Re: [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used

From: Christophe Leroy
Date: Tue Mar 12 2019 - 17:07:03 EST


On 03/12/2019 08:29 PM, Mathieu Malaterre wrote:
In commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
when possible") a buffer 'dummy_copy_buffer' was introduced. gcc does
not see this buffer being used in the inline assembly within function
'__switch_to', explicitly marked this variable as being used.

Prefer using '__aligned' to get passed line over 80 characters warning
in checkpatch.

Powerpc accepts 90 characters, use arch/powerpc/tools/checkpatch.sh


This remove the following warning:

arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used [-Werror=unused-const-variable=]

commit 2bf1071a8d50 ("powerpc/64s: Remove POWER9 DD1 support") has removed the fonction using 'dummy_copy_buffer' so you should remove it completely.

Christophe



Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>
---
arch/powerpc/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 77e44275d025..5acf63d45802 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1153,7 +1153,7 @@ static inline void restore_sprs(struct thread_struct *old_thread,
#ifdef CONFIG_PPC_BOOK3S_64
#define CP_SIZE 128
-static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE)));
+static const u8 dummy_copy_buffer[CP_SIZE] __aligned(CP_SIZE) __used;
#endif
struct task_struct *__switch_to(struct task_struct *prev,