[PATCH v2 2/2] livepatch: Free klp_{object,func}_ext data after initialization
From: Petr Pavlu <petr.pavlu@suse.com>
Date: 2026-01-21 08:29:20
Also in:
live-patching, lkml
Subsystem:
live patching, module support, objtool, the rest · Maintainers:
Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen, Peter Zijlstra, Linus Torvalds
The klp_object_ext and klp_func_ext data, which are stored in the __klp_objects and __klp_funcs sections, respectively, are not needed after they are used to create the actual klp_object and klp_func instances. This operation is implemented by the init function in scripts/livepatch/init.c. Prefix the two sections with ".init" so they are freed after the module is initializated. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> --- scripts/livepatch/init.c | 2 +- scripts/module.lds.S | 4 ++-- tools/objtool/check.c | 2 +- tools/objtool/include/objtool/klp.h | 10 +++++----- tools/objtool/klp-diff.c | 2 +- 5 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/scripts/livepatch/init.c b/scripts/livepatch/init.c
index a02252e1de03..3e658db5dfe8 100644
--- a/scripts/livepatch/init.c
+++ b/scripts/livepatch/init.c@@ -18,7 +18,7 @@ static int __init livepatch_mod_init(void) unsigned int nr_objs; int ret; - obj_exts = klp_locate_section_objs(THIS_MODULE, "__klp_objects", + obj_exts = klp_locate_section_objs(THIS_MODULE, ".init.klp_objects", sizeof(*obj_exts), &nr_objs); if (!nr_objs) { pr_err("nothing to patch!\n");
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 383d19beffb4..054ef99e8288 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S@@ -34,8 +34,8 @@ SECTIONS { __patchable_function_entries : { *(__patchable_function_entries) } - __klp_funcs 0: ALIGN(8) { KEEP(*(__klp_funcs)) } - __klp_objects 0: ALIGN(8) { KEEP(*(__klp_objects)) } + .init.klp_funcs 0 : ALIGN(8) { KEEP(*(.init.klp_funcs)) } + .init.klp_objects 0 : ALIGN(8) { KEEP(*(.init.klp_objects)) } #ifdef CONFIG_ARCH_USES_CFI_TRAPS __kcfi_traps : { KEEP(*(.kcfi_traps)) }
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3f7999317f4d..933868ee3beb 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c@@ -4761,7 +4761,7 @@ static int validate_ibt(struct objtool_file *file) !strcmp(sec->name, "__bug_table") || !strcmp(sec->name, "__ex_table") || !strcmp(sec->name, "__jump_table") || - !strcmp(sec->name, "__klp_funcs") || + !strcmp(sec->name, ".init.klp_funcs") || !strcmp(sec->name, "__mcount_loc") || !strcmp(sec->name, ".llvm.call-graph-profile") || !strcmp(sec->name, ".llvm_bb_addr_map") ||
diff --git a/tools/objtool/include/objtool/klp.h b/tools/objtool/include/objtool/klp.h
index ad830a7ce55b..e32e5e8bc631 100644
--- a/tools/objtool/include/objtool/klp.h
+++ b/tools/objtool/include/objtool/klp.h@@ -6,12 +6,12 @@ #define SHN_LIVEPATCH 0xff20 /* - * __klp_objects and __klp_funcs are created by klp diff and used by the patch - * module init code to build the klp_patch, klp_object and klp_func structs - * needed by the livepatch API. + * .init.klp_objects and .init.klp_funcs are created by klp diff and used by the + * patch module init code to build the klp_patch, klp_object and klp_func + * structs needed by the livepatch API. */ -#define KLP_OBJECTS_SEC "__klp_objects" -#define KLP_FUNCS_SEC "__klp_funcs" +#define KLP_OBJECTS_SEC ".init.klp_objects" +#define KLP_FUNCS_SEC ".init.klp_funcs" /* * __klp_relocs is an intermediate section which are created by klp diff and
diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
index 4d1f9e9977eb..fd64d5e3c3b6 100644
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c@@ -1439,7 +1439,7 @@ static int clone_special_sections(struct elfs *e) } /* - * Create __klp_objects and __klp_funcs sections which are intermediate + * Create .init.klp_objects and .init.klp_funcs sections which are intermediate * sections provided as input to the patch module's init code for building the * klp_patch, klp_object and klp_func structs for the livepatch API. */
--
2.52.0