[PATCH] Fix m68k syscall API and support 6-argument syscalls.
Thorsten Glaser
tg at mirbsd.de
Sat Jan 29 09:19:10 PST 2011
Debian: (Closes: #334917)
Signed-off-by: Thorsten Glaser <tg at mirbsd.de>
---
usr/klibc/arch/m68k/syscall.S | 42 +++++++++++++++++++++++++++++++++-------
usr/klibc/arch/m68k/vfork.S | 13 +++--------
2 files changed, 38 insertions(+), 17 deletions(-)
diff --git a/usr/klibc/arch/m68k/syscall.S b/usr/klibc/arch/m68k/syscall.S
index 966c92d..f468678 100644
--- a/usr/klibc/arch/m68k/syscall.S
+++ b/usr/klibc/arch/m68k/syscall.S
@@ -11,17 +11,43 @@
.globl __syscall_common
.type __syscall_common, @function
__syscall_common:
- movem.l %d2-%d6, -(%sp) /* 5 registers saved */
- movem.l 24(%sp), %d1-%d6
+ /*
+ * According to eglibc, separate moves are faster than movem;
+ * speed is important and this code is not duplicated anyway,
+ * so we do the same here. We use %a1 as scratch register for
+ * saving; syscall arguments are to be in %d1 to %d5 and %a0.
+ */
+ move.l 24(%sp), %a0 /* orig.sp+24: arg 6 */
+ move.l %d5, -(%sp) /* push d5 (callee saved) */
+ move.l 24(%sp), %d5 /* orig.sp+20: arg 5 */
+ move.l %d4, -(%sp) /* push d4 (callee saved) */
+ move.l 24(%sp), %d4 /* orig.sp+16: arg 4 */
+ move.l %d3, -(%sp) /* push d3 (callee saved) */
+ move.l 24(%sp), %d3 /* orig.sp+12: arg 3 */
+ move.l %d2, %a1 /* save d2 (callee saved) in a1 */
+ move.l 20(%sp), %d2 /* orig.sp+8: arg 2 */
+ move.l 16(%sp), %d1 /* orig.sp+4: arg 1 */
trap #0
- cmpi.l #-4095, %d0
- blt.l 1f
+ move.l %a1, %d2 /* restore d2 from a1 (scratch) */
+ move.l (%sp)+, %d3 /* pop d3..d5, see above */
+ move.l (%sp)+, %d4
+ move.l (%sp)+, %d5
+
+ /* syscall is done, result in %d0, registers are restored */
+ .globl __syscall_checkandout
+__syscall_checkandout:
+ /* now check for error */
+ cmp.l #-4095, %d0
+ bcs.l 1f /* jmp short if _not_ error */
+
+ /* prepare for error return */
neg.l %d0
move.l %d0, (errno)
- moveq #-1, %d0
-1:
- movea.l %d0, %a0 /* Redundant return */
- movem.l (%sp)+, %d2-%d6 /* Restore registers */
+ move.l #-1, %d0
+ /* fallthrough to common return path */
+
+1: /* copy return value to %a0 for syscalls returning pointers */
+ move.l %d0, %a0
rts
.size __syscall_common,.-__syscall_common
diff --git a/usr/klibc/arch/m68k/vfork.S b/usr/klibc/arch/m68k/vfork.S
index a3a7e44..ec8baeb 100644
--- a/usr/klibc/arch/m68k/vfork.S
+++ b/usr/klibc/arch/m68k/vfork.S
@@ -15,14 +15,9 @@ vfork:
move.l (%sp)+, %d1 /* Return address */
move.l # __NR_vfork, %d0
trap #0
- move.l %d1, -(%sp)
- cmpi.l #-4095, %d0
- blt.l 1f
- neg.l %d0
- move.l %d0, (errno)
- moveq #-1, %d0
-1:
- movea.l %d0, %a0
- rts
+ move.l %d1, -(%sp) /* restore stack */
+
+ /* common code from syscall.S */
+ bra __syscall_checkandout
.size vfork, .-vfork
--
1.7.2.3
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