Fix asm! macro options

Author: paulcacheux

mythril/src/error.rs

@@ -52,9 +52,12 @@ pub fn check_vm_insruction(rflags: u64, error: String) -> Result<()> {
     } else if rflags.contains(RFlags::FLAGS_ZF) {
         let errno = unsafe {
             let value: u64;
-            asm!("vmread rdx, rax",
-                    in("rax") vmcs::VmcsField::VmInstructionError as u64,
-                    out("rdx") value);
+            asm!(
+                "vmread rdx, rax",
+                in("rax") vmcs::VmcsField::VmInstructionError as u64,
+                out("rdx") value,
+                options(nostack)
+            );
             value
         };
         let vm_error = VmInstructionError::try_from(errno)
@@ -135,7 +138,7 @@ fn panic_handler(info: &core::panic::PanicInfo) -> ! {
     loop {
         unsafe {
             // Try to at least keep CPU from running at 100%
-            asm!("hlt");
+            asm!("hlt", options(nostack, nomem));
         }
     }
 }

mythril/src/interrupt/mod.rs

@@ -5,9 +5,9 @@ pub const TIMER_VECTOR: u8 = 48;
 pub const IPC_VECTOR: u8 = 49;
 
 pub unsafe fn enable_interrupts() {
-    asm!("sti");
+    asm!("sti", options(nomem, nostack));
 }
 
 pub unsafe fn disable_interrupts() {
-    asm!("cli");
+    asm!("cli", options(nomem, nostack));
 }

mythril/src/logger.rs

@@ -89,6 +89,7 @@ pub unsafe fn raw_write_console(s: impl AsRef<str>) {
         in("rdx") 0x3f8,
         in("rcx") len as u64,
         inout("rsi") ptr as u64 => _,
+        options(nostack)
     );
 }
 

mythril/src/percore.rs

@@ -81,8 +81,11 @@ impl fmt::Display for CoreId {
 pub fn read_core_id() -> CoreId {
     unsafe {
         let value: u64;
-        asm!("mov rax, fs",
-             out("rax") value);
+        asm!(
+            "mov rax, fs",
+            lateout("rax") value,
+            options(nomem, nostack)
+        );
         ((value >> 3) as u32).into() // Shift away the RPL and TI bits (they will always be 0)
     }
 }

mythril/src/registers.rs

@@ -15,7 +15,8 @@ impl IdtrBase {
             };
             asm!(
                 "sidt fword ptr [{0}]",
-                in(reg) &mut info
+                in(reg) &mut info,
+                options(nostack)
             );
             info.base_addr
         }
@@ -36,7 +37,8 @@ impl GdtrBase {
             let mut info = GdtInfo { size: 0, offset: 0 };
             asm!(
                 "sgdt fword ptr [{0}]",
-                in(reg) &mut info
+                in(reg) &mut info,
+                options(nostack)
             );
             info.offset
         }

mythril/src/vmx.rs

@@ -26,7 +26,7 @@ impl Vmx {
                 "mov cr0, rax",
                 in("rdx") 0x20,
                 lateout("rax") _,
-                options(nomem)
+                options(nomem, nostack)
             );
 
             // Enable vmx in CR4
@@ -36,7 +36,7 @@ impl Vmx {
                 "mov cr4, rax",
                 in("rdx") VMX_ENABLE_FLAG,
                 lateout("rax") _,
-                options(nomem)
+                options(nomem, nostack)
             );
         }