49 lines
1.5 KiB
Rust
49 lines
1.5 KiB
Rust
// This file is part of libfringe, a low-level green threading library.
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// Copyright (c) edef <edef@edef.eu>
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// See the LICENSE file included in this distribution.
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extern crate libc;
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use self::libc::{c_void, c_int, size_t};
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use self::libc::{mmap, mprotect, munmap};
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use self::libc::MAP_FAILED;
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use super::page_size;
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use core::ptr;
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#[cold]
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pub fn sys_page_size() -> usize {
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unsafe {
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libc::sysconf(libc::_SC_PAGESIZE) as usize
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}
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}
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const GUARD_PROT: c_int = libc::PROT_NONE;
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const STACK_PROT: c_int = libc::PROT_READ
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| libc::PROT_WRITE;
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#[cfg(not(any(target_os = "freebsd", target_os = "dragonfly")))]
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const STACK_FLAGS: c_int = libc::MAP_STACK
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| libc::MAP_PRIVATE
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| libc::MAP_ANON;
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// workaround for http://lists.freebsd.org/pipermail/freebsd-bugs/2011-July/044840.html
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// according to libgreen, DragonFlyBSD suffers from this too
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#[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
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const STACK_FLAGS: c_int = libc::MAP_PRIVATE
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| libc::MAP_ANON;
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pub unsafe fn map_stack(len: usize) -> Option<*mut u8> {
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let ptr = mmap(ptr::null_mut(), len as size_t,
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STACK_PROT, STACK_FLAGS, -1, 0);
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if ptr == MAP_FAILED {
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None
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} else {
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Some(ptr as *mut u8)
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}
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}
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pub unsafe fn protect_stack(ptr: *mut u8) -> bool {
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mprotect(ptr as *mut c_void, page_size() as size_t, GUARD_PROT) == 0
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}
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pub unsafe fn unmap_stack(ptr: *mut u8, len: usize) -> bool {
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munmap(ptr as *mut c_void, len as size_t) == 0
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}
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