i386: prepare shared kernel/ptrace.c
authorThomas Gleixner <tglx@linutronix.de>
Thu, 11 Oct 2007 09:12:53 +0000 (11:12 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 11 Oct 2007 09:12:53 +0000 (11:12 +0200)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/i386/kernel/Makefile
arch/i386/kernel/ptrace.c [deleted file]
arch/i386/kernel/ptrace_32.c [new file with mode: 0644]

index ce8dd0ad8a7960b4aa05d37dc797d799bcfeea46..b3a8c9aae0ab128779ee21189420a56649238aed 100644 (file)
@@ -5,7 +5,7 @@
 extra-y := head.o init_task.o vmlinux.lds
 
 obj-y  := process.o signal_32.o entry.o traps_32.o irq.o \
-               ptrace.o time_32.o ioport_32.o ldt.o setup_32.o i8259_32.o sys_i386_32.o \
+               ptrace_32.o time_32.o ioport_32.o ldt.o setup_32.o i8259_32.o sys_i386_32.o \
                pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\
                quirks.o i8237.o topology.o alternative.o i8253_32.o tsc.o
 
diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
deleted file mode 100644 (file)
index 7c1b925..0000000
+++ /dev/null
@@ -1,723 +0,0 @@
-/* ptrace.c */
-/* By Ross Biro 1/23/92 */
-/*
- * Pentium III FXSR, SSE support
- *     Gareth Hughes <gareth@valinux.com>, May 2000
- */
-
-#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>
-
-/*
- * 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), NT(14), IOPL(12-13), IF(9).
- * Also masks reserved bits (31-22, 15, 5, 3, 1).
- */
-#define FLAG_MASK 0x00050dd5
-
-/* set's the trap flag. */
-#define TRAP_FLAG 0x100
-
-/*
- * Offset of eflags on child stack..
- */
-#define EFL_OFFSET offsetof(struct pt_regs, eflags)
-
-static inline struct pt_regs *get_child_regs(struct task_struct *task)
-{
-       void *stack_top = (void *)task->thread.esp0;
-       return stack_top - sizeof(struct pt_regs);
-}
-
-/*
- * This routine will get a word off of the processes privileged stack.
- * the offset is bytes into the pt_regs structure on the stack.
- * This routine assumes that all the privileged stacks are in our
- * data space.
- */   
-static inline int get_stack_long(struct task_struct *task, int offset)
-{
-       unsigned char *stack;
-
-       stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
-       stack += offset;
-       return (*((int *)stack));
-}
-
-/*
- * This routine will put a word on the processes privileged stack.
- * the offset is bytes into the pt_regs structure on the stack.
- * This routine assumes that all the privileged stacks are in our
- * data space.
- */
-static inline int put_stack_long(struct task_struct *task, int offset,
-       unsigned long data)
-{
-       unsigned char * stack;
-
-       stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
-       stack += offset;
-       *(unsigned long *) stack = data;
-       return 0;
-}
-
-static int putreg(struct task_struct *child,
-       unsigned long regno, unsigned long value)
-{
-       switch (regno >> 2) {
-               case GS:
-                       if (value && (value & 3) != 3)
-                               return -EIO;
-                       child->thread.gs = value;
-                       return 0;
-               case DS:
-               case ES:
-               case FS:
-                       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;
-                       value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
-                       break;
-       }
-       if (regno > FS*4)
-               regno -= 1*4;
-       put_stack_long(child, regno, value);
-       return 0;
-}
-
-static unsigned long getreg(struct task_struct *child,
-       unsigned long regno)
-{
-       unsigned long retval = ~0UL;
-
-       switch (regno >> 2) {
-               case GS:
-                       retval = child->thread.gs;
-                       break;
-               case DS:
-               case ES:
-               case FS:
-               case SS:
-               case CS:
-                       retval = 0xffff;
-                       /* fall through */
-               default:
-                       if (regno > FS*4)
-                               regno -= 1*4;
-                       retval &= get_stack_long(child, regno);
-       }
-       return retval;
-}
-
-#define LDT_SEGMENT 4
-
-static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs)
-{
-       unsigned long addr, seg;
-
-       addr = regs->eip;
-       seg = regs->xcs & 0xffff;
-       if (regs->eflags & VM_MASK) {
-               addr = (addr & 0xffff) + (seg << 4);
-               return addr;
-       }
-
-       /*
-        * 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 inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
-{
-       int i, copied;
-       unsigned char opcode[15];
-       unsigned long addr = convert_eip_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;
-               /* 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 0xf0: case 0xf2: case 0xf3:
-                       continue;
-
-               /*
-                * 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 = get_child_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 = get_child_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);
-       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-}
-
-/*
- * Perform get_thread_area on behalf of the traced child.
- */
-static int
-ptrace_get_thread_area(struct task_struct *child,
-                      int idx, struct user_desc __user *user_desc)
-{
-       struct user_desc info;
-       struct desc_struct *desc;
-
-/*
- * Get the current Thread-Local Storage area:
- */
-
-#define GET_BASE(desc) ( \
-       (((desc)->a >> 16) & 0x0000ffff) | \
-       (((desc)->b << 16) & 0x00ff0000) | \
-       ( (desc)->b        & 0xff000000)   )
-
-#define GET_LIMIT(desc) ( \
-       ((desc)->a & 0x0ffff) | \
-        ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc)                (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc)     (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc)     (((desc)->b >>  9) & 1)
-#define GET_LIMIT_PAGES(desc)  (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc)      (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc)      (((desc)->b >> 20) & 1)
-
-       if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
-               return -EINVAL;
-
-       desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-
-       info.entry_number = idx;
-       info.base_addr = GET_BASE(desc);
-       info.limit = GET_LIMIT(desc);
-       info.seg_32bit = GET_32BIT(desc);
-       info.contents = GET_CONTENTS(desc);
-       info.read_exec_only = !GET_WRITABLE(desc);
-       info.limit_in_pages = GET_LIMIT_PAGES(desc);
-       info.seg_not_present = !GET_PRESENT(desc);
-       info.useable = GET_USEABLE(desc);
-
-       if (copy_to_user(user_desc, &info, sizeof(info)))
-               return -EFAULT;
-
-       return 0;
-}
-
-/*
- * Perform set_thread_area on behalf of the traced child.
- */
-static int
-ptrace_set_thread_area(struct task_struct *child,
-                      int idx, struct user_desc __user *user_desc)
-{
-       struct user_desc info;
-       struct desc_struct *desc;
-
-       if (copy_from_user(&info, user_desc, sizeof(info)))
-               return -EFAULT;
-
-       if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
-               return -EINVAL;
-
-       desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-       if (LDT_empty(&info)) {
-               desc->a = 0;
-               desc->b = 0;
-       } else {
-               desc->a = LDT_entry_a(&info);
-               desc->b = LDT_entry_b(&info);
-       }
-
-       return 0;
-}
-
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
-       struct user * dummy = NULL;
-       int i, ret;
-       unsigned long __user *datap = (unsigned long __user *)data;
-
-       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 & 3) || addr < 0 || 
-                   addr > sizeof(struct user) - 3)
-                       break;
-
-               tmp = 0;  /* Default return condition */
-               if(addr < FRAME_SIZE*sizeof(long))
-                       tmp = getreg(child, addr);
-               if(addr >= (long) &dummy->u_debugreg[0] &&
-                  addr <= (long) &dummy->u_debugreg[7]){
-                       addr -= (long) &dummy->u_debugreg[0];
-                       addr = addr >> 2;
-                       tmp = child->thread.debugreg[addr];
-               }
-               ret = put_user(tmp, datap);
-               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 */
-               ret = -EIO;
-               if ((addr & 3) || addr < 0 || 
-                   addr > sizeof(struct user) - 3)
-                       break;
-
-               if (addr < FRAME_SIZE*sizeof(long)) {
-                       ret = putreg(child, addr, data);
-                       break;
-               }
-               /* We need to be very careful here.  We implicitly
-                  want to modify a portion of the task_struct, and we
-                  have to be selective about what portions we allow someone
-                  to modify. */
-
-                 ret = -EIO;
-                 if(addr >= (long) &dummy->u_debugreg[0] &&
-                    addr <= (long) &dummy->u_debugreg[7]){
-
-                         if(addr == (long) &dummy->u_debugreg[4]) break;
-                         if(addr == (long) &dummy->u_debugreg[5]) break;
-                         if(addr < (long) &dummy->u_debugreg[4] &&
-                            ((unsigned long) data) >= TASK_SIZE-3) break;
-                         
-                         /* Sanity-check data. Take one half-byte at once with
-                          * check = (val >> (16 + 4*i)) & 0xf. It contains the
-                          * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
-                          * 2 and 3 are LENi. Given a list of invalid values,
-                          * we do mask |= 1 << invalid_value, so that
-                          * (mask >> check) & 1 is a correct test for invalid
-                          * values.
-                          *
-                          * R/Wi contains the type of the breakpoint /
-                          * watchpoint, LENi contains the length of the watched
-                          * data in the watchpoint case.
-                          *
-                          * The invalid values are:
-                          * - LENi == 0x10 (undefined), so mask |= 0x0f00.
-                          * - R/Wi == 0x10 (break on I/O reads or writes), so
-                          *   mask |= 0x4444.
-                          * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
-                          *   0x1110.
-                          *
-                          * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
-                          *
-                          * See the Intel Manual "System Programming Guide",
-                          * 15.2.4
-                          *
-                          * Note that LENi == 0x10 is defined on x86_64 in long
-                          * mode (i.e. even for 32-bit userspace software, but
-                          * 64-bit kernel), so the x86_64 mask value is 0x5454.
-                          * See the AMD manual no. 24593 (AMD64 System
-                          * Programming)*/
-
-                         if(addr == (long) &dummy->u_debugreg[7]) {
-                                 data &= ~DR_CONTROL_RESERVED;
-                                 for(i=0; i<4; i++)
-                                         if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
-                                                 goto out_tsk;
-                                 if (data)
-                                         set_tsk_thread_flag(child, TIF_DEBUG);
-                                 else
-                                         clear_tsk_thread_flag(child, TIF_DEBUG);
-                         }
-                         addr -= (long) &dummy->u_debugreg;
-                         addr = addr >> 2;
-                         child->thread.debugreg[addr] = data;
-                         ret = 0;
-                 }
-                 break;
-
-       case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */
-       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_SYSEMU) {
-                       set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-                       clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-               } else if (request == PTRACE_SYSCALL) {
-                       set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-               } else {
-                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-                       clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-               }
-               child->exit_code = data;
-               /* make sure the single step bit is not set. */
-               clear_singlestep(child);
-               wake_up_process(child);
-               ret = 0;
-               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;
-               child->exit_code = SIGKILL;
-               /* make sure the single step bit is not set. */
-               clear_singlestep(child);
-               wake_up_process(child);
-               break;
-
-       case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */
-       case PTRACE_SINGLESTEP: /* set the trap flag. */
-               ret = -EIO;
-               if (!valid_signal(data))
-                       break;
-
-               if (request == PTRACE_SYSEMU_SINGLESTEP)
-                       set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-               else
-                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-
-               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, datap, FRAME_SIZE*sizeof(long))) {
-                       ret = -EIO;
-                       break;
-               }
-               for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
-                       __put_user(getreg(child, i), datap);
-                       datap++;
-               }
-               ret = 0;
-               break;
-       }
-
-       case PTRACE_SETREGS: { /* Set all gp regs in the child. */
-               unsigned long tmp;
-               if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
-                       ret = -EIO;
-                       break;
-               }
-               for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
-                       __get_user(tmp, datap);
-                       putreg(child, i, tmp);
-                       datap++;
-               }
-               ret = 0;
-               break;
-       }
-
-       case PTRACE_GETFPREGS: { /* Get the child FPU state. */
-               if (!access_ok(VERIFY_WRITE, datap,
-                              sizeof(struct user_i387_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               ret = 0;
-               if (!tsk_used_math(child))
-                       init_fpu(child);
-               get_fpregs((struct user_i387_struct __user *)data, child);
-               break;
-       }
-
-       case PTRACE_SETFPREGS: { /* Set the child FPU state. */
-               if (!access_ok(VERIFY_READ, datap,
-                              sizeof(struct user_i387_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               set_stopped_child_used_math(child);
-               set_fpregs(child, (struct user_i387_struct __user *)data);
-               ret = 0;
-               break;
-       }
-
-       case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
-               if (!access_ok(VERIFY_WRITE, datap,
-                              sizeof(struct user_fxsr_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               if (!tsk_used_math(child))
-                       init_fpu(child);
-               ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
-               break;
-       }
-
-       case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
-               if (!access_ok(VERIFY_READ, datap,
-                              sizeof(struct user_fxsr_struct))) {
-                       ret = -EIO;
-                       break;
-               }
-               set_stopped_child_used_math(child);
-               ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
-               break;
-       }
-
-       case PTRACE_GET_THREAD_AREA:
-               ret = ptrace_get_thread_area(child, addr,
-                                       (struct user_desc __user *) data);
-               break;
-
-       case PTRACE_SET_THREAD_AREA:
-               ret = ptrace_set_thread_area(child, addr,
-                                       (struct user_desc __user *) data);
-               break;
-
-       default:
-               ret = ptrace_request(child, request, addr, data);
-               break;
-       }
- out_tsk:
-       return ret;
-}
-
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
-{
-       struct siginfo info;
-
-       tsk->thread.trap_no = 1;
-       tsk->thread.error_code = error_code;
-
-       memset(&info, 0, sizeof(info));
-       info.si_signo = SIGTRAP;
-       info.si_code = TRAP_BRKPT;
-
-       /* User-mode eip? */
-       info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
-
-       /* Send us the fakey SIGTRAP */
-       force_sig_info(SIGTRAP, &info, tsk);
-}
-
-/* notification of system call entry/exit
- * - triggered by current->work.syscall_trace
- */
-__attribute__((regparm(3)))
-int do_syscall_trace(struct pt_regs *regs, int entryexit)
-{
-       int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
-       /*
-        * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
-        * interception
-        */
-       int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
-       int ret = 0;
-
-       /* do the secure computing check first */
-       if (!entryexit)
-               secure_computing(regs->orig_eax);
-
-       if (unlikely(current->audit_context)) {
-               if (entryexit)
-                       audit_syscall_exit(AUDITSC_RESULT(regs->eax),
-                                               regs->eax);
-               /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
-                * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
-                * not used, entry.S will call us only on syscall exit, not
-                * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
-                * calling send_sigtrap() on syscall entry.
-                *
-                * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
-                * is_singlestep is false, despite his name, so we will still do
-                * the correct thing.
-                */
-               else if (is_singlestep)
-                       goto out;
-       }
-
-       if (!(current->ptrace & PT_PTRACED))
-               goto out;
-
-       /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
-        * and then is resumed with SYSEMU_SINGLESTEP, it will come in
-        * here. We have to check this and return */
-       if (is_sysemu && entryexit)
-               return 0;
-
-       /* Fake a debug trap */
-       if (is_singlestep)
-               send_sigtrap(current, regs, 0);
-
-       if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
-               goto out;
-
-       /* the 0x80 provides a way for the tracing parent to distinguish
-          between a syscall stop and SIGTRAP delivery */
-       /* Note that the debugger could change the result of test_thread_flag!*/
-       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;
-       }
-       ret = is_sysemu;
-out:
-       if (unlikely(current->audit_context) && !entryexit)
-               audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax,
-                                   regs->ebx, regs->ecx, regs->edx, regs->esi);
-       if (ret == 0)
-               return 0;
-
-       regs->orig_eax = -1; /* force skip of syscall restarting */
-       if (unlikely(current->audit_context))
-               audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);
-       return 1;
-}
diff --git a/arch/i386/kernel/ptrace_32.c b/arch/i386/kernel/ptrace_32.c
new file mode 100644 (file)
index 0000000..7c1b925
--- /dev/null
@@ -0,0 +1,723 @@
+/* ptrace.c */
+/* By Ross Biro 1/23/92 */
+/*
+ * Pentium III FXSR, SSE support
+ *     Gareth Hughes <gareth@valinux.com>, May 2000
+ */
+
+#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>
+
+/*
+ * 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), NT(14), IOPL(12-13), IF(9).
+ * Also masks reserved bits (31-22, 15, 5, 3, 1).
+ */
+#define FLAG_MASK 0x00050dd5
+
+/* set's the trap flag. */
+#define TRAP_FLAG 0x100
+
+/*
+ * Offset of eflags on child stack..
+ */
+#define EFL_OFFSET offsetof(struct pt_regs, eflags)
+
+static inline struct pt_regs *get_child_regs(struct task_struct *task)
+{
+       void *stack_top = (void *)task->thread.esp0;
+       return stack_top - sizeof(struct pt_regs);
+}
+
+/*
+ * This routine will get a word off of the processes privileged stack.
+ * the offset is bytes into the pt_regs structure on the stack.
+ * This routine assumes that all the privileged stacks are in our
+ * data space.
+ */   
+static inline int get_stack_long(struct task_struct *task, int offset)
+{
+       unsigned char *stack;
+
+       stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
+       stack += offset;
+       return (*((int *)stack));
+}
+
+/*
+ * This routine will put a word on the processes privileged stack.
+ * the offset is bytes into the pt_regs structure on the stack.
+ * This routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline int put_stack_long(struct task_struct *task, int offset,
+       unsigned long data)
+{
+       unsigned char * stack;
+
+       stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
+       stack += offset;
+       *(unsigned long *) stack = data;
+       return 0;
+}
+
+static int putreg(struct task_struct *child,
+       unsigned long regno, unsigned long value)
+{
+       switch (regno >> 2) {
+               case GS:
+                       if (value && (value & 3) != 3)
+                               return -EIO;
+                       child->thread.gs = value;
+                       return 0;
+               case DS:
+               case ES:
+               case FS:
+                       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;
+                       value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
+                       break;
+       }
+       if (regno > FS*4)
+               regno -= 1*4;
+       put_stack_long(child, regno, value);
+       return 0;
+}
+
+static unsigned long getreg(struct task_struct *child,
+       unsigned long regno)
+{
+       unsigned long retval = ~0UL;
+
+       switch (regno >> 2) {
+               case GS:
+                       retval = child->thread.gs;
+                       break;
+               case DS:
+               case ES:
+               case FS:
+               case SS:
+               case CS:
+                       retval = 0xffff;
+                       /* fall through */
+               default:
+                       if (regno > FS*4)
+                               regno -= 1*4;
+                       retval &= get_stack_long(child, regno);
+       }
+       return retval;
+}
+
+#define LDT_SEGMENT 4
+
+static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs)
+{
+       unsigned long addr, seg;
+
+       addr = regs->eip;
+       seg = regs->xcs & 0xffff;
+       if (regs->eflags & VM_MASK) {
+               addr = (addr & 0xffff) + (seg << 4);
+               return addr;
+       }
+
+       /*
+        * 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 inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
+{
+       int i, copied;
+       unsigned char opcode[15];
+       unsigned long addr = convert_eip_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;
+               /* 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 0xf0: case 0xf2: case 0xf3:
+                       continue;
+
+               /*
+                * 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 = get_child_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 = get_child_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);
+       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+}
+
+/*
+ * Perform get_thread_area on behalf of the traced child.
+ */
+static int
+ptrace_get_thread_area(struct task_struct *child,
+                      int idx, struct user_desc __user *user_desc)
+{
+       struct user_desc info;
+       struct desc_struct *desc;
+
+/*
+ * Get the current Thread-Local Storage area:
+ */
+
+#define GET_BASE(desc) ( \
+       (((desc)->a >> 16) & 0x0000ffff) | \
+       (((desc)->b << 16) & 0x00ff0000) | \
+       ( (desc)->b        & 0xff000000)   )
+
+#define GET_LIMIT(desc) ( \
+       ((desc)->a & 0x0ffff) | \
+        ((desc)->b & 0xf0000) )
+
+#define GET_32BIT(desc)                (((desc)->b >> 22) & 1)
+#define GET_CONTENTS(desc)     (((desc)->b >> 10) & 3)
+#define GET_WRITABLE(desc)     (((desc)->b >>  9) & 1)
+#define GET_LIMIT_PAGES(desc)  (((desc)->b >> 23) & 1)
+#define GET_PRESENT(desc)      (((desc)->b >> 15) & 1)
+#define GET_USEABLE(desc)      (((desc)->b >> 20) & 1)
+
+       if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+               return -EINVAL;
+
+       desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
+
+       info.entry_number = idx;
+       info.base_addr = GET_BASE(desc);
+       info.limit = GET_LIMIT(desc);
+       info.seg_32bit = GET_32BIT(desc);
+       info.contents = GET_CONTENTS(desc);
+       info.read_exec_only = !GET_WRITABLE(desc);
+       info.limit_in_pages = GET_LIMIT_PAGES(desc);
+       info.seg_not_present = !GET_PRESENT(desc);
+       info.useable = GET_USEABLE(desc);
+
+       if (copy_to_user(user_desc, &info, sizeof(info)))
+               return -EFAULT;
+
+       return 0;
+}
+
+/*
+ * Perform set_thread_area on behalf of the traced child.
+ */
+static int
+ptrace_set_thread_area(struct task_struct *child,
+                      int idx, struct user_desc __user *user_desc)
+{
+       struct user_desc info;
+       struct desc_struct *desc;
+
+       if (copy_from_user(&info, user_desc, sizeof(info)))
+               return -EFAULT;
+
+       if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+               return -EINVAL;
+
+       desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
+       if (LDT_empty(&info)) {
+               desc->a = 0;
+               desc->b = 0;
+       } else {
+               desc->a = LDT_entry_a(&info);
+               desc->b = LDT_entry_b(&info);
+       }
+
+       return 0;
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+       struct user * dummy = NULL;
+       int i, ret;
+       unsigned long __user *datap = (unsigned long __user *)data;
+
+       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 & 3) || addr < 0 || 
+                   addr > sizeof(struct user) - 3)
+                       break;
+
+               tmp = 0;  /* Default return condition */
+               if(addr < FRAME_SIZE*sizeof(long))
+                       tmp = getreg(child, addr);
+               if(addr >= (long) &dummy->u_debugreg[0] &&
+                  addr <= (long) &dummy->u_debugreg[7]){
+                       addr -= (long) &dummy->u_debugreg[0];
+                       addr = addr >> 2;
+                       tmp = child->thread.debugreg[addr];
+               }
+               ret = put_user(tmp, datap);
+               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 */
+               ret = -EIO;
+               if ((addr & 3) || addr < 0 || 
+                   addr > sizeof(struct user) - 3)
+                       break;
+
+               if (addr < FRAME_SIZE*sizeof(long)) {
+                       ret = putreg(child, addr, data);
+                       break;
+               }
+               /* We need to be very careful here.  We implicitly
+                  want to modify a portion of the task_struct, and we
+                  have to be selective about what portions we allow someone
+                  to modify. */
+
+                 ret = -EIO;
+                 if(addr >= (long) &dummy->u_debugreg[0] &&
+                    addr <= (long) &dummy->u_debugreg[7]){
+
+                         if(addr == (long) &dummy->u_debugreg[4]) break;
+                         if(addr == (long) &dummy->u_debugreg[5]) break;
+                         if(addr < (long) &dummy->u_debugreg[4] &&
+                            ((unsigned long) data) >= TASK_SIZE-3) break;
+                         
+                         /* Sanity-check data. Take one half-byte at once with
+                          * check = (val >> (16 + 4*i)) & 0xf. It contains the
+                          * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
+                          * 2 and 3 are LENi. Given a list of invalid values,
+                          * we do mask |= 1 << invalid_value, so that
+                          * (mask >> check) & 1 is a correct test for invalid
+                          * values.
+                          *
+                          * R/Wi contains the type of the breakpoint /
+                          * watchpoint, LENi contains the length of the watched
+                          * data in the watchpoint case.
+                          *
+                          * The invalid values are:
+                          * - LENi == 0x10 (undefined), so mask |= 0x0f00.
+                          * - R/Wi == 0x10 (break on I/O reads or writes), so
+                          *   mask |= 0x4444.
+                          * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
+                          *   0x1110.
+                          *
+                          * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
+                          *
+                          * See the Intel Manual "System Programming Guide",
+                          * 15.2.4
+                          *
+                          * Note that LENi == 0x10 is defined on x86_64 in long
+                          * mode (i.e. even for 32-bit userspace software, but
+                          * 64-bit kernel), so the x86_64 mask value is 0x5454.
+                          * See the AMD manual no. 24593 (AMD64 System
+                          * Programming)*/
+
+                         if(addr == (long) &dummy->u_debugreg[7]) {
+                                 data &= ~DR_CONTROL_RESERVED;
+                                 for(i=0; i<4; i++)
+                                         if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
+                                                 goto out_tsk;
+                                 if (data)
+                                         set_tsk_thread_flag(child, TIF_DEBUG);
+                                 else
+                                         clear_tsk_thread_flag(child, TIF_DEBUG);
+                         }
+                         addr -= (long) &dummy->u_debugreg;
+                         addr = addr >> 2;
+                         child->thread.debugreg[addr] = data;
+                         ret = 0;
+                 }
+                 break;
+
+       case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */
+       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_SYSEMU) {
+                       set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+                       clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+               } else if (request == PTRACE_SYSCALL) {
+                       set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+               } else {
+                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+                       clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+               }
+               child->exit_code = data;
+               /* make sure the single step bit is not set. */
+               clear_singlestep(child);
+               wake_up_process(child);
+               ret = 0;
+               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;
+               child->exit_code = SIGKILL;
+               /* make sure the single step bit is not set. */
+               clear_singlestep(child);
+               wake_up_process(child);
+               break;
+
+       case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */
+       case PTRACE_SINGLESTEP: /* set the trap flag. */
+               ret = -EIO;
+               if (!valid_signal(data))
+                       break;
+
+               if (request == PTRACE_SYSEMU_SINGLESTEP)
+                       set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+               else
+                       clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+
+               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, datap, FRAME_SIZE*sizeof(long))) {
+                       ret = -EIO;
+                       break;
+               }
+               for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
+                       __put_user(getreg(child, i), datap);
+                       datap++;
+               }
+               ret = 0;
+               break;
+       }
+
+       case PTRACE_SETREGS: { /* Set all gp regs in the child. */
+               unsigned long tmp;
+               if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
+                       ret = -EIO;
+                       break;
+               }
+               for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
+                       __get_user(tmp, datap);
+                       putreg(child, i, tmp);
+                       datap++;
+               }
+               ret = 0;
+               break;
+       }
+
+       case PTRACE_GETFPREGS: { /* Get the child FPU state. */
+               if (!access_ok(VERIFY_WRITE, datap,
+                              sizeof(struct user_i387_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               ret = 0;
+               if (!tsk_used_math(child))
+                       init_fpu(child);
+               get_fpregs((struct user_i387_struct __user *)data, child);
+               break;
+       }
+
+       case PTRACE_SETFPREGS: { /* Set the child FPU state. */
+               if (!access_ok(VERIFY_READ, datap,
+                              sizeof(struct user_i387_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               set_stopped_child_used_math(child);
+               set_fpregs(child, (struct user_i387_struct __user *)data);
+               ret = 0;
+               break;
+       }
+
+       case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
+               if (!access_ok(VERIFY_WRITE, datap,
+                              sizeof(struct user_fxsr_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               if (!tsk_used_math(child))
+                       init_fpu(child);
+               ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
+               break;
+       }
+
+       case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
+               if (!access_ok(VERIFY_READ, datap,
+                              sizeof(struct user_fxsr_struct))) {
+                       ret = -EIO;
+                       break;
+               }
+               set_stopped_child_used_math(child);
+               ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
+               break;
+       }
+
+       case PTRACE_GET_THREAD_AREA:
+               ret = ptrace_get_thread_area(child, addr,
+                                       (struct user_desc __user *) data);
+               break;
+
+       case PTRACE_SET_THREAD_AREA:
+               ret = ptrace_set_thread_area(child, addr,
+                                       (struct user_desc __user *) data);
+               break;
+
+       default:
+               ret = ptrace_request(child, request, addr, data);
+               break;
+       }
+ out_tsk:
+       return ret;
+}
+
+void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
+{
+       struct siginfo info;
+
+       tsk->thread.trap_no = 1;
+       tsk->thread.error_code = error_code;
+
+       memset(&info, 0, sizeof(info));
+       info.si_signo = SIGTRAP;
+       info.si_code = TRAP_BRKPT;
+
+       /* User-mode eip? */
+       info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
+
+       /* Send us the fakey SIGTRAP */
+       force_sig_info(SIGTRAP, &info, tsk);
+}
+
+/* notification of system call entry/exit
+ * - triggered by current->work.syscall_trace
+ */
+__attribute__((regparm(3)))
+int do_syscall_trace(struct pt_regs *regs, int entryexit)
+{
+       int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
+       /*
+        * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
+        * interception
+        */
+       int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
+       int ret = 0;
+
+       /* do the secure computing check first */
+       if (!entryexit)
+               secure_computing(regs->orig_eax);
+
+       if (unlikely(current->audit_context)) {
+               if (entryexit)
+                       audit_syscall_exit(AUDITSC_RESULT(regs->eax),
+                                               regs->eax);
+               /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
+                * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
+                * not used, entry.S will call us only on syscall exit, not
+                * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
+                * calling send_sigtrap() on syscall entry.
+                *
+                * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
+                * is_singlestep is false, despite his name, so we will still do
+                * the correct thing.
+                */
+               else if (is_singlestep)
+                       goto out;
+       }
+
+       if (!(current->ptrace & PT_PTRACED))
+               goto out;
+
+       /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
+        * and then is resumed with SYSEMU_SINGLESTEP, it will come in
+        * here. We have to check this and return */
+       if (is_sysemu && entryexit)
+               return 0;
+
+       /* Fake a debug trap */
+       if (is_singlestep)
+               send_sigtrap(current, regs, 0);
+
+       if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
+               goto out;
+
+       /* the 0x80 provides a way for the tracing parent to distinguish
+          between a syscall stop and SIGTRAP delivery */
+       /* Note that the debugger could change the result of test_thread_flag!*/
+       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;
+       }
+       ret = is_sysemu;
+out:
+       if (unlikely(current->audit_context) && !entryexit)
+               audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax,
+                                   regs->ebx, regs->ecx, regs->edx, regs->esi);
+       if (ret == 0)
+               return 0;
+
+       regs->orig_eax = -1; /* force skip of syscall restarting */
+       if (unlikely(current->audit_context))
+               audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);
+       return 1;
+}