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x86/its: move its_pages array to struct mod_arch_specific

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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: 872df34d7c ("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
This commit is contained in:
Mike Rapoport (Microsoft) 2025-06-03 14:14:43 +03:00 committed by Peter Zijlstra
parent 47410d839f
commit 0b0cae7119
3 changed files with 18 additions and 14 deletions
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8
arch/x86/include/asm/module.h
View File

@ -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 */

19
arch/x86/kernel/alternative.c
View File

@ -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);
}

5
include/linux/module.h
View File

@ -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;