ARM: fix nommu builds with 48be69a02 (ARM: move signal handlers into a vdso-like page)

Olof reports that noMMU builds error out with:

arch/arm/kernel/signal.c: In function 'setup_return':
arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member named 'sigpage'

This shows one of the evilnesses of IS_ENABLED().  Get rid of it here
and replace it with #ifdef's - and as no noMMU platform can make use
of sigpage, depend on CONIFG_MMU not CONFIG_ARM_MPU.

Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 7 insertions, 2 deletions

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 9c9b30717fda..56211f2084ef 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -130,8 +130,10 @@ struct mm_struct;
 extern unsigned long arch_randomize_brk(struct mm_struct *mm);
 #define arch_randomize_brk arch_randomize_brk
 
+#ifdef CONFIG_MMU
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 struct linux_binprm;
 int arch_setup_additional_pages(struct linux_binprm *, int);
+#endif
 
 #endif
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 39e7105a9b70..ab3304225272 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -402,7 +402,8 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
                     __put_user(sigreturn_codes[idx+1], rc+1))
                         return 1;
 
-                if ((cpsr & MODE32_BIT) && !IS_ENABLED(CONFIG_ARM_MPU)) {
+#ifdef CONFIG_MMU
+                if (cpsr & MODE32_BIT) {
                         struct mm_struct *mm = current->mm;
 
                         /*
@@ -412,7 +413,9 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
                          */
                         retcode = mm->context.sigpage + signal_return_offset +
                                   (idx << 2) + thumb;
-                } else {
+                } else
+#endif
+                {
                         /*
                          * Ensure that the instruction cache sees
                          * the return code written onto the stack.