kernel_test: add a VTS test to ensure that the kernel has efficient u…

…naligned access. This is a requirement for some of our bpf code to load correctly. Discovered by running (a new test of NetBpfLoad I'm developing) on x86_64 UML (user mode Linux - via the net/test framework). UML doesn't have this feature, most likely it erroneously fails to inherit it from the host architecture. Both aarch64 & x86 support it of course. Test: TreeHugger Signed-off-by: Maciej Żenczykowski <[email protected]> Change-Id: Id4e27df208f9b6f6089f627baa84642e0da64c05
GrapheneOS · Aug 22, 2024 · 997e3b3 · 997e3b3
1 parent 6121465
commit 997e3b3
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/tests/kernel_test.cpp b/tests/kernel_test.cpp
@@ -88,6 +88,13 @@ TEST(KernelTest, TestBpfJitAlwaysOn) {
     ASSERT_TRUE(configVerifier.hasOption("CONFIG_BPF_JIT_ALWAYS_ON"));
 }
 
+TEST(KernelTest, TestHaveEfficientUnalignedAccess) {
+    // Turns out the bpf verifier is stricter if you don't have this option.
+    // At least *some* of our bpf code fails to verify without it.
+    KernelConfigVerifier configVerifier;
+    ASSERT_TRUE(configVerifier.hasOption("CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS"));
+}
+
 /* Android 14/U should only launch on 64-bit kernels
  *   T launches on 5.10/5.15
  *   U launches on 5.15/6.1