From 5e214f2e43e453d862ebbbd2a4f7ee3fe650f209 Mon Sep 17 00:00:00 2001 From: Connor O'Brien Date: Wed, 23 Feb 2022 01:28:14 +0000 Subject: bpf: Add config to allow loading modules with BTF mismatches MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BTF mismatch can occur for a separately-built module even when the ABI is otherwise compatible and nothing else would prevent successfully loading. Add a new Kconfig to control how mismatches are handled. By default, preserve the current behavior of refusing to load the module. If MODULE_ALLOW_BTF_MISMATCH is enabled, load the module but ignore its BTF information. Suggested-by: Yonghong Song Suggested-by: Michal Suchánek Signed-off-by: Connor O'Brien Signed-off-by: Daniel Borkmann Acked-by: Shung-Hsi Yu Acked-by: Song Liu Link: https://lore.kernel.org/bpf/CAADnVQJ+OVPnBz8z3vNu8gKXX42jCUqfuvhWAyCQDu8N_yqqwQ@mail.gmail.com Link: https://lore.kernel.org/bpf/20220223012814.1898677-1-connoro@google.com --- kernel/bpf/btf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 0890e56e8b08..b472cf0c8fdb 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6398,7 +6398,8 @@ static int btf_module_notify(struct notifier_block *nb, unsigned long op, pr_warn("failed to validate module [%s] BTF: %ld\n", mod->name, PTR_ERR(btf)); kfree(btf_mod); - err = PTR_ERR(btf); + if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) + err = PTR_ERR(btf); goto out; } err = btf_alloc_id(btf); -- cgit v1.2.3-59-g8ed1b