[PATCH 5.15 28/59] x86/its: Fix build errors when CONFIG_MODULES=n

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@google.com>

commit 9f35e33144ae5377d6a8de86dd3bd4d995c6ac65 upstream.

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++) {

  [ pawan: backport: Bring ITS dynamic thunk code under CONFIG_MODULES ]

Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/alternative.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -399,6 +399,7 @@ static int emit_indirect(int op, int reg
 
 #ifdef CONFIG_MITIGATION_ITS
 
+#ifdef CONFIG_MODULES
 static struct module *its_mod;
 static void *its_page;
 static unsigned int its_offset;
@@ -519,6 +520,14 @@ static void *its_allocate_thunk(int reg)
 
 	return thunk;
 }
+#else /* CONFIG_MODULES */
+
+static void *its_allocate_thunk(int reg)
+{
+	return NULL;
+}
+
+#endif /* CONFIG_MODULES */
 
 static int __emit_trampoline(void *addr, struct insn *insn, u8 *bytes,
 			     void *call_dest, void *jmp_dest)