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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use libc;
use core::prelude::*;
use self::imp::{make_handler, drop_handler};
pub use self::imp::{init, cleanup};
pub struct Handler {
_data: *mut libc::c_void
}
impl Handler {
pub unsafe fn new() -> Handler {
make_handler()
}
}
impl Drop for Handler {
fn drop(&mut self) {
unsafe {
drop_handler(self);
}
}
}
#[cfg(any(target_os = "linux",
target_os = "macos",
target_os = "bitrig",
target_os = "netbsd",
target_os = "openbsd"))]
mod imp {
use sys_common::stack;
use super::Handler;
use rt::util::report_overflow;
use mem;
use ptr;
use intrinsics;
use sys::c::{siginfo, sigaction, SIGBUS, SIG_DFL,
SA_SIGINFO, SA_ONSTACK, sigaltstack,
SIGSTKSZ, sighandler_t, raise};
use libc;
use libc::funcs::posix88::mman::{mmap, munmap};
use libc::funcs::posix01::signal::signal;
use libc::consts::os::posix88::{SIGSEGV,
PROT_READ,
PROT_WRITE,
MAP_PRIVATE,
MAP_ANON,
MAP_FAILED};
use sys_common::thread_info;
// This is initialized in init() and only read from after
static mut PAGE_SIZE: usize = 0;
#[no_stack_check]
unsafe extern fn signal_handler(signum: libc::c_int,
info: *mut siginfo,
_data: *mut libc::c_void) {
// We can not return from a SIGSEGV or SIGBUS signal.
// See: https://www.gnu.org/software/libc/manual/html_node/Handler-Returns.html
unsafe fn term(signum: libc::c_int) -> ! {
use core::mem::transmute;
signal(signum, transmute(SIG_DFL));
raise(signum);
intrinsics::abort();
}
// We're calling into functions with stack checks
stack::record_sp_limit(0);
let guard = thread_info::stack_guard().unwrap_or(0);
let addr = (*info).si_addr as usize;
if guard == 0 || addr < guard - PAGE_SIZE || addr >= guard {
term(signum);
}
report_overflow();
intrinsics::abort()
}
static mut MAIN_ALTSTACK: *mut libc::c_void = 0 as *mut libc::c_void;
pub unsafe fn init() {
let psize = libc::sysconf(libc::consts::os::sysconf::_SC_PAGESIZE);
if psize == -1 {
panic!("failed to get page size");
}
PAGE_SIZE = psize as usize;
let mut action: sigaction = mem::zeroed();
action.sa_flags = SA_SIGINFO | SA_ONSTACK;
action.sa_sigaction = signal_handler as sighandler_t;
sigaction(SIGSEGV, &action, ptr::null_mut());
sigaction(SIGBUS, &action, ptr::null_mut());
let handler = make_handler();
MAIN_ALTSTACK = handler._data;
mem::forget(handler);
}
pub unsafe fn cleanup() {
Handler { _data: MAIN_ALTSTACK };
}
pub unsafe fn make_handler() -> Handler {
let alt_stack = mmap(ptr::null_mut(),
SIGSTKSZ,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON,
-1,
0);
if alt_stack == MAP_FAILED {
panic!("failed to allocate an alternative stack");
}
let mut stack: sigaltstack = mem::zeroed();
stack.ss_sp = alt_stack;
stack.ss_flags = 0;
stack.ss_size = SIGSTKSZ;
sigaltstack(&stack, ptr::null_mut());
Handler { _data: alt_stack }
}
pub unsafe fn drop_handler(handler: &mut Handler) {
munmap(handler._data, SIGSTKSZ);
}
}
#[cfg(not(any(target_os = "linux",
target_os = "macos",
target_os = "bitrig",
target_os = "netbsd",
target_os = "openbsd")))]
mod imp {
use libc;
pub unsafe fn init() {
}
pub unsafe fn cleanup() {
}
pub unsafe fn make_handler() -> super::Handler {
super::Handler { _data: 0 as *mut libc::c_void }
}
pub unsafe fn drop_handler(_handler: &mut super::Handler) {
}
}
|
