From ab10815472fcbc2c772dc21a979460b7f74f0145 Mon Sep 17 00:00:00 2001 From: Petr Pavlu Date: Fri, 23 Jan 2026 11:26:56 +0100 Subject: livepatch: Fix having __klp_objects relics in non-livepatch modules The linker script scripts/module.lds.S specifies that all input __klp_objects sections should be consolidated into an output section of the same name, and start/stop symbols should be created to enable scripts/livepatch/init.c to locate this data. This start/stop pattern is not ideal for modules because the symbols are created even if no __klp_objects input sections are present. Consequently, a dummy __klp_objects section also appears in the resulting module. This unnecessarily pollutes non-livepatch modules. Instead, since modules are relocatable files, the usual method for locating consolidated data in a module is to read its section table. This approach avoids the aforementioned problem. The klp_modinfo already stores a copy of the entire section table with the final addresses. Introduce a helper function that scripts/livepatch/init.c can call to obtain the location of the __klp_objects section from this data. Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files") Signed-off-by: Petr Pavlu Acked-by: Joe Lawrence Acked-by: Miroslav Benes Reviewed-by: Aaron Tomlin Link: https://patch.msgid.link/20260123102825.3521961-2-petr.pavlu@suse.com Signed-off-by: Josh Poimboeuf --- kernel/livepatch/core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'kernel/livepatch') diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 9917756dae46..1acbad2dbfdf 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -1356,6 +1356,25 @@ void klp_module_going(struct module *mod) mutex_unlock(&klp_mutex); } +void *klp_find_section_by_name(const struct module *mod, const char *name, + size_t *sec_size) +{ + struct klp_modinfo *info = mod->klp_info; + + for (int i = 1; i < info->hdr.e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + + if (!strcmp(info->secstrings + shdr->sh_name, name)) { + *sec_size = shdr->sh_size; + return (void *)shdr->sh_addr; + } + } + + *sec_size = 0; + return NULL; +} +EXPORT_SYMBOL_GPL(klp_find_section_by_name); + static int __init klp_init(void) { klp_root_kobj = kobject_create_and_add("livepatch", kernel_kobj); -- cgit v1.2.3 From 69050f8d6d075dc01af7a5f2f550a8067510366f Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 20 Feb 2026 23:49:23 -0800 Subject: treewide: Replace kmalloc with kmalloc_obj for non-scalar types This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook --- kernel/livepatch/core.c | 4 ++-- kernel/livepatch/patch.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/livepatch') diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 1acbad2dbfdf..0d52e48918eb 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -525,7 +525,7 @@ static struct klp_object *klp_alloc_object_dynamic(const char *name, { struct klp_object *obj; - obj = kzalloc(sizeof(*obj), GFP_KERNEL); + obj = kzalloc_obj(*obj, GFP_KERNEL); if (!obj) return NULL; @@ -554,7 +554,7 @@ static struct klp_func *klp_alloc_func_nop(struct klp_func *old_func, { struct klp_func *func; - func = kzalloc(sizeof(*func), GFP_KERNEL); + func = kzalloc_obj(*func, GFP_KERNEL); if (!func) return NULL; diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 90408500e5a3..1149840cd538 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -179,7 +179,7 @@ static int klp_patch_func(struct klp_func *func) return -EINVAL; } - ops = kzalloc(sizeof(*ops), GFP_KERNEL); + ops = kzalloc_obj(*ops, GFP_KERNEL); if (!ops) return -ENOMEM; -- cgit v1.2.3 From bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 21 Feb 2026 16:37:42 -0800 Subject: Convert 'alloc_obj' family to use the new default GFP_KERNEL argument This was done entirely with mindless brute force, using git grep -l '\ --- kernel/livepatch/core.c | 4 ++-- kernel/livepatch/patch.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/livepatch') diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 0d52e48918eb..28d15ba58a26 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -525,7 +525,7 @@ static struct klp_object *klp_alloc_object_dynamic(const char *name, { struct klp_object *obj; - obj = kzalloc_obj(*obj, GFP_KERNEL); + obj = kzalloc_obj(*obj); if (!obj) return NULL; @@ -554,7 +554,7 @@ static struct klp_func *klp_alloc_func_nop(struct klp_func *old_func, { struct klp_func *func; - func = kzalloc_obj(*func, GFP_KERNEL); + func = kzalloc_obj(*func); if (!func) return NULL; diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 1149840cd538..3f54a017bbf6 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -179,7 +179,7 @@ static int klp_patch_func(struct klp_func *func) return -EINVAL; } - ops = kzalloc_obj(*ops, GFP_KERNEL); + ops = kzalloc_obj(*ops); if (!ops) return -ENOMEM; -- cgit v1.2.3