commit 4782ab1b9ec630454c1020a1c6ae33c6c896f0bd
author Maciej Żenczykowski <maze@google.com> Sat May 20 23:11:52 2023 +0000
committer Maciej Żenczykowski <maze@google.com> Sun May 21 02:33:55 2023 +0000
tree c5ad3866dd179a4bad101cc8b11b086ade0123b0
parent 1c4ba307f408dec01e2acec3db0a38f237d1e7e9

KernelUtils.h: explicitly do not support x32

x86 has 2 obvious ABIs:
32-bit registers/pointers/system calls (i386/i486/i586/i686)
64-bit registers/pointers/system calls (amd64 / x86_64)

but there also exists a third:
the memory optimizing hybrid 'x32' which uses 64-bit registers,
with 32-bit pointers, and 64-bit system calls (with minor tweaks).

(there is also technically an aarch64/arm64-ilp32 ABI mirroring x32)

Note: It would probably be trivial to add support if we wanted to.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I82138c5bafbc3bd37cad98eeb79441701d94c386

staticlibs/native/bpf_headers/include/bpf/KernelUtils.h

diff --git a/staticlibs/native/bpf_headers/include/bpf/KernelUtils.h b/staticlibs/native/bpf_headers/include/bpf/KernelUtils.h
index b3dd86c..769ec4b 100644
--- a/staticlibs/native/bpf_headers/include/bpf/KernelUtils.h
+++ b/staticlibs/native/bpf_headers/include/bpf/KernelUtils.h
@@ -119,7 +119,11 @@
 }
 
 static constexpr bool isArm() {
-#if defined(__arm__) || defined(__aarch64__)
+#if defined(__arm__)
+    static_assert(isUserspace32bit(), "huh? arm must be 32 bit");
+    return true;
+#elif defined(__aarch64__)
+    static_assert(isUserspace64bit(), "aarch64 must be LP64 - no support for ILP32");
     return true;
 #else
     return false;
@@ -127,7 +131,11 @@
 }
 
 static constexpr bool isX86() {
-#if defined(__i386__) || defined(__x86_64__)
+#if defined(__i386__)
+    static_assert(isUserspace32bit(), "huh? i386 must be 32 bit");
+    return true;
+#elif defined(__x86_64__)
+    static_assert(isUserspace64bit(), "x86_64 must be LP64 - no support for ILP32 (x32)");
     return true;
 #else
     return false;