[PATCH] x86/its: Fix build errors when CONFIG_MODULES=n

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Fix several build errors when CONFIG_MODULES=n, including the following:

../arch/x86/kernel/alternative.c:195:25: error: incomplete definition of type 'struct module'
  195 |         for (int i = 0; i < mod->its_num_pages; i++) {

Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 arch/x86/kernel/alternative.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 48fd04e90114..45bcff181cba 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -131,11 +131,13 @@ const unsigned char * const x86_nops[ASM_NOP_MAX+1] =
 static bool cfi_paranoid __ro_after_init;
 #endif
 
 #ifdef CONFIG_MITIGATION_ITS
 
+#ifdef CONFIG_MODULES
 static struct module *its_mod;
+#endif
 static void *its_page;
 static unsigned int its_offset;
 
 /* Initialize a thunk with the "jmp *reg; int3" instructions. */
 static void *its_init_thunk(void *thunk, int reg)
@@ -169,10 +171,11 @@ static void *its_init_thunk(void *thunk, int reg)
 	bytes[i++] = 0xcc;
 
 	return thunk + offset;
 }
 
+#ifdef CONFIG_MODULES
 void its_init_mod(struct module *mod)
 {
 	if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS))
 		return;
 
@@ -207,18 +210,20 @@ void its_free_mod(struct module *mod)
 		void *page = mod->its_page_array[i];
 		execmem_free(page);
 	}
 	kfree(mod->its_page_array);
 }
+#endif /* CONFIG_MODULES */
 
 static void *its_alloc(void)
 {
 	void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE);
 
 	if (!page)
 		return NULL;
 
+#ifdef CONFIG_MODULES
 	if (its_mod) {
 		void *tmp = krealloc(its_mod->its_page_array,
 				     (its_mod->its_num_pages+1) * sizeof(void *),
 				     GFP_KERNEL);
 		if (!tmp)
@@ -227,10 +232,11 @@ static void *its_alloc(void)
 		its_mod->its_page_array = tmp;
 		its_mod->its_page_array[its_mod->its_num_pages++] = page;
 
 		execmem_make_temp_rw(page, PAGE_SIZE);
 	}
+#endif /* CONFIG_MODULES */
 
 	return no_free_ptr(page);
 }
 
 static void *its_allocate_thunk(int reg)

base-commit: 627277ba7c2398dc4f95cc9be8222bb2d9477800
-- 
2.49.0