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move {get,set}_sp_limit into Rust-land

This commit is contained in:
edef 2014-12-25 12:24:02 +01:00
parent b961956ea5
commit 612e854acb
3 changed files with 17 additions and 21 deletions

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@ -9,10 +9,6 @@ extern "C" {
pub fn bootstrap();
#[link_name = "lwt_swapcontext"]
pub fn swapcontext(save: *mut Registers, restore: *mut Registers);
#[link_name = "lwt_get_sp_limit"]
pub fn get_sp_limit() -> *const u8;
#[link_name = "lwt_set_sp_limit"]
pub fn set_sp_limit(limit: *const u8);
#[link_name = "lwt_abort"]
pub fn abort() -> !;
}
@ -77,6 +73,22 @@ pub fn initialise_call_frame(stack: &mut Stack, init: uintptr_t, args: &[uintptr
regs
}
// Rust stores a stack limit at [fs:0x70]. These two functions set and retrieve
// the limit. They're marked as #[inline(always)] so that they can be used in
// situations where the stack limit is invalid.
#[inline(always)]
pub unsafe fn get_sp_limit() -> *const u8 {
let limit;
asm!("movq %fs:0x70, $0" : "=r"(limit) ::: "volatile");
limit
}
#[inline(always)]
pub unsafe fn set_sp_limit(limit: *const u8) {
asm!("movq $0, %fs:0x70" :: "r"(limit) :: "volatile");
}
#[inline]
fn align_down_mut<T>(sp: *mut T, n: uint) -> *mut T {
let sp = (sp as uint) & !(n - 1);

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@ -91,22 +91,6 @@ lwt_bootstrap:
mov r8, r15
jmp rbx
;; Rust stores a stack limit at [fs:0x70]. These two functions set and retrieve
;; the limit. They could alternatively be implemented as #[inline(always)] Rust
;; functions, with inline assembly, but I prefer keeping all the assembly-land
;; stuff in here.
global lwt_set_sp_limit
lwt_set_sp_limit:
mov [fs:0x70], rdi
ret
global lwt_get_sp_limit
lwt_get_sp_limit:
mov rax, [fs:0x70]
ret
global lwt_abort
lwt_abort:
;; when a context is created for a native thread, it should only be switched

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@ -1,4 +1,4 @@
#![feature(default_type_params, macro_rules, phase, globs)]
#![feature(default_type_params, macro_rules, phase, globs, asm)]
#![no_std]
#[phase(plugin, link)]