m68k: Define sigcontext ABI of ColdFire

The following patch defines sigcontext ABI of ColdFire.  Due to ISA
restrictions ColdFire needs different rt_sigreturn trampoline.

And due to ColdFire FP registers being 8-bytes instead of 12-bytes on
m68k, sigcontext and fpregset structures should be updated.

Regarding the sc_fpstate[16+6*8] field, it would've been enough 16
bytes to store ColdFire's FP state.  To accomodate GLIBC's libSegFault
it would'be been enough 6*8 bytes (room for the 6 non-call-clobbered
FP registers).  I set it to 16+6*8 to provide some extra space for any
future changes in the ColdFire FPU.

Signed-off-by: Maxim Kuvyrkov <maxim@codesourcery.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index de2d05ddd86d..4b387538706f 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -897,10 +897,17 @@ static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* Set up to return from userspace.  */
         err |= __put_user(frame->retcode, &frame->pretcode);
+#ifdef __mcoldfire__
+        /* movel #__NR_rt_sigreturn,d0; trap #0 */
+        err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
+        err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
+                          (long __user *)(frame->retcode + 4));
+#else
         /* moveq #,d0; notb d0; trap #0 */
         err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
                           (long __user *)(frame->retcode + 0));
         err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
+#endif
 
         if (err)
                 goto give_sigsegv;