From 002648b782f8af41b4916e6cebd6b68d1d076513 Mon Sep 17 00:00:00 2001
From: Weijia Wang <9713184+wegank@users.noreply.github.com>
Date: Fri, 1 May 2026 01:55:57 +0200
Subject: [PATCH] nixos: unset vm.mmap_rnd_compat_bits on loongarch64

---
 nixos/modules/config/sysctl.nix | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/nixos/modules/config/sysctl.nix b/nixos/modules/config/sysctl.nix
index 1d5a1487bb3d..4a2ecd11e103 100644
--- a/nixos/modules/config/sysctl.nix
+++ b/nixos/modules/config/sysctl.nix
@@ -72,20 +72,25 @@ in
           {
             inherit (config.boot.kernelPackages.kernel) configfile;
           }
-          ''
-            mmap_rnd_bits_max=$(grep "^CONFIG_ARCH_MMAP_RND_BITS_MAX=" $configfile | grep --only-matching "[0-9]*$")
-            if [[ -z "$mmap_rnd_bits_max" ]]; then
-              echo "Unable to determine mmap_rnd_bits_max. Check your kernel configfile is valid."
-              exit 1
-            fi
-            mmap_rnd_compat_bits_max=$(grep "^CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=" $configfile | grep --only-matching "[0-9]*$")
-            if [[ -z "$mmap_rnd_compat_bits_max" ]]; then
-              echo "Unable to determine mmap_rnd_compat_bits_max. Check your kernel configfile is valid."
-              exit 1
-            fi
-            echo "vm.mmap_rnd_bits=$mmap_rnd_bits_max" >> $out
-            echo "vm.mmap_rnd_compat_bits=$mmap_rnd_compat_bits_max" >> $out
-          '';
+          (
+            ''
+              mmap_rnd_bits_max=$(grep "^CONFIG_ARCH_MMAP_RND_BITS_MAX=" $configfile | grep --only-matching "[0-9]*$")
+              if [[ -z "$mmap_rnd_bits_max" ]]; then
+                echo "Unable to determine mmap_rnd_bits_max. Check your kernel configfile is valid."
+                exit 1
+              fi
+              echo "vm.mmap_rnd_bits=$mmap_rnd_bits_max" >> $out
+            ''
+            # HAVE_ARCH_MMAP_RND_COMPAT_BITS is not defined for LoongArch64
+            + lib.optionalString (!pkgs.stdenv.hostPlatform.isLoongArch64) ''
+              mmap_rnd_compat_bits_max=$(grep "^CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=" $configfile | grep --only-matching "[0-9]*$")
+              if [[ -z "$mmap_rnd_compat_bits_max" ]]; then
+                echo "Unable to determine mmap_rnd_compat_bits_max. Check your kernel configfile is valid."
+                exit 1
+              fi
+              echo "vm.mmap_rnd_compat_bits=$mmap_rnd_compat_bits_max" >> $out
+            ''
+          );
       "sysctl.d/60-nixos.conf".text = lib.concatStrings (
         lib.mapAttrsToList (
           n: v: lib.optionalString (v != null) "${n}=${if v == false then "0" else toString v}\n"