stdenv: Move paxmark function to paxctl's setup hook

pkgs/os-specific/linux/paxctl/default.nix

···
     "MANDIR=share/man/man1"
   ];
 
+  setupHook = ./setup-hook.sh;
+
   meta = with stdenv.lib; {
     description = "A tool for controlling PaX flags on a per binary basis";
     homepage    = "https://pax.grsecurity.net";

pkgs/os-specific/linux/paxctl/setup-hook.sh

···
+# PaX-mark binaries.
+paxmark() {
+    local flags="$1"
+    shift
+
+    paxctl -c "$@"
+    paxctl -zex -${flags} "$@"
+}

pkgs/stdenv/generic/builder.sh

···
 sed -e "s^@initialPath@^$initialPath^g" \
     -e "s^@gcc@^$gcc^g" \
     -e "s^@shell@^$shell^g" \
-    -e "s^@needsPax@^$needsPax^g" \
     < $out/setup > $out/setup.tmp
 mv $out/setup.tmp $out/setup
 

pkgs/stdenv/generic/default.nix

···
 , setupScript ? ./setup.sh
 
 , extraBuildInputs ? []
-
-, skipPaxMarking ? false
 }:
 
 let
···
       setup = setupScript;
 
       inherit preHook initialPath gcc shell;
-
-      # Whether we should run paxctl to pax-mark binaries
-      needsPax = result.isLinux && !skipPaxMarking;
 
       propagatedUserEnvPkgs = [gcc] ++
         lib.filter lib.isDerivation initialPath;
···
       isArm = system == "armv5tel-linux"
            || system == "armv6l-linux"
            || system == "armv7l-linux";
+
+      # Whether we should run paxctl to pax-mark binaries.
+      needsPax = isLinux;
 
       # For convenience, bring in the library functions in lib/ so
       # packages don't have to do that themselves.

pkgs/stdenv/generic/setup.sh

···
 export NIX_BUILD_CORES
 
 
-######################################################################
-# Misc. helper functions.
-
-
-# PaX-mark binaries
-paxmark() {
-    local flags="$1"
-    shift
-
-    if [ -z "@needsPax@" ]; then
-        return
-    fi
-
-    paxctl -c "$@"
-    paxctl -zex -${flags} "$@"
-}
+# Dummy implementation of the paxmark function. On Linux, this is
+# overwritten by paxctl's setup hook.
+paxmark() { true; }
 
 
 ######################################################################