The following directory structure will allow for cases when the same
function name exists in a single object.
/sys/kernel/livepatch/<patch>/<object>/<function.number>
The number corresponds to the nth occurrence of the symbol name in
kallsyms for the patched object.
An example of this issue is documented here:
https://github.com/dynup/kpatch/issues/493
Signed-off-by: Chris J Arges <chris.j.ar...@canonical.com>
---
Documentation/ABI/testing/sysfs-kernel-livepatch | 2 +-
kernel/livepatch/core.c | 45 ++++++++++++++++++++++--
2 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-kernel-livepatch
b/Documentation/ABI/testing/sysfs-kernel-livepatch
index 5bf42a8..dcd36db 100644
--- a/Documentation/ABI/testing/sysfs-kernel-livepatch
+++ b/Documentation/ABI/testing/sysfs-kernel-livepatch
@@ -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.number>
Date: Nov 2014
KernelVersion: 3.19.0
Contact: live-patch...@vger.kernel.org
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 6e53441..6bcf600 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -587,7 +587,7 @@ 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>/<func.number>
*/
static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -727,13 +727,54 @@ static void klp_free_patch(struct klp_patch *patch)
kobject_put(&patch->kobj);
}
+static int klp_get_func_pos_callback(void *data, const char *name,
+ struct module *mod, unsigned long addr)
+{
+ struct klp_find_arg *args = data;
+
+ if ((mod && !args->objname) || (!mod && args->objname))
+ return 0;
+
+ if (strcmp(args->name, name))
+ return 0;
+
+ if (args->objname && strcmp(args->objname, mod->name))
+ return 0;
+
+ /* on address match, return 1 to break kallsyms_on_each_symbol loop */
+ if (args->addr == addr)
+ return 1;
+
+ /* if we don't match addr, count instance of named symbol */
+ args->count++;
+
+ return 0;
+}
+
+static int klp_get_func_pos(struct klp_object *obj, struct klp_func *func)
+{
+ struct klp_find_arg args = {
+ .objname = obj->name,
+ .name = func->old_name,
+ .addr = func->old_addr,
+ .count = 0,
+ };
+
+ mutex_lock(&module_mutex);
+ kallsyms_on_each_symbol(klp_get_func_pos_callback, &args);
+ mutex_unlock(&module_mutex);
+
+ return args.count;
+}
+
static int klp_init_func(struct klp_object *obj, struct klp_func *func)
{
INIT_LIST_HEAD(&func->stack_node);
func->state = KLP_DISABLED;
return kobject_init_and_add(&func->kobj, &klp_ktype_func,
- &obj->kobj, "%s", func->old_name);
+ &obj->kobj, "%s,%d", func->old_name,
+ klp_get_func_pos(obj, func));
}
/* parts of the initialization that is done only when the object is loaded */
--
1.9.1
--
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