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@xxxxxxxxxx>
---
include/linux/btf_ids.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 3a4f7cd882ca..00950cc03bff 100644
--- 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
---
base-commit: 36e5e391a25af28dc1f4586f95d577b38ff4ed72
change-id: 20230307-bpf-kfuncs-warray-bounds-c2040e8ee7ee
Best regards,
--
Nathan Chancellor <nathan@xxxxxxxxxx>
