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 patching multiple symbols can be found here:
https://github.com/dynup/kpatch/issues/493
Signed-off-by: Chris J Arges <[email protected]>
---
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..21b6bc1 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: [email protected]
@@ -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
+ 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 4eb8691..ed2cbbf 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -542,7 +542,7 @@ 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,
@@ -687,8 +687,14 @@ 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 <func,number> where number is
+ * the occurrence of this symbol in kallsyms. 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
On Wed, Nov 11, 2015 at 10:29:01AM -0600, Chris J Arges wrote:
> 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 patching multiple symbols can be found here:
> https://github.com/dynup/kpatch/issues/493
Instead of 'function,number' here and everywhere else, maybe
'function,sympos' would be a little clearer.
Also, s/old_name/function/ in the patch subject to be consistent.
> Signed-off-by: Chris J Arges <[email protected]>
> ---
> 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..21b6bc1 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: [email protected]
> @@ -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
> + 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 4eb8691..ed2cbbf 100644
> --- a/kernel/livepatch/core.c
> +++ b/kernel/livepatch/core.c
> @@ -542,7 +542,7 @@ 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,
> @@ -687,8 +687,14 @@ 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 <func,number> where number is
> + * the occurrence of this symbol in kallsyms. If the user selects 0 for
... of this symbol in kallsyms *for the patched object*.
> + * 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
--
Josh