x86/its: Fix build error for its_static_thunk()

Due to a likely merge resolution error of backport commit 772934d9062a
("x86/its: FineIBT-paranoid vs ITS"), the function its_static_thunk() was
placed in the wrong ifdef block, causing a build error when
CONFIG_MITIGATION_ITS and CONFIG_FINEIBT are both disabled:

  /linux-6.6/arch/x86/kernel/alternative.c:1452:5: error: redefinition of 'its_static_thunk'
   1452 | u8 *its_static_thunk(int reg)
        |     ^~~~~~~~~~~~~~~~

Fix it by moving its_static_thunk() under CONFIG_MITIGATION_ITS.

Fixes: e52c1dc7455d ("x86/its: FineIBT-paranoid vs ITS")
Reported-by: Natanael Copa <ncopa@alpinelinux.org>
Link: https://lore.kernel.org/all/20250519164717.18738b4e@ncopa-desktop/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 4817e424d6965875b7e56ed9aeee5cd6ba8ed5b0..8e6cad42b296ee08aa16df2598ba7196f70b609c 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -730,7 +730,15 @@ static bool cpu_wants_indirect_its_thunk_at(unsigned long addr, int reg)
        /* Lower-half of the cacheline? */
        return !(addr & 0x20);
 }
-#endif
+
+u8 *its_static_thunk(int reg)
+{
+       u8 *thunk = __x86_indirect_its_thunk_array[reg];
+
+       return thunk;
+}
+
+#endif /* CONFIG_MITIGATION_ITS */
 
 /*
  * Rewrite the compiler generated retpoline thunk calls.
@@ -1449,13 +1457,6 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
 static void poison_cfi(void *addr) { }
 #endif
 
-u8 *its_static_thunk(int reg)
-{
-       u8 *thunk = __x86_indirect_its_thunk_array[reg];
-
-       return thunk;
-}
-
 #endif
 
 void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,