[PATCH v7 for-next 4/8] livepatch: Deprecate stack_order
From: Yafang Shao <hidden>
Date: 2026-08-25 11:47:20
Subsystem:
live patching, the rest · Maintainers:
Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Linus Torvalds
stack_order is no longer needed for atomic-replace livepatches, as a single function can only be modified by a unique replace_set. Since this livepatch sysfs interface is mainly intended for kernel developers, backward compatibility does not need to be maintained. Signed-off-by: Yafang Shao <redacted> Cc: Wardenjohn <redacted> Acked-by: Song Liu <song@kernel.org> --- .../ABI/removed/sysfs-kernel-livepatch | 16 +++++++++++++ .../ABI/testing/sysfs-kernel-livepatch | 9 ------- kernel/livepatch/core.c | 24 ------------------- 3 files changed, 16 insertions(+), 33 deletions(-) create mode 100644 Documentation/ABI/removed/sysfs-kernel-livepatch
diff --git a/Documentation/ABI/removed/sysfs-kernel-livepatch b/Documentation/ABI/removed/sysfs-kernel-livepatch
new file mode 100644
index 000000000000..fb6ff9c3b43e
--- /dev/null
+++ b/Documentation/ABI/removed/sysfs-kernel-livepatch@@ -0,0 +1,16 @@ +What: /sys/kernel/livepatch/<patch>/replace +Date: Jun 2024 +KernelVersion: 6.11.0 +Contact: live-patching@vger.kernel.org +Description: + An attribute which indicates whether the patch supports + atomic-replace. + +What: /sys/kernel/livepatch/<patch>/stack_order +Date: Jan 2025 +KernelVersion: 6.14.0 +Description: + This attribute specifies the sequence in which live patch modules + are applied to the system. If multiple live patches modify the same + function, the implementation with the biggest 'stack_order' number + is used, unless a transition is currently in progress.
diff --git a/Documentation/ABI/testing/sysfs-kernel-livepatch b/Documentation/ABI/testing/sysfs-kernel-livepatch
index 2588f676deb1..3564b3e4385f 100644
--- a/Documentation/ABI/testing/sysfs-kernel-livepatch
+++ b/Documentation/ABI/testing/sysfs-kernel-livepatch@@ -67,15 +67,6 @@ Description: either this patch's provides id or any id in the obsoletes list will be atomically replaced. -What: /sys/kernel/livepatch/<patch>/stack_order -Date: Jan 2025 -KernelVersion: 6.14.0 -Description: - This attribute specifies the sequence in which live patch modules - are applied to the system. If multiple live patches modify the same - function, the implementation with the biggest 'stack_order' number - is used, unless a transition is currently in progress. - What: /sys/kernel/livepatch/<patch>/<object> Date: Nov 2014 KernelVersion: 3.19.0
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 81e9d7aa1de7..27f3891176dd 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c@@ -352,7 +352,6 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, * /sys/kernel/livepatch/<patch>/force * /sys/kernel/livepatch/<patch>/provides * /sys/kernel/livepatch/<patch>/obsoletes - * /sys/kernel/livepatch/<patch>/stack_order * /sys/kernel/livepatch/<patch>/<object> * /sys/kernel/livepatch/<patch>/<object>/patched * /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
@@ -477,40 +476,17 @@ static ssize_t obsoletes_show(struct kobject *kobj, return len; } -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); - - mutex_lock(&klp_mutex); - - klp_for_each_patch(patch) { - stack_order++; - if (patch == this_patch) - break; - } - - mutex_unlock(&klp_mutex); - - return sysfs_emit(buf, "%d\n", stack_order); -} - static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled); static struct kobj_attribute transition_kobj_attr = __ATTR_RO(transition); static struct kobj_attribute force_kobj_attr = __ATTR_WO(force); static struct kobj_attribute provides_kobj_attr = __ATTR_RO(provides); static struct kobj_attribute obsoletes_kobj_attr = __ATTR_RO(obsoletes); -static struct kobj_attribute stack_order_kobj_attr = __ATTR_RO(stack_order); static struct attribute *klp_patch_attrs[] = { &enabled_kobj_attr.attr, &transition_kobj_attr.attr, &force_kobj_attr.attr, &provides_kobj_attr.attr, &obsoletes_kobj_attr.attr, - &stack_order_kobj_attr.attr, NULL }; ATTRIBUTE_GROUPS(klp_patch);
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2.52.0