[src/trunk]: src/libexec/ld.elf_so/arch/arm Don't use GOT relocations. Use P...

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

details:   https://anonhg.NetBSD.org/src/rev/8ad295e9d558
branches:  trunk
changeset: 325067:8ad295e9d558
user:      matt <matt%NetBSD.org@localhost>
date:      Tue Dec 03 00:19:56 2013 +0000

description:
Don't use GOT relocations.  Use PC relative for the GOT and GOTOFF for
_DYNAMIC.  Make thumb friendly.

diffstat:

 libexec/ld.elf_so/arch/arm/rtld_start.S |  68 ++++++++++++++------------------
 1 files changed, 30 insertions(+), 38 deletions(-)

diffs (104 lines):

diff -r 0bce36bd5db1 -r 8ad295e9d558 libexec/ld.elf_so/arch/arm/rtld_start.S
--- a/libexec/ld.elf_so/arch/arm/rtld_start.S   Mon Dec 02 23:06:35 2013 +0000
+++ b/libexec/ld.elf_so/arch/arm/rtld_start.S   Tue Dec 03 00:19:56 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld_start.S,v 1.11 2012/08/13 02:53:25 matt Exp $     */
+/*     $NetBSD: rtld_start.S,v 1.12 2013/12/03 00:19:56 matt Exp $     */
 
 /*-
  * Copyright (c) 1998, 2002 The NetBSD Foundation, Inc.
@@ -31,55 +31,51 @@
 
 #include <machine/asm.h>
 
-RCSID("$NetBSD: rtld_start.S,v 1.11 2012/08/13 02:53:25 matt Exp $")
+RCSID("$NetBSD: rtld_start.S,v 1.12 2013/12/03 00:19:56 matt Exp $")
 
-       .text
-       .align  0
-       .globl  _rtld_start
-       .type   _rtld_start,%function
-_rtld_start:
+ENTRY_NP(_rtld_start)
        sub     sp, sp, #8              /* make room for obj_main & exit proc */
-       mov     r4, r0                  /* save ps_strings */
+       movs    r4, r0                  /* save ps_strings */
 
-       ldr     sl, .L2
-       ldr     r5, .L2+4
-       ldr     r0, .L2+8
-.L1:
-       add     sl, pc, sl
-       ldr     r5, [sl, r5]
-       ldr     r0, [sl, r0]
-
-       sub     r1, sl, r5              /* relocbase */
-       add     r0, r1, r0              /* &_DYNAMIC */
+       ldr     r6, .Lgot
+       ldr     r5, .Ldynamic
+       add     r6, r6, pc              /* r6 = &GOT[0]; pc = &LPIC1; */
+       adds    r0, r6, r5              /* arg0 = &_DYNAMIC */
+.LPIC1:
+       ldr     r5, [r6]                /* GOT[0] = &_DYNAMIC */
+       subs    r5, r0, r5              /* relocbase = GOT[0] - &_DYNAMIC */
+       movs    r1, r5                  /* arg1 = relocabase */
        bl      _rtld_relocate_nonplt_self
 
-       sub     r1, sl, r5              /* relocbase */
+       movs    r1, r5                  /* relocbase */
        mov     r0, sp                  /* sp */
        bl      _rtld                   /* call the shared loader */
-       mov     r3, r0                  /* save entry point */
+       movs    r3, r0                  /* save entry point */
 
+#ifdef __thumb__
+       ldr     r2, [sp, #0]            /* pop r2 = cleanup */
+       ldr     r1, [sp, #4]            /* pop r1 = obj_main */
+       add     sp, sp, #8
+#else
        ldr     r2, [sp], #4            /* pop r2 = cleanup */
        ldr     r1, [sp], #4            /* pop r1 = obj_main */
-       mov     r0, r4                  /* restore ps_strings */
-#ifdef _ARM_ARCH_4T
-       bx      r3                      /* jump to the entry point */
-#else
-       mov     pc, r3                  /* jump to the entry point */
 #endif
-.L2:
-       .word   _GLOBAL_OFFSET_TABLE_ - (.L1+8)
-       .word   _GLOBAL_OFFSET_TABLE_(GOT)
-       .word   _DYNAMIC(GOT)
+       movs    r0, r4                  /* restore ps_strings */
+       RETr(r3)
 
        .align  0
-       .globl  _rtld_bind_start
-       .type   _rtld_bind_start,%function
+.Lgot:
+       .word   _GLOBAL_OFFSET_TABLE_ - .LPIC1
+.Ldynamic:
+       .word   _DYNAMIC(GOTOFF)
+END(_rtld_start)
+
 /*
  *     stack[0] = RA
  *     ip = &GOT[n+3]
  *     lr = &GOT[2]
  */
-_rtld_bind_start:
+ARM_ENTRY_NP(_rtld_bind_start)
        stmdb   sp!,{r0-r4,sl,fp}       /* 8 byte aligned (lr already saved) */
 
        sub     r1, ip, lr              /* r1 = 4 * (n + 1) */
@@ -95,9 +91,5 @@
        mov     ip, r0                  /* save new address */
 
        ldmia   sp!,{r0-r4,sl,fp,lr}    /* restore the stack */
-#ifdef _ARM_ARCH_4T
-       bx      ip                      /* jump to the new address */
-#else
-       mov     pc, ip                  /* jump to the new address */
-#endif
-
+       RETr(ip)                        /* jump to the new address */
+END(_rtld_bind_start)