[src/trunk]: src/libexec/ld.elf_so/arch/vax Once we know the bound routine, r...

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

details:   https://anonhg.NetBSD.org/src/rev/febee5979dbb
branches:  trunk
changeset: 327861:febee5979dbb
user:      matt <matt%NetBSD.org@localhost>
date:      Wed Mar 19 02:39:22 2014 +0000

description:
Once we know the bound routine, rebuilt a new callframe that can be unwound
properly.

diffstat:

 libexec/ld.elf_so/arch/vax/rtld_start.S |  110 +++++++++++++++++++++++++------
 1 files changed, 87 insertions(+), 23 deletions(-)

diffs (127 lines):

diff -r 289f3a7a868f -r febee5979dbb libexec/ld.elf_so/arch/vax/rtld_start.S
--- a/libexec/ld.elf_so/arch/vax/rtld_start.S   Wed Mar 19 01:24:32 2014 +0000
+++ b/libexec/ld.elf_so/arch/vax/rtld_start.S   Wed Mar 19 02:39:22 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld_start.S,v 1.17 2014/03/18 23:43:38 matt Exp $     */
+/*     $NetBSD: rtld_start.S,v 1.18 2014/03/19 02:39:22 matt Exp $     */
 
 /*
  * Copyright 1996 Matt Thomas <matt%3am-software.com@localhost>
@@ -64,31 +64,95 @@
  * hence the `optimization' to avoid the callg opportunistically.
  */
 ALTENTRY(_rtld_bind_start)
-       .cfi_startproc
-       .cfi_def_cfa 13, 60
-       .cfi_offset 16, -56
-       .cfi_offset 12, -52
-       .cfi_offset 13, -48
-       .cfi_offset 15, -44
-       .cfi_offset 2, -40
-       .cfi_offset 3, -36
-       .cfi_offset 4, -32
-       .cfi_offset 5, -28
-       .cfi_offset 6, -24
-       .cfi_offset 7, -20
-       .cfi_offset 8, -16
-       .cfi_offset 9, -12
-       .cfi_offset 10, -8
-       .cfi_offset 11, -4
+       movab   -64(%sp),%sp    /* reserve some space */
        pushr   $0x3f           /* save R0-R5 */
-       movq    24(%sp),%r0     /* get addresses of plt.got & reloc index */
+       movq    -8(%fp),%r0     /* get addresses of plt.got & reloc index */
        pushl   (%r1)           /* push relocation index */
        pushl   %r0             /* push address of obj entry */
        calls   $2,_rtld_bind
-       movl    %r0,28(%sp)     /* save return address onto stack */
+
+       movl    %r0,%r3         /* save routine address */
+       extzv   $0,$12,(%r0),%r1        /* get entry mask */
+       extzv   $0,$12,6(%fp),%r2       /* get saved mask */
+       cmpw    %r1,%r2         /* compare them */
+       bneq    12f             /* if they are different, rebuild */
+       movl    %r0,-4(%fp)     /* save routine address */
+       popr    $0x3f           /* pop registers */
+       movab   68(%sp),%sp     /* restore sp */
+       rsb                     /* and jump to it */
+
+       /*
+        * We need to rebuild the callframe.  Save the current one in case
+        * we might overwrite it.
+        */
+12:    movq    4(%fp),-(%sp)   /* save PSW and AP */
+       movq    12(%fp),-(%sp)  /* save FP and return address */
+       /*
+        * Find out where this this call frame ends.
+        */
+       movl    %ap,%r0         /* get past callframe and registers */
+       bbs     $29,4(%fp),22f  /* calls is easy, it's where AP is */
+       /*
+        * Callg not so much
+        */
+       movab   20(%fp),%r0     /* past fixed callframe */
+       tstw    %r2             /* no saved registers? */
+       beql    22f             /*    none, so we are done. */
+       movl    $11,%r4         /* start with register 11 */
+20:    bbc     %r4,%r2,21f     /* save this register? */
+       addl2   $4,%r0          /*   yes, adjust for saved register */
+21:    sobgeq  %r4,20b         /* try next register */
+
+22:
+       /*
+        * First "push" the caller saved registers (if there any that
+        * need to saved.)
+        */
+       tstw    %r1             /* if there are no registers to save */
+       beql    1f              /* just push the callframe */
+       cmpw    %r1,$63         /* if there are no caller-saved registers */
+       blequ   5f              /* skip them */
+       bbc     $11,%r1,10f     /* does it need to be saved? */
+       movl    %r11,-(%r0)
+10:    bbc     $10,%r1,9f      /* does it need to be saved? */
+       movl    %r10,-(%r0)
+9:     bbc     $9,%r1,8f       /* does it need to be saved? */
+       movl    %r9,-(%r0)
+8:     bbc     $8,%r1,7f       /* does it need to be saved? */
+       movl    %r8,-(%r0)
+7:     bbc     $7,%r1,6f       /* does it need to be saved? */
+       movl    %r7,-(%r0)
+6:     bbc     $6,%r1,5f       /* does it need to be saved? */
+       movl    %r6,-(%r0)
+5:     
+       /*
+        * r0-r5 are not normally preserved so we should be done.
+        */
+       cmpw    %r1,$63
+       bgtru   1f
+       /*
+        * For some reason, we have to preserve these.
+        */
+       movab   16(%sp),%r2
+       bbc     $5,%r1,4f       /* does it need to be saved? */
+       movl    20(%r2),-(%r0)
+4:     bbc     $4,%r1,3f       /* does it need to be saved? */
+       movl    16(%r2),-(%r0)
+3:     bbc     $3,%r1,2f       /* does it need to be saved? */
+       movl    12(%r2),-(%r0)
+2:     bbc     $2,%r1,1f       /* does it need to be saved? */
+       movl    8(%r2),-(%r0)
+
+       /*
+        * Now we save the fixed part of the callframe.
+        */
+1:     clrl    %r4             /* clear condition handler slot */
+       movq    (%sp)+,-(%r0)   /* move FP and PC into place */
+       movq    (%sp)+,-(%r0)   /* move PSW/save-mask/etc + AP into place */
+       movq    %r3,-(%r0)      /* move routine address + cond handle slot */
+       addl3   $4,%r0,%fp      /* get start of new callframe */
+       insv    $0,$12,%r1,6(%fp) /* insert new saved mask */
        popr    $0x3f           /* restore R0-R5 (cond flags not modified) */
-       addl2   $4,%sp
-       callg   (%ap),*(%sp)+   /* return value from _rtld_bind() == actual */
-       ret
-       .cfi_endproc
+       subl3   $4,%fp,%sp      /* sp needs to be equal to fp */
+       rsb                     /* and jmp to the routine */
 END(_rtld_bind_start)