From 37c22b9d308a2536eb8a3d07919fcc29ac9c7101 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 7 Oct 2019 20:24:29 +0200
Subject: [PATCH] Revive systemd.coredump.enable

---
 nixos/doc/manual/release-notes/rl-1909.xml | 17 ++++++++++-------
 nixos/modules/rename.nix                   |  1 -
 nixos/modules/system/boot/systemd.nix      | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/nixos/doc/manual/release-notes/rl-1909.xml b/nixos/doc/manual/release-notes/rl-1909.xml
index a33027bdbd1..4d9229becc9 100644
--- a/nixos/doc/manual/release-notes/rl-1909.xml
+++ b/nixos/doc/manual/release-notes/rl-1909.xml
@@ -739,7 +739,7 @@
       </para>
      </listitem>
     </itemizedlist>
-     This also configures the kernel to pass coredumps to <literal>systemd-coredump</literal>,
+     This also configures the kernel to pass core dumps to <literal>systemd-coredump</literal>,
      and restricts the SysRq key combinations to the sync command only.
      These sysctl snippets can be found in <literal>/etc/sysctl.d/50-*.conf</literal>,
      and overridden via <link linkend="opt-boot.kernel.sysctl">boot.kernel.sysctl</link>
@@ -748,12 +748,15 @@
    </listitem>
    <listitem>
     <para>
-      Coredumps are now acquired by <literal>systemd-coredump</literal> by default.
-      <literal>systemd-coredump</literal> behaviour can still be modified via
-      <option>systemd.coredump.extraConfig</option>.
-      To stick to the old behaviour (having the kernel dump to a file called <literal>core</literal>
-      in the working directory), without piping it through <literal>systemd-coredump</literal>, set
-      <option>boot.kernel.sysctl."kernel.core_pattern"</option> to <literal>"core"</literal>.
+      Core dumps are now processed by <literal>systemd-coredump</literal>
+      by default. <literal>systemd-coredump</literal> behaviour can
+      still be modified via
+      <option>systemd.coredump.extraConfig</option>. To stick to the
+      old behaviour (having the kernel dump to a file called
+      <literal>core</literal> in the working directory), without piping
+      it through <literal>systemd-coredump</literal>, set
+      <option>systemd.coredump.enable</option> to
+      <literal>false</literal>.
     </para>
    </listitem>
    <listitem>
diff --git a/nixos/modules/rename.nix b/nixos/modules/rename.nix
index 564c53465e3..df8ebe50584 100644
--- a/nixos/modules/rename.nix
+++ b/nixos/modules/rename.nix
@@ -233,7 +233,6 @@ with lib;
     (mkRemovedOptionModule [ "services" "mysql" "rootPassword" ] "Use socket authentication or set the password outside of the nix store.")
     (mkRemovedOptionModule [ "services" "zabbixServer" "dbPassword" ] "Use services.zabbixServer.database.passwordFile instead.")
     (mkRemovedOptionModule [ "systemd" "generator-packages" ] "Use systemd.packages instead.")
-    (mkRemovedOptionModule [ "systemd" "coredump" "enable" ] "Enabled by default. Set boot.kernel.sysctl.\"kernel.core_pattern\" = \"core\"; to disable.")
 
     # ZSH
     (mkRenamedOptionModule [ "programs" "zsh" "enableSyntaxHighlighting" ] [ "programs" "zsh" "syntaxHighlighting" "enable" ])
diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index 5cf437bfbcb..669eb6a7056 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -546,6 +546,16 @@ in
       '';
     };
 
+    systemd.coredump.enable = mkOption {
+      default = true;
+      type = types.bool;
+      description = ''
+        Whether core dumps should be processed by
+        <command>systemd-coredump</command>. If disabled, core dumps
+        appear in the current directory of the crashing process.
+      '';
+    };
+
     systemd.coredump.extraConfig = mkOption {
       default = "";
       type = types.lines;
@@ -983,6 +993,10 @@ in
     # Don't bother with certain units in containers.
     systemd.services.systemd-remount-fs.unitConfig.ConditionVirtualization = "!container";
     systemd.services.systemd-random-seed.unitConfig.ConditionVirtualization = "!container";
+
+    boot.kernel.sysctl = mkIf (!cfg.coredump.enable) {
+      "kernel.core_pattern" = "core";
+    };
   };
 
   # FIXME: Remove these eventually.