commit 1c2187ace9adf41e3c0886866915bb83d1b87a02
author Maciej Żenczykowski <maze@google.com> Tue Sep 03 16:03:45 2024 -0700
committer Maciej Żenczykowski <maze@google.com> Tue Sep 03 23:43:24 2024 +0000
tree 97b37a8ef7d47e9b2b60c4a9576fdf3fde5b4ea0
parent 9b6a994984891aeb6779886bfecefaecd5b97fb5

NetBpfLoad: allow Arm 32-bit userspace with 6.6 kernel uprev

Bug: 329269188
Test: Treehugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iba87f62743f76f532e51f4dbb156054e50d6dd5d

bpf/loader/NetBpfLoad.cpp

diff --git a/bpf/loader/NetBpfLoad.cpp b/bpf/loader/NetBpfLoad.cpp
index 495cbab..04393a0 100644
--- a/bpf/loader/NetBpfLoad.cpp
+++ b/bpf/loader/NetBpfLoad.cpp
@@ -1399,6 +1399,8 @@
     const bool isAtLeastV = (effective_api_level >= __ANDROID_API_V__);
     const bool isAtLeastW = (effective_api_level >  __ANDROID_API_V__);  // TODO: switch to W
 
+    const int first_api_level = base::GetIntProperty("ro.board.first_api_level", effective_api_level);
+
     // last in U QPR2 beta1
     const bool has_platform_bpfloader_rc = exists("/system/etc/init/bpfloader.rc");
     // first in U QPR2 beta~2
@@ -1524,9 +1526,24 @@
      * and 32-bit userspace on 64-bit kernel bpf ringbuffer compatibility is broken.
      */
     if (isUserspace32bit() && isAtLeastKernelVersion(6, 2, 0)) {
-        ALOGE("64-bit userspace required on 6.2+ kernels.");
-        // Stuff won't work reliably, but exempt TVs & Arm Wear devices
-        if (!isTV() && !(isWear() && isArm())) return 1;
+        // Stuff won't work reliably, but...
+        if (isTV()) {
+            // exempt TVs... they don't really need functional advanced networking
+            ALOGW("[TV] 32-bit userspace unsupported on 6.2+ kernels.");
+        } else if (isWear() && isArm()) {
+            // exempt Arm Wear devices (arm32 ABI is far less problematic than x86-32)
+            ALOGW("[Arm Wear] 32-bit userspace unsupported on 6.2+ kernels.");
+        } else if (first_api_level <= __ANDROID_API_T__ && isArm()) {
+            // also exempt Arm devices upgrading with major kernel rev from T-
+            // might possibly be better for them to run with a newer kernel...
+            ALOGW("[Arm KernelUpRev] 32-bit userspace unsupported on 6.2+ kernels.");
+        } else if (isArm()) {
+            ALOGE("[Arm] 64-bit userspace required on 6.2+ kernels (%d).", first_api_level);
+            return 1;
+        } else { // x86 since RiscV cannot be 32-bit
+            ALOGE("[x86] 64-bit userspace required on 6.2+ kernels.");
+            return 1;
+        }
     }
 
     // Note: 6.6 is highest version supported by Android V (sdk=35), so this is for sdk=36+