[src/trunk]: src/libexec/ld.elf_so binutils 2.31.1 can put copy relocations i...

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

details:   https://anonhg.NetBSD.org/src/rev/4acbfa9ca7e8
branches:  trunk
changeset: 447068:4acbfa9ca7e8
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Dec 30 01:48:37 2018 +0000

description:
binutils 2.31.1 can put copy relocations in the relro segment. Delay
protecting the relro segment for the main object until copy relocations
are done.

diffstat:

 libexec/ld.elf_so/reloc.c |  22 +++++++++-------------
 libexec/ld.elf_so/rtld.c  |  23 +++++++++++++++++++++--
 libexec/ld.elf_so/rtld.h  |   4 +++-
 3 files changed, 33 insertions(+), 16 deletions(-)

diffs (121 lines):

diff -r 70d5dfc26457 -r 4acbfa9ca7e8 libexec/ld.elf_so/reloc.c
--- a/libexec/ld.elf_so/reloc.c Sun Dec 30 00:42:47 2018 +0000
+++ b/libexec/ld.elf_so/reloc.c Sun Dec 30 01:48:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: reloc.c,v 1.113 2018/10/17 23:36:58 joerg Exp $         */
+/*     $NetBSD: reloc.c,v 1.114 2018/12/30 01:48:37 christos Exp $      */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -39,7 +39,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: reloc.c,v 1.113 2018/10/17 23:36:58 joerg Exp $");
+__RCSID("$NetBSD: reloc.c,v 1.114 2018/12/30 01:48:37 christos Exp $");
 #endif /* not lint */
 
 #include <err.h>
@@ -102,10 +102,10 @@
                return (-1);
        }
        srcaddr = (const void *)(srcobj->relocbase + srcsym->st_value);
-       (void)memcpy(dstaddr, srcaddr, size);
        rdbg(("COPY %s %s %s --> src=%p dst=%p size %ld",
            dstobj->path, srcobj->path, name, srcaddr,
            (void *)dstaddr, (long)size));
+       (void)memcpy(dstaddr, srcaddr, size);
        return (0);
 }
 #endif /* RTLD_INHIBIT_COPY_RELOCS */
@@ -149,6 +149,10 @@
                        }
                }
        }
+#ifdef GNU_RELRO
+       if (_rtld_relro(dstobj, true) == -1)
+               return -1;
+#endif
 #endif /* RTLD_INHIBIT_COPY_RELOCS */
 
        return (0);
@@ -225,18 +229,10 @@
                if (obj->pltgot != NULL)
                        _rtld_setup_pltgot(obj);
 #ifdef GNU_RELRO
-               if (obj->relro_size > 0) {
-                       if (mprotect(obj->relro_page, obj->relro_size,
-                           PROT_READ) == -1) {
-                               _rtld_error("%s: Cannot enforce relro "
-                                   "protection: %s", obj->path,
-                                   xstrerror(errno));
-                               return -1;
-                       }
-               }
+               if (_rtld_relro(obj, false) == -1)
+                       return -1;
 #endif
        }
-
        return 0;
 }
 
diff -r 70d5dfc26457 -r 4acbfa9ca7e8 libexec/ld.elf_so/rtld.c
--- a/libexec/ld.elf_so/rtld.c  Sun Dec 30 00:42:47 2018 +0000
+++ b/libexec/ld.elf_so/rtld.c  Sun Dec 30 01:48:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld.c,v 1.194 2018/12/27 18:57:43 christos Exp $       */
+/*     $NetBSD: rtld.c,v 1.195 2018/12/30 01:48:37 christos Exp $       */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.194 2018/12/27 18:57:43 christos Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.195 2018/12/30 01:48:37 christos Exp $");
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -1746,3 +1746,22 @@
 
        sigprocmask(SIG_SETMASK, mask, NULL);
 }
+
+int
+_rtld_relro(const Obj_Entry *obj, bool wantmain)
+{
+#ifdef GNU_RELRO
+       if (obj->relro_size == 0)
+               return 0;
+       if (wantmain != (obj ==_rtld_objmain))
+               return 0;
+
+       dbg(("RELRO %s %p %lx\n", obj->path, obj->relro_page, obj->relro_size));
+       if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) {
+               _rtld_error("%s: Cannot enforce relro " "protection: %s",
+                   obj->path, xstrerror(errno));
+               return -1;
+       }
+#endif
+       return 0;
+}
diff -r 70d5dfc26457 -r 4acbfa9ca7e8 libexec/ld.elf_so/rtld.h
--- a/libexec/ld.elf_so/rtld.h  Sun Dec 30 00:42:47 2018 +0000
+++ b/libexec/ld.elf_so/rtld.h  Sun Dec 30 01:48:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld.h,v 1.135 2018/11/26 17:40:26 joerg Exp $  */
+/*     $NetBSD: rtld.h,v 1.136 2018/12/30 01:48:37 christos Exp $       */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -372,6 +372,8 @@
 void _rtld_exclusive_enter(sigset_t *);
 void _rtld_exclusive_exit(sigset_t *);
 
+int _rtld_relro(const Obj_Entry *, bool);
+
 /* expand.c */
 size_t _rtld_expand_path(char *, size_t, const char *, const char *,\
     const char *);