Implement x86 chkstk in "rust"

This commit is contained in:
Matt Ickstadt 2017-09-15 17:18:54 -05:00
parent 35dec6bd8a
commit b3679bcfba
5 changed files with 114 additions and 40 deletions

View File

@ -159,8 +159,8 @@ features = ["c"]
- [x] floatunsisf.c - [x] floatunsisf.c
- [ ] i386/ashldi3.S - [ ] i386/ashldi3.S
- [ ] i386/ashrdi3.S - [ ] i386/ashrdi3.S
- [ ] i386/chkstk.S - [x] i386/chkstk.S
- [ ] i386/chkstk2.S - [x] i386/chkstk2.S
- [ ] i386/divdi3.S - [ ] i386/divdi3.S
- [ ] i386/lshrdi3.S - [ ] i386/lshrdi3.S
- [ ] i386/moddi3.S - [ ] i386/moddi3.S

View File

@ -4176,8 +4176,6 @@ mod c {
&[ &[
"i386/ashldi3.S", "i386/ashldi3.S",
"i386/ashrdi3.S", "i386/ashrdi3.S",
"i386/chkstk.S",
"i386/chkstk2.S",
"i386/divdi3.S", "i386/divdi3.S",
"i386/floatdidf.S", "i386/floatdidf.S",
"i386/floatdisf.S", "i386/floatdisf.S",

View File

@ -51,6 +51,9 @@ pub mod mem;
#[cfg(target_arch = "arm")] #[cfg(target_arch = "arm")]
pub mod arm; pub mod arm;
#[cfg(target_arch = "x86")]
pub mod x86;
#[cfg(target_arch = "x86_64")] #[cfg(target_arch = "x86_64")]
pub mod x86_64; pub mod x86_64;

71
src/x86.rs Normal file
View File

@ -0,0 +1,71 @@
#![allow(unused_imports)]
use core::intrinsics;
// NOTE These functions are implemented using assembly because they using a custom
// calling convention which can't be implemented using a normal Rust function
// NOTE These functions are never mangled as they are not tested against compiler-rt
// and mangling ___chkstk would break the `jmp ___chkstk` instruction in __alloca
#[cfg(all(windows, target_env = "gnu"))]
#[naked]
#[cfg_attr(not(feature = "mangled-names"), no_mangle)]
pub unsafe fn ___chkstk_ms() {
asm!("
push %ecx
push %eax
cmp $$0x1000,%eax
lea 12(%esp),%ecx
jb 1f
2:
sub $$0x1000,%ecx
test %ecx,(%ecx)
sub $$0x1000,%eax
cmp $$0x1000,%eax
ja 2b
1:
sub %eax,%ecx
test %ecx,(%ecx)
pop %eax
pop %ecx
ret");
intrinsics::unreachable();
}
// FIXME: __alloca should be an alias to __chkstk
#[cfg(all(windows, target_env = "gnu"))]
#[naked]
#[cfg_attr(not(feature = "mangled-names"), no_mangle)]
pub unsafe fn __alloca() {
asm!("jmp ___chkstk // Jump to ___chkstk since fallthrough may be unreliable");
intrinsics::unreachable();
}
#[cfg(all(windows, target_env = "gnu"))]
#[naked]
#[cfg_attr(not(feature = "mangled-names"), no_mangle)]
pub unsafe fn ___chkstk() {
asm!("
push %ecx
cmp $$0x1000,%eax
lea 8(%esp),%ecx // esp before calling this routine -> ecx
jb 1f
2:
sub $$0x1000,%ecx
test %ecx,(%ecx)
sub $$0x1000,%eax
cmp $$0x1000,%eax
ja 2b
1:
sub %eax,%ecx
test %ecx,(%ecx)
lea 4(%esp),%eax // load pointer to the return address into eax
mov %ecx,%esp // install the new top of stack pointer into esp
mov -4(%eax),%ecx // restore ecx
push (%eax) // push return address onto the stack
sub %esp,%eax // restore the original value in eax
ret");
intrinsics::unreachable();
}

View File

@ -12,7 +12,8 @@ use core::intrinsics;
#[naked] #[naked]
#[cfg_attr(not(feature = "mangled-names"), no_mangle)] #[cfg_attr(not(feature = "mangled-names"), no_mangle)]
pub unsafe fn ___chkstk_ms() { pub unsafe fn ___chkstk_ms() {
asm!("push %rcx asm!("
push %rcx
push %rax push %rax
cmp $$0x1000,%rax cmp $$0x1000,%rax
lea 24(%rsp),%rcx lea 24(%rsp),%rcx
@ -45,7 +46,8 @@ pub unsafe fn __alloca() {
#[naked] #[naked]
#[cfg_attr(not(feature = "mangled-names"), no_mangle)] #[cfg_attr(not(feature = "mangled-names"), no_mangle)]
pub unsafe fn ___chkstk() { pub unsafe fn ___chkstk() {
asm!("push %rcx asm!("
push %rcx
cmp $$0x1000,%rax cmp $$0x1000,%rax
lea 16(%rsp),%rcx // rsp before calling this routine -> rcx lea 16(%rsp),%rcx // rsp before calling this routine -> rcx
jb 1f jb 1f