When compiling the BPF selftests with Clang versions that do not support the addr_space_cast builtin, the build fails with assembly errors in "verifier_ldsx.c" [1].
The root cause is that the inline assembly using addr_space_cast is being processed by a compiler that lacks this feature. To resolve this, wrap the affected code sections (specifically the arena_ldsx_* test functions) with #if defined(__BPF_FEATURE_ADDR_SPACE_CAST). This ensures the code is only compiled when the Clang supports the necessary feature, preventing build failures on older or incompatible compiler versions.
This change maintains test coverage for systems with support while allowing the tests to build successfully in all environments.
[1]: root:tools/testing/selftests/bpf$ make
CLNG-BPF [test_progs] verifier_ldsx.bpf.o progs/verifier_ldsx.c:322:2: error: invalid operand for instruction 322 | "r1 = %[arena] ll;" | ^ <inline asm>:1:52: note: instantiated into assembly here 1 | r1 = arena ll;r0 = 0xdeadbeef;r0 = addr_space_cast(r0,... | ^
Fixes: f61654912404 ("selftests: bpf: Add tests for signed loads from arena") Signed-off-by: Jiayuan Chen jiayuan.chen@linux.dev --- tools/testing/selftests/bpf/progs/verifier_ldsx.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c index c8494b682c31..cefa02e417d3 100644 --- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c @@ -263,6 +263,7 @@ __naked void ldsx_ctx_8(void) : __clobber_all); }
+#if defined(__BPF_FEATURE_ADDR_SPACE_CAST) SEC("syscall") __description("Arena LDSX Disasm") __success @@ -425,6 +426,7 @@ __naked void arena_ldsx_s32(void *ctx) : __clobber_all ); } +#endif
/* to retain debug info for BTF generation */ void kfunc_root(void)