1 // Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 use self::imp::{make_handler, drop_handler};
15 pub use self::imp::{init, cleanup};
18 _data: *mut libc::c_void
22 pub unsafe fn new() -> Handler {
27 impl Drop for Handler {
35 #[cfg(any(target_os = "linux",
38 target_os = "openbsd"))]
40 use sys_common::stack;
43 use rt::util::report_overflow;
47 use self::signal::{siginfo, sigaction, SIGBUS, SIG_DFL,
48 SA_SIGINFO, SA_ONSTACK, sigaltstack,
51 use libc::funcs::posix88::mman::{mmap, munmap};
52 use libc::consts::os::posix88::{SIGSEGV,
59 use sys_common::thread_info;
62 // This is initialized in init() and only read from after
63 static mut PAGE_SIZE: usize = 0;
66 unsafe extern fn signal_handler(signum: libc::c_int,
68 _data: *mut libc::c_void) {
70 // We can not return from a SIGSEGV or SIGBUS signal.
71 // See: https://www.gnu.org/software/libc/manual/html_node/Handler-Returns.html
73 unsafe fn term(signum: libc::c_int) -> ! {
74 use core::mem::transmute;
76 signal(signum, transmute(SIG_DFL));
81 // We're calling into functions with stack checks
82 stack::record_sp_limit(0);
84 let guard = thread_info::stack_guard().unwrap_or(0);
85 let addr = (*info).si_addr as usize;
87 if guard == 0 || addr < guard - PAGE_SIZE || addr >= guard {
96 static mut MAIN_ALTSTACK: *mut libc::c_void = 0 as *mut libc::c_void;
98 pub unsafe fn init() {
99 let psize = libc::sysconf(libc::consts::os::sysconf::_SC_PAGESIZE);
101 panic!("failed to get page size");
104 PAGE_SIZE = psize as usize;
106 let mut action: sigaction = mem::zeroed();
107 action.sa_flags = SA_SIGINFO | SA_ONSTACK;
108 action.sa_sigaction = signal_handler as sighandler_t;
109 sigaction(SIGSEGV, &action, ptr::null_mut());
110 sigaction(SIGBUS, &action, ptr::null_mut());
112 let handler = make_handler();
113 MAIN_ALTSTACK = handler._data;
114 mem::forget(handler);
117 pub unsafe fn cleanup() {
118 Handler { _data: MAIN_ALTSTACK };
121 pub unsafe fn make_handler() -> Handler {
122 let alt_stack = mmap(ptr::null_mut(),
124 PROT_READ | PROT_WRITE,
125 MAP_PRIVATE | MAP_ANON,
128 if alt_stack == MAP_FAILED {
129 panic!("failed to allocate an alternative stack");
132 let mut stack: sigaltstack = mem::zeroed();
134 stack.ss_sp = alt_stack;
136 stack.ss_size = SIGSTKSZ;
138 sigaltstack(&stack, ptr::null_mut());
140 Handler { _data: alt_stack }
143 pub unsafe fn drop_handler(handler: &mut Handler) {
144 munmap(handler._data, SIGSTKSZ);
147 pub type sighandler_t = *mut libc::c_void;
149 #[cfg(any(all(target_os = "linux", target_arch = "x86"), // may not match
150 all(target_os = "linux", target_arch = "x86_64"),
151 all(target_os = "linux", target_arch = "arm"), // may not match
152 all(target_os = "linux", target_arch = "aarch64"),
153 all(target_os = "linux", target_arch = "mips"), // may not match
154 all(target_os = "linux", target_arch = "mipsel"), // may not match
155 all(target_os = "linux", target_arch = "powerpc"), // may not match
156 target_os = "android"))] // may not match
159 pub use super::sighandler_t;
161 pub static SA_ONSTACK: libc::c_int = 0x08000000;
162 pub static SA_SIGINFO: libc::c_int = 0x00000004;
163 pub static SIGBUS: libc::c_int = 7;
165 pub static SIGSTKSZ: libc::size_t = 8192;
167 pub const SIG_DFL: sighandler_t = 0 as sighandler_t;
169 // This definition is not as accurate as it could be, {si_addr} is
170 // actually a giant union. Currently we're only interested in that field,
174 si_signo: libc::c_int,
175 si_errno: libc::c_int,
176 si_code: libc::c_int,
177 pub si_addr: *mut libc::c_void
181 pub struct sigaction {
182 pub sa_sigaction: sighandler_t,
183 pub sa_mask: sigset_t,
184 pub sa_flags: libc::c_int,
185 sa_restorer: *mut libc::c_void,
188 #[cfg(target_pointer_width = "32")]
190 pub struct sigset_t {
191 __val: [libc::c_ulong; 32],
193 #[cfg(target_pointer_width = "64")]
195 pub struct sigset_t {
196 __val: [libc::c_ulong; 16],
200 pub struct sigaltstack {
201 pub ss_sp: *mut libc::c_void,
202 pub ss_flags: libc::c_int,
203 pub ss_size: libc::size_t
208 #[cfg(any(target_os = "macos",
209 target_os = "bitrig",
210 target_os = "openbsd"))]
213 pub use super::sighandler_t;
215 pub const SA_ONSTACK: libc::c_int = 0x0001;
216 pub const SA_SIGINFO: libc::c_int = 0x0040;
217 pub const SIGBUS: libc::c_int = 10;
219 #[cfg(target_os = "macos")]
220 pub const SIGSTKSZ: libc::size_t = 131072;
221 #[cfg(any(target_os = "bitrig", target_os = "openbsd"))]
222 pub const SIGSTKSZ: libc::size_t = 40960;
224 pub const SIG_DFL: sighandler_t = 0 as sighandler_t;
226 pub type sigset_t = u32;
228 // This structure has more fields, but we're not all that interested in
230 #[cfg(target_os = "macos")]
233 pub si_signo: libc::c_int,
234 pub si_errno: libc::c_int,
235 pub si_code: libc::c_int,
236 pub pid: libc::pid_t,
237 pub uid: libc::uid_t,
238 pub status: libc::c_int,
239 pub si_addr: *mut libc::c_void
242 #[cfg(any(target_os = "bitrig", target_os = "openbsd"))]
245 pub si_signo: libc::c_int,
246 pub si_code: libc::c_int,
247 pub si_errno: libc::c_int,
249 pub si_addr: *mut libc::c_void
253 pub struct sigaltstack {
254 pub ss_sp: *mut libc::c_void,
255 pub ss_size: libc::size_t,
256 pub ss_flags: libc::c_int
260 pub struct sigaction {
261 pub sa_sigaction: sighandler_t,
262 pub sa_mask: sigset_t,
263 pub sa_flags: libc::c_int,
268 pub fn signal(signum: libc::c_int, handler: sighandler_t) -> sighandler_t;
269 pub fn raise(signum: libc::c_int) -> libc::c_int;
271 pub fn sigaction(signum: libc::c_int,
272 act: *const sigaction,
273 oldact: *mut sigaction) -> libc::c_int;
275 pub fn sigaltstack(ss: *const sigaltstack,
276 oss: *mut sigaltstack) -> libc::c_int;
280 #[cfg(not(any(target_os = "linux",
282 target_os = "bitrig",
283 target_os = "openbsd")))]
287 pub unsafe fn init() {
290 pub unsafe fn cleanup() {
293 pub unsafe fn make_handler() -> super::Handler {
294 super::Handler { _data: 0 as *mut libc::c_void }
297 pub unsafe fn drop_handler(_handler: &mut super::Handler) {