[tip: x86/entry] x86/entry: Fix allnoconfig build warning

[tip-bot2 for Ingo Molnar]

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     d121f9483b18c423037ce6088feba24ae83891d1
Gitweb:        https://git.kernel.org/tip/d121f9483b18c423037ce6088feba24ae83891d1
Author:        Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate:    Mon, 25 May 2020 09:42:41 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 25 May 2020 09:45:27 +02:00

x86/entry: Fix allnoconfig build warning

The following commit:

  095b7a3e7745 ("x86/entry: Convert double fault exception to IDTENTRY_DF")

introduced a new build warning on 64-bit allnoconfig kernels, that have CONFIG_VMAP_STACK disabled:

  arch/x86/kernel/traps.c:332:16: warning: unused variable âaddressâ [-Wunused-variable]

This variable is only used if CONFIG_VMAP_STACK is defined, so make it
dependent on that, not CONFIG_X86_64.

Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
---
 arch/x86/kernel/traps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 35298c1..9e5d81c 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -328,7 +328,7 @@ DEFINE_IDTENTRY_DF(exc_double_fault)
 	static const char str[] = "double fault";
 	struct task_struct *tsk = current;
 
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_VMAP_STACK
 	unsigned long address = read_cr2();
 #endif