x86/its: move its_pages array to struct mod_arch_specific

The of pages with ITS thunks allocated for modules are tracked by an
array in 'struct module'.

Since this is very architecture specific data structure, move it to
'struct mod_arch_specific'.

No functional changes.

Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org

diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h
index e988bac0a4a1c316fffac9525b2a094cde9b2a51..3c2de4ce3b10de2ff406d15305c2e8d7abddbaa0 100644 (file)
--- a/arch/x86/include/asm/module.h
+++ b/arch/x86/include/asm/module.h
@@ -5,12 +5,20 @@
 #include <asm-generic/module.h>
 #include <asm/orc_types.h>
 
+struct its_array {
+#ifdef CONFIG_MITIGATION_ITS
+       void **pages;
+       int num;
+#endif
+};
+
 struct mod_arch_specific {
 #ifdef CONFIG_UNWINDER_ORC
        unsigned int num_orcs;
        int *orc_unwind_ip;
        struct orc_entry *orc_unwind;
 #endif
+       struct its_array its_pages;
 };
 
 #endif /* _ASM_X86_MODULE_H */

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index ecfe7b497cad2611e1f7338837a7bf6bfc50c1eb..b50fe6ce4655e83e6bca8c97a99c62e1fbf9c68b 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -173,8 +173,8 @@ void its_fini_mod(struct module *mod)
        its_page = NULL;
        mutex_unlock(&text_mutex);
 
-       for (int i = 0; i < mod->its_num_pages; i++) {
-               void *page = mod->its_page_array[i];
+       for (int i = 0; i < mod->arch.its_pages.num; i++) {
+               void *page = mod->arch.its_pages.pages[i];
                execmem_restore_rox(page, PAGE_SIZE);
        }
 }
@@ -184,11 +184,11 @@ void its_free_mod(struct module *mod)
        if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS))
                return;
 
-       for (int i = 0; i < mod->its_num_pages; i++) {
-               void *page = mod->its_page_array[i];
+       for (int i = 0; i < mod->arch.its_pages.num; i++) {
+               void *page = mod->arch.its_pages.pages[i];
                execmem_free(page);
        }
-       kfree(mod->its_page_array);
+       kfree(mod->arch.its_pages.pages);
 }
 #endif /* CONFIG_MODULES */
 
@@ -201,14 +201,15 @@ static void *its_alloc(void)
 
 #ifdef CONFIG_MODULES
        if (its_mod) {
-               void *tmp = krealloc(its_mod->its_page_array,
-                                    (its_mod->its_num_pages+1) * sizeof(void *),
+               struct its_array *pages = &its_mod->arch.its_pages;
+               void *tmp = krealloc(pages->pages,
+                                    (pages->num+1) * sizeof(void *),
                                     GFP_KERNEL);
                if (!tmp)
                        return NULL;
 
-               its_mod->its_page_array = tmp;
-               its_mod->its_page_array[its_mod->its_num_pages++] = page;
+               pages->pages = tmp;
+               pages->pages[pages->num++] = page;
 
                execmem_make_temp_rw(page, PAGE_SIZE);
        }

diff --git a/include/linux/module.h b/include/linux/module.h
index 92e1420fccdffc9de9f49da9061546cc1e0c89d1..5faa1fb1f4b4d5cfe350b346cb1d8204885eea91 100644 (file)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -586,11 +586,6 @@ struct module {
        atomic_t refcnt;
 #endif
 
-#ifdef CONFIG_MITIGATION_ITS
-       int its_num_pages;
-       void **its_page_array;
-#endif
-
 #ifdef CONFIG_CONSTRUCTORS
        /* Constructor functions. */
        ctor_fn_t *ctors;