Hi,
I would change the subject to something like
"livepatch: Add "stack_order" sysfs attribute"
to keep it somehow consistent with what we have there so far.
On Wed, 25 Sep 2024, Wardenjohn wrote:
> This feature can provide livepatch patch order information.
> With the order of sysfs interface of one klp_patch, we can
> use patch order to find out which function of the patch is
> now activate.
>
> After the discussion, we decided that patch-level sysfs
> interface is the only accaptable way to introduce this
> information.
>
> This feature is like:
> cat /sys/kernel/livepatch/livepatch_1/stack_order -> 1
> means this livepatch_1 module is the 1st klp patch applied.
>
> cat /sys/kernel/livepatch/livepatch_module/stack_order -> N
> means this lviepatch_module is the Nth klp patch applied
> to the system.
Perhaps something like
"
Add "stack_order" sysfs attribute which holds the order in which a live
patch module was loaded into the system. A user can then determine an
active live patched version of a function.
cat /sys/kernel/livepatch/livepatch_1/stack_order -> 1
means that livepatch_1 is the first live patch applied
cat /sys/kernel/livepatch/livepatch_module/stack_order -> N
means that livepatch_module is the Nth live patch applied
"
?
> Suggested-by: Petr Mladek <pmladek@xxxxxxxx>
> Suggested-by: Miroslav Benes <mbenes@xxxxxxx>
> Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Signed-off-by: Wardenjohn <zhangwarden@xxxxxxxxx>
How do you prepare your patches?
"---" delimiter is missing here.
> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
> index ecbc9b6aba3a..914b7cabf8fe 100644
> --- a/kernel/livepatch/core.c
> +++ b/kernel/livepatch/core.c
> @@ -346,6 +346,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
> * /sys/kernel/livepatch/<patch>/enabled
> * /sys/kernel/livepatch/<patch>/transition
> * /sys/kernel/livepatch/<patch>/force
> + * /sys/kernel/livepatch/<patch>/stack_order
> * /sys/kernel/livepatch/<patch>/<object>
> * /sys/kernel/livepatch/<patch>/<object>/patched
> * /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
> @@ -443,13 +444,37 @@ static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
> return count;
> }
>
> +static ssize_t stack_order_show(struct kobject *kobj,
> + struct kobj_attribute *attr, char *buf)
> +{
> + struct klp_patch *patch, *this_patch;
> + int stack_order = 0;
> +
> + this_patch = container_of(kobj, struct klp_patch, kobj);
> +
> + /* make sure the calculate of patch order correct */
The comment is not necessary.
> + mutex_lock(&klp_mutex);
> +
> + klp_for_each_patch(patch) {
> + stack_order++;
> + if (patch == this_patch)
> + break;
> + }
> +
> + mutex_unlock(&klp_mutex);
Please add an empty line before return here.
>+ return sysfs_emit(buf, "%d\n", stack_order);
>+}
Miroslav
