[guest/setjmp] remove custom setjmp custom impl in favour of musl's

Our implementations of setjmp and longjmp conformed to the win64 ABI. With removal of PE support, we can leverage
 musl's implementation instead.

Signed-off-by: danbugs <[email protected]>

Author: danbugs

src/hyperlight_guest/build.rs

@@ -121,7 +121,6 @@ fn cargo_main() {
         copy_includes(&include_dir, "third_party/printf/");
     }
     if cfg!(feature = "libc") {
-        copy_includes(&include_dir, "include");
         copy_includes(&include_dir, "third_party/musl/include");
         copy_includes(&include_dir, "third_party/musl/arch/generic");
         copy_includes(&include_dir, "third_party/musl/arch/x86_64");

src/hyperlight_guest/include/setjmp.h

@@ -42,7 +42,6 @@ pub(crate) mod guest_logger;
 pub mod memory;
 pub mod print;
 pub(crate) mod security_check;
-pub mod setjmp;
 
 pub mod chkstk;
 pub mod error;

src/hyperlight_guest/src/lib.rs

@@ -0,0 +1,49 @@
+#ifndef	_SETJMP_H
+#define	_SETJMP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#include <bits/setjmp.h>
+
+typedef struct __jmp_buf_tag {
+	__jmp_buf __jb;
+	unsigned long __fl;
+	unsigned long __ss[128/sizeof(long)];
+} jmp_buf[1];
+
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
+#define __setjmp_attr __attribute__((__returns_twice__))
+#else
+#define __setjmp_attr
+#endif
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+typedef jmp_buf sigjmp_buf;
+int sigsetjmp (sigjmp_buf, int) __setjmp_attr;
+_Noreturn void siglongjmp (sigjmp_buf, int);
+#endif
+
+#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+int _setjmp (jmp_buf) __setjmp_attr;
+_Noreturn void _longjmp (jmp_buf, int);
+#endif
+
+int setjmp (jmp_buf) __setjmp_attr;
+_Noreturn void longjmp (jmp_buf, int);
+
+#define setjmp setjmp
+
+#undef __setjmp_attr
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/hyperlight_guest/src/setjmp.rs

@@ -0,0 +1,18 @@
+/* Copyright 2011-2012 Nicholas J. Kain, licensed under standard MIT license */
+.global _longjmp
+.global longjmp
+.type _longjmp,@function
+.type longjmp,@function
+_longjmp:
+longjmp:
+	xor %eax,%eax
+	cmp $1,%esi             /* CF = val ? 0 : 1 */
+	adc %esi,%eax           /* eax = val + !val */
+	mov (%rdi),%rbx         /* rdi is the jmp_buf, restore regs from it */
+	mov 8(%rdi),%rbp
+	mov 16(%rdi),%r12
+	mov 24(%rdi),%r13
+	mov 32(%rdi),%r14
+	mov 40(%rdi),%r15
+	mov 48(%rdi),%rsp
+	jmp *56(%rdi)           /* goto saved address without altering rsp */

src/hyperlight_guest/third_party/musl/include/setjmp.h

@@ -0,0 +1,22 @@
+/* Copyright 2011-2012 Nicholas J. Kain, licensed under standard MIT license */
+.global __setjmp
+.global _setjmp
+.global setjmp
+.type __setjmp,@function
+.type _setjmp,@function
+.type setjmp,@function
+__setjmp:
+_setjmp:
+setjmp:
+	mov %rbx,(%rdi)         /* rdi is jmp_buf, move registers onto it */
+	mov %rbp,8(%rdi)
+	mov %r12,16(%rdi)
+	mov %r13,24(%rdi)
+	mov %r14,32(%rdi)
+	mov %r15,40(%rdi)
+	lea 8(%rsp),%rdx        /* this is our rsp WITHOUT current ret addr */
+	mov %rdx,48(%rdi)
+	mov (%rsp),%rdx         /* save return addr ptr for new rip */
+	mov %rdx,56(%rdi)
+	xor %eax,%eax           /* always return 0 */
+	ret