6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ivan Babrou <ivan@xxxxxxxxxxxxxx> [ Upstream commit f4aba3471cfb9ccf69b476463f19b4c50fef6b14 ] LLVM 17 started treating const structs as constants: * https://github.com/llvm/llvm-project/commit/0b2d5b967d98 Combined with pointer laundering via ptr_to_u64, which takes a const ptr, but in reality treats the underlying memory as mutable, this makes clang always pass zero to btf__type_by_id, which breaks full name resolution. Disassembly before (LLVM 16) and after (LLVM 17): - 8b 75 cc mov -0x34(%rbp),%esi - e8 47 8d 02 00 call 3f5b0 <btf__type_by_id> + 31 f6 xor %esi,%esi + e8 a9 8c 02 00 call 3f510 <btf__type_by_id> It's a bigger project to fix this properly (and a question whether LLVM itself should detect this), but for right now let's just fix bpftool. For more information, see this thread in bpf mailing list: * https://lore.kernel.org/bpf/CABWYdi0ymezpYsQsPv7qzpx2fWuTkoD1-wG1eT-9x-TSREFrQg@xxxxxxxxxxxxxx/T/ Fixes: b662000aff84 ("bpftool: Adding support for BTF program names") Signed-off-by: Ivan Babrou <ivan@xxxxxxxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Acked-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx> Link: https://lore.kernel.org/bpf/20240520225149.5517-1-ivan@xxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/bpf/bpftool/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 958e92acca8e2..9b75639434b81 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -410,7 +410,7 @@ void get_prog_full_name(const struct bpf_prog_info *prog_info, int prog_fd, { const char *prog_name = prog_info->name; const struct btf_type *func_type; - const struct bpf_func_info finfo = {}; + struct bpf_func_info finfo = {}; struct bpf_prog_info info = {}; __u32 info_len = sizeof(info); struct btf *prog_btf = NULL; -- 2.43.0
