1 files changed, 277 insertions, 0 deletions
diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c
new file mode 100644
index 000000000..2497bac56
--- /dev/null
+++ b/arch/x86/um/ptrace_32.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <asm/ptrace-abi.h>
+#include <skas.h>
+
+extern int arch_switch_tls(struct task_struct *to);
+
+void arch_switch_to(struct task_struct *to)
+{
+	int err = arch_switch_tls(to);
+	if (!err)
+		return;
+
+	if (err != -EINVAL)
+		printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
+		       "not EINVAL\n", -err);
+	else
+		printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
+}
+
+int is_syscall(unsigned long addr)
+{
+	unsigned short instr;
+	int n;
+
+	n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
+	if (n) {
+		/* access_process_vm() grants access to vsyscall and stub,
+		 * while copy_from_user doesn't. Maybe access_process_vm is
+		 * slow, but that doesn't matter, since it will be called only
+		 * in case of singlestepping, if copy_from_user failed.
+		 */
+		n = access_process_vm(current, addr, &instr, sizeof(instr),
+				FOLL_FORCE);
+		if (n != sizeof(instr)) {
+			printk(KERN_ERR "is_syscall : failed to read "
+			       "instruction from 0x%lx\n", addr);
+			return 1;
+		}
+	}
+	/* int 0x80 or sysenter */
+	return (instr == 0x80cd) || (instr == 0x340f);
+}
+
+/* determines which flags the user has access to. */
+/* 1 = access 0 = no access */
+#define FLAG_MASK 0x00044dd5
+
+static const int reg_offsets[] = {
+	[EBX] = HOST_BX,
+	[ECX] = HOST_CX,
+	[EDX] = HOST_DX,
+	[ESI] = HOST_SI,
+	[EDI] = HOST_DI,
+	[EBP] = HOST_BP,
+	[EAX] = HOST_AX,
+	[DS] = HOST_DS,
+	[ES] = HOST_ES,
+	[FS] = HOST_FS,
+	[GS] = HOST_GS,
+	[EIP] = HOST_IP,
+	[CS] = HOST_CS,
+	[EFL] = HOST_EFLAGS,
+	[UESP] = HOST_SP,
+	[SS] = HOST_SS,
+	[ORIG_EAX] = HOST_ORIG_AX,
+};
+
+int putreg(struct task_struct *child, int regno, unsigned long value)
+{
+	regno >>= 2;
+	switch (regno) {
+	case EBX:
+	case ECX:
+	case EDX:
+	case ESI:
+	case EDI:
+	case EBP:
+	case EAX:
+	case EIP:
+	case UESP:
+		break;
+	case ORIG_EAX:
+		/* Update the syscall number. */
+		UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
+		break;
+	case FS:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		break;
+	case GS:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		break;
+	case DS:
+	case ES:
+		if (value && (value & 3) != 3)
+			return -EIO;
+		value &= 0xffff;
+		break;
+	case SS:
+	case CS:
+		if ((value & 3) != 3)
+			return -EIO;
+		value &= 0xffff;
+		break;
+	case EFL:
+		value &= FLAG_MASK;
+		child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
+		return 0;
+	default :
+		panic("Bad register in putreg() : %d\n", regno);
+	}
+	child->thread.regs.regs.gp[reg_offsets[regno]] = value;
+	return 0;
+}
+
+int poke_user(struct task_struct *child, long addr, long data)
+{
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	if (addr < MAX_REG_OFFSET)
+		return putreg(child, addr, data);
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		 (addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 2;
+		if ((addr == 4) || (addr == 5))
+			return -EIO;
+		child->thread.arch.debugregs[addr] = data;
+		return 0;
+	}
+	return -EIO;
+}
+
+unsigned long getreg(struct task_struct *child, int regno)
+{
+	unsigned long mask = ~0UL;
+
+	regno >>= 2;
+	switch (regno) {
+	case FS:
+	case GS:
+	case DS:
+	case ES:
+	case SS:
+	case CS:
+		mask = 0xffff;
+		break;
+	case EIP:
+	case UESP:
+	case EAX:
+	case EBX:
+	case ECX:
+	case EDX:
+	case ESI:
+	case EDI:
+	case EBP:
+	case EFL:
+	case ORIG_EAX:
+		break;
+	default:
+		panic("Bad register in getreg() : %d\n", regno);
+	}
+	return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
+}
+
+/* read the word at location addr in the USER area. */
+int peek_user(struct task_struct *child, long addr, long data)
+{
+	unsigned long tmp;
+
+	if ((addr & 3) || addr < 0)
+		return -EIO;
+
+	tmp = 0;  /* Default return condition */
+	if (addr < MAX_REG_OFFSET) {
+		tmp = getreg(child, addr);
+	}
+	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
+		 (addr <= offsetof(struct user, u_debugreg[7]))) {
+		addr -= offsetof(struct user, u_debugreg[0]);
+		addr = addr >> 2;
+		tmp = child->thread.arch.debugregs[addr];
+	}
+	return put_user(tmp, (unsigned long __user *) data);
+}
+
+static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int err, n, cpu = task_cpu(child);
+	struct user_i387_struct fpregs;
+
+	err = save_i387_registers(userspace_pid[cpu],
+				  (unsigned long *) &fpregs);
+	if (err)
+		return err;
+
+	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
+	if(n > 0)
+		return -EFAULT;
+
+	return n;
+}
+
+static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
+{
+	int n, cpu = task_cpu(child);
+	struct user_i387_struct fpregs;
+
+	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return restore_i387_registers(userspace_pid[cpu],
+				    (unsigned long *) &fpregs);
+}
+
+static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
+{
+	int err, n, cpu = task_cpu(child);
+	struct user_fxsr_struct fpregs;
+
+	err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
+	if (err)
+		return err;
+
+	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
+	if(n > 0)
+		return -EFAULT;
+
+	return n;
+}
+
+static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
+{
+	int n, cpu = task_cpu(child);
+	struct user_fxsr_struct fpregs;
+
+	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
+	if (n > 0)
+		return -EFAULT;
+
+	return restore_fpx_registers(userspace_pid[cpu],
+				     (unsigned long *) &fpregs);
+}
+
+long subarch_ptrace(struct task_struct *child, long request,
+		    unsigned long addr, unsigned long data)
+{
+	int ret = -EIO;
+	void __user *datap = (void __user *) data;
+	switch (request) {
+	case PTRACE_GETFPREGS: /* Get the child FPU state. */
+		ret = get_fpregs(datap, child);
+		break;
+	case PTRACE_SETFPREGS: /* Set the child FPU state. */
+		ret = set_fpregs(datap, child);
+		break;
+	case PTRACE_GETFPXREGS: /* Get the child FPU state. */
+		ret = get_fpxregs(datap, child);
+		break;
+	case PTRACE_SETFPXREGS: /* Set the child FPU state. */
+		ret = set_fpxregs(datap, child);
+		break;
+	default:
+		ret = -EIO;
+	}
+	return ret;
+}