librasan: Use dynasm for patching supported architectures

Author: wfdewith

libafl_qemu/librasan/asan/Cargo.toml

@@ -54,6 +54,7 @@ baby-mimalloc = { version = "0.2.1", default-features = false, features = [
 bitflags = { version = "2.8.0", default-features = false }
 document-features = { version = "0.2.11", optional = true }
 dlmalloc = { version = "0.2.7", default-features = false, optional = true }
+dynasmrt = "3.2.0"
 itertools = { version = "0.14.0", default-features = false }
 log = { version = "0.4.22", default-features = false, features = [
   "release_max_level_info",

libafl_qemu/librasan/asan/src/patch/raw.rs

@@ -35,28 +35,28 @@ impl Patch for RawPatch {
 impl RawPatch {
     #[cfg(target_arch = "x86_64")]
     fn get_patch(_target: GuestAddr, destination: GuestAddr) -> Vec<u8> {
-        // mov rax, 0xdeadfacef00dd00d
-        // jmp rax
-        let addr = destination.to_ne_bytes();
-        #[rustfmt::skip]
-        let insns: &[&[u8]] = &[
-            &[0x48, 0xb8], &addr,
-            &[0xff, 0xe0],
-        ];
-        insns.concat()
+        use dynasmrt::{DynasmApi, VecAssembler, dynasm, x64::X64Relocation};
+        let mut assembler = VecAssembler::<X64Relocation>::new(0);
+
+        dynasm!(assembler
+            ; .arch x64
+            ; mov rax, QWORD destination as _
+            ; jmp rax
+        );
+        assembler.finalize().expect("valid static assembly")
     }
 
     #[cfg(target_arch = "x86")]
     fn get_patch(_target: GuestAddr, destination: GuestAddr) -> Vec<u8> {
-        // mov eax, 0xdeadface
-        // jmp eax
-        let addr = destination.to_ne_bytes();
-        #[rustfmt::skip]
-        let insns: &[&[u8]] = &[
-            &[0xb8], &addr,
-            &[0xff, 0xe0],
-        ];
-        insns.concat()
+        use dynasmrt::{DynasmApi, VecAssembler, dynasm, x86::X86Relocation};
+        let mut assembler = VecAssembler::<X86Relocation>::new(0);
+
+        dynasm!(assembler
+            ; .arch x86
+            ; mov eax, DWORD destination as _
+            ; jmp eax
+        );
+        assembler.finalize().expect("valid static assembly")
     }
 
     #[cfg(target_arch = "arm")]
@@ -88,17 +88,17 @@ impl RawPatch {
 
     #[cfg(target_arch = "aarch64")]
     fn get_patch(_target: GuestAddr, destination: GuestAddr) -> Vec<u8> {
-        // ldr x16, #8
-        // br  x16
-        // .quad 0xdeadfacef00dd00d
-        let addr = destination.to_ne_bytes();
-        #[rustfmt::skip]
-        let insns: &[&[u8]] = &[
-            &[0x50, 0x00, 0x00, 0x58],
-            &[0x00, 0x02, 0x1f, 0xd6],
-            &addr
-        ];
-        insns.concat()
+        use dynasmrt::{DynasmApi, VecAssembler, aarch64::Aarch64Relocation, dynasm};
+        let mut assembler = VecAssembler::<Aarch64Relocation>::new(0);
+
+        dynasm!(assembler
+            ; .arch aarch64
+            ; ldr x16, #8
+            ; br x16
+            ; .i64 destination as _
+        );
+
+        assembler.finalize().expect("valid static assembly")
     }
 
     #[cfg(target_arch = "powerpc")]