[src/trunk]: src/libexec/ld.elf_so/arch/mips Restore handling of reloc entrie...

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

details:   https://anonhg.NetBSD.org/src/rev/1349bac304be
branches:  trunk
changeset: 555509:1349bac304be
user:      simonb <simonb%NetBSD.org@localhost>
date:      Wed Nov 19 19:41:57 2003 +0000

description:
Restore handling of reloc entries that point to unaligned locations
that seems to have disappeared in rev 1.34.

Thanks to Jason Thorpe for suggesting where to look.
Fixes the simple test case in PR port-mips/23366.

diffstat:

 libexec/ld.elf_so/arch/mips/mips_reloc.c |  77 +++++++++++++++++++------------
 1 files changed, 47 insertions(+), 30 deletions(-)

diffs (127 lines):

diff -r 444464cdcb4e -r 1349bac304be libexec/ld.elf_so/arch/mips/mips_reloc.c
--- a/libexec/ld.elf_so/arch/mips/mips_reloc.c  Wed Nov 19 18:39:34 2003 +0000
+++ b/libexec/ld.elf_so/arch/mips/mips_reloc.c  Wed Nov 19 19:41:57 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mips_reloc.c,v 1.44 2003/09/24 10:25:26 mycroft Exp $  */
+/*     $NetBSD: mips_reloc.c,v 1.45 2003/11/19 19:41:57 simonb Exp $   */
 
 /*
  * Copyright 1997 Michael L. Hitch <mhitch%montana.edu@localhost>
@@ -43,6 +43,31 @@
 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
 caddr_t _rtld_bind(Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr);
 
+/*
+ * It is possible for the compiler to emit relocations for unaligned data.
+ * We handle this situation with these inlines.
+ */
+#define        RELOC_ALIGNED_P(x) \
+       (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
+
+static __inline Elf_Addr
+load_ptr(void *where)
+{
+       Elf_Addr res;
+
+       memcpy(&res, where, sizeof(res));
+
+       return res;
+}
+
+static __inline void
+store_ptr(void *where, Elf_Addr val)
+{
+
+       memcpy(where, &val, sizeof(val));
+}
+
+
 void
 _rtld_setup_pltgot(const Obj_Entry *obj)
 {
@@ -114,7 +139,11 @@
                        sym = symtab + ELF_R_SYM(rel->r_info);
                        assert(sym->st_info ==
                            ELF_ST_INFO(STB_LOCAL, STT_SECTION));
-                       *where += (Elf_Addr)(sym->st_value + relocbase);
+                       if (__predict_true(RELOC_ALIGNED_P(where)))
+                               *where += (Elf_Addr)(sym->st_value + relocbase);
+                       else
+                               store_ptr(where, load_ptr(where) +
+                                   (Elf_Addr)(sym->st_value + relocbase));
                        break;
 
                default:
@@ -123,30 +152,6 @@
        }
 }
 
-/*
- * It is possible for the compiler to emit relocations for unaligned data.
- * We handle this situation with these inlines.
- */
-#define        RELOC_ALIGNED_P(x) \
-       (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
-
-static __inline Elf_Addr
-load_ptr(void *where)
-{
-       Elf_Addr res;
-
-       memcpy(&res, where, sizeof(res));
-
-       return (res);
-}
-
-static __inline void
-store_ptr(void *where, Elf_Addr val)
-{
-
-       memcpy(where, &val, sizeof(val));
-}
-
 int
 _rtld_relocate_nonplt_objects(const Obj_Entry *obj)
 {
@@ -252,9 +257,15 @@
                        def = obj->symtab + symnum;
 
                        if (symnum >= obj->gotsym) {
-                               tmp = *where;
+                               if (__predict_true(RELOC_ALIGNED_P(where)))
+                                       tmp = *where;
+                               else
+                                       tmp = load_ptr(where);
                                tmp += got[obj->local_gotno + symnum - obj->gotsym];
-                               *where = tmp;
+                               if (__predict_true(RELOC_ALIGNED_P(where)))
+                                       *where = tmp;
+                               else
+                                       store_ptr(where, tmp);
 
                                rdbg(("REL32/G %s in %s --> %p in %s",
                                    obj->strtab + def->st_name, obj->path,
@@ -276,7 +287,10 @@
                                 *
                                 * --rkb, Oct 6, 2001
                                 */
-                               tmp = *where;
+                               if (__predict_true(RELOC_ALIGNED_P(where)))
+                                       tmp = *where;
+                               else
+                                       tmp = load_ptr(where);
 
                                if (def->st_info ==
                                    ELF_ST_INFO(STB_LOCAL, STT_SECTION)
@@ -287,7 +301,10 @@
                                        tmp += (Elf_Addr)def->st_value;
 
                                tmp += (Elf_Addr)obj->relocbase;
-                               *where = tmp;
+                               if (__predict_true(RELOC_ALIGNED_P(where)))
+                                       *where = tmp;
+                               else
+                                       store_ptr(where, tmp);
 
                                rdbg(("REL32/L %s in %s --> %p in %s",
                                    obj->strtab + def->st_name, obj->path,