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authorChris J Arges <chris.j.arges@canonical.com>2015-12-01 20:40:56 -0600
committerJiri Kosina <jkosina@suse.cz>2015-12-03 23:01:27 +0100
commit444f9e99a840c4050c0530cfef81801a21a59f4c (patch)
tree72d000288180fa3d6312965110a26ea3b06fa09e /kernel/livepatch
parent064c89df6247cd829a7880cc8a87b7ed2cdfccd8 (diff)
downloadlinux-444f9e99a840c4050c0530cfef81801a21a59f4c.tar.gz
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>
Diffstat (limited to 'kernel/livepatch')
-rw-r--r--kernel/livepatch/core.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index e842534d3493..94893e844e44 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -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 */