nixos/stub-ld: init module

nixos/modules/config/stub-ld.nix

@@ -0,0 +1,56 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) optionalString mkOption types mdDoc mkIf mkDefault;
+
+  cfg = config.environment.stub-ld;
+
+  message = ''
+    NixOS cannot run dynamically linked executables intended for generic
+    linux environments out of the box. For more information, see:
+    https://nix.dev/permalink/stub-ld
+  '';
+
+  stub-ld-for = pkgsArg: messageArg: pkgsArg.pkgsStatic.runCommandCC "stub-ld" {
+    nativeBuildInputs = [ pkgsArg.unixtools.xxd ];
+    inherit messageArg;
+  } ''
+    printf "%s" "$messageArg" | xxd -i -n message >main.c
+    cat <<EOF >>main.c
+    #include <stdio.h>
+    int main(int argc, char * argv[]) {
+      fprintf(stderr, "Could not start dynamically linked executable: %s\n", argv[0]);
+      fwrite(message, sizeof(unsigned char), message_len, stderr);
+      return 127; // matches behavior of bash and zsh without a loader. fish uses 139
+    }
+    EOF
+    $CC -Os main.c -o $out
+  '';
+
+  pkgs32 = pkgs.pkgsi686Linux;
+
+  stub-ld = stub-ld-for pkgs message;
+  stub-ld32 = stub-ld-for pkgs32 message;
+in {
+  options = {
+    environment.stub-ld = {
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        example = false;
+        description = mdDoc ''
+          Install a stub ELF loader to print an informative error message
+          in the event that a user attempts to run an ELF binary not
+          compiled for NixOS.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.ldso = mkDefault stub-ld;
+    environment.ldso32 = mkIf pkgs.stdenv.isx86_64 (mkDefault stub-ld32);
+  };
+
+  meta.maintainers = with lib.maintainers; [ tejing ];
+}