commit e7a621f8e9801d13b9a0506a103024a9971f512e · pyrox.dev/nixpkgs

+13

nixos/modules/programs/wayland/sway.nix

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             <https://github.com/swaywm/sway/wiki> and

     

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             "man 5 sway" for more information'');

     

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       +
           enableRealtime = mkEnableOption (lib.mdDoc ''

     

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             add CAP_SYS_NICE capability on `sway` binary for realtime scheduling

     

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             privileges. This may improve latency and reduce stuttering, specially in

     

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             high load scenarios'') // { default = true; };

     

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           package = mkOption {

     

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             type = with types; nullOr package;

     

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             default = defaultSwayPackage;

     
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                   '';

     

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                 } // optionalAttrs (cfg.package != null) {

     

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                   "sway/config".source = mkOptionDefault "${cfg.package}/etc/sway/config";

     

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                 };

     

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               };

     

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               security.wrappers = mkIf (cfg.enableRealtime && cfg.package != null) {

     

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                 sway = {

     

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                   owner = "root";

     

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                   group = "root";

     

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                   source = "${cfg.package}/bin/sway";

     

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                   capabilities = "cap_sys_nice+ep";

     

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                 };

     

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               };

     

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               # To make a Sway session available if a display manager like SDDM is enabled:

pkgs/applications/window-managers/sway/default.nix

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           # Use /run/current-system/sw/share and /etc instead of /nix/store

     

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           # references:

     

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           ./sway-config-nixos-paths.patch

     

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           # Drop ambient capabilities after getting SCHED_RR

     

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           ./drop_ambient_capabilities.patch

     

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         ];

     

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         strictDeps = true;

+41

pkgs/applications/window-managers/sway/drop_ambient_capabilities.patch

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       From e7d9098e81289ae99d07ec3eac1fec1d303b8fe4 Mon Sep 17 00:00:00 2001

     

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       From: Thiago Kenji Okada <thiagokokada@gmail.com>

     

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       Date: Thu, 5 Oct 2023 15:23:35 +0100

     

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       Subject: [PATCH] drop ambient capabilities

     

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       Within NixOS the only possibility to gain cap_sys_nice is using the

     

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       security.wrapper infrastructure. However to pass the capabilities to the

     

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       wrapped program, they are raised to the ambient set. To fix this we make

     

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       sure to drop the ambient capabilities during sway startup and realtime

     

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       setup. Otherwise all programs started by sway also gain cap_sys_nice,

     

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       which is not something we want.

     

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       Co-authored-by: Rouven Czerwinski <rouven@czerwinskis.de>

     

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       ---

     

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        sway/realtime.c | 3 +++

     

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        1 file changed, 3 insertions(+)

     

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       diff --git a/sway/realtime.c b/sway/realtime.c

     

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       index 11154af0..06f872a8 100644

     

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       --- a/sway/realtime.c

     

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       +++ b/sway/realtime.c

     

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       @@ -3,6 +3,7 @@

     

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        #include <unistd.h>

     

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        #include <pthread.h>

     

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        #include "sway/server.h"

     

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       +#include "sys/prctl.h"

     

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        #include "log.h"

     

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        static void child_fork_callback(void) {

     

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       @@ -10,6 +11,8 @@ static void child_fork_callback(void) {

     

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        	param.sched_priority = 0;

     

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       +	prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);

     

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       +

     

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        	int ret = pthread_setschedparam(pthread_self(), SCHED_OTHER, &param);

     

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        	if (ret != 0) {

     

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        		sway_log(SWAY_ERROR, "Failed to reset scheduler policy on fork");

     

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       -- 

     

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       2.42.0

     

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