[src/trunk]: src/libexec/ld.elf_so/arch/powerpc Fix problem with bss-plt obje...

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

details:   https://anonhg.NetBSD.org/src/rev/a1ebe7a2441d
branches:  trunk
changeset: 761874:a1ebe7a2441d
user:      matt <matt%NetBSD.org@localhost>
date:      Thu Feb 10 02:28:20 2011 +0000

description:
Fix problem with bss-plt objects which a reloc index, not offset.
(secure-plt uses an offset (index*sizeof(rela), bss-plt uses an index)
secure-plt will now take the offset and divide by 12 for an index.

diffstat:

 libexec/ld.elf_so/arch/powerpc/ppc_reloc.c  |  13 ++++++++++---
 libexec/ld.elf_so/arch/powerpc/rtld_start.S |  22 +++++++++++++++++-----
 2 files changed, 27 insertions(+), 8 deletions(-)

diffs (88 lines):

diff -r 23ee3bc18fca -r a1ebe7a2441d libexec/ld.elf_so/arch/powerpc/ppc_reloc.c
--- a/libexec/ld.elf_so/arch/powerpc/ppc_reloc.c        Thu Feb 10 01:49:51 2011 +0000
+++ b/libexec/ld.elf_so/arch/powerpc/ppc_reloc.c        Thu Feb 10 02:28:20 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ppc_reloc.c,v 1.46 2011/01/16 01:22:29 matt Exp $      */
+/*     $NetBSD: ppc_reloc.c,v 1.47 2011/02/10 02:28:20 matt Exp $      */
 
 /*-
  * Copyright (C) 1998  Tsubai Masanari
@@ -30,7 +30,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: ppc_reloc.c,v 1.46 2011/01/16 01:22:29 matt Exp $");
+__RCSID("$NetBSD: ppc_reloc.c,v 1.47 2011/02/10 02:28:20 matt Exp $");
 #endif /* not lint */
 
 #include <stdarg.h>
@@ -82,6 +82,9 @@
        if (obj->gotptr != NULL) {
                obj->gotptr[1] = (Elf_Addr) _rtld_bind_secureplt_start;
                obj->gotptr[2] = (Elf_Addr) obj;
+               dbg(("obj %s secure-plt gotptr=%p start=%p obj=%p",
+                   obj->path, obj->gotptr,
+                   (void *) obj->gotptr[1], (void *) obj->gotptr[2]));
        } else {
                Elf_Word *pltcall, *pltresolve;
                Elf_Word *jmptab;
@@ -91,6 +94,10 @@
                if (N > 8192)
                        N += N-8192;
 
+               dbg(("obj %s bss-plt pltgot=%p jmptab=%u start=%p obj=%p",
+                   obj->path, obj->pltgot, 18 + N * 2,
+                   _rtld_bind_bssplt_start, obj));
+
                pltcall = obj->pltgot;
                jmptab = pltcall + 18 + N * 2;
 
@@ -343,7 +350,7 @@
 caddr_t
 _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
 {
-       const Elf_Rela *rela = (const void *)((const char *)obj->pltrela + reloff);
+       const Elf_Rela *rela = obj->pltrela + reloff;
        Elf_Addr new_value;
        int err;
 
diff -r 23ee3bc18fca -r a1ebe7a2441d libexec/ld.elf_so/arch/powerpc/rtld_start.S
--- a/libexec/ld.elf_so/arch/powerpc/rtld_start.S       Thu Feb 10 01:49:51 2011 +0000
+++ b/libexec/ld.elf_so/arch/powerpc/rtld_start.S       Thu Feb 10 02:28:20 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld_start.S,v 1.14 2011/01/16 01:22:29 matt Exp $     */
+/*     $NetBSD: rtld_start.S,v 1.15 2011/02/10 02:28:20 matt Exp $     */
 
 /*-
  * Copyright (C) 1998  Tsubai Masanari
@@ -84,14 +84,26 @@
  * bss-plt expects %r11 to be index of the rela entry.
  * So for bss-plt, we multiply the index by 12 to get the offset.
  */
+ENTRY_NOPROFILE(_rtld_bind_secureplt_start)
+       stwu    %r1,-160(%r1)
+       stw     %r0,20(%r1)
+
+       /*
+        * Instead of division which is costly we will use multiplicative
+        * inverse.  a / n = ((a * inv(n)) >> 32)
+        * where inv(n) = (0x100000000 + n - 1) / n
+        */
+       mr      %r0,%r11
+       lis     %r11,0x10000000b/12@h   # load multiplicative inverse of 12
+       ori     %r11,%r11,0x10000000b/12@l
+       mulhwu  %r11,%r11,%r0           # get high half of multiplication
+
+       b       1f
 ENTRY_NOPROFILE(_rtld_bind_bssplt_start)
-       slwi    %r11,%r11,2
-       add     %r0,%r11,%r11
-       add     %r11,%r11,%r0
-ENTRY_NOPROFILE(_rtld_bind_secureplt_start)
        stwu    %r1,-160(%r1)
 
        stw     %r0,20(%r1)
+1:
        mflr    %r0
        stw     %r0,16(%r1)             # save lr
        mfcr    %r0