[PATCH] powerpc/signal32: Fix build failure with CONFIG_SPE

[Christophe Leroy]

Add missing fault exit label in unsafe_copy_from_user() in order to
avoid following build failure with CONFIG_SPE

  CC      arch/powerpc/kernel/signal_32.o
arch/powerpc/kernel/signal_32.c: In function 'restore_user_regs':
arch/powerpc/kernel/signal_32.c:565:36: error: macro "unsafe_copy_from_user" requires 4 arguments, but only 3 given
  565 |           ELF_NEVRREG * sizeof(u32));
      |                                    ^
In file included from ./include/linux/uaccess.h:11,
                 from ./include/linux/sched/task.h:11,
                 from ./include/linux/sched/signal.h:9,
                 from ./include/linux/rcuwait.h:6,
                 from ./include/linux/percpu-rwsem.h:7,
                 from ./include/linux/fs.h:33,
                 from ./include/linux/huge_mm.h:8,
                 from ./include/linux/mm.h:707,
                 from arch/powerpc/kernel/signal_32.c:17:
./arch/powerpc/include/asm/uaccess.h:428: note: macro "unsafe_copy_from_user" defined here
  428 | #define unsafe_copy_from_user(d, s, l, e) \
      |
arch/powerpc/kernel/signal_32.c:564:3: error: 'unsafe_copy_from_user' undeclared (first use in this function); did you mean 'raw_copy_from_user'?
  564 |   unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
      |   ^~~~~~~~~~~~~~~~~~~~~
      |   raw_copy_from_user
arch/powerpc/kernel/signal_32.c:564:3: note: each undeclared identifier is reported only once for each function it appears in
make[3]: *** [arch/powerpc/kernel/signal_32.o] Error 1

Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
Fixes: 627b72bee84d ("powerpc/signal32: Convert restore_[tm]_user_regs() to user access block")
Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Guenter Roeck <linux at roeck-us.net>
---
 arch/powerpc/kernel/signal_32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 23fdb364b511..d489ccea2ab3 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -562,7 +562,7 @@ static long restore_user_regs(struct pt_regs *regs,
 	if (msr & MSR_SPE) {
 		/* restore spe registers from the stack */
 		unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
-				      ELF_NEVRREG * sizeof(u32));
+				      ELF_NEVRREG * sizeof(u32), failed);
 		current->thread.used_spe = true;
 	} else if (current->thread.used_spe)
 		memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
-- 
2.25.0