1 #![cfg_attr(test, allow(unused))] // RT initialization logic is not compiled for test
2
3 use crate::io::Write;
4 use core::arch::global_asm;
5 use core::sync::atomic::{AtomicUsize, Ordering};
6
7 // runtime features
8 pub(super) mod panic;
9 mod reloc;
10
11 // library features
12 pub mod mem;
13 pub mod thread;
14 pub mod tls;
15 #[macro_use]
16 pub mod usercalls;
17
18 #[cfg(not(test))]
19 global_asm!(include_str!("entry.S"), options(att_syntax));
20
21 #[repr(C)]
22 struct EntryReturn(u64, u64);
23
24 #[cfg(not(test))]
25 #[no_mangle]
tcs_init(secondary: bool)26 unsafe extern "C" fn tcs_init(secondary: bool) {
27 // Be very careful when changing this code: it runs before the binary has been
28 // relocated. Any indirect accesses to symbols will likely fail.
29 const UNINIT: usize = 0;
30 const BUSY: usize = 1;
31 const DONE: usize = 2;
32 // Three-state spin-lock
33 static RELOC_STATE: AtomicUsize = AtomicUsize::new(UNINIT);
34
35 if secondary && RELOC_STATE.load(Ordering::Relaxed) != DONE {
36 rtabort!("Entered secondary TCS before main TCS!")
37 }
38
39 // Try to atomically swap UNINIT with BUSY. The returned state can be:
40 match RELOC_STATE.compare_exchange(UNINIT, BUSY, Ordering::Acquire, Ordering::Acquire) {
41 // This thread just obtained the lock and other threads will observe BUSY
42 Ok(_) => {
43 reloc::relocate_elf_rela();
44 RELOC_STATE.store(DONE, Ordering::Release);
45 }
46 // We need to wait until the initialization is done.
47 Err(BUSY) => {
48 while RELOC_STATE.load(Ordering::Acquire) == BUSY {
49 core::hint::spin_loop();
50 }
51 }
52 // Initialization is done.
53 Err(DONE) => {}
54 _ => unreachable!(),
55 }
56 }
57
58 // FIXME: this item should only exist if this is linked into an executable
59 // (main function exists). If this is a library, the crate author should be
60 // able to specify this
61 #[cfg(not(test))]
62 #[no_mangle]
entry(p1: u64, p2: u64, p3: u64, secondary: bool, p4: u64, p5: u64) -> EntryReturn63 extern "C" fn entry(p1: u64, p2: u64, p3: u64, secondary: bool, p4: u64, p5: u64) -> EntryReturn {
64 // FIXME: how to support TLS in library mode?
65 let tls = Box::new(tls::Tls::new());
66 let tls_guard = unsafe { tls.activate() };
67
68 if secondary {
69 let join_notifier = super::thread::Thread::entry();
70 drop(tls_guard);
71 drop(join_notifier);
72
73 EntryReturn(0, 0)
74 } else {
75 extern "C" {
76 fn main(argc: isize, argv: *const *const u8) -> isize;
77 }
78
79 // check entry is being called according to ABI
80 rtassert!(p3 == 0);
81 rtassert!(p4 == 0);
82 rtassert!(p5 == 0);
83
84 unsafe {
85 // The actual types of these arguments are `p1: *const Arg, p2:
86 // usize`. We can't currently customize the argument list of Rust's
87 // main function, so we pass these in as the standard pointer-sized
88 // values in `argc` and `argv`.
89 let ret = main(p2 as _, p1 as _);
90 exit_with_code(ret)
91 }
92 }
93 }
94
exit_with_code(code: isize) -> !95 pub(super) fn exit_with_code(code: isize) -> ! {
96 if code != 0 {
97 if let Some(mut out) = panic::SgxPanicOutput::new() {
98 let _ = write!(out, "Exited with status code {code}");
99 }
100 }
101 usercalls::exit(code != 0);
102 }
103
104 #[cfg(not(test))]
105 #[no_mangle]
abort_reentry() -> !106 extern "C" fn abort_reentry() -> ! {
107 usercalls::exit(false)
108 }
109