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

   1 /* Machine-dependent details of interruptible RPC messaging.  i386 version.
   2    Copyright (C) 1995-2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19
  20 /* Note that we must mark OPTION and TIMEOUT as outputs of this operation,
  21    to indicate that the signal thread might mutate them as part
  22    of sending us to a signal handler.  */
  23 #define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify) \
  24 ({                                                                            \
  25   error_t err;                                                                \
  26   asm (".globl _hurd_intr_rpc_msg_do_trap\n"                                  \
  27        ".globl _hurd_intr_rpc_msg_in_trap\n"                                  \
  28        ".globl _hurd_intr_rpc_msg_cx_sp\n"                                    \
  29        ".globl _hurd_intr_rpc_msg_sp_restored\n"                              \
  30        "                                movl %%esp, %%ecx\n"                  \
  31        "                                leal %3, %%esp\n"                     \
  32        "_hurd_intr_rpc_msg_cx_sp:       movl $-25, %%eax\n"                   \
  33        "_hurd_intr_rpc_msg_do_trap:     lcall $7, $0 # status in %0\n"        \
  34        "_hurd_intr_rpc_msg_in_trap:     movl %%ecx, %%esp\n"                  \
  35        "_hurd_intr_rpc_msg_sp_restored:"                                      \
  36        : "=a" (err), "=m" (option), "=m" (timeout)                            \
  37        : "m" ((&msg)[-1]), "1" (option), "2" (timeout)                        \
  38        : "%ecx");                                                             \
  39   err;                                                                        \
  40 })
  41
  42
  43 static void inline
  44 INTR_MSG_BACK_OUT (struct i386_thread_state *state)
  45 {
  46   extern const void _hurd_intr_rpc_msg_cx_sp;
  47   if (state->eip >= (natural_t) &_hurd_intr_rpc_msg_cx_sp)
  48     state->uesp = state->ecx;
  49   else
  50     state->ecx = state->uesp;
  51 }
  52 \f
  53 #include "hurdfault.h"
  54
  55 /* This cannot be an inline function because it calls setjmp.  */
  56 #define SYSCALL_EXAMINE(state, callno)                                        \
  57 ({                                                                            \
  58   struct { unsigned int c[2]; } *p = (void *) ((state)->eip - 7);             \
  59   int result;                                                                 \
  60   if (_hurdsig_catch_memory_fault (p))                                        \
  61     return 0;                                                                 \
  62   if (result = p->c[0] == 0x0000009a && (p->c[1] & 0x00ffffff) == 0x00000700) \
  63     /* The PC is just after an `lcall $7,$0' instruction.                     \
  64        This is a system call in progress; %eax holds the call number.  */     \
  65     *(callno) = (state)->eax;                                                 \
  66   _hurdsig_end_catch_fault ();                                                \
  67   result;                                                                     \
  68 })
  69
  70
  71 struct mach_msg_trap_args
  72   {
  73     void *retaddr;              /* Address mach_msg_trap will return to.  */
  74     /* This is the order of arguments to mach_msg_trap.  */
  75     mach_msg_header_t *msg;
  76     mach_msg_option_t option;
  77     mach_msg_size_t send_size;
  78     mach_msg_size_t rcv_size;
  79     mach_port_t rcv_name;
  80     mach_msg_timeout_t timeout;
  81     mach_port_t notify;
  82   };
  83
  84
  85 /* This cannot be an inline function because it calls setjmp.  */
  86 #define MSG_EXAMINE(state, msgid, rcvname, send_name, opt, tmout)             \
  87 ({                                                                            \
  88   const struct mach_msg_trap_args *args = (const void *) (state)->uesp;       \
  89   mach_msg_header_t *msg;                                                     \
  90   _hurdsig_catch_memory_fault (args) ? -1 :                                   \
  91     ({                                                                        \
  92       msg = args->msg;                                                        \
  93       *(opt) = args->option;                                                  \
  94       *(tmout) = args->timeout;                                               \
  95       *(rcvname) = args->rcv_name;                                            \
  96       _hurdsig_end_catch_fault ();                                            \
  97       if (msg == 0)                                                           \
  98         {                                                                     \
  99           *(send_name) = MACH_PORT_NULL;                                      \
 100           *(msgid) = 0;                                                       \
 101         }                                                                     \
 102       else                                                                    \
 103         {                                                                     \
 104           if (_hurdsig_catch_memory_fault (msg))                              \
 105             return -1;                                                        \
 106           *(send_name) = msg->msgh_remote_port;                               \
 107           *(msgid) = msg->msgh_id;                                            \
 108           _hurdsig_end_catch_fault ();                                        \
 109         }                                                                     \
 110       0;                                                                      \
 111     });                                                                       \
 112 })