fixing linking issue on qemu build (#990)

* fixing linking issue

* insteading of linking lib we dont use. just disable them

* fixing the keyutils problem

Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>

libafl_qemu/libafl_qemu_build/Cargo.toml

@@ -9,7 +9,13 @@ readme = "./README.md"
 license = "MIT OR Apache-2.0"
 keywords = ["fuzzing", "qemu", "instrumentation"]
 edition = "2021"
-categories = ["development-tools::testing", "emulators", "embedded", "os", "no-std"]
+categories = [
+    "development-tools::testing",
+    "emulators",
+    "embedded",
+    "os",
+    "no-std",
+]
 
 [features]
 slirp = [] # build qemu with host libslirp (for user networking)
@@ -22,3 +28,4 @@ cc = "1.0"
 which = "4.2"
 json = "0.12"
 shell-words = "1.1"
+pkg-config = "0.3.26"

libafl_qemu/libafl_qemu_build/src/build.rs

@@ -266,7 +266,9 @@ pub fn build(
                 .arg("--disable-xen")
                 .arg("--disable-xen-pci-passthrough")
                 .arg("--disable-xkbcommon")
-                .arg("--disable-zstd");
+                .arg("--disable-zstd")
+                .arg("--disable-capstone")
+                .arg("--disable-sndio");
             if cfg!(feature = "debug_assertions") {
                 cmd.arg("--enable-debug");
             }
@@ -400,6 +402,9 @@ pub fn build(
     println!("cargo:rustc-link-lib=glib-2.0");
     println!("cargo:rustc-link-lib=stdc++");
     println!("cargo:rustc-link-lib=z");
+    // if keyutils is available, qemu meson script will compile code with keyutils.
+    // therefore, we need to link with keyutils if our system have libkeyutils.
+    let _ = pkg_config::Config::new().probe("libkeyutils");
 
     if !is_usermode {
         println!("cargo:rustc-link-lib=pixman-1");