cap_sys_nice, set caps on gsr-kms-server and gpu-screen-recorder

2 files changed, 18 insertions, 1 deletions

diff --git a/install.sh b/install.sh
index fe0ab2c..983aaf7 100755
--- a/install.sh
+++ b/install.sh
@@ -9,6 +9,8 @@ cd "$script_dir"
 strip gsr-kms-server
 strip gpu-screen-recorder
 rm -f "/usr/local/bin/gpu-screen-recorder"
+setcap cap_sys_admin+ep gsr-kms-server
+setcap cap_sys_nice+ep gpu-screen-recorder
 install -Dm755 "gsr-kms-server" "/usr/bin/gsr-kms-server"
 install -Dm755 "gpu-screen-recorder" "/usr/bin/gpu-screen-recorder"
 
diff --git a/src/egl.c b/src/egl.c
index 2875f88..00a5b22 100644
--- a/src/egl.c
+++ b/src/egl.c
@@ -10,6 +10,7 @@
 #include <wayland-egl.h>
 #include "../external/wlr-export-dmabuf-unstable-v1-client-protocol.h"
 #include <unistd.h>
+#include <sys/capability.h>
 
 // Move this shit to a separate wayland file, and have a separate file for x11.
 
@@ -206,6 +207,18 @@ static gsr_wayland_output* get_wayland_output_by_name(gsr_egl *egl, const char *
     return NULL;
 }
 
+static void reset_cap_nice(void) {
+    cap_t caps = cap_get_proc();
+    if(!caps)
+        return;
+
+    const cap_value_t cap_to_remove = CAP_SYS_NICE;
+    cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_to_remove, CAP_CLEAR);
+    cap_set_flag(caps, CAP_PERMITTED, 1, &cap_to_remove, CAP_CLEAR);
+    cap_set_proc(caps);
+    cap_free(caps);
+}
+
 // TODO: Create egl context without surface (in other words, x11/wayland agnostic, doesn't require x11/wayland dependency)
 static bool gsr_egl_create_window(gsr_egl *self, bool wayland) {
     EGLConfig  ecfg;
@@ -219,7 +232,7 @@ static bool gsr_egl_create_window(gsr_egl *self, bool wayland) {
 
     const int32_t ctxattr[] = {
         EGL_CONTEXT_CLIENT_VERSION, 2,
-        EGL_CONTEXT_PRIORITY_LEVEL_IMG, EGL_CONTEXT_PRIORITY_HIGH_IMG,
+        EGL_CONTEXT_PRIORITY_LEVEL_IMG, EGL_CONTEXT_PRIORITY_HIGH_IMG, /* requires cap_sys_nice, ignored otherwise */
         EGL_NONE, EGL_NONE
     };
 
@@ -294,9 +307,11 @@ static bool gsr_egl_create_window(gsr_egl *self, bool wayland) {
         goto fail;
     }
 
+    reset_cap_nice();
     return true;
 
     fail:
+    reset_cap_nice();
     gsr_egl_unload(self);
     return false;
 }