Merge pull request #52 from Mic92/exe-support

avoid integer underflow when calling memset with 0

flake.nix

@@ -1,25 +1,23 @@
 {
   description = "nix-ld: run unpatched dynamic binaries on NixOS";
 
-  inputs.utils.url = "github:numtide/flake-utils";
   inputs.nixpkgs.url = "github:NixOS/nixpkgs";
 
   nixConfig.extra-substituters = [ "https://cache.garnix.io" ];
   nixConfig.extra-trusted-public-keys = [ "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=" ];
 
-  outputs = {
-    self,
-    nixpkgs,
-    utils,
-  }:
-    {
-      nixosModules.nix-ld = import ./modules/nix-ld.nix;
-    }
-    // utils.lib.eachSystem ["x86_64-linux" "aarch64-linux"] (system: let
-      pkgs = nixpkgs.legacyPackages.${system};
-    in {
-      packages.nix-ld = pkgs.callPackage ./default.nix {};
-      packages.default = self.packages.${system}.nix-ld;
-      checks = self.packages.${system}.nix-ld.tests;
-    });
+  outputs = { self, nixpkgs }: {
+    nixosModules.nix-ld = import ./modules/nix-ld.nix;
+    packages = nixpkgs.lib.genAttrs [ "x86_64-linux" "aarch64-linux" ] (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        nix-ld = pkgs.callPackage ./default.nix { };
+        default = self.packages.${system}.nix-ld;
+      });
+    checks = nixpkgs.lib.genAttrs [ "x86_64-linux" "aarch64-linux" ] (system:
+      self.packages.${system}.nix-ld.tests
+    );
+  };
 }

src/nix-ld.c

@@ -202,7 +202,9 @@ static int elf_map(struct ld_ctx *ctx, int fd, const Phdr *prog_headers,
       size_t brk = ctx->load_addr + ph->p_vaddr + ph->p_filesz;
       size_t pgbrk = page_align(ctx, brk);
       size_t this_max = page_align(ctx, ph->p_vaddr + ph->p_memsz);
-      memset((void *)brk, 0, page_offset(ctx, pgbrk - brk));
+      if (page_offset(ctx, pgbrk - brk)) {
+        memset((void *)brk, 0, page_offset(ctx, pgbrk - brk));
+      }
 
       if (pgbrk - ctx->load_addr < this_max) {
         void *res = mmap((void *)pgbrk, ctx->load_addr + this_max - pgbrk, prot,