#define PTRACE_GET_THREAD_AREA 25
#define PTRACE_SET_THREAD_AREA 26
+#define PTRACE_SYSEMU 31
+#define PTRACE_SYSEMU_SINGLESTEP 32
+
#ifdef __KERNEL__
#include <asm/vm86.h>
struct task_struct;
extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code);
+/*
+ * user_mode_vm(regs) determines whether a register set came from user mode.
+ * This is true if V8086 mode was enabled OR if the register set was from
+ * protected mode with RPL-3 CS value. This tricky test checks that with
+ * one comparison. Many places in the kernel can bypass this full check
+ * if they have already ruled out V8086 mode, so user_mode(regs) can be used.
+ */
static inline int user_mode(struct pt_regs *regs)
{
return (regs->xcs & 3) != 0;