server/context_x86_64.c

   1 /*
   2  * x86-64 register context support
   3  *
   4  * Copyright (C) 1999, 2005 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22
  23 #ifdef __x86_64__
  24
  25 #include <assert.h>
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <unistd.h>
  29 #ifdef HAVE_SYS_PTRACE_H
  30 # include <sys/ptrace.h>
  31 #endif
  32 #ifdef HAVE_SYS_PARAM_H
  33 # include <sys/param.h>
  34 #endif
  35
  36 #define NONAMELESSUNION
  37 #include "windef.h"
  38 #include "winbase.h"
  39
  40 #include "file.h"
  41 #include "thread.h"
  42 #include "request.h"
  43
  44 #ifdef __linux__
  45
  46 #ifdef HAVE_SYS_USER_H
  47 # include <sys/user.h>
  48 #endif
  49
  50 /* debug register offset in struct user */
  51 #define DR_OFFSET(dr) ((unsigned long)((((struct user *)0)->u_debugreg) + (dr)))
  52
  53 /* retrieve a debug register */
  54 static inline int get_debug_reg( int pid, int num, DWORD64 *data )
  55 {
  56     int res;
  57     errno = 0;
  58     res = ptrace( PTRACE_PEEKUSER, pid, DR_OFFSET(num), 0 );
  59     if ((res == -1) && errno)
  60     {
  61         file_set_error();
  62         return -1;
  63     }
  64     *data = res;
  65     return 0;
  66 }
  67
  68 /* retrieve a thread context */
  69 static void get_thread_context_ptrace( struct thread *thread, unsigned int flags, CONTEXT *context )
  70 {
  71     int pid = get_ptrace_pid(thread);
  72     if (flags & CONTEXT_FULL)
  73     {
  74         struct user_regs_struct regs;
  75         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
  76         if (flags & CONTEXT_INTEGER)
  77         {
  78             context->Rax = regs.rax;
  79             context->Rbx = regs.rbx;
  80             context->Rcx = regs.rcx;
  81             context->Rdx = regs.rdx;
  82             context->Rsi = regs.rsi;
  83             context->Rdi = regs.rdi;
  84             context->R8  = regs.r8;
  85             context->R9  = regs.r9;
  86             context->R10 = regs.r10;
  87             context->R11 = regs.r11;
  88             context->R12 = regs.r12;
  89             context->R13 = regs.r13;
  90             context->R14 = regs.r14;
  91             context->R15 = regs.r15;
  92         }
  93         if (flags & CONTEXT_CONTROL)
  94         {
  95             context->Rbp    = regs.rbp;
  96             context->Rsp    = regs.rsp;
  97             context->Rip    = regs.rip;
  98             context->SegCs  = regs.cs;
  99             context->SegSs  = regs.ss;
 100             context->EFlags = regs.eflags;
 101         }
 102         if (flags & CONTEXT_SEGMENTS)
 103         {
 104             context->SegDs = regs.ds;
 105             context->SegEs = regs.es;
 106             context->SegFs = regs.fs;
 107             context->SegGs = regs.gs;
 108         }
 109         context->ContextFlags |= flags & CONTEXT_FULL;
 110     }
 111     if (flags & CONTEXT_DEBUG_REGISTERS)
 112     {
 113         if (get_debug_reg( pid, 0, &context->Dr0 ) == -1) goto error;
 114         if (get_debug_reg( pid, 1, &context->Dr1 ) == -1) goto error;
 115         if (get_debug_reg( pid, 2, &context->Dr2 ) == -1) goto error;
 116         if (get_debug_reg( pid, 3, &context->Dr3 ) == -1) goto error;
 117         if (get_debug_reg( pid, 6, &context->Dr6 ) == -1) goto error;
 118         if (get_debug_reg( pid, 7, &context->Dr7 ) == -1) goto error;
 119         context->ContextFlags |= CONTEXT_DEBUG_REGISTERS;
 120     }
 121     if (flags & CONTEXT_FLOATING_POINT)
 122     {
 123         /* we can use context->FloatSave directly as it is using the */
 124         /* correct structure (the same as fsave/frstor) */
 125         if (ptrace( PTRACE_GETFPREGS, pid, 0, &context->u.FltSave ) == -1) goto error;
 126         context->ContextFlags |= CONTEXT_FLOATING_POINT;
 127     }
 128     return;
 129  error:
 130     file_set_error();
 131 }
 132
 133
 134 /* set a thread context */
 135 static void set_thread_context_ptrace( struct thread *thread, unsigned int flags, const CONTEXT *context )
 136 {
 137     int pid = get_ptrace_pid(thread);
 138     if (flags & CONTEXT_FULL)
 139     {
 140         struct user_regs_struct regs;
 141
 142         /* need to preserve some registers (at a minimum orig_eax must always be preserved) */
 143         if (ptrace( PTRACE_GETREGS, pid, 0, &regs ) == -1) goto error;
 144
 145         if (flags & CONTEXT_INTEGER)
 146         {
 147             regs.rax = context->Rax;
 148             regs.rbx = context->Rbx;
 149             regs.rcx = context->Rcx;
 150             regs.rdx = context->Rdx;
 151             regs.rsi = context->Rsi;
 152             regs.rdi = context->Rdi;
 153             regs.r8  = context->R8;
 154             regs.r9  = context->R9;
 155             regs.r10 = context->R10;
 156             regs.r11 = context->R11;
 157             regs.r12 = context->R12;
 158             regs.r13 = context->R13;
 159             regs.r14 = context->R14;
 160             regs.r15 = context->R15;
 161         }
 162         if (flags & CONTEXT_CONTROL)
 163         {
 164             regs.rbp = context->Rbp;
 165             regs.rip = context->Rip;
 166             regs.rsp = context->Rsp;
 167             regs.cs  = context->SegCs;
 168             regs.ss  = context->SegSs;
 169             regs.eflags = context->EFlags;
 170         }
 171         if (flags & CONTEXT_SEGMENTS)
 172         {
 173             regs.ds = context->SegDs;
 174             regs.es = context->SegEs;
 175             regs.fs = context->SegFs;
 176             regs.gs = context->SegGs;
 177         }
 178         if (ptrace( PTRACE_SETREGS, pid, 0, &regs ) == -1) goto error;
 179     }
 180     if (flags & CONTEXT_DEBUG_REGISTERS)
 181     {
 182         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->Dr0 ) == -1) goto error;
 183         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->Dr1 ) == -1) goto error;
 184         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->Dr2 ) == -1) goto error;
 185         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->Dr3 ) == -1) goto error;
 186         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->Dr6 ) == -1) goto error;
 187         if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->Dr7 ) == -1) goto error;
 188     }
 189     if (flags & CONTEXT_FLOATING_POINT)
 190     {
 191         /* we can use context->FloatSave directly as it is using the */
 192         /* correct structure (the same as fsave/frstor) */
 193         if (ptrace( PTRACE_SETFPREGS, pid, 0, &context->u.FltSave ) == -1) goto error;
 194     }
 195     return;
 196  error:
 197     file_set_error();
 198 }
 199
 200 #else  /* linux */
 201 #error You must implement get/set_thread_context_ptrace for your platform
 202 #endif  /* linux */
 203
 204
 205 /* copy a context structure according to the flags */
 206 static void copy_context( CONTEXT *to, const CONTEXT *from, unsigned int flags )
 207 {
 208     if (flags & CONTEXT_CONTROL)
 209     {
 210         to->Rbp    = from->Rbp;
 211         to->Rip    = from->Rip;
 212         to->Rsp    = from->Rsp;
 213         to->SegCs  = from->SegCs;
 214         to->SegSs  = from->SegSs;
 215         to->EFlags = from->EFlags;
 216         to->MxCsr  = from->MxCsr;
 217     }
 218     if (flags & CONTEXT_INTEGER)
 219     {
 220         to->Rax = from->Rax;
 221         to->Rcx = from->Rcx;
 222         to->Rdx = from->Rdx;
 223         to->Rbx = from->Rbx;
 224         to->Rsi = from->Rsi;
 225         to->Rdi = from->Rdi;
 226         to->R8  = from->R8;
 227         to->R9  = from->R9;
 228         to->R10 = from->R10;
 229         to->R11 = from->R11;
 230         to->R12 = from->R12;
 231         to->R13 = from->R13;
 232         to->R14 = from->R14;
 233         to->R15 = from->R15;
 234     }
 235     if (flags & CONTEXT_SEGMENTS)
 236     {
 237         to->SegDs = from->SegDs;
 238         to->SegEs = from->SegEs;
 239         to->SegFs = from->SegFs;
 240         to->SegGs = from->SegGs;
 241     }
 242     if (flags & CONTEXT_FLOATING_POINT)
 243     {
 244         to->u.FltSave = from->u.FltSave;
 245     }
 246     /* we don't bother copying the debug registers, since they */
 247     /* always need to be accessed by ptrace anyway */
 248     to->ContextFlags |= flags & ~CONTEXT_DEBUG_REGISTERS;
 249 }
 250
 251 /* retrieve the current instruction pointer of a thread */
 252 void *get_thread_ip( struct thread *thread )
 253 {
 254     CONTEXT context;
 255     context.Rip = 0;
 256     if (suspend_for_ptrace( thread ))
 257     {
 258         get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
 259         resume_after_ptrace( thread );
 260     }
 261     return (void *)context.Rip;
 262 }
 263
 264 /* determine if we should continue the thread in single-step mode */
 265 int get_thread_single_step( struct thread *thread )
 266 {
 267     CONTEXT context;
 268     if (thread->context) return 0;  /* don't single-step inside exception event */
 269     get_thread_context_ptrace( thread, CONTEXT_CONTROL, &context );
 270     return (context.EFlags & 0x100) != 0;
 271 }
 272
 273 /* send a signal to a specific thread */
 274 int tkill( int tgid, int pid, int sig )
 275 {
 276 #ifdef __linux__
 277     int ret;
 278     __asm__( "syscall" : "=a" (ret)
 279              : "0" (200) /*SYS_tkill*/, "D" (pid), "S" (sig) );
 280     if (ret >= 0) return ret;
 281     errno = -ret;
 282     return -1;
 283 #else
 284     errno = ENOSYS;
 285     return -1;
 286 #endif
 287 }
 288
 289 /* retrieve the thread context */
 290 void get_thread_context( struct thread *thread, CONTEXT *context, unsigned int flags )
 291 {
 292     context->ContextFlags |= CONTEXT_AMD64;
 293     flags &= ~CONTEXT_AMD64;  /* get rid of CPU id */
 294
 295     if (thread->context)  /* thread is inside an exception event or suspended */
 296     {
 297         copy_context( context, thread->context, flags );
 298         flags &= CONTEXT_DEBUG_REGISTERS;
 299     }
 300
 301     if (flags && suspend_for_ptrace( thread ))
 302     {
 303         get_thread_context_ptrace( thread, flags, context );
 304         resume_after_ptrace( thread );
 305     }
 306 }
 307
 308 /* set the thread context */
 309 void set_thread_context( struct thread *thread, const CONTEXT *context, unsigned int flags )
 310 {
 311     flags &= ~CONTEXT_AMD64;  /* get rid of CPU id */
 312
 313     if (thread->context)  /* thread is inside an exception event or suspended */
 314     {
 315         copy_context( thread->context, context, flags );
 316         flags &= CONTEXT_DEBUG_REGISTERS;
 317     }
 318
 319     if (flags && suspend_for_ptrace( thread ))
 320     {
 321         set_thread_context_ptrace( thread, flags, context );
 322         resume_after_ptrace( thread );
 323     }
 324 }
 325
 326 #endif  /* __x86_64__ */