From 7f38c74a532b536c2f8b2e3a948ab1391387adca Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Thu, 16 Jan 2025 15:34:47 +0100
Subject: [PATCH] udev: set clock group for PTP and RTC devices

Add a new group for clock devices to enable applications like linuxptp
to open clocks without root privileges.

(cherry picked from commit af96ccfc24bc4803078a46b4ef2cdeb5decdfbcd)

Resolves: RHEL-113051
---
 README                           | 3 ++-
 meson.build                      | 1 +
 meson_options.txt                | 2 ++
 rules.d/50-udev-default.rules.in | 2 ++
 sysusers.d/basic.conf.in         | 1 +
 5 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/README b/README
index 9b84bf7e7a..b9a58389ad 100644
--- a/README
+++ b/README
@@ -351,7 +351,8 @@ USERS AND GROUPS:
         need to be resolvable by getgrnam() at any time, even in the very early
         boot stages, where no other databases and network are available:
 
-        audio, cdrom, dialout, disk, input, kmem, kvm, lp, render, tape, tty, video
+        audio, cdrom, clock, dialout, disk, input, kmem, kvm, lp, render, tape,
+        tty, video
 
         During runtime, the journal daemon requires the "systemd-journal" system
         group to exist. New journal files will be readable by this group (but
diff --git a/meson.build b/meson.build
index cfb202eb30..873d70f8d3 100644
--- a/meson.build
+++ b/meson.build
@@ -950,6 +950,7 @@ static_ugids = []
 foreach option : ['adm-gid',
                   'audio-gid',
                   'cdrom-gid',
+                  'clock-gid',
                   'dialout-gid',
                   'disk-gid',
                   'input-gid',
diff --git a/meson_options.txt b/meson_options.txt
index f30b3f5238..78b7c5fe30 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -289,6 +289,8 @@ option('audio-gid', type : 'integer', value : 0,
        description : 'soft-static allocation for the "audio" group')
 option('cdrom-gid', type : 'integer', value : 0,
        description : 'soft-static allocation for the "cdrom" group')
+option('clock-gid', type : 'integer', value : 0,
+       description : 'soft-static allocation for the "clock" group')
 option('dialout-gid', type : 'integer', value : 0,
        description : 'soft-static allocation for the "dialout" group')
 option('disk-gid', type : 'integer', value : 0,
diff --git a/rules.d/50-udev-default.rules.in b/rules.d/50-udev-default.rules.in
index 08b2de7047..9264b8e021 100644
--- a/rules.d/50-udev-default.rules.in
+++ b/rules.d/50-udev-default.rules.in
@@ -10,6 +10,7 @@ SUBSYSTEM=="block", KERNEL=="md*", ENV{ID_IGNORE_DISKSEQ}="1"
 
 SUBSYSTEM=="virtio-ports", KERNEL=="vport*", ATTR{name}=="?*", SYMLINK+="virtio-ports/$attr{name}"
 
+SUBSYSTEM=="rtc", GROUP="clock", MODE="0660"
 # select "system RTC" or just use the first one
 SUBSYSTEM=="rtc", ATTR{hctosys}=="1", SYMLINK+="rtc"
 SUBSYSTEM=="rtc", KERNEL=="rtc0", SYMLINK+="rtc", OPTIONS+="link_priority=-100"
@@ -30,6 +31,7 @@ SUBSYSTEM=="pci|usb|platform", IMPORT{builtin}="path_id"
 
 SUBSYSTEM=="net", IMPORT{builtin}="net_driver"
 
+SUBSYSTEM=="ptp", GROUP="clock", MODE="0660"
 SUBSYSTEM=="ptp", ATTR{clock_name}=="KVM virtual PTP", SYMLINK+="ptp_kvm"
 SUBSYSTEM=="ptp", ATTR{clock_name}=="hyperv", SYMLINK+="ptp_hyperv"
 SUBSYSTEM=="ptp", ATTR{clock_name}=="s390 Physical Clock", SYMLINK+="ptp_s390_physical"
diff --git a/sysusers.d/basic.conf.in b/sysusers.d/basic.conf.in
index 992af346ca..baf31cb739 100644
--- a/sysusers.d/basic.conf.in
+++ b/sysusers.d/basic.conf.in
@@ -25,6 +25,7 @@ g utmp    {{UTMP_GID   }}     -            -
 # Physical and virtual hardware access groups
 g audio   {{AUDIO_GID  }}     -            -
 g cdrom   {{CDROM_GID  }}     -            -
+g clock   {{CLOCK_GID  }}     -            -
 g dialout {{DIALOUT_GID}}     -            -
 g disk    {{DISK_GID   }}     -            -
 g input   {{INPUT_GID  }}     -            -