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>

2 files changed, 10 insertions, 0 deletions

diff --git a/arch/m68k/include/asm/sigcontext.h b/arch/m68k/include/asm/sigcontext.h
index 523db2a51cf3..1320eaa4cc2a 100644
--- a/arch/m68k/include/asm/sigcontext.h
+++ b/arch/m68k/include/asm/sigcontext.h
@@ -15,9 +15,15 @@ struct sigcontext {
         unsigned long  sc_pc;
         unsigned short sc_formatvec;
 #ifndef __uClinux__
+# ifdef __mcoldfire__
+        unsigned long  sc_fpregs[2][2]; /* room for two fp registers */
+        unsigned long  sc_fpcntl[3];
+        unsigned char  sc_fpstate[16+6*8];
+# else
         unsigned long  sc_fpregs[2*3];  /* room for two fp registers */
         unsigned long  sc_fpcntl[3];
         unsigned char  sc_fpstate[216];
+# endif
 #endif
 };
 
diff --git a/arch/m68k/include/asm/ucontext.h b/arch/m68k/include/asm/ucontext.h
index e4e22669edc0..00dcc5176c57 100644
--- a/arch/m68k/include/asm/ucontext.h
+++ b/arch/m68k/include/asm/ucontext.h
@@ -7,7 +7,11 @@ typedef greg_t gregset_t[NGREG];
 
 typedef struct fpregset {
         int f_fpcntl[3];
+#ifdef __mcoldfire__
+        int f_fpregs[8][2];
+#else
         int f_fpregs[8*3];
+#endif
 } fpregset_t;
 
 struct mcontext {