Bump kernel recommended baseline to v5.4

diff --git a/NEWS b/NEWS
index 47cd6ad45ddd940492b42a121ff6e79a6ce60f14..321750b7e114ea10b0b0b82586f049a52dfcd5ea 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -47,6 +47,12 @@ CHANGES WITH 257 in spe:
           migrated between cgroups. It might be fully removed in a future release
           (reach out if you have use cases).
 
+        * The recommended kernel baseline version has been bumped to v5.4
+          (released in 2019). Expect limited testing on older kernel versions,
+          where "old-kernel" taint flag would also be set. Support for them
+          will be phased out in a future release in 2025, i.e. we expect to bump
+          the minimum baseline to v5.4 then too.
+
         * Support for cgroup v1 ('legacy' and 'hybrid' hierarchies) is now
           considered obsolete and systemd by default will refuse to boot under
           it. To forcibly reenable cgroup v1 support,

diff --git a/README b/README
index 7c7bbaf0701517b977ed73648d9e85b337935fb7..9b84bf7e7ae4e6c304c17e75d48ab8ae74a2e13f 100644 (file)
--- a/README
+++ b/README
@@ -39,16 +39,16 @@ REQUIREMENTS:
                      ≥ 4.17 for cgroup-bpf socket address hooks
                      ≥ 4.20 for PSI (used by systemd-oomd)
                      ≥ 5.3 for bounded loops in BPF program
-                     ≥ 5.4 for signed Verity images
-                     ≥ 5.7 for BPF links and the BPF LSM hook
+                     ≥ 5.4 for pidfd and signed Verity images
+                     ≥ 5.7 for CLONE_INTO_CGROUP, BPF links and the BPF LSM hook
 
         ⛔ Kernel versions below 3.15 ("minimum baseline") are not supported at
         all, and are missing required functionality (e.g. CLOCK_BOOTTIME
         support for timerfd_create()).
 
-        ⚠️ Kernel versions below 4.15 ("recommended baseline") have significant
+        ⚠️ Kernel versions below 5.4 ("recommended baseline") have significant
         gaps in functionality and are not recommended for use with this version
-        of systemd (e.g. lack sufficiently comprehensive and working cgroupv2
+        of systemd (e.g. lack race-free process tracking by pidfd and new mount API
         support). Taint flag 'old-kernel' will be set. systemd will most likely
         still function, but upstream support and testing are limited.
 

diff --git a/src/basic/constants.h b/src/basic/constants.h
index e70817c51f8467843a33ab9d2a50d701f06aa0e2..5aaf8f535c2203213ce5eab36bcfe2abec8c385c 100644 (file)
--- a/src/basic/constants.h
+++ b/src/basic/constants.h
@@ -85,4 +85,4 @@
 /* Path where systemd-oomd listens for varlink connections from user managers to report changes in ManagedOOM settings. */
 #define VARLINK_ADDR_PATH_MANAGED_OOM_USER "/run/systemd/oom/io.systemd.ManagedOOM"
 
-#define KERNEL_BASELINE_VERSION "4.15"
+#define KERNEL_BASELINE_VERSION "5.4"