Force 5-byte JMP in x86 and x86-64

src/arch/x86.rs

@@ -43,16 +43,17 @@ macro_rules! arch_static_key_init_nop_asm_template {
     };
 }
 
-// The `0x90,0x90,0x90` are three NOPs, which is to make sure the `jmp {0}` is at least 5 bytes long.
+// Here we do not use `jmp {0}` because it may be compiled into a 3-byte jmp instead of 5 byte.
+// See https://stackoverflow.com/q/74771372/10005095
 #[doc(hidden)]
 #[macro_export]
 macro_rules! arch_static_key_init_jmp_asm_template {
     () => {
         ::core::concat!(
             r#"
             2:
-                jmp {0}
-            .byte 0x90,0x90,0x90
+            .byte 0xe9
+            .long ({0} - 4) - .
             .pushsection "#,
             $crate::os_static_key_sec_name_attr!(),
             r#"

src/arch/x86_64.rs

@@ -43,7 +43,8 @@ macro_rules! arch_static_key_init_nop_asm_template {
     };
 }
 
-// The `0x90,0x90,0x90` are three NOPs, which is to make sure the `jmp {0}` is at least 5 bytes long.
+// Here we do not use `jmp {0}` because it may be compiled into a 3-byte jmp instead of 5 byte.
+// See https://stackoverflow.com/q/74771372/10005095
 #[doc(hidden)]
 #[macro_export]
 macro_rules! arch_static_key_init_jmp_asm_template {