[PATCH] bpf: extend btf id list

From: Tom Rix
Date: Tue Mar 07 2023 - 10:18:10 EST


With clang and W=1, there is this error

kernel/bpf/verifier.c:10298:24: error: array index 16 is past
the end of the array (that has type 'u32[16]'
(aka 'unsigned int[16]')) [-Werror,-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];

When KF_bpf_dynptr_slice_rdwr was added to the enum special_kfunc_type
the total exceeded 16. Increase the array size to 32.

Fixes: 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr")
Signed-off-by: Tom Rix <trix@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..166c387b48f7 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[32];
#define BTF_ID(prefix, name)
#define BTF_ID_FLAGS(prefix, name, ...)
#define BTF_ID_UNUSED
--
2.27.0