x86_64: prepare shared kernel/ptrace.c
authorThomas Gleixner <tglx@linutronix.de>
Thu, 11 Oct 2007 09:14:59 +0000 (11:14 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 11 Oct 2007 09:14:59 +0000 (11:14 +0200)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86_64/kernel/Makefile
arch/x86_64/kernel/ptrace.c [deleted file]
arch/x86_64/kernel/ptrace_64.c [new file with mode: 0644]

index 2da29ed79c13896e8a09814d247eede6404e6408..6905cdfe75fbcdab0aef04770c2851637a9bd88d 100644 (file)
@@ -5,7 +5,7 @@
 extra-y        := head.o head64.o init_task.o vmlinux.lds
 EXTRA_AFLAGS   := -traditional
 obj-y  := process.o signal_64.o entry.o traps_64.o irq.o \
-               ptrace.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \
+               ptrace_64.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \
                x8664_ksyms.o i387_64.o syscall.o vsyscall_64.o \
                setup64.o bootflag.o e820_64.o reboot.o quirks.o i8237.o \
                pci-dma_64.o pci-nommu_64.o alternative.o hpet_64.o tsc.o bugs_64.o \
diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
deleted file mode 100644 (file)
index eea3702..0000000
+++ /dev/null
@@ -1,627 +0,0 @@
-/* ptrace.c */
-/* By Ross Biro 1/23/92 */
-/*
- * Pentium III FXSR, SSE support
- *     Gareth Hughes <gareth@valinux.com>, May 2000
- * 
- * x86-64 port 2000-2002 Andi Kleen
- */
-
-#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/security.h>
-#include <linux/audit.h>
-#include <linux/seccomp.h>
-#include <linux/signal.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/system.h>
-#include <asm/processor.h>
-#include <asm/i387.h>
-#include <asm/debugreg.h>
-#include <asm/ldt.h>
-#include <asm/desc.h>
-#include <asm/proto.h>
-#include <asm/ia32.h>
-
-/*
- * does not yet catch signals sent when the child dies.
- * in exit.c or in signal.c.
- */
-
-/*
- * Determines which flags the user has access to [1 = access, 0 = no access].
- * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
- * Also masks reserved bits (63-22, 15, 5, 3, 1).
- */
-#define FLAG_MASK 0x54dd5UL
-
-/* set's the trap flag. */
-#define TRAP_FLAG 0x100UL
-
-/*
- * eflags and offset of eflags on child stack..
- */
-#define EFLAGS offsetof(struct pt_regs, eflags)
-#define EFL_OFFSET ((int)(EFLAGS-sizeof(struct pt_regs)))
-
-/*
- * this routine will get a word off of the processes privileged stack. 
- * the offset is how far from the base addr as stored in the TSS.  
- * this routine assumes that all the privileged stacks are in our
- * data space.
- */   
-static inline unsigned long get_stack_long(struct task_struct *task, int offset)
-{
-       unsigned char *stack;
-
-       stack = (unsigned char *)task->thread.rsp0;
-       stack += offset;
-       return (*((unsigned long *)stack));
-}
-
-/*
- * this routine will put a word on the processes privileged stack. 
- * the offset is how far from the base addr as stored in the TSS.  
- * this routine assumes that all the privileged stacks are in our
- * data space.
- */
-static inline long put_stack_long(struct task_struct *task, int offset,
-       unsigned long data)
-{
-       unsigned char * stack;
-
-       stack = (unsigned char *) task->thread.rsp0;
-       stack += offset;
-       *(unsigned long *) stack = data;
-       return 0;
-}
-
-#define LDT_SEGMENT 4
-
-unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
-{
-       unsigned long addr, seg;
-
-       addr = regs->rip;
-       seg = regs->cs & 0xffff;
-
-       /*
-        * We'll assume that the code segments in the GDT
-        * are all zero-based. That is largely true: the
-        * TLS segments are used for data, and the PNPBIOS
-        * and APM bios ones we just ignore here.
-        */
-       if (seg & LDT_SEGMENT) {
-               u32 *desc;
-               unsigned long base;
-
-               seg &= ~7UL;
-
-               down(&child->mm->context.sem);
-               if (unlikely((seg >> 3) >= child->mm->context.size))
-                       addr = -1L; /* bogus selector, access would fault */
-               else {
-                       desc = child->mm->context.ldt + seg;
-                       base = ((desc[0] >> 16) |
-                               ((desc[1] & 0xff) << 16) |
-                               (desc[1] & 0xff000000));
-
-                       /* 16-bit code segment? */
-                       if (!((desc[1] >> 22) & 1))
-                               addr &= 0xffff;
-                       addr += base;
-               }
-               up(&child->mm->context.sem);
-       }
-
-       return addr;
-}
-
-static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
-{
-       int i, copied;
-       unsigned char opcode[15];
-       unsigned long addr = convert_rip_to_linear(child, regs);
-
-       copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
-       for (i = 0; i < copied; i++) {
-               switch (opcode[i]) {
-               /* popf and iret */
-               case 0x9d: case 0xcf:
-                       return 1;
-
-                       /* CHECKME: 64 65 */
-
-               /* opcode and address size prefixes */
-               case 0x66: case 0x67:
-                       continue;
-               /* irrelevant prefixes (segment overrides and repeats) */
-               case 0x26: case 0x2e:
-               case 0x36: case 0x3e:
-               case 0x64: case 0x65:
-               case 0xf2: case 0xf3:
-                       continue;
-
-               case 0x40 ... 0x4f:
-                       if (regs->cs != __USER_CS)
-                               /* 32-bit mode: register increment */
-                               return 0;
-                       /* 64-bit mode: REX prefix */
-                       continue;
-
-                       /* CHECKME: f2, f3 */
-
-               /*
-                * pushf: NOTE! We should probably not let
-                * the user see the TF bit being set. But
-                * it's more pain than it's worth to avoid
-                * it, and a debugger could emulate this
-                * all in user space if it _really_ cares.
-                */
-               case 0x9c:
-               default:
-                       return 0;
-               }
-       }
-       return 0;
-}
-
-static void set_singlestep(struct task_struct *child)
-{
-       struct pt_regs *regs = task_pt_regs(child);
-
-       /*
-        * Always set TIF_SINGLESTEP - this guarantees that
-        * we single-step system calls etc..  This will also
-        * cause us to set TF when returning to user mode.
-        */
-       set_tsk_thread_flag(child, TIF_SINGLESTEP);
-
-       /*
-        * If TF was already set, don't do anything else
-        */
-       if (regs->eflags & TRAP_FLAG)
-               return;
-
-       /* Set TF on the kernel stack.. */
-       regs->eflags |= TRAP_FLAG;
-
-       /*
-        * ..but if TF is changed by the instruction we will trace,
-        * don't mark it as being "us" that set it, so that we
-        * won't clear it by hand later.
-        */
-       if (is_setting_trap_flag(child, regs))
-               return;
-
-       child->ptrace |= PT_DTRACE;
-}
-
-static void clear_singlestep(struct task_struct *child)
-{
-       /* Always clear TIF_SINGLESTEP... */
-       clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-
-       /* But touch TF only if it was set by us.. */
-       if (child->ptrace & PT_DTRACE) {
-               struct pt_regs *regs = task_pt_regs(child);
-               regs->eflags &= ~TRAP_FLAG;
-               child->ptrace &= ~PT_DTRACE;
-       }
-}
-
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure the single step bit is not set.
- */
-void ptrace_disable(struct task_struct *child)
-{ 
-       clear_singlestep(child);
-}
-
-static int putreg(struct task_struct *child,
-       unsigned long regno, unsigned long value)
-{
-       unsigned long tmp; 
-       
-       switch (regno) {
-               case offsetof(struct user_regs_struct,fs):
-                       if (value && (value & 3) != 3)
-                               return -EIO;
-                       child->thread.fsindex = value & 0xffff; 
-                       return 0;
-               case offsetof(struct user_regs_struct,gs):
-                       if (value && (value & 3) != 3)
-                               return -EIO;
-                       child->thread.gsindex = value & 0xffff;
-                       return 0;
-               case offsetof(struct user_regs_struct,ds):
-                       if (value && (value & 3) != 3)
-                               return -EIO;
-                       child->thread.ds = value & 0xffff;
-                       return 0;
-               case offsetof(struct user_regs_struct,es): 
-                       if (value && (value & 3) != 3)
-                               return -EIO;
-                       child->thread.es = value & 0xffff;
-                       return 0;
-               case offsetof(struct user_regs_struct,ss):
-                       if ((value & 3) != 3)
-                               return -EIO;
-                       value &= 0xffff;
-                       return 0;
-               case offsetof(struct user_regs_struct,fs_base):
-                       if (value >= TASK_SIZE_OF(child))
-                               return -EIO;
-                       child->thread.fs = value;
-                       return 0;
-               case offsetof(struct user_regs_struct,gs_base):
-                       if (value >= TASK_SIZE_OF(child))
-                               return -EIO;
-                       child->thread.gs = value;
-                       return 0;
-               case offsetof(struct user_regs_struct, eflags):
-                       value &= FLAG_MASK;
-                       tmp = get_stack_long(child, EFL_OFFSET); 
-                       tmp &= ~FLAG_MASK; 
-                       value |= tmp;
-                       break;
-               case offsetof(struct user_regs_struct,cs): 
-                       if ((value & 3) != 3)
-                               return -EIO;
-                       value &= 0xffff;
-                       break;
-       }
-       put_stack_long(child, regno - sizeof(struct pt_regs), value);
-       return 0;
-}
-
-static unsigned long getreg(struct task_struct *child, unsigned long regno)
-{
-       unsigned long val;
-       switch (regno) {
-               case offsetof(struct user_regs_struct, fs):
-                       return child->thread.fsindex;
-               case offsetof(struct user_regs_struct, gs):
-                       return child->thread.gsindex;
-               case offsetof(struct user_regs_struct, ds):
-                       return child->thread.ds;
-               case offsetof(struct user_regs_struct, es):
-                       return child->thread.es; 
-               case offsetof(struct user_regs_struct, fs_base):
-                       return child->thread.fs;
-               case offsetof(struct user_regs_struct, gs_base):
-                       return child->thread.gs;
-               default:
-                       regno = regno - sizeof(struct pt_regs);
-                       val = get_stack_long(child, regno);
-                       if (test_tsk_thread_flag(child, TIF_IA32))
-                               val &= 0xffffffff;
-                       return val;
-       }
-
-}
-
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
-       long i, ret;
-       unsigned ui;
-
-       switch (request) {
-       /* when I and D space are separate, these will need to be fixed. */
-       case PTRACE_PEEKTEXT: /* read word at location addr. */ 
-       case PTRACE_PEEKDATA:
-               ret = generic_ptrace_peekdata(child, addr, data);
-               break;
-
-       /* read the word at location addr in the USER area. */
-       case PTRACE_PEEKUSR: {
-               unsigned long tmp;
-
-               ret = -EIO;
-               if ((addr & 7) ||
-                   addr > sizeof(struct user) - 7)
-                       break;
-
-               switch (addr) { 
-               case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
-                       tmp = getreg(child, addr);
-                       break;
-               case offsetof(struct user, u_debugreg[0]):
-                       tmp = child->thread.debugreg0;
-                       break;
-               case offsetof(struct user, u_debugreg[1]):
-                       tmp = child->thread.debugreg1;
-                       break;
-               case offsetof(struct user, u_debugreg[2]):
-                       tmp = child->thread.debugreg2;
-                       break;
-               case offsetof(struct user, u_debugreg[3]):
-                       tmp = child->thread.debugreg3;
-                       break;
-               case offsetof(struct user, u_debugreg[6]):
-                       tmp = child->thread.debugreg6;
-                       break;
-               case offsetof(struct user, u_debugreg[7]):
-                       tmp = child->thread.debugreg7;
-                       break;
-               default:
-                       tmp = 0;
-                       break;
-               }
-               ret = put_user(tmp,(unsigned long __user *) data);
-               break;
-       }
-
-       /* when I and D space are separate, this will have to be fixed. */
-       case PTRACE_POKETEXT: /* write the word at location addr. */
-       case PTRACE_POKEDATA:
-               ret = generic_ptrace_pokedata(child, addr, data);
-               break;
-
-       case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
-       {
-               int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;
-               ret = -EIO;
-               if ((addr & 7) ||
-                   addr > sizeof(struct user) - 7)
-                       break;
-
-               switch (addr) { 
-               case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
-                       ret = putreg(child, addr, data);
-                       break;
-               /* Disallows to set a breakpoint into the vsyscall */
-               case offsetof(struct user, u_debugreg[0]):
-                       if (data >= TASK_SIZE_OF(child) - dsize) break;
-                       child->thread.debugreg0 = data;
-                       ret = 0;
-                       break;
-               case offsetof(struct user, u_debugreg[1]):
-                       if (data >= TASK_SIZE_OF(child) - dsize) break;
-                       child->thread.debugreg1 = data;
-                       ret = 0;
-                       break;
-               case offsetof(struct user, u_debugreg[2]):
-                       if (data >= TASK_SIZE_OF(child) - dsize) break;
-                       child->thread.debugreg2 = data;
-                       ret = 0;
-                       break;
-               case offsetof(struct user, u_debugreg[3]):
-                       if (data >= TASK_SIZE_OF(child) - dsize) break;
-                       child->thread.debugreg3 = data;
-                       ret = 0;
-                       break;
-               case offsetof(struct user, u_debugreg[6]):
-                                 if (data >> 32)
-                               break; 
-                       child->thread.debugreg6 = data;
-                       ret = 0;
-                       break;
-               case offsetof(struct user, u_debugreg[7]):
-                       /* See arch/i386/kernel/ptrace.c for an explanation of
-                        * this awkward check.*/
-                       data &= ~DR_CONTROL_RESERVED;
-                       for(i=0; i<4; i++)
-                               if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
-                                       break;
-                       if (i == 4) {
-                         child->thread.debugreg7 = data;
-                         if (data)
-                               set_tsk_thread_flag(child, TIF_DEBUG);
-                         else
-                               clear_tsk_thread_flag(child, TIF_DEBUG);
-                         ret = 0;
-                       }
-                 break;
-               }
-               break;
-       }
-       case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
-       case PTRACE_CONT:    /* restart after signal. */
-
-               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);
-               clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-               child->exit_code = data;
-               /* make sure the single step bit is not set. */
-               clear_singlestep(child);
-               wake_up_process(child);
-               ret = 0;
-               break;
-
-#ifdef CONFIG_IA32_EMULATION
-               /* This makes only sense with 32bit programs. Allow a
-                  64bit debugger to fully examine them too. Better
-                  don't use it against 64bit processes, use
-                  PTRACE_ARCH_PRCTL instead. */
-       case PTRACE_SET_THREAD_AREA: {
-               struct user_desc __user *p;
-               int old; 
-               p = (struct user_desc __user *)data;
-               get_user(old,  &p->entry_number); 
-               put_user(addr, &p->entry_number);
-               ret = do_set_thread_area(&child->thread, p);
-               put_user(old,  &p->entry_number); 
-               break;
-       case PTRACE_GET_THREAD_AREA:
-               p = (struct user_desc __user *)data;
-               get_user(old,  &p->entry_number); 
-               put_user(addr, &p->entry_number);
-               ret = do_get_thread_area(&child->thread, p);
-               put_user(old,  &p->entry_number); 
-               break;
-       } 
-#endif
-               /* normal 64bit interface to access TLS data. 
-                  Works just like arch_prctl, except that the arguments
-                  are reversed. */
-       case PTRACE_ARCH_PRCTL: 
-               ret = do_arch_prctl(child, data, addr);
-               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;
-               clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-               child->exit_code = SIGKILL;
-               /* make sure the single step bit is not set. */
-               clear_singlestep(child);
-               wake_up_process(child);
-               break;
-
-       case PTRACE_SINGLESTEP:    /* set the trap flag. */
-               ret = -EIO;
-               if (!valid_signal(data))
-                       break;
-               clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
-               set_singlestep(child);
-               child->exit_code = data;
-               /* give it a chance to run. */
-               wake_up_process(child);
-               ret = 0;
-               break;
-
-       case PTRACE_DETACH:
-               /* detach a process that was attached. */
-               ret = ptrace_detach(child, data);
-               break;
-
-       case PTRACE_GETREGS: { /* Get all gp regs from the child. */
-               if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
-                              sizeof(struct user_regs_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               ret = 0;
-               for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
-                       ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
-                       data += sizeof(long);
-               }
-               break;
-       }
-
-       case PTRACE_SETREGS: { /* Set all gp regs in the child. */
-               unsigned long tmp;
-               if (!access_ok(VERIFY_READ, (unsigned __user *)data,
-                              sizeof(struct user_regs_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               ret = 0;
-               for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
-                       ret = __get_user(tmp, (unsigned long __user *) data);
-                       if (ret)
-                               break;
-                       ret = putreg(child, ui, tmp);
-                       if (ret)
-                               break;
-                       data += sizeof(long);
-               }
-               break;
-       }
-
-       case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
-               if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
-                              sizeof(struct user_i387_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               ret = get_fpregs((struct user_i387_struct __user *)data, child);
-               break;
-       }
-
-       case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
-               if (!access_ok(VERIFY_READ, (unsigned __user *)data,
-                              sizeof(struct user_i387_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               set_stopped_child_used_math(child);
-               ret = set_fpregs(child, (struct user_i387_struct __user *)data);
-               break;
-       }
-
-       default:
-               ret = ptrace_request(child, request, addr, data);
-               break;
-       }
-       return ret;
-}
-
-static void syscall_trace(struct pt_regs *regs)
-{
-
-#if 0
-       printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
-              current->comm,
-              regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
-              current_thread_info()->flags, current->ptrace); 
-#endif
-
-       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;
-       }
-}
-
-asmlinkage void syscall_trace_enter(struct pt_regs *regs)
-{
-       /* do the secure computing check first */
-       secure_computing(regs->orig_rax);
-
-       if (test_thread_flag(TIF_SYSCALL_TRACE)
-           && (current->ptrace & PT_PTRACED))
-               syscall_trace(regs);
-
-       if (unlikely(current->audit_context)) {
-               if (test_thread_flag(TIF_IA32)) {
-                       audit_syscall_entry(AUDIT_ARCH_I386,
-                                           regs->orig_rax,
-                                           regs->rbx, regs->rcx,
-                                           regs->rdx, regs->rsi);
-               } else {
-                       audit_syscall_entry(AUDIT_ARCH_X86_64,
-                                           regs->orig_rax,
-                                           regs->rdi, regs->rsi,
-                                           regs->rdx, regs->r10);
-               }
-       }
-}
-
-asmlinkage void syscall_trace_leave(struct pt_regs *regs)
-{
-       if (unlikely(current->audit_context))
-               audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);
-
-       if ((test_thread_flag(TIF_SYSCALL_TRACE)
-            || test_thread_flag(TIF_SINGLESTEP))
-           && (current->ptrace & PT_PTRACED))
-               syscall_trace(regs);
-}
diff --git a/arch/x86_64/kernel/ptrace_64.c b/arch/x86_64/kernel/ptrace_64.c
new file mode 100644 (file)
index 0000000..eea3702
--- /dev/null
@@ -0,0 +1,627 @@
+/* ptrace.c */
+/* By Ross Biro 1/23/92 */
+/*
+ * Pentium III FXSR, SSE support
+ *     Gareth Hughes <gareth@valinux.com>, May 2000
+ * 
+ * x86-64 port 2000-2002 Andi Kleen
+ */
+
+#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/security.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <linux/signal.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/i387.h>
+#include <asm/debugreg.h>
+#include <asm/ldt.h>
+#include <asm/desc.h>
+#include <asm/proto.h>
+#include <asm/ia32.h>
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Determines which flags the user has access to [1 = access, 0 = no access].
+ * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
+ * Also masks reserved bits (63-22, 15, 5, 3, 1).
+ */
+#define FLAG_MASK 0x54dd5UL
+
+/* set's the trap flag. */
+#define TRAP_FLAG 0x100UL
+
+/*
+ * eflags and offset of eflags on child stack..
+ */
+#define EFLAGS offsetof(struct pt_regs, eflags)
+#define EFL_OFFSET ((int)(EFLAGS-sizeof(struct pt_regs)))
+
+/*
+ * this routine will get a word off of the processes privileged stack. 
+ * the offset is how far from the base addr as stored in the TSS.  
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */   
+static inline unsigned long get_stack_long(struct task_struct *task, int offset)
+{
+       unsigned char *stack;
+
+       stack = (unsigned char *)task->thread.rsp0;
+       stack += offset;
+       return (*((unsigned long *)stack));
+}
+
+/*
+ * this routine will put a word on the processes privileged stack. 
+ * the offset is how far from the base addr as stored in the TSS.  
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline long put_stack_long(struct task_struct *task, int offset,
+       unsigned long data)
+{
+       unsigned char * stack;
+
+       stack = (unsigned char *) task->thread.rsp0;
+       stack += offset;
+       *(unsigned long *) stack = data;
+       return 0;
+}
+
+#define LDT_SEGMENT 4
+
+unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs)
+{
+       unsigned long addr, seg;
+
+       addr = regs->rip;
+       seg = regs->cs & 0xffff;
+
+       /*
+        * We'll assume that the code segments in the GDT
+        * are all zero-based. That is largely true: the
+        * TLS segments are used for data, and the PNPBIOS
+        * and APM bios ones we just ignore here.
+        */
+       if (seg & LDT_SEGMENT) {
+               u32 *desc;
+               unsigned long base;
+
+               seg &= ~7UL;
+
+               down(&child->mm->context.sem);
+               if (unlikely((seg >> 3) >= child->mm->context.size))
+                       addr = -1L; /* bogus selector, access would fault */
+               else {
+                       desc = child->mm->context.ldt + seg;
+                       base = ((desc[0] >> 16) |
+                               ((desc[1] & 0xff) << 16) |
+                               (desc[1] & 0xff000000));
+
+                       /* 16-bit code segment? */
+                       if (!((desc[1] >> 22) & 1))
+                               addr &= 0xffff;
+                       addr += base;
+               }
+               up(&child->mm->context.sem);
+       }
+
+       return addr;
+}
+
+static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
+{
+       int i, copied;
+       unsigned char opcode[15];
+       unsigned long addr = convert_rip_to_linear(child, regs);
+
+       copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
+       for (i = 0; i < copied; i++) {
+               switch (opcode[i]) {
+               /* popf and iret */
+               case 0x9d: case 0xcf:
+                       return 1;
+
+                       /* CHECKME: 64 65 */
+
+               /* opcode and address size prefixes */
+               case 0x66: case 0x67:
+                       continue;
+               /* irrelevant prefixes (segment overrides and repeats) */
+               case 0x26: case 0x2e:
+               case 0x36: case 0x3e:
+               case 0x64: case 0x65:
+               case 0xf2: case 0xf3:
+                       continue;
+
+               case 0x40 ... 0x4f:
+                       if (regs->cs != __USER_CS)
+                               /* 32-bit mode: register increment */
+                               return 0;
+                       /* 64-bit mode: REX prefix */
+                       continue;
+
+                       /* CHECKME: f2, f3 */
+
+               /*
+                * pushf: NOTE! We should probably not let
+                * the user see the TF bit being set. But
+                * it's more pain than it's worth to avoid
+                * it, and a debugger could emulate this
+                * all in user space if it _really_ cares.
+                */
+               case 0x9c:
+               default:
+                       return 0;
+               }
+       }
+       return 0;
+}
+
+static void set_singlestep(struct task_struct *child)
+{
+       struct pt_regs *regs = task_pt_regs(child);
+
+       /*
+        * Always set TIF_SINGLESTEP - this guarantees that
+        * we single-step system calls etc..  This will also
+        * cause us to set TF when returning to user mode.
+        */
+       set_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+       /*
+        * If TF was already set, don't do anything else
+        */
+       if (regs->eflags & TRAP_FLAG)
+               return;
+
+       /* Set TF on the kernel stack.. */
+       regs->eflags |= TRAP_FLAG;
+
+       /*
+        * ..but if TF is changed by the instruction we will trace,
+        * don't mark it as being "us" that set it, so that we
+        * won't clear it by hand later.
+        */
+       if (is_setting_trap_flag(child, regs))
+               return;
+
+       child->ptrace |= PT_DTRACE;
+}
+
+static void clear_singlestep(struct task_struct *child)
+{
+       /* Always clear TIF_SINGLESTEP... */
+       clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+
+       /* But touch TF only if it was set by us.. */
+       if (child->ptrace & PT_DTRACE) {
+               struct pt_regs *regs = task_pt_regs(child);
+               regs->eflags &= ~TRAP_FLAG;
+               child->ptrace &= ~PT_DTRACE;
+       }
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{ 
+       clear_singlestep(child);
+}
+
+static int putreg(struct task_struct *child,
+       unsigned long regno, unsigned long value)
+{
+       unsigned long tmp; 
+       
+       switch (regno) {
+               case offsetof(struct user_regs_struct,fs):
+                       if (value && (value & 3) != 3)
+                               return -EIO;
+                       child->thread.fsindex = value & 0xffff; 
+                       return 0;
+               case offsetof(struct user_regs_struct,gs):
+                       if (value && (value & 3) != 3)
+                               return -EIO;
+                       child->thread.gsindex = value & 0xffff;
+                       return 0;
+               case offsetof(struct user_regs_struct,ds):
+                       if (value && (value & 3) != 3)
+                               return -EIO;
+                       child->thread.ds = value & 0xffff;
+                       return 0;
+               case offsetof(struct user_regs_struct,es): 
+                       if (value && (value & 3) != 3)
+                               return -EIO;
+                       child->thread.es = value & 0xffff;
+                       return 0;
+               case offsetof(struct user_regs_struct,ss):
+                       if ((value & 3) != 3)
+                               return -EIO;
+                       value &= 0xffff;
+                       return 0;
+               case offsetof(struct user_regs_struct,fs_base):
+                       if (value >= TASK_SIZE_OF(child))
+                               return -EIO;
+                       child->thread.fs = value;
+                       return 0;
+               case offsetof(struct user_regs_struct,gs_base):
+                       if (value >= TASK_SIZE_OF(child))
+                               return -EIO;
+                       child->thread.gs = value;
+                       return 0;
+               case offsetof(struct user_regs_struct, eflags):
+                       value &= FLAG_MASK;
+                       tmp = get_stack_long(child, EFL_OFFSET); 
+                       tmp &= ~FLAG_MASK; 
+                       value |= tmp;
+                       break;
+               case offsetof(struct user_regs_struct,cs): 
+                       if ((value & 3) != 3)
+                               return -EIO;
+                       value &= 0xffff;
+                       break;
+       }
+       put_stack_long(child, regno - sizeof(struct pt_regs), value);
+       return 0;
+}
+
+static unsigned long getreg(struct task_struct *child, unsigned long regno)
+{
+       unsigned long val;
+       switch (regno) {
+               case offsetof(struct user_regs_struct, fs):
+                       return child->thread.fsindex;
+               case offsetof(struct user_regs_struct, gs):
+                       return child->thread.gsindex;
+               case offsetof(struct user_regs_struct, ds):
+                       return child->thread.ds;
+               case offsetof(struct user_regs_struct, es):
+                       return child->thread.es; 
+               case offsetof(struct user_regs_struct, fs_base):
+                       return child->thread.fs;
+               case offsetof(struct user_regs_struct, gs_base):
+                       return child->thread.gs;
+               default:
+                       regno = regno - sizeof(struct pt_regs);
+                       val = get_stack_long(child, regno);
+                       if (test_tsk_thread_flag(child, TIF_IA32))
+                               val &= 0xffffffff;
+                       return val;
+       }
+
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+       long i, ret;
+       unsigned ui;
+
+       switch (request) {
+       /* when I and D space are separate, these will need to be fixed. */
+       case PTRACE_PEEKTEXT: /* read word at location addr. */ 
+       case PTRACE_PEEKDATA:
+               ret = generic_ptrace_peekdata(child, addr, data);
+               break;
+
+       /* read the word at location addr in the USER area. */
+       case PTRACE_PEEKUSR: {
+               unsigned long tmp;
+
+               ret = -EIO;
+               if ((addr & 7) ||
+                   addr > sizeof(struct user) - 7)
+                       break;
+
+               switch (addr) { 
+               case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
+                       tmp = getreg(child, addr);
+                       break;
+               case offsetof(struct user, u_debugreg[0]):
+                       tmp = child->thread.debugreg0;
+                       break;
+               case offsetof(struct user, u_debugreg[1]):
+                       tmp = child->thread.debugreg1;
+                       break;
+               case offsetof(struct user, u_debugreg[2]):
+                       tmp = child->thread.debugreg2;
+                       break;
+               case offsetof(struct user, u_debugreg[3]):
+                       tmp = child->thread.debugreg3;
+                       break;
+               case offsetof(struct user, u_debugreg[6]):
+                       tmp = child->thread.debugreg6;
+                       break;
+               case offsetof(struct user, u_debugreg[7]):
+                       tmp = child->thread.debugreg7;
+                       break;
+               default:
+                       tmp = 0;
+                       break;
+               }
+               ret = put_user(tmp,(unsigned long __user *) data);
+               break;
+       }
+
+       /* when I and D space are separate, this will have to be fixed. */
+       case PTRACE_POKETEXT: /* write the word at location addr. */
+       case PTRACE_POKEDATA:
+               ret = generic_ptrace_pokedata(child, addr, data);
+               break;
+
+       case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
+       {
+               int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;
+               ret = -EIO;
+               if ((addr & 7) ||
+                   addr > sizeof(struct user) - 7)
+                       break;
+
+               switch (addr) { 
+               case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
+                       ret = putreg(child, addr, data);
+                       break;
+               /* Disallows to set a breakpoint into the vsyscall */
+               case offsetof(struct user, u_debugreg[0]):
+                       if (data >= TASK_SIZE_OF(child) - dsize) break;
+                       child->thread.debugreg0 = data;
+                       ret = 0;
+                       break;
+               case offsetof(struct user, u_debugreg[1]):
+                       if (data >= TASK_SIZE_OF(child) - dsize) break;
+                       child->thread.debugreg1 = data;
+                       ret = 0;
+                       break;
+               case offsetof(struct user, u_debugreg[2]):
+                       if (data >= TASK_SIZE_OF(child) - dsize) break;
+                       child->thread.debugreg2 = data;
+                       ret = 0;
+                       break;
+               case offsetof(struct user, u_debugreg[3]):
+                       if (data >= TASK_SIZE_OF(child) - dsize) break;
+                       child->thread.debugreg3 = data;
+                       ret = 0;
+                       break;
+               case offsetof(struct user, u_debugreg[6]):
+                                 if (data >> 32)
+                               break; 
+                       child->thread.debugreg6 = data;
+                       ret = 0;
+                       break;
+               case offsetof(struct user, u_debugreg[7]):
+                       /* See arch/i386/kernel/ptrace.c for an explanation of
+                        * this awkward check.*/
+                       data &= ~DR_CONTROL_RESERVED;
+                       for(i=0; i<4; i++)
+                               if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
+                                       break;
+                       if (i == 4) {
+                         child->thread.debugreg7 = data;
+                         if (data)
+                               set_tsk_thread_flag(child, TIF_DEBUG);
+                         else
+                               clear_tsk_thread_flag(child, TIF_DEBUG);
+                         ret = 0;
+                       }
+                 break;
+               }
+               break;
+       }
+       case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
+       case PTRACE_CONT:    /* restart after signal. */
+
+               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);
+               clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+               child->exit_code = data;
+               /* make sure the single step bit is not set. */
+               clear_singlestep(child);
+               wake_up_process(child);
+               ret = 0;
+               break;
+
+#ifdef CONFIG_IA32_EMULATION
+               /* This makes only sense with 32bit programs. Allow a
+                  64bit debugger to fully examine them too. Better
+                  don't use it against 64bit processes, use
+                  PTRACE_ARCH_PRCTL instead. */
+       case PTRACE_SET_THREAD_AREA: {
+               struct user_desc __user *p;
+               int old; 
+               p = (struct user_desc __user *)data;
+               get_user(old,  &p->entry_number); 
+               put_user(addr, &p->entry_number);
+               ret = do_set_thread_area(&child->thread, p);
+               put_user(old,  &p->entry_number); 
+               break;
+       case PTRACE_GET_THREAD_AREA:
+               p = (struct user_desc __user *)data;
+               get_user(old,  &p->entry_number); 
+               put_user(addr, &p->entry_number);
+               ret = do_get_thread_area(&child->thread, p);
+               put_user(old,  &p->entry_number); 
+               break;
+       } 
+#endif
+               /* normal 64bit interface to access TLS data. 
+                  Works just like arch_prctl, except that the arguments
+                  are reversed. */
+       case PTRACE_ARCH_PRCTL: 
+               ret = do_arch_prctl(child, data, addr);
+               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;
+               clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+               child->exit_code = SIGKILL;
+               /* make sure the single step bit is not set. */
+               clear_singlestep(child);
+               wake_up_process(child);
+               break;
+
+       case PTRACE_SINGLESTEP:    /* set the trap flag. */
+               ret = -EIO;
+               if (!valid_signal(data))
+                       break;
+               clear_tsk_thread_flag(child,TIF_SYSCALL_TRACE);
+               set_singlestep(child);
+               child->exit_code = data;
+               /* give it a chance to run. */
+               wake_up_process(child);
+               ret = 0;
+               break;
+
+       case PTRACE_DETACH:
+               /* detach a process that was attached. */
+               ret = ptrace_detach(child, data);
+               break;
+
+       case PTRACE_GETREGS: { /* Get all gp regs from the child. */
+               if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
+                              sizeof(struct user_regs_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               ret = 0;
+               for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
+                       ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
+                       data += sizeof(long);
+               }
+               break;
+       }
+
+       case PTRACE_SETREGS: { /* Set all gp regs in the child. */
+               unsigned long tmp;
+               if (!access_ok(VERIFY_READ, (unsigned __user *)data,
+                              sizeof(struct user_regs_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               ret = 0;
+               for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
+                       ret = __get_user(tmp, (unsigned long __user *) data);
+                       if (ret)
+                               break;
+                       ret = putreg(child, ui, tmp);
+                       if (ret)
+                               break;
+                       data += sizeof(long);
+               }
+               break;
+       }
+
+       case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
+               if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
+                              sizeof(struct user_i387_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               ret = get_fpregs((struct user_i387_struct __user *)data, child);
+               break;
+       }
+
+       case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
+               if (!access_ok(VERIFY_READ, (unsigned __user *)data,
+                              sizeof(struct user_i387_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               set_stopped_child_used_math(child);
+               ret = set_fpregs(child, (struct user_i387_struct __user *)data);
+               break;
+       }
+
+       default:
+               ret = ptrace_request(child, request, addr, data);
+               break;
+       }
+       return ret;
+}
+
+static void syscall_trace(struct pt_regs *regs)
+{
+
+#if 0
+       printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
+              current->comm,
+              regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
+              current_thread_info()->flags, current->ptrace); 
+#endif
+
+       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;
+       }
+}
+
+asmlinkage void syscall_trace_enter(struct pt_regs *regs)
+{
+       /* do the secure computing check first */
+       secure_computing(regs->orig_rax);
+
+       if (test_thread_flag(TIF_SYSCALL_TRACE)
+           && (current->ptrace & PT_PTRACED))
+               syscall_trace(regs);
+
+       if (unlikely(current->audit_context)) {
+               if (test_thread_flag(TIF_IA32)) {
+                       audit_syscall_entry(AUDIT_ARCH_I386,
+                                           regs->orig_rax,
+                                           regs->rbx, regs->rcx,
+                                           regs->rdx, regs->rsi);
+               } else {
+                       audit_syscall_entry(AUDIT_ARCH_X86_64,
+                                           regs->orig_rax,
+                                           regs->rdi, regs->rsi,
+                                           regs->rdx, regs->r10);
+               }
+       }
+}
+
+asmlinkage void syscall_trace_leave(struct pt_regs *regs)
+{
+       if (unlikely(current->audit_context))
+               audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);
+
+       if ((test_thread_flag(TIF_SYSCALL_TRACE)
+            || test_thread_flag(TIF_SINGLESTEP))
+           && (current->ptrace & PT_PTRACED))
+               syscall_trace(regs);
+}