sysdeps/mach/hurd/i386/intr-msg.h

   1 /* Machine-dependent details of interruptible RPC messaging.  i386 version.
   2    Copyright (C) 1995,96,97,99,2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20
  21 /* Note that we must mark OPTION and TIMEOUT as outputs of this operation,
  22    to indicate that the signal thread might mutate them as part
  23    of sending us to a signal handler.  */
  24 #define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify) \
  25 ({                                                                            \
  26   error_t err;                                                                \
  27   asm (".globl _hurd_intr_rpc_msg_do_trap\n"                                  \
  28        ".globl _hurd_intr_rpc_msg_in_trap\n"                                  \
  29        ".globl _hurd_intr_rpc_msg_cx_sp\n"                                    \
  30        ".globl _hurd_intr_rpc_msg_sp_restored\n"                              \
  31        "                                movl %%esp, %%ecx\n"                  \
  32        "                                leal %3, %%esp\n"                     \
  33        "_hurd_intr_rpc_msg_cx_sp:       movl $-25, %%eax\n"                   \
  34        "_hurd_intr_rpc_msg_do_trap:     lcall $7, $0 # status in %0\n"        \
  35        "_hurd_intr_rpc_msg_in_trap:     movl %%ecx, %%esp\n"                  \
  36        "_hurd_intr_rpc_msg_sp_restored:"                                      \
  37        : "=a" (err), "=m" (option), "=m" (timeout)                            \
  38        : "m" ((&msg)[-1]), "1" (option), "2" (timeout)                        \
  39        : "%ecx");                                                             \
  40   err;                                                                        \
  41 })
  42
  43
  44 static void inline
  45 INTR_MSG_BACK_OUT (struct i386_thread_state *state)
  46 {
  47   extern const void _hurd_intr_rpc_msg_cx_sp;
  48   if (state->eip >= (natural_t) &_hurd_intr_rpc_msg_cx_sp)
  49     state->uesp = state->ecx;
  50   else
  51     state->ecx = state->uesp;
  52 }
  53 \f
  54 #include "hurdfault.h"
  55
  56 /* This cannot be an inline function because it calls setjmp.  */
  57 #define SYSCALL_EXAMINE(state, callno)                                        \
  58 ({                                                                            \
  59   struct { unsigned int c[2]; } *p = (void *) ((state)->eip - 7);             \
  60   int result;                                                                 \
  61   if (_hurdsig_catch_memory_fault (p))                                        \
  62     return 0;                                                                 \
  63   if (result = p->c[0] == 0x0000009a && (p->c[1] & 0x00ffffff) == 0x00000700) \
  64     /* The PC is just after an `lcall $7,$0' instruction.                     \
  65        This is a system call in progress; %eax holds the call number.  */     \
  66     *(callno) = (state)->eax;                                                 \
  67   _hurdsig_end_catch_fault ();                                                \
  68   result;                                                                     \
  69 })
  70
  71
  72 struct mach_msg_trap_args
  73   {
  74     void *retaddr;              /* Address mach_msg_trap will return to.  */
  75     /* This is the order of arguments to mach_msg_trap.  */
  76     mach_msg_header_t *msg;
  77     mach_msg_option_t option;
  78     mach_msg_size_t send_size;
  79     mach_msg_size_t rcv_size;
  80     mach_port_t rcv_name;
  81     mach_msg_timeout_t timeout;
  82     mach_port_t notify;
  83   };
  84
  85
  86 /* This cannot be an inline function because it calls setjmp.  */
  87 #define MSG_EXAMINE(state, msgid, rcvname, send_name, opt, tmout)             \
  88 ({                                                                            \
  89   const struct mach_msg_trap_args *args = (const void *) (state)->uesp;       \
  90   mach_msg_header_t *msg;                                                     \
  91   _hurdsig_catch_memory_fault (args) ? -1 :                                   \
  92     ({                                                                        \
  93       msg = args->msg;                                                        \
  94       *(opt) = args->option;                                                  \
  95       *(tmout) = args->timeout;                                               \
  96       *(rcvname) = args->rcv_name;                                            \
  97       _hurdsig_end_catch_fault ();                                            \
  98       if (msg == 0)                                                           \
  99         {                                                                     \
 100           *(send_name) = MACH_PORT_NULL;                                      \
 101           *(msgid) = 0;                                                       \
 102         }                                                                     \
 103       else                                                                    \
 104         {                                                                     \
 105           if (_hurdsig_catch_memory_fault (msg))                              \
 106             return -1;                                                        \
 107           *(send_name) = msg->msgh_remote_port;                               \
 108           *(msgid) = msg->msgh_id;                                            \
 109           _hurdsig_end_catch_fault ();                                        \
 110         }                                                                     \
 111       0;                                                                      \
 112     });                                                                       \
 113 })