[PATCH 3/3 v8] livepatch: function,sympos scheme in livepatch sysfs directory
From: Chris J Arges <hidden>
Date: 2015-11-20 17:25:58
Also in:
lkml
Subsystem:
live patching, the rest · Maintainers:
Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Linus Torvalds
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 <redacted> --- Documentation/ABI/testing/sysfs-kernel-livepatch | 6 +++++- kernel/livepatch/core.c | 10 ++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-kernel-livepatch b/Documentation/ABI/testing/sysfs-kernel-livepatch
index 5bf42a8..da87f43 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,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.
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index c9f924e..0e86c45 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c@@ -534,7 +534,7 @@ 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,
@@ -679,8 +679,14 @@ 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 */
--
1.9.1