commit 004dad9a6a167a501467409a6c9bce7092a29781
author Alexander Potapenko <glider@google.com> Wed Sep 29 12:14:35 2021 +0000
committer Android Build Coastguard Worker <android-build-coastguard-worker@google.com> Sat Dec 25 00:35:08 2021 +0000
tree 62b50aeb7db333b5494ce8f2e94318e6d8898b17
parent 1d37c4499249b17f143df12cebc5ee9ea3600ce3

init: introduce ro.kernel.version property

This property will hold the major.minor part of the kernel version (e.g. "5.4"), allowing init scripts to act depending on that version, enabling and disabling certain features.

Bug: 194156700
Test: manual on a Pixel device
Signed-off-by: Alexander Potapenko <glider@google.com>
Merged-In: Icec640b8a7150b344d9aa3bc0bdbcdae050c7c45
Change-Id: I5af411e39da600e5e0f6703f3a2a4930d509e29d
(cherry picked from commit 1c496e94e0b7fb4425d05b6b9764700842723dfd)
Merged-In:I5af411e39da600e5e0f6703f3a2a4930d509e29d

init/init.cpp

diff --git a/init/init.cpp b/init/init.cpp
index a7325ca..942feb9 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -27,6 +27,7 @@
 #include <sys/mount.h>
 #include <sys/signalfd.h>
 #include <sys/types.h>
+#include <sys/utsname.h>
 #include <unistd.h>
 
 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
@@ -554,6 +555,19 @@
     }
 }
 
+/// Set ro.kernel.version property to contain the major.minor pair as returned
+/// by uname(2).
+static void SetKernelVersion() {
+    struct utsname uts;
+    unsigned int major, minor;
+
+    if ((uname(&uts) != 0) || (sscanf(uts.release, "%u.%u", &major, &minor) != 2)) {
+        LOG(ERROR) << "Could not parse the kernel version from uname";
+        return;
+    }
+    SetProperty("ro.kernel.version", android::base::StringPrintf("%u.%u", major, minor));
+}
+
 static void HandleSigtermSignal(const signalfd_siginfo& siginfo) {
     if (siginfo.ssi_pid != 0) {
         // Drop any userspace SIGTERM requests.
@@ -824,6 +838,7 @@
     export_oem_lock_status();
     MountHandler mount_handler(&epoll);
     SetUsbController();
+    SetKernelVersion();
 
     const BuiltinFunctionMap& function_map = GetBuiltinFunctionMap();
     Action::set_function_map(&function_map);