79 lines
1.9 KiB
Rust
79 lines
1.9 KiB
Rust
extern crate libc;
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extern crate std;
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use self::std::prelude::v1::*;
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use self::std::os::{errno, page_size, MemoryMap};
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use self::std::os::MapOption::{MapReadable, MapWritable, MapNonStandardFlags};
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use stack;
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extern "C" {
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#[link_name = "lwt_stack_register"]
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fn stack_register(start: *const u8, end: *const u8) -> libc::c_uint;
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#[link_name = "lwt_stack_deregister"]
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fn stack_deregister(id: libc::c_uint);
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}
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pub struct Stack {
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buf: MemoryMap,
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valgrind_id: libc::c_uint
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}
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const STACK_FLAGS: libc::c_int = libc::MAP_STACK
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| libc::MAP_PRIVATE
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| libc::MAP_ANON;
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impl Stack {
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pub fn new(size: usize) -> Stack {
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let buf = match MemoryMap::new(size, &[MapReadable, MapWritable,
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MapNonStandardFlags(STACK_FLAGS)]) {
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Ok(map) => map,
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Err(e) => panic!("mmap for stack of size {} failed: {:?}", size, e)
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};
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if !protect_last_page(&buf) {
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panic!("Could not memory-protect guard page. stack={:p}, errno={}",
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buf.data(), errno());
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}
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let valgrind_id = unsafe {
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stack_register(buf.data().offset(buf.len() as isize) as *const _,
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buf.data() as *const _)
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};
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Stack {
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buf: buf,
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valgrind_id: valgrind_id
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}
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}
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}
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fn protect_last_page(stack: &MemoryMap) -> bool {
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unsafe {
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let last_page = stack.data() as *mut libc::c_void;
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libc::mprotect(last_page, page_size() as libc::size_t,
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libc::PROT_NONE) != -1
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}
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}
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impl Drop for Stack {
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fn drop(&mut self) {
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unsafe {
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stack_deregister(self.valgrind_id);
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}
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}
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}
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impl stack::Stack for Stack {
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fn top(&mut self) -> *mut u8 {
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unsafe {
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self.buf.data().offset(self.buf.len() as isize)
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}
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}
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fn limit(&self) -> *const u8 {
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unsafe {
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self.buf.data().offset(page_size() as isize) as *const _
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}
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}
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}
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