Commit 0b0cae71 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Peter Zijlstra
Browse files

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: 872df34d ("x86/its: Use dynamic thunks for indirect branches")
Suggested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org
parent 47410d83

arch/x86/include/asm/module.h

+8 −0
Original line number Diff line number Diff line
@@ -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 */

arch/x86/kernel/alternative.c

+10 −9
Original line number Diff line number Diff line
@@ -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);

	}

include/linux/module.h

+0 −5
Original line number Diff line number Diff line
@@ -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;