
+ * If @child is non-NULL, ocd_disable() checks if debugging is enabled
+ * for @child, and if it isn't, does nothing.
+ *
+ * If @child is NULL (e.g. when debugging the kernel), or debugging is
+ * enabled, ocd_disable() decrements the reference count, and if it
+ * reaches zero, disables the debugging hardware.
+ */
+void ocd_disable(struct task_struct *child)
+{
+	u32 dc;
+
+	if (!child)
+		pr_debug("ocd_disable (no child)\n");
+	else if (test_tsk_thread_flag(child, TIF_DEBUG))
+		pr_debug("ocd_disable: child=%s [%u]\n",
+				child->comm, child->pid);
+
+	if (!child || test_and_clear_tsk_thread_flag(child, TIF_DEBUG)) {
+		spin_lock(&ocd_lock);
+		ocd_count--;
+
+		WARN_ON(ocd_count < 0);
+
+		if (ocd_count <= 0) {
+			dc = ocd_read(DC);
+			dc &= ~((1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT));
+			ocd_write(DC, dc);
+		}
+		spin_unlock(&ocd_lock);
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/module.h>
+
+static struct dentry *ocd_debugfs_root;
+static struct dentry *ocd_debugfs_DC;
+static struct dentry *ocd_debugfs_DS;
+static struct dentry *ocd_debugfs_count;
+
+static u64 ocd_DC_get(void *data)
+{
+	return ocd_read(DC);
+}
+static void ocd_DC_set(void *data, u64 val)
+{
+	ocd_write(DC, val);
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_DC, ocd_DC_get, ocd_DC_set, "0x%08llx\n");
+
+static u64 ocd_DS_get(void *data)
+{
+	return ocd_read(DS);
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_DS, ocd_DS_get, NULL, "0x%08llx\n");
+
+static u64 ocd_count_get(void *data)
+{
+	return ocd_count;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_count, ocd_count_get, NULL, "%lld\n");
+
+static void ocd_debugfs_init(void)
+{
+	struct dentry *root;
+
+	root = debugfs_create_dir("ocd", NULL);
+	if (IS_ERR(root) || !root)
+		goto err_root;
+	ocd_debugfs_root = root;
+
+	ocd_debugfs_DC = debugfs_create_file("DC", S_IRUSR | S_IWUSR,
+				root, NULL, &fops_DC);
+	if (!ocd_debugfs_DC)
+		goto err_DC;
+
+	ocd_debugfs_DS = debugfs_create_file("DS", S_IRUSR, root,
+				NULL, &fops_DS);
+	if (!ocd_debugfs_DS)
+		goto err_DS;
+
+	ocd_debugfs_count = debugfs_create_file("count", S_IRUSR, root,
+				NULL, &fops_count);
+	if (!ocd_debugfs_count)
+		goto err_count;
+
+	return;
+
+err_count:
+	debugfs_remove(ocd_debugfs_DS);
+err_DS:
+	debugfs_remove(ocd_debugfs_DC);
+err_DC:
+	debugfs_remove(ocd_debugfs_root);
+err_root:
+	printk(KERN_WARNING "OCD: Failed to create debugfs entries\n");
+}
+#else
+static inline void ocd_debugfs_init(void)
+{
+
+}
+#endif
+
+static int __init ocd_init(void)
+{
+	spin_lock_init(&ocd_lock);
+	ocd_debugfs_init();
+	return 0;
+}
+arch_initcall(ocd_init);

trunk/arch/avr32/kernel/process.c

@@ -103,7 +103,7 @@ EXPORT_SYMBOL(kernel_thread);
  */
 void exit_thread(void)
 {
-	/* nothing to do */
+	ocd_disable(current);
 }
 
 void flush_thread(void)
@@ -345,6 +345,9 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 	p->thread.cpu_context.ksp = (unsigned long)childregs;
 	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
 
+	if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
+		ocd_enable(p);
+
 	return 0;
 }
 

trunk/arch/avr32/kernel/ptrace.c

@@ -58,6 +58,7 @@ void ptrace_disable(struct task_struct *child)
 {
 	clear_tsk_thread_flag(child, TIF_SINGLE_STEP);
 	clear_tsk_thread_flag(child, TIF_BREAKPOINT);
+	ocd_disable(child);
 }
 
 /*
@@ -144,10 +145,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	int ret;
 
-	pr_debug("ptrace: Enabling monitor mode...\n");
-	ocd_write(DC, ocd_read(DC) | (1 << OCD_DC_MM_BIT)
-			| (1 << OCD_DC_DBE_BIT));
-
 	switch (request) {
 	/* Read the word at location addr in the child process */
 	case PTRACE_PEEKTEXT:

trunk/include/asm-avr32/ocd.h

@@ -533,6 +533,11 @@ static inline void __ocd_write(unsigned int reg, unsigned long value)
 #define ocd_read(reg)			__ocd_read(OCD_##reg)
 #define ocd_write(reg, value)		__ocd_write(OCD_##reg, value)
 
+struct task_struct;
+
+void ocd_enable(struct task_struct *child);
+void ocd_disable(struct task_struct *child);
+
 #endif /* !__ASSEMBLER__ */
 
 #endif /* __ASM_AVR32_OCD_H */

trunk/include/asm-avr32/ptrace.h

@@ -121,7 +121,15 @@ struct pt_regs {
 };
 
 #ifdef __KERNEL__
-# define user_mode(regs) (((regs)->sr & MODE_MASK) == MODE_USER)
+
+#include <asm/ocd.h>
+
+#define arch_ptrace_attach(child)       ocd_enable(child)
+
+#define user_mode(regs)                 (((regs)->sr & MODE_MASK) == MODE_USER)
+#define instruction_pointer(regs)       ((regs)->pc)
+#define profile_pc(regs)                instruction_pointer(regs)
+
 extern void show_regs (struct pt_regs *);
 
 static __inline__ int valid_user_regs(struct pt_regs *regs)
@@ -141,9 +149,6 @@ static __inline__ int valid_user_regs(struct pt_regs *regs)
 	return 0;
 }
 
-#define instruction_pointer(regs) ((regs)->pc)
-
-#define profile_pc(regs) instruction_pointer(regs)
 
 #endif /* __KERNEL__ */
 

trunk/include/asm-avr32/thread_info.h

@@ -88,6 +88,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_MEMDIE		6
 #define TIF_RESTORE_SIGMASK	7	/* restore signal mask in do_signal */
 #define TIF_CPU_GOING_TO_SLEEP	8	/* CPU is entering sleep 0 mode */
+#define TIF_DEBUG		30	/* debugging enabled */
 #define TIF_USERSPACE		31      /* true if FS sets userspace */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)