bpf: Add config to allow loading modules with BTF mismatches

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.

Connor O'Brien committed 4 years ago

Commit 5e214f21 parent dda75962 files · +12 −1Browse files

Showing the changes to kernel (1 of 2 files). Show all

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kernel/bpf/btf.c+2−1

@@ -6398,7 +6398,8 @@ static int btf_module_notify(struct notifier_block *nb, unsigned long op, · 6397 unmodified lines
6398	6398	pr_warn("failed to validate module [%s] BTF: %ld\n",
6399	6399	mod->name, PTR_ERR(btf));
6400	6400	kfree(btf_mod);
6401		− err = PTR_ERR(btf);
	6401	+ if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
	6402	+ err = PTR_ERR(btf);
6402	6403	goto out;
6403	6404	}
6404	6405	err = btf_alloc_id(btf);