Revert "Merge pull request #28029 from cstrahan/hardening-fix"

This reverts commit 0dbc006760, reversing
changes made to cb7f774265.

Should go into staging.

pkgs/build-support/bintools-wrapper/add-flags.sh

@@ -5,7 +5,6 @@ var_templates_list=(
     NIX+LDFLAGS_BEFORE
     NIX+LDFLAGS_AFTER
     NIX+LDFLAGS_HARDEN
-    NIX+HARDENING_ENABLE
 )
 var_templates_bool=(
     NIX+SET_BUILD_ID
@@ -24,10 +23,10 @@ if [ "${NIX_BINTOOLS_WRAPPER_@infixSalt@_TARGET_TARGET:-}" ]; then
 fi
 
 for var in "${var_templates_list[@]}"; do
-    mangleVarList "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarList "$var" "${role_infixes[@]}"
 done
 for var in "${var_templates_bool[@]}"; do
-    mangleVarBool "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarBool "$var" "${role_infixes[@]}"
 done
 
 if [ -e @out@/nix-support/libc-ldflags ]; then

pkgs/build-support/bintools-wrapper/add-hardening.sh

@@ -1,58 +1,53 @@
-declare -a hardeningLDFlags=()
+hardeningFlags=(relro bindnow)
+# Intentionally word-split in case 'hardeningEnable' is defined in
+# Nix. Also, our bootstrap tools version of bash is old enough that
+# undefined arrays trip `set -u`.
+if [[ -v hardeningEnable[@] ]]; then
+  hardeningFlags+=(${hardeningEnable[@]})
+fi
+hardeningLDFlags=()
 
-declare -A hardeningEnableMap=()
+declare -A hardeningDisableMap
 
-# Intentionally word-split in case 'NIX_HARDENING_ENABLE' is defined in Nix. The
-# array expansion also prevents undefined variables from causing trouble with
-# `set -u`.
-for flag in ${NIX_@infixSalt@_HARDENING_ENABLE-}; do
-  hardeningEnableMap["$flag"]=1
-done
-
-# Remove unsupported flags.
-for flag in @hardening_unsupported_flags@; do
-  unset -v hardeningEnableMap["$flag"]
+# Intentionally word-split in case 'hardeningDisable' is defined in Nix.
+for flag in ${hardeningDisable[@]:-IGNORED_KEY} @hardening_unsupported_flags@
+do
+  hardeningDisableMap[$flag]=1
 done
 
 if (( "${NIX_DEBUG:-0}" >= 1 )); then
-  declare -a allHardeningFlags=(pie relro bindnow)
-  declare -A hardeningDisableMap=()
-
-  # Determine which flags were effectively disabled so we can report below.
-  for flag in "${allHardeningFlags[@]}"; do
-    if [[ -z "${hardeningEnableMap[$flag]-}" ]]; then
-      hardeningDisableMap[$flag]=1
-    fi
-  done
-
   printf 'HARDENING: disabled flags:' >&2
   (( "${#hardeningDisableMap[@]}" )) && printf ' %q' "${!hardeningDisableMap[@]}" >&2
   echo >&2
-
-  if (( "${#hardeningEnableMap[@]}" )); then
-    echo 'HARDENING: Is active (not completely disabled with "all" flag)' >&2;
-  fi
 fi
 
-for flag in "${!hardeningEnableMap[@]}"; do
-  case $flag in
-    pie)
-      if [[ ! ("$*" =~ " -shared " || "$*" =~ " -static ") ]]; then
-        if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling LDFlags -pie >&2; fi
-        hardeningLDFlags+=('-pie')
-      fi
-      ;;
-    relro)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling relro >&2; fi
-      hardeningLDFlags+=('-z' 'relro')
-      ;;
-    bindnow)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling bindnow >&2; fi
-      hardeningLDFlags+=('-z' 'now')
-      ;;
-    *)
-      # Ignore unsupported. Checked in Nix that at least *some*
-      # tool supports each flag.
-      ;;
-  esac
-done
+if [[ -z "${hardeningDisableMap[all]:-}" ]]; then
+  if (( "${NIX_DEBUG:-0}" >= 1 )); then
+    echo 'HARDENING: Is active (not completely disabled with "all" flag)' >&2;
+  fi
+  for flag in "${hardeningFlags[@]}"
+  do
+    if [[ -z "${hardeningDisableMap[$flag]:-}" ]]; then
+      case $flag in
+        pie)
+          if [[ ! ("$*" =~ " -shared " || "$*" =~ " -static ") ]]; then
+            if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling LDFlags -pie >&2; fi
+            hardeningLDFlags+=('-pie')
+          fi
+          ;;
+        relro)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling relro >&2; fi
+          hardeningLDFlags+=('-z' 'relro')
+          ;;
+        bindnow)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling bindnow >&2; fi
+          hardeningLDFlags+=('-z' 'now')
+          ;;
+        *)
+          # Ignore unsupported. Checked in Nix that at least *some*
+          # tool supports each flag.
+          ;;
+      esac
+    fi
+  done
+fi

pkgs/build-support/bintools-wrapper/ld-wrapper.sh

@@ -57,8 +57,8 @@ fi
 
 source @out@/nix-support/add-hardening.sh
 
-extraAfter=()
-extraBefore=(${hardeningLDFlags[@]+"${hardeningLDFlags[@]}"})
+extraAfter=("${hardeningLDFlags[@]}")
+extraBefore=()
 
 if [ -z "${NIX_@infixSalt@_LDFLAGS_SET:-}" ]; then
     extraAfter+=($NIX_@infixSalt@_LDFLAGS)

pkgs/build-support/bintools-wrapper/setup-hook.sh

@@ -83,10 +83,6 @@ do
     fi
 done
 
-# If unset, assume the default hardening flags.
-: ${NIX_HARDENING_ENABLE="fortify stackprotector pic strictoverflow format relro bindnow"}
-export NIX_HARDENING_ENABLE
-
 # No local scope in sourced file
 unset -v role_pre role_post cmd upper_case
 set +u