File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mn10300/kernel/ptrace.c b/arch/mn10300/kernel/ptrace.c
new file mode 100644
index 0000000..5bd5851
--- /dev/null
+++ b/arch/mn10300/kernel/ptrace.c
@@ -0,0 +1,385 @@
+/* MN10300 Process tracing
+ *
+ * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Modified by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+#include <linux/tracehook.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/cacheflush.h>
+#include <asm/fpu.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * translate ptrace register IDs into struct pt_regs offsets
+ */
+static const u8 ptrace_regid_to_frame[] = {
+	[PT_A3 << 2]		= REG_A3,
+	[PT_A2 << 2]		= REG_A2,
+	[PT_D3 << 2]		= REG_D3,
+	[PT_D2 << 2]		= REG_D2,
+	[PT_MCVF << 2]		= REG_MCVF,
+	[PT_MCRL << 2]		= REG_MCRL,
+	[PT_MCRH << 2]		= REG_MCRH,
+	[PT_MDRQ << 2]		= REG_MDRQ,
+	[PT_E1 << 2]		= REG_E1,
+	[PT_E0 << 2]		= REG_E0,
+	[PT_E7 << 2]		= REG_E7,
+	[PT_E6 << 2]		= REG_E6,
+	[PT_E5 << 2]		= REG_E5,
+	[PT_E4 << 2]		= REG_E4,
+	[PT_E3 << 2]		= REG_E3,
+	[PT_E2 << 2]		= REG_E2,
+	[PT_SP << 2]		= REG_SP,
+	[PT_LAR << 2]		= REG_LAR,
+	[PT_LIR << 2]		= REG_LIR,
+	[PT_MDR << 2]		= REG_MDR,
+	[PT_A1 << 2]		= REG_A1,
+	[PT_A0 << 2]		= REG_A0,
+	[PT_D1 << 2]		= REG_D1,
+	[PT_D0 << 2]		= REG_D0,
+	[PT_ORIG_D0 << 2]	= REG_ORIG_D0,
+	[PT_EPSW << 2]		= REG_EPSW,
+	[PT_PC << 2]		= REG_PC,
+};
+
+static inline int get_stack_long(struct task_struct *task, int offset)
+{
+	return *(unsigned long *)
+		((unsigned long) task->thread.uregs + offset);
+}
+
+static inline
+int put_stack_long(struct task_struct *task, int offset, unsigned long data)
+{
+	unsigned long stack;
+
+	stack = (unsigned long) task->thread.uregs + offset;
+	*(unsigned long *) stack = data;
+	return 0;
+}
+
+/*
+ * retrieve the contents of MN10300 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)
+{
+	const struct pt_regs *regs = task_pt_regs(target);
+	int ret;
+
+	/* we need to skip regs->next */
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  regs, 0, PT_ORIG_D0 * sizeof(long));
+	if (ret < 0)
+		return ret;
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
+				  NR_PTREGS * sizeof(long));
+	if (ret < 0)
+		return ret;
+
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					NR_PTREGS * sizeof(long), -1);
+}
+
+/*
+ * update the contents of the MN10300 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);
+	unsigned long tmp;
+	int ret;
+
+	/* we need to skip regs->next */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 regs, 0, PT_ORIG_D0 * sizeof(long));
+	if (ret < 0)
+		return ret;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
+				 PT_EPSW * sizeof(long));
+	if (ret < 0)
+		return ret;
+
+	/* we need to mask off changes to EPSW */
+	tmp = regs->epsw;
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &tmp, PT_EPSW * sizeof(long),
+				 PT_PC * sizeof(long));
+	tmp &= EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N | EPSW_FLAG_Z;
+	tmp |= regs->epsw & ~(EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N |
+			      EPSW_FLAG_Z);
+	regs->epsw = tmp;
+
+	if (ret < 0)
+		return ret;
+
+	/* and finally load the PC */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs->pc, PT_PC * sizeof(long),
+				 NR_PTREGS * sizeof(long));
+
+	if (ret < 0)
+		return ret;
+
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 NR_PTREGS * sizeof(long), -1);
+}
+
+/*
+ * retrieve the contents of MN10300 userspace FPU registers
+ */
+static int fpuregs_get(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       void *kbuf, void __user *ubuf)
+{
+	const struct fpu_state_struct *fpregs = &target->thread.fpu_state;
+	int ret;
+
+	unlazy_fpu(target);
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  fpregs, 0, sizeof(*fpregs));
+	if (ret < 0)
+		return ret;
+
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					sizeof(*fpregs), -1);
+}
+
+/*
+ * update the contents of the MN10300 userspace FPU registers
+ */
+static int fpuregs_set(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       const void *kbuf, const void __user *ubuf)
+{
+	struct fpu_state_struct fpu_state = target->thread.fpu_state;
+	int ret;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &fpu_state, 0, sizeof(fpu_state));
+	if (ret < 0)
+		return ret;
+
+	fpu_kill_state(target);
+	target->thread.fpu_state = fpu_state;
+	set_using_fpu(target);
+
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 sizeof(fpu_state), -1);
+}
+
+/*
+ * determine if the FPU registers have actually been used
+ */
+static int fpuregs_active(struct task_struct *target,
+			  const struct user_regset *regset)
+{
+	return is_using_fpu(target) ? regset->n : 0;
+}
+
+/*
+ * Define the register sets available on the MN10300 under Linux
+ */
+enum mn10300_regset {
+	REGSET_GENERAL,
+	REGSET_FPU,
+};
+
+static const struct user_regset mn10300_regsets[] = {
+	/*
+	 * General register format is:
+	 *	A3, A2, D3, D2, MCVF, MCRL, MCRH, MDRQ
+	 *	E1, E0, E7...E2, SP, LAR, LIR, MDR
+	 *	A1, A0, D1, D0, ORIG_D0, EPSW, PC
+	 */
+	[REGSET_GENERAL] = {
+		.core_note_type	= NT_PRSTATUS,
+		.n		= ELF_NGREG,
+		.size		= sizeof(long),
+		.align		= sizeof(long),
+		.get		= genregs_get,
+		.set		= genregs_set,
+	},
+	/*
+	 * FPU register format is:
+	 *	FS0-31, FPCR
+	 */
+	[REGSET_FPU] = {
+		.core_note_type	= NT_PRFPREG,
+		.n		= sizeof(struct fpu_state_struct) / sizeof(long),
+		.size		= sizeof(long),
+		.align		= sizeof(long),
+		.get		= fpuregs_get,
+		.set		= fpuregs_set,
+		.active		= fpuregs_active,
+	},
+};
+
+static const struct user_regset_view user_mn10300_native_view = {
+	.name		= "mn10300",
+	.e_machine	= EM_MN10300,
+	.regsets	= mn10300_regsets,
+	.n		= ARRAY_SIZE(mn10300_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_mn10300_native_view;
+}
+
+/*
+ * set the single-step bit
+ */
+void user_enable_single_step(struct task_struct *child)
+{
+#ifndef CONFIG_MN10300_USING_JTAG
+	struct user *dummy = NULL;
+	long tmp;
+
+	tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
+	tmp |= EPSW_T;
+	put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
+#endif
+}
+
+/*
+ * make sure the single-step bit is not set
+ */
+void user_disable_single_step(struct task_struct *child)
+{
+#ifndef CONFIG_MN10300_USING_JTAG
+	struct user *dummy = NULL;
+	long tmp;
+
+	tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
+	tmp &= ~EPSW_T;
+	put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
+#endif
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+	user_disable_single_step(child);
+}
+
+/*
+ * handle the arch-specific side of process tracing
+ */
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	unsigned long tmp;
+	int ret;
+	unsigned long __user *datap = (unsigned long __user *) data;
+
+	switch (request) {
+	/* read the word at location addr in the USER area. */
+	case PTRACE_PEEKUSR:
+		ret = -EIO;
+		if ((addr & 3) || addr > sizeof(struct user) - 3)
+			break;
+
+		tmp = 0;  /* Default return condition */
+		if (addr < NR_PTREGS << 2)
+			tmp = get_stack_long(child,
+					     ptrace_regid_to_frame[addr]);
+		ret = put_user(tmp, datap);
+		break;
+
+		/* write the word at location addr in the USER area */
+	case PTRACE_POKEUSR:
+		ret = -EIO;
+		if ((addr & 3) || addr > sizeof(struct user) - 3)
+			break;
+
+		ret = 0;
+		if (addr < NR_PTREGS << 2)
+			ret = put_stack_long(child, ptrace_regid_to_frame[addr],
+					     data);
+		break;
+
+	case PTRACE_GETREGS:	/* Get all integer regs from the child. */
+		return copy_regset_to_user(child, &user_mn10300_native_view,
+					   REGSET_GENERAL,
+					   0, NR_PTREGS * sizeof(long),
+					   datap);
+
+	case PTRACE_SETREGS:	/* Set all integer regs in the child. */
+		return copy_regset_from_user(child, &user_mn10300_native_view,
+					     REGSET_GENERAL,
+					     0, NR_PTREGS * sizeof(long),
+					     datap);
+
+	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
+		return copy_regset_to_user(child, &user_mn10300_native_view,
+					   REGSET_FPU,
+					   0, sizeof(struct fpu_state_struct),
+					   datap);
+
+	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
+		return copy_regset_from_user(child, &user_mn10300_native_view,
+					     REGSET_FPU,
+					     0, sizeof(struct fpu_state_struct),
+					     datap);
+
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * handle tracing of system call entry
+ * - return the revised system call number or ULONG_MAX to cause ENOSYS
+ */
+asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
+{
+	if (tracehook_report_syscall_entry(regs))
+		/* tracing decided this syscall should not happen, so
+		 * We'll return a bogus call number to get an ENOSYS
+		 * error, but leave the original number in
+		 * regs->orig_d0
+		 */
+		return ULONG_MAX;
+
+	return regs->orig_d0;
+}
+
+/*
+ * handle tracing of system call exit
+ */
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
+	tracehook_report_syscall_exit(regs, 0);
+}