[src/trunk]: src/lib/libc/arch/sh3/gen On swapcontext(3) preserve r12 too. P...

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a4bf79dddbf3
branches:  trunk
changeset: 807331:a4bf79dddbf3
user:      uwe <uwe%NetBSD.org@localhost>
date:      Mon Apr 06 01:50:46 2015 +0000

description:
On swapcontext(3) preserve r12 too.  Properly fixes PR port-sh3/49597.

diffstat:

 lib/libc/arch/sh3/gen/swapcontext.S |  51 ++++++++++++++----------------------
 1 files changed, 20 insertions(+), 31 deletions(-)

diffs (81 lines):

diff -r 77b4ac789a9a -r a4bf79dddbf3 lib/libc/arch/sh3/gen/swapcontext.S
--- a/lib/libc/arch/sh3/gen/swapcontext.S       Mon Apr 06 01:11:19 2015 +0000
+++ b/lib/libc/arch/sh3/gen/swapcontext.S       Mon Apr 06 01:50:46 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: swapcontext.S,v 1.11 2015/01/25 01:32:26 uwe Exp $     */
+/*     $NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe Exp $     */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include <machine/asm.h>
 #if defined(SYSLIBC_SCCS) && !defined(lint)
-       RCSID("$NetBSD: swapcontext.S,v 1.11 2015/01/25 01:32:26 uwe Exp $")
+       RCSID("$NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe Exp $")
 #endif /* SYSLIBC_SCCS and not lint */
 
 /*
@@ -40,44 +40,33 @@
  */
 ENTRY(swapcontext)
        PIC_PROLOGUE(.L_got)
-       mov.l   r5, @-sp
        sts.l   pr, @-sp
 
        mov.l   .L__getcontext, r0
-1:     CALL    r0                      /* _getcontext(oucp) */
+       mov.l   r5, @-sp
+1:     CALL    r0                      ! _getcontext(oucp)
         mov.l  r4, @-sp
-       mov.l   @sp+, r1
-       tst     r0, r0
-       bf      3f                      /* return error from getcontext */
-
-       /* Note: getcontext does _UC_MACHINE_INTRV(oucp) = 0 for us */
-       mov.l   @sp, r0
-       mov.l   r0, @(36 + 1 * 4, r1)   /* _UC_MACHINE_SET_PC(oucp, pr) */
+       !! getcontext captures oucp resuming here with r12 (when PIC),
+       !! pr, r5 and r4 pushed onto the stack
 
-       /* Adjust stack pointer in oucp */
-       mov     sp, r2
-       mov     #(36 + 21 * 4), r0      /* offset to _UC_MACHINE_SP */
-#ifdef __PIC__
-       add     #12, r2                 /* "drop" r12, r5, pr */
-#else
-       add     #8, r2                  /* "drop" r5, pr */
-#endif
-       mov.l   r2, @(r0, r1)           /* set _UC_MACHINE_SP(oucp) */
+       tst     r0, r0
+       bf.s    3f                      ! return error from getcontext
+        mov.l  @sp, r1                 ! saved oucp
+
+       !! adjust oucp to resume after setcontext below
+       mova    3f, r0
+       mov.l   r0, @(36 + 1 * 4, r1)   ! _UC_MACHINE_SET_PC(oucp, pr)
 
        mov.l   .L_setcontext, r2
-2:     CALL    r2                      /* setcontext(ucp) */
-        mov.l  @(4, sp), r4
-       /* if we get here, return error from setcontext */
-3:
+2:     CALL    r2                      ! setcontext(ucp)
+        mov.l  @(4, sp), r4            ! saved ucp
+
+       .align  2
+3:     !! we get here on errors and when resuming oucp
+       add     #8, sp                  ! skip r4 and r5
        lds.l   @sp+, pr
-#ifdef __PIC__
-       add     #4, sp
        rts
-        PIC_EPILOGUE
-#else
-       rts
-        add    #4, sp
-#endif
+        PIC_EPILOGUE_SLOT
 
        .align  2
 .L_got:                        PIC_GOT_DATUM