Messages in this thread | | | Date | Tue, 18 Nov 2014 15:45:22 +0100 (CET) | From | Miroslav Benes <> | Subject | Re: [PATCHv2 2/3] kernel: add support for live patching |
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On Sun, 16 Nov 2014, Seth Jennings wrote:
[...]
> diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h > new file mode 100644 > index 0000000..8b68fef > --- /dev/null > +++ b/include/linux/livepatch.h > @@ -0,0 +1,68 @@ > +/* > + * livepatch.h - Live Kernel Patching Core > + * > + * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com> > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * as published by the Free Software Foundation; either version 2 > + * of the License, or (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, see <http://www.gnu.org/licenses/>. > + */ > + > +#ifndef _LINUX_LIVEPATCH_H_ > +#define _LINUX_LIVEPATCH_H_ > + > +#include <linux/module.h> > +
I think we need something like
#if IS_ENABLED(CONFIG_LIVE_PATCHING)
here. Otherwise kernel module with live patch itself would be built even with live patching support disabled (as the structures and needed functions are declared).
> +/* TODO: add kernel-doc for structures once agreed upon */ > + > +struct lp_func { > + const char *old_name; /* function to be patched */ > + void *new_func; /* replacement function in patch module */ > + /* > + * The old_addr field is optional and can be used to resolve > + * duplicate symbol names in the vmlinux object. If this > + * information is not present, the symbol is located by name > + * with kallsyms. If the name is not unique and old_addr is > + * not provided, the patch application fails as there is no > + * way to resolve the ambiguity. > + */ > + unsigned long old_addr; > +}; > + > +struct lp_reloc { > + unsigned long dest; > + unsigned long src; > + unsigned long type; > + const char *name; > + int addend; > + int external; > +}; > + > +struct lp_object { > + const char *name; /* "vmlinux" or module name */ > + struct lp_func *funcs; > + struct lp_reloc *relocs; > +}; > + > +struct lp_patch { > + struct module *mod; /* module containing the patch */ > + struct lp_object *objs; > +}; > + > +int lp_register_patch(struct lp_patch *); > +int lp_unregister_patch(struct lp_patch *); > +int lp_enable_patch(struct lp_patch *); > +int lp_disable_patch(struct lp_patch *); > + > +#include <asm/livepatch.h>
and #endif for CONFIG_LIVE_PATCHING here.
> + > +#endif /* _LINUX_LIVEPATCH_H_ */
Thanks, -- Miroslav Benes SUSE Labs
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