Rewrite the hppa assembly code to avoid reads from .text, by using the

standard PIC magic.  This makes the code similar to what we already use
for rcrt0.o.  This makes it ready for execute-only.

Build C code using -fno-jump-tables to make it ready for execute-only.

ok deraadt@, miod@

diff --git a/libexec/ld.so/hppa/Makefile.inc b/libexec/ld.so/hppa/Makefile.inc
index 9b81691..2797f45 100644 (file)
--- a/libexec/ld.so/hppa/Makefile.inc
+++ b/libexec/ld.so/hppa/Makefile.inc
@@ -1,6 +1,6 @@
-#      $OpenBSD: Makefile.inc,v 1.7 2022/12/05 07:49:07 kettenis Exp $
+#      $OpenBSD: Makefile.inc,v 1.8 2023/01/09 13:52:42 kettenis Exp $
 
-CFLAGS += -fpic
+CFLAGS += -fpic -fno-jump-tables
 AFLAGS += -fpic
 LD_SCRIPT = ${.CURDIR}/${MACHINE_CPU}/ld.script
 

diff --git a/libexec/ld.so/hppa/ldasm.S b/libexec/ld.so/hppa/ldasm.S
index 4d19f9b..6f52548 100644 (file)
--- a/libexec/ld.so/hppa/ldasm.S
+++ b/libexec/ld.so/hppa/ldasm.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ldasm.S,v 1.25 2023/01/09 13:45:55 kettenis Exp $     */
+/*     $OpenBSD: ldasm.S,v 1.26 2023/01/09 13:52:42 kettenis Exp $     */
 
 /*
  * Copyright (c) 2004 Michael Shalayeff
@@ -33,34 +33,27 @@
 #include <machine/vmparam.h>
 #undef _LOCORE
 
+       .import $global$, data
+
 ENTRY(_dl_start,32)
        copy    r3, r1
        copy    sp, r3
        stwm    r1, HPPA_FRAME_SIZE+16*4(sp)
 
-       stw     %arg0, HPPA_FRAME_ARG(0)(r3)    /* ps_strings */
-
-#define        ADDR(s,r) \
-       bl      4, t1                                                   !\
-       depi    0, 31, 2, t1    /* kill pl bits */                      !\
-       b       s               /* cold brunch -- never done */         !\
-       ldw     0(t1), t2       /* cat(w,w1,w2{10},w2{0..9}) << 2 */    !\
-       extru   t2, 28, 10, t3  /* w2{0..9} */                          !\
-       extru   t2, 26, 16, r   /* w1 */                                !\
-       dep     t3, 31, 11, r                                           !\
-       extru,= t2, 31, 1, r0   /* w */                                 !\
-       depi    1, 15, 1, r                                             !\
-       extru,= t2, 29, 1, r0   /* w2{10} */                            !\
-       depi    1, 21, 1, r                                             !\
-       sh2add  r, t1, r        /* plus the base */                     !\
-       addi    8, r, r         /* bl target is -8 */
-
-       ADDR(_GLOBAL_OFFSET_TABLE_, r19)
-       ADDR(_DYNAMIC, arg2)
+       stw     arg0, HPPA_FRAME_ARG(0)(r3)     /* ps_strings */
+
+       bl      1f, r19
+       depi    0, 31, 2, r19
+1:     addil   L'$global$ - ($PIC_pcrel$0 - 8), r19
+       ldo     R'$global$ - ($PIC_pcrel$0 - 12)(r1), r19
+       bl      1f, arg2
+       depi    0, 31, 2, arg2
+1:     addil   L'_DYNAMIC - ($PIC_pcrel$0 - 8), arg2
+       ldo     R'_DYNAMIC - ($PIC_pcrel$0 - 12)(r1), arg2
        stw     arg2, HPPA_FRAME_ARG(1)(r3)
 
        /* make sure to get a fault until it's set proper */
-       ldi     -1, %dp
+       ldi     -1, dp
 
        ldw     0(arg0), arg0
        ldo     4(r3), arg1                     /* dl_data */
@@ -79,7 +72,8 @@ ENTRY(_dl_start,32)
        ldo     4(r3), arg3                     /* dl_data */
 
        ldw     HPPA_FRAME_ARG(0)(r3), arg0     /* ps_strings */
-       ADDR(_hppa_dl_dtors_plabel, arg1)
+       addil   LT'_dl_dtors_plabel, r19
+       ldw     RT'_dl_dtors_plabel(r1), arg1
        ldw     0(arg1), arg1                   /* cleanup */
 
        ldo     HPPA_FRAME_SIZE(r3), sp
@@ -88,19 +82,10 @@ ENTRY(_dl_start,32)
        ldwm    -HPPA_FRAME_SIZE(sp), r3
 EXIT(_dl_start)
 
-/*
- * void _hppa_dl_dtors(void);
- */
-ENTRY(_hppa_dl_dtors,0)
-       ADDR(_GLOBAL_OFFSET_TABLE_, r19)
-       b       _dl_dtors
-       nop
-EXIT(_hppa_dl_dtors)
-
        .section .data
        .align 4
-_hppa_dl_dtors_plabel:
-       .word P%_hppa_dl_dtors
+_dl_dtors_plabel:
+       .word P%_dl_dtors
        .previous
 
 LEAF_ENTRY(_hppa_dl_set_dp)