+ /* 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 = 0;
+ if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
+ break;
+ ret = -EIO;
+ 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;