bpf: Increase size of BTF_ID_LIST without CONFIG_DEBUG_INFO_BTF again

After commit 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr"),
clang builds without CONFIG_DEBUG_INFO_BTF warn:

  kernel/bpf/verifier.c:10298:24: warning: array index 16 is past the end of the array (that has type 'u32[16]' (aka 'unsigned int[16]')) [-Warray-bounds]
                                     meta.func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) {
                                                     ^                  ~~~~~~~~~~~~~~~~~~~~~~~~
  kernel/bpf/verifier.c:9150:1: note: array 'special_kfunc_list' declared here
  BTF_ID_LIST(special_kfunc_list)
  ^
  include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
  #define BTF_ID_LIST(name) static u32 __maybe_unused name[16];
                            ^
  1 warning generated.

A warning of this nature was previously addressed by
commit beb3d47d1d3d ("bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set")
but there have been new kfuncs added since then.

Quadruple the size of the CONFIG_DEBUG_INFO_BTF=n definition so that
this problem is unlikely to show up for some time.

Link: https://github.com/ClangBuiltLinux/linux/issues/1810
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230307-bpf-kfuncs-warray-bounds-v1-1-00ad3191f3a6@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 3a4f7cd..00950cc 100644 (file)
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -204,7 +204,7 @@ extern struct btf_id_set8 name;
 
 #else
 
-#define BTF_ID_LIST(name) static u32 __maybe_unused name[16];
+#define BTF_ID_LIST(name) static u32 __maybe_unused name[64];
 #define BTF_ID(prefix, name)
 #define BTF_ID_FLAGS(prefix, name, ...)
 #define BTF_ID_UNUSED