1 files changed, 165 insertions, 195 deletions

diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c
index 65567dc..43eb969 100644
--- a/arch/blackfin/kernel/ptrace.c
+++ b/arch/blackfin/kernel/ptrace.c
@@ -1,6 +1,6 @@
 /*
  * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
- * these modifications are Copyright 2004-2009 Analog Devices Inc.
+ * these modifications are Copyright 2004-2010 Analog Devices Inc.
  *
  * Licensed under the GPL-2
  */
@@ -9,10 +9,13 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
+#include <linux/elf.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
+#include <linux/regset.h>
 #include <linux/signal.h>
+#include <linux/tracehook.h>
 #include <linux/uaccess.h>
 
 #include <asm/page.h>
@@ -25,90 +28,57 @@
 #include <asm/cacheflush.h>
 #include <asm/mem_map.h>
 
-#define TEXT_OFFSET 0
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
  */
 
-/* determines which bits in the SYSCFG reg the user has access to. */
-/* 1 = access 0 = no access */
-#define SYSCFG_MASK 0x0007	/* SYSCFG reg */
-/* sets the trace bits. */
-#define TRACE_BITS 0x0001
-
-/* Find the stack offset for a register, relative to thread.esp0. */
-#define PT_REG(reg)	((long)&((struct pt_regs *)0)->reg)
-
-/*
- * Get the address of the live pt_regs for the specified task.
- * These are saved onto the top kernel stack when the process
- * is not running.
- *
- * Note: if a user thread is execve'd from kernel space, the
- * kernel stack will not be empty on entry to the kernel, so
- * ptracing these tasks will fail.
- */
-static inline struct pt_regs *get_user_regs(struct task_struct *task)
-{
-	return (struct pt_regs *)
-	    ((unsigned long)task_stack_page(task) +
-	     (THREAD_SIZE - sizeof(struct pt_regs)));
-}
-
-/*
- * Get all user integer registers.
- */
-static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
-{
-	struct pt_regs regs;
-	memcpy(&regs, get_user_regs(tsk), sizeof(regs));
-	regs.usp = tsk->thread.usp;
-	return copy_to_user(uregs, &regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
-}
-
-/* Mapping from PT_xxx to the stack offset at which the register is
- * saved.  Notice that usp has no stack-slot and needs to be treated
- * specially (see get_reg/put_reg below).
- */
-
 /*
  * Get contents of register REGNO in task TASK.
  */
-static inline long get_reg(struct task_struct *task, int regno)
+static inline long
+get_reg(struct task_struct *task, long regno, unsigned long __user *datap)
 {
-	unsigned char *reg_ptr;
+	long tmp;
+	struct pt_regs *regs = task_pt_regs(task);
 
-	struct pt_regs *regs =
-	    (struct pt_regs *)((unsigned long)task_stack_page(task) +
-			       (THREAD_SIZE - sizeof(struct pt_regs)));
-	reg_ptr = (char *)regs;
+	if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
+		return -EIO;
 
 	switch (regno) {
+	case PT_TEXT_ADDR:
+		tmp = task->mm->start_code;
+		break;
+	case PT_TEXT_END_ADDR:
+		tmp = task->mm->end_code;
+		break;
+	case PT_DATA_ADDR:
+		tmp = task->mm->start_data;
+		break;
 	case PT_USP:
-		return task->thread.usp;
+		tmp = task->thread.usp;
+		break;
 	default:
-		if (regno <= 216)
-			return *(long *)(reg_ptr + regno);
+		if (regno < sizeof(*regs)) {
+			void *reg_ptr = regs;
+			tmp = *(long *)(reg_ptr + regno);
+		} else
+			return -EIO;
 	}
-	/* slight mystery ... never seems to come here but kernel misbehaves without this code! */
 
-	printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
-	return 0;
+	return put_user(tmp, datap);
 }
 
 /*
  * Write contents of register REGNO in task TASK.
  */
 static inline int
-put_reg(struct task_struct *task, int regno, unsigned long data)
+put_reg(struct task_struct *task, long regno, unsigned long data)
 {
-	char *reg_ptr;
+	struct pt_regs *regs = task_pt_regs(task);
 
-	struct pt_regs *regs =
-	    (struct pt_regs *)((unsigned long)task_stack_page(task) +
-			       (THREAD_SIZE - sizeof(struct pt_regs)));
-	reg_ptr = (char *)regs;
+	if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
+		return -EIO;
 
 	switch (regno) {
 	case PT_PC:
@@ -125,10 +95,18 @@ put_reg(struct task_struct *task, int regno, unsigned long data)
 		regs->usp = data;
 		task->thread.usp = data;
 		break;
+	case PT_SYSCFG:	/* don't let userspace screw with this */
+		if ((data & ~1) != 0x6)
+			pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
+		break;		/* regs->syscfg = data; break; */
 	default:
-		if (regno <= 216)
-			*(long *)(reg_ptr + regno) = data;
+		if (regno < sizeof(*regs)) {
+			void *reg_offset = regs;
+			*(long *)(reg_offset + regno) = data;
+		}
+		/* Ignore writes to pseudo registers */
 	}
+
 	return 0;
 }
 
@@ -160,24 +138,98 @@ static inline int is_user_addr_valid(struct task_struct *child,
 	return -EIO;
 }
 
-void ptrace_enable(struct task_struct *child)
+/*
+ * retrieve the contents of Blackfin userspace general registers
+ */
+static int genregs_get(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       void *kbuf, void __user *ubuf)
 {
-	unsigned long tmp;
-	tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
-	put_reg(child, PT_SYSCFG, tmp);
+	struct pt_regs *regs = task_pt_regs(target);
+	int ret;
+
+	/* This sucks ... */
+	regs->usp = target->thread.usp;
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  regs, 0, sizeof(*regs));
+	if (ret < 0)
+		return ret;
+
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					sizeof(*regs), -1);
 }
 
 /*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure the single step bit is not set.
+ * update the contents of the Blackfin userspace general registers
+ */
+static int genregs_set(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       const void *kbuf, const void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	int ret;
+
+	/* Don't let people set SYSCFG (it's at the end of pt_regs) */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 regs, 0, PT_SYSCFG);
+	if (ret < 0)
+		return ret;
+
+	/* This sucks ... */
+	target->thread.usp = regs->usp;
+	/* regs->retx = regs->pc; */
+
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					PT_SYSCFG, -1);
+}
+
+/*
+ * Define the register sets available on the Blackfin under Linux
  */
-void ptrace_disable(struct task_struct *child)
+enum bfin_regset {
+	REGSET_GENERAL,
+};
+
+static const struct user_regset bfin_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type = NT_PRSTATUS,
+		.n              = sizeof(struct pt_regs) / sizeof(long),
+		.size           = sizeof(long),
+		.align          = sizeof(long),
+		.get            = genregs_get,
+		.set            = genregs_set,
+	},
+};
+
+static const struct user_regset_view user_bfin_native_view = {
+	.name      = "Blackfin",
+	.e_machine = EM_BLACKFIN,
+	.regsets   = bfin_regsets,
+	.n         = ARRAY_SIZE(bfin_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_bfin_native_view;
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+	struct pt_regs *regs = task_pt_regs(child);
+	regs->syscfg |= SYSCFG_SSSTEP;
+
+	set_tsk_thread_flag(child, TIF_SINGLESTEP);
+}
+
+void user_disable_single_step(struct task_struct *child)
 {
-	unsigned long tmp;
-	/* make sure the single step bit is not set. */
-	tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
-	put_reg(child, PT_SYSCFG, tmp);
+	struct pt_regs *regs = task_pt_regs(child);
+	regs->syscfg &= ~SYSCFG_SSSTEP;
+
+	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
 }
 
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
@@ -240,40 +292,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			break;
 		}
 
-		/* read the word at location addr in the USER area. */
-	case PTRACE_PEEKUSR:
-		{
-			unsigned long tmp;
-			ret = -EIO;
-			tmp = 0;
-			if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
-				printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
-				                    "0 - %x sizeof(pt_regs) is %lx\n",
-				     (int)addr, sizeof(struct pt_regs));
-				break;
-			}
-			if (addr == sizeof(struct pt_regs)) {
-				/* PT_TEXT_ADDR */
-				tmp = child->mm->start_code + TEXT_OFFSET;
-			} else if (addr == (sizeof(struct pt_regs) + 4)) {
-				/* PT_TEXT_END_ADDR */
-				tmp = child->mm->end_code;
-			} else if (addr == (sizeof(struct pt_regs) + 8)) {
-				/* PT_DATA_ADDR */
-				tmp = child->mm->start_data;
-#ifdef CONFIG_BINFMT_ELF_FDPIC
-			} else if (addr == (sizeof(struct pt_regs) + 12)) {
-				goto case_PTRACE_GETFDPIC_EXEC;
-			} else if (addr == (sizeof(struct pt_regs) + 16)) {
-				goto case_PTRACE_GETFDPIC_INTERP;
-#endif
-			} else {
-				tmp = get_reg(child, addr);
-			}
-			ret = put_user(tmp, datap);
-			break;
-		}
-
 #ifdef CONFIG_BINFMT_ELF_FDPIC
 	case PTRACE_GETFDPIC: {
 		unsigned long tmp = 0;
@@ -336,78 +354,36 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			break;
 		}
 
-	case PTRACE_POKEUSR:	/* write the word at location addr in the USER area */
-		ret = -EIO;
-		if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
-			printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
-			break;
-		}
-
-		if (addr >= (sizeof(struct pt_regs))) {
-			ret = 0;
-			break;
-		}
-		if (addr == PT_SYSCFG) {
-			data &= SYSCFG_MASK;
-			data |= get_reg(child, PT_SYSCFG);
+	case PTRACE_PEEKUSR:
+		switch (addr) {
+#ifdef CONFIG_BINFMT_ELF_FDPIC	/* backwards compat */
+		case PT_FDPIC_EXEC:   goto case_PTRACE_GETFDPIC_EXEC;
+		case PT_FDPIC_INTERP: goto case_PTRACE_GETFDPIC_INTERP;
+#endif
+		default:
+			ret = get_reg(child, addr, datap);
 		}
-		ret = put_reg(child, addr, data);
+		pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
 		break;
 
-	case PTRACE_SYSCALL:	/* continue and stop at next (return from) syscall */
-	case PTRACE_CONT:	/* restart after signal. */
-		pr_debug("ptrace: syscall/cont\n");
-
-		ret = -EIO;
-		if (!valid_signal(data))
-			break;
-		if (request == PTRACE_SYSCALL)
-			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		else
-			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		child->exit_code = data;
-		ptrace_disable(child);
-		pr_debug("ptrace: before wake_up_process\n");
-		wake_up_process(child);
-		ret = 0;
-		break;
-
-	/*
-	 * make the child exit.  Best I can do is send it a sigkill.
-	 * perhaps it should be put in the status that it wants to
-	 * exit.
-	 */
-	case PTRACE_KILL:
-		ret = 0;
-		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
-			break;
-		child->exit_code = SIGKILL;
-		ptrace_disable(child);
-		wake_up_process(child);
-		break;
-
-	case PTRACE_SINGLESTEP:	/* set the trap flag. */
-		pr_debug("ptrace: single step\n");
-		ret = -EIO;
-		if (!valid_signal(data))
-			break;
-		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		ptrace_enable(child);
-		child->exit_code = data;
-		wake_up_process(child);
-		ret = 0;
+	case PTRACE_POKEUSR:
+		ret = put_reg(child, addr, data);
+		pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
 		break;
 
 	case PTRACE_GETREGS:
-		/* Get all gp regs from the child. */
-		ret = ptrace_getregs(child, datap);
-		break;
+		pr_debug("ptrace: PTRACE_GETREGS\n");
+		return copy_regset_to_user(child, &user_bfin_native_view,
+					   REGSET_GENERAL,
+					   0, sizeof(struct pt_regs),
+					   (void __user *)data);
 
 	case PTRACE_SETREGS:
-		printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
-		/* Set all gp regs in the child. */
-		ret = 0;
-		break;
+		pr_debug("ptrace: PTRACE_SETREGS\n");
+		return copy_regset_from_user(child, &user_bfin_native_view,
+					     REGSET_GENERAL,
+					     0, sizeof(struct pt_regs),
+					     (const void __user *)data);
 
 	default:
 		ret = ptrace_request(child, request, addr, data);
@@ -417,27 +393,21 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	return ret;
 }
 
-asmlinkage void syscall_trace(void)
+asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
-
-	if (!(current->ptrace & PT_PTRACED))
-		return;
-
-	/* the 0x80 provides a way for the tracing parent to distinguish
-	 * between a syscall stop and SIGTRAP delivery
-	 */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
-
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
+	int ret = 0;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		ret = tracehook_report_syscall_entry(regs);
+
+	return ret;
+}
+
+asmlinkage void syscall_trace_leave(struct pt_regs *regs)
+{
+	int step;
+
+	step = test_thread_flag(TIF_SINGLESTEP);
+	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, step);
 }