1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/* Machine-dependent details of interruptible RPC messaging. i386 version.
Copyright (C) 1995-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Note that we must mark OPTION and TIMEOUT as outputs of this operation,
to indicate that the signal thread might mutate them as part
of sending us to a signal handler. */
#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify, cancel_p, intr_port_p) \
({ \
error_t err; \
asm (".globl _hurd_intr_rpc_msg_about_to\n" \
".globl _hurd_intr_rpc_msg_setup_done\n" \
".globl _hurd_intr_rpc_msg_in_trap\n" \
/* Clear eax before we do the check for cancel below. This is to
detect eax being set to non-zero (actually MACH_SEND_INTERRUPTED)
from the outside (namely, _hurdsig_abort_rpcs), which signals us
to skip the trap we were about to enter. */ \
" xorl %0, %0\n" \
"_hurd_intr_rpc_msg_about_to:" \
/* We need to make a last check of cancel, in case we got interrupted
right before _hurd_intr_rpc_msg_about_to. */ \
" cmpl $0, %5\n" \
" jz _hurd_intr_rpc_msg_do\n" \
/* We got interrupted, note so and return EINTR. */ \
" movl $0, %3\n" \
" movl %6, %0\n" \
" jmp _hurd_intr_rpc_msg_sp_restored\n" \
"_hurd_intr_rpc_msg_do:" \
/* Ok, push the mach_msg_trap arguments and a fake return address. */ \
" pushl 24(%4)\n" \
" pushl %2\n" \
" pushl 16(%4)\n" \
" pushl 12(%4)\n" \
" pushl 8(%4)\n" \
" pushl %1\n" \
" pushl (%4)\n" \
" pushl $0\n" \
"_hurd_intr_rpc_msg_setup_done:" \
/* From here on, it is safe to make us jump over the syscall. Now
check if we have been told to skip the syscall while running
the above. */ \
" test %0, %0\n" \
" jnz _hurd_intr_rpc_msg_in_trap\n" \
/* Do the actual syscall. */ \
" movl $-25, %%eax\n" \
"_hurd_intr_rpc_msg_do_trap: lcall $7, $0 # status in %0\n" \
"_hurd_intr_rpc_msg_in_trap:" \
/* Ok, clean the arguments and update OPTION and TIMEOUT. */ \
" addl $8, %%esp\n" \
" popl %1\n" \
" addl $12, %%esp\n" \
" popl %2\n" \
" addl $4, %%esp\n" \
"_hurd_intr_rpc_msg_sp_restored:" \
: "=&a" (err), "+r" (option), "+r" (timeout), "=m" (*intr_port_p) \
: "r" (&msg), "m" (*cancel_p), "i" (EINTR)); \
err; \
})
#include "hurdfault.h"
/* This cannot be an inline function because it calls setjmp. */
#define SYSCALL_EXAMINE(state, callno) \
({ \
struct { unsigned int c[2]; } *p = (void *) ((state)->eip - 7); \
int result; \
if (_hurdsig_catch_memory_fault (p)) \
return 0; \
if (result = p->c[0] == 0x0000009a && (p->c[1] & 0x00ffffff) == 0x00000700) \
/* The PC is just after an `lcall $7,$0' instruction. \
This is a system call in progress; %eax holds the call number. */ \
*(callno) = (state)->eax; \
_hurdsig_end_catch_fault (); \
result; \
})
struct mach_msg_trap_args
{
void *retaddr; /* Address mach_msg_trap will return to. */
/* This is the order of arguments to mach_msg_trap. */
mach_msg_header_t *msg;
mach_msg_option_t option;
mach_msg_size_t send_size;
mach_msg_size_t rcv_size;
mach_port_t rcv_name;
mach_msg_timeout_t timeout;
mach_port_t notify;
};
/* This cannot be an inline function because it calls setjmp. */
#define MSG_EXAMINE(state, msgid, rcvname, send_name, opt, tmout) \
({ \
const struct mach_msg_trap_args *args = (const void *) (state)->uesp; \
mach_msg_header_t *msg; \
_hurdsig_catch_memory_fault (args) ? -1 : \
({ \
msg = args->msg; \
*(opt) = args->option; \
*(tmout) = args->timeout; \
*(rcvname) = args->rcv_name; \
_hurdsig_end_catch_fault (); \
if (msg == 0) \
{ \
*(send_name) = MACH_PORT_NULL; \
*(msgid) = 0; \
} \
else \
{ \
if (_hurdsig_catch_memory_fault (msg)) \
return -1; \
*(send_name) = msg->msgh_remote_port; \
*(msgid) = msg->msgh_id; \
_hurdsig_end_catch_fault (); \
} \
0; \
}); \
})
|
