Re: [PATCH 04/21] powerpc: Mark both tmp variables as unused

[Christophe LEROY]

Le 25/02/2018 à 18:22, Mathieu Malaterre a écrit :

Since the value of `tmp` is never intended to be read, declare both `tmp`
variables as unused. Fix warning (treated as error in W=1):

What about using fault_in_pages_readable() instead ?

Christophe

   CC      arch/powerpc/kernel/signal_32.o
arch/powerpc/kernel/signal_32.c: In function ‘sys_swapcontext’:
arch/powerpc/kernel/signal_32.c:1048:16: error: variable ‘tmp’ set but not used 
[-Werror=unused-but-set-variable]
   unsigned char tmp;
                 ^~~
arch/powerpc/kernel/signal_32.c: In function ‘sys_debug_setcontext’:
arch/powerpc/kernel/signal_32.c:1234:16: error: variable ‘tmp’ set but not used 
[-Werror=unused-but-set-variable]
   unsigned char tmp;
                 ^~~
cc1: all warnings being treated as errors

Signed-off-by: Mathieu Malaterre <ma...@debian.org>
---
  arch/powerpc/kernel/signal_32.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index a46de0035214..492f03451877 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -1045,7 +1045,7 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
                     struct ucontext __user *new_ctx,
                     int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
  {
-       unsigned char tmp;
+       unsigned char tmp __maybe_unused;
        int ctx_has_vsx_region = 0;

#ifdef CONFIG_PPC64

@@ -1231,7 +1231,7 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
  {
        struct sig_dbg_op op;
        int i;
-       unsigned char tmp;
+       unsigned char tmp __maybe_unused;
        unsigned long new_msr = regs->msr;
  #ifdef CONFIG_PPC_ADV_DEBUG_REGS
        unsigned long new_dbcr0 = current->thread.debug.dbcr0;