livepatch: function,sympos scheme in livepatch sysfs directory

The following directory structure will allow for cases when the same
function name exists in a single object.
	/sys/kernel/livepatch/<patch>/<object>/<function,sympos>

The sympos number corresponds to the nth occurrence of the symbol name in
kallsyms for the patched object.

An example of patching multiple symbols can be found here:
	https://github.com/dynup/kpatch/issues/493

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Chris J Arges 2015-12-01 20:40:56 -06:00 committed by Jiri Kosina
parent 064c89df62
commit 444f9e99a8
2 changed files with 13 additions and 3 deletions

View File

@ -33,7 +33,7 @@ Description:
The object directory contains subdirectories for each function
that is patched within the object.
What: /sys/kernel/livepatch/<patch>/<object>/<function>
What: /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
Date: Nov 2014
KernelVersion: 3.19.0
Contact: live-patching@vger.kernel.org
@ -41,4 +41,8 @@ Description:
The function directory contains attributes regarding the
properties and state of the patched function.
The directory name contains the patched function name and a
sympos number corresponding to the nth occurrence of the symbol
name in kallsyms for the patched object.
There are currently no such attributes.

View File

@ -535,7 +535,7 @@ EXPORT_SYMBOL_GPL(klp_enable_patch);
* /sys/kernel/livepatch/<patch>
* /sys/kernel/livepatch/<patch>/enabled
* /sys/kernel/livepatch/<patch>/<object>
* /sys/kernel/livepatch/<patch>/<object>/<func>
* /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
*/
static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr,
@ -680,8 +680,14 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
INIT_LIST_HEAD(&func->stack_node);
func->state = KLP_DISABLED;
/* The format for the sysfs directory is <function,sympos> where sympos
* is the nth occurrence of this symbol in kallsyms for the patched
* object. If the user selects 0 for old_sympos, then 1 will be used
* since a unique symbol will be the first occurrence.
*/
return kobject_init_and_add(&func->kobj, &klp_ktype_func,
&obj->kobj, "%s", func->old_name);
&obj->kobj, "%s,%lu", func->old_name,
func->old_sympos ? func->old_sympos : 1);
}
/* parts of the initialization that is done only when the object is loaded */