1 files changed, 348 insertions, 0 deletions
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
new file mode 100644
index 000000000..cd0172d29
--- /dev/null
+++ b/arch/m68k/kernel/ptrace.c
@@ -0,0 +1,348 @@
+/*
+ *  linux/arch/m68k/kernel/ptrace.c
+ *
+ *  Copyright (C) 1994 by Hamish Macdonald
+ *  Taken from linux/kernel/ptrace.c and modified for M680x0.
+ *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/signal.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+#include <linux/seccomp.h>
+#include <linux/uaccess.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/* determines which bits in the SR the user has access to. */
+/* 1 = access 0 = no access */
+#define SR_MASK 0x001f
+
+/* sets the trace bits. */
+#define TRACE_BITS 0xC000
+#define T1_BIT 0x8000
+#define T0_BIT 0x4000
+
+/* Find the stack offset for a register, relative to thread.esp0. */
+#define PT_REG(reg)	((long)&((struct pt_regs *)0)->reg)
+#define SW_REG(reg)	((long)&((struct switch_stack *)0)->reg \
+			 - sizeof(struct switch_stack))
+/* 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). */
+static const int regoff[] = {
+	[0]	= PT_REG(d1),
+	[1]	= PT_REG(d2),
+	[2]	= PT_REG(d3),
+	[3]	= PT_REG(d4),
+	[4]	= PT_REG(d5),
+	[5]	= SW_REG(d6),
+	[6]	= SW_REG(d7),
+	[7]	= PT_REG(a0),
+	[8]	= PT_REG(a1),
+	[9]	= PT_REG(a2),
+	[10]	= SW_REG(a3),
+	[11]	= SW_REG(a4),
+	[12]	= SW_REG(a5),
+	[13]	= SW_REG(a6),
+	[14]	= PT_REG(d0),
+	[15]	= -1,
+	[16]	= PT_REG(orig_d0),
+	[17]	= PT_REG(sr),
+	[18]	= PT_REG(pc),
+};
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+static inline long get_reg(struct task_struct *task, int regno)
+{
+	unsigned long *addr;
+
+	if (regno == PT_USP)
+		addr = &task->thread.usp;
+	else if (regno < ARRAY_SIZE(regoff))
+		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
+	else
+		return 0;
+	/* Need to take stkadj into account. */
+	if (regno == PT_SR || regno == PT_PC) {
+		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
+		addr = (unsigned long *) ((unsigned long)addr + stkadj);
+		/* The sr is actually a 16 bit register.  */
+		if (regno == PT_SR)
+			return *(unsigned short *)addr;
+	}
+	return *addr;
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static inline int put_reg(struct task_struct *task, int regno,
+			  unsigned long data)
+{
+	unsigned long *addr;
+
+	if (regno == PT_USP)
+		addr = &task->thread.usp;
+	else if (regno < ARRAY_SIZE(regoff))
+		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
+	else
+		return -1;
+	/* Need to take stkadj into account. */
+	if (regno == PT_SR || regno == PT_PC) {
+		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
+		addr = (unsigned long *) ((unsigned long)addr + stkadj);
+		/* The sr is actually a 16 bit register.  */
+		if (regno == PT_SR) {
+			*(unsigned short *)addr = data;
+			return 0;
+		}
+	}
+	*addr = data;
+	return 0;
+}
+
+/*
+ * Make sure the single step bit is not set.
+ */
+static inline void singlestep_disable(struct task_struct *child)
+{
+	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
+	put_reg(child, PT_SR, tmp);
+	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ */
+void ptrace_disable(struct task_struct *child)
+{
+	singlestep_disable(child);
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
+	put_reg(child, PT_SR, tmp | T1_BIT);
+	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
+}
+
+#ifdef CONFIG_MMU
+void user_enable_block_step(struct task_struct *child)
+{
+	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
+	put_reg(child, PT_SR, tmp | T0_BIT);
+}
+#endif
+
+void user_disable_single_step(struct task_struct *child)
+{
+	singlestep_disable(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	unsigned long tmp;
+	int i, ret = 0;
+	int regno = addr >> 2; /* temporary hack. */
+	unsigned long __user *datap = (unsigned long __user *) data;
+
+	switch (request) {
+	/* read the word at location addr in the USER area. */
+	case PTRACE_PEEKUSR:
+		if (addr & 3)
+			goto out_eio;
+
+		if (regno >= 0 && regno < 19) {
+			tmp = get_reg(child, regno);
+		} else if (regno >= 21 && regno < 49) {
+			tmp = child->thread.fp[regno - 21];
+			/* Convert internal fpu reg representation
+			 * into long double format
+			 */
+			if (FPU_IS_EMU && (regno < 45) && !(regno % 3))
+				tmp = ((tmp & 0xffff0000) << 15) |
+				      ((tmp & 0x0000ffff) << 16);
+#ifndef CONFIG_MMU
+		} else if (regno == 49) {
+			tmp = child->mm->start_code;
+		} else if (regno == 50) {
+			tmp = child->mm->start_data;
+		} else if (regno == 51) {
+			tmp = child->mm->end_code;
+#endif
+		} else
+			goto out_eio;
+		ret = put_user(tmp, datap);
+		break;
+
+	case PTRACE_POKEUSR:
+	/* write the word at location addr in the USER area */
+		if (addr & 3)
+			goto out_eio;
+
+		if (regno == PT_SR) {
+			data &= SR_MASK;
+			data |= get_reg(child, PT_SR) & ~SR_MASK;
+		}
+		if (regno >= 0 && regno < 19) {
+			if (put_reg(child, regno, data))
+				goto out_eio;
+		} else if (regno >= 21 && regno < 48) {
+			/* Convert long double format
+			 * into internal fpu reg representation
+			 */
+			if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) {
+				data <<= 15;
+				data = (data & 0xffff0000) |
+				       ((data & 0x0000ffff) >> 1);
+			}
+			child->thread.fp[regno - 21] = data;
+		} else
+			goto out_eio;
+		break;
+
+	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
+		for (i = 0; i < 19; i++) {
+			tmp = get_reg(child, i);
+			ret = put_user(tmp, datap);
+			if (ret)
+				break;
+			datap++;
+		}
+		break;
+
+	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
+		for (i = 0; i < 19; i++) {
+			ret = get_user(tmp, datap);
+			if (ret)
+				break;
+			if (i == PT_SR) {
+				tmp &= SR_MASK;
+				tmp |= get_reg(child, PT_SR) & ~SR_MASK;
+			}
+			put_reg(child, i, tmp);
+			datap++;
+		}
+		break;
+
+	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
+		if (copy_to_user(datap, &child->thread.fp,
+				 sizeof(struct user_m68kfp_struct)))
+			ret = -EFAULT;
+		break;
+
+	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
+		if (copy_from_user(&child->thread.fp, datap,
+				   sizeof(struct user_m68kfp_struct)))
+			ret = -EFAULT;
+		break;
+
+	case PTRACE_GET_THREAD_AREA:
+		ret = put_user(task_thread_info(child)->tp_value, datap);
+		break;
+
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+out_eio:
+	return -EIO;
+}
+
+asmlinkage int syscall_trace_enter(void)
+{
+	int ret = 0;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		ret = ptrace_report_syscall_entry(task_pt_regs(current));
+
+	if (secure_computing() == -1)
+		return -1;
+
+	return ret;
+}
+
+asmlinkage void syscall_trace_leave(void)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		ptrace_report_syscall_exit(task_pt_regs(current), 0);
+}
+
+#if defined(CONFIG_BINFMT_ELF_FDPIC) && defined(CONFIG_ELF_CORE)
+/*
+ * Currently the only thing that needs to use regsets for m68k is the
+ * coredump support of the elf_fdpic loader. Implement the minimum
+ * definitions required for that.
+ */
+static int m68k_regset_get(struct task_struct *target,
+			   const struct user_regset *regset,
+			   struct membuf to)
+{
+	struct pt_regs *ptregs = task_pt_regs(target);
+	u32 uregs[ELF_NGREG];
+
+	ELF_CORE_COPY_REGS(uregs, ptregs);
+	return membuf_write(&to, uregs, sizeof(uregs));
+}
+
+enum m68k_regset {
+	REGSET_GPR,
+#ifdef CONFIG_FPU
+	REGSET_FPU,
+#endif
+};
+
+static const struct user_regset m68k_user_regsets[] = {
+	[REGSET_GPR] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(u32),
+		.align = sizeof(u16),
+		.regset_get = m68k_regset_get,
+	},
+#ifdef CONFIG_FPU
+	[REGSET_FPU] = {
+		.core_note_type = NT_PRFPREG,
+		.n = sizeof(struct user_m68kfp_struct) / sizeof(u32),
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+	}
+#endif /* CONFIG_FPU */
+};
+
+static const struct user_regset_view user_m68k_view = {
+	.name = "m68k",
+	.e_machine = EM_68K,
+	.ei_osabi = ELF_OSABI,
+	.regsets = m68k_user_regsets,
+	.n = ARRAY_SIZE(m68k_user_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_m68k_view;
+}
+#endif /* CONFIG_BINFMT_ELF_FDPIC && CONFIG_ELF_CORE */