Index: libexec/rtld-elf/amd64/reloc.c
===================================================================
--- libexec/rtld-elf/amd64/reloc.c
+++ libexec/rtld-elf/amd64/reloc.c
@@ -67,7 +67,7 @@
 
     assert(dstobj->mainprog);	/* COPY relocations are invalid elsewhere */
 
-    relalim = (const Elf_Rela *) ((caddr_t) dstobj->rela + dstobj->relasize);
+    relalim = (const Elf_Rela *) ((const char*) dstobj->rela + dstobj->relasize);
     for (rela = dstobj->rela;  rela < relalim;  rela++) {
 	if (ELF_R_TYPE(rela->r_info) == R_X86_64_COPY) {
 	    void *dstaddr;
@@ -147,7 +147,7 @@
 	} else
 		cache = NULL;
 
-	relalim = (const Elf_Rela *)((caddr_t)obj->rela + obj->relasize);
+	relalim = (const Elf_Rela *)((const char*)obj->rela + obj->relasize);
 	for (rela = obj->rela;  rela < relalim;  rela++) {
 		/*
 		 * First, resolve symbol for relocations which
@@ -254,7 +254,8 @@
 			 * of space, we generate an error.
 			 */
 			if (!defobj->tls_done) {
-				if (!allocate_tls_offset((Obj_Entry*) defobj)) {
+				if (!allocate_tls_offset(
+				    __DECONST(Obj_Entry*, defobj))) {
 					_rtld_error("%s: No space available "
 					    "for static Thread Local Storage",
 					    obj->path);
@@ -274,7 +275,8 @@
 			 * of space, we generate an error.
 			 */
 			if (!defobj->tls_done) {
-				if (!allocate_tls_offset((Obj_Entry*) defobj)) {
+				if (!allocate_tls_offset(
+				    __DECONST(Obj_Entry*, defobj))) {
 					_rtld_error("%s: No space available "
 					    "for static Thread Local Storage",
 					    obj->path);
@@ -322,7 +324,7 @@
     const Elf_Rela *relalim;
     const Elf_Rela *rela;
 
-    relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+    relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
     for (rela = obj->pltrela;  rela < relalim;  rela++) {
 	Elf_Addr *where;
 
@@ -355,7 +357,7 @@
 
     if (obj->jmpslots_done)
 	return 0;
-    relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+    relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
     for (rela = obj->pltrela;  rela < relalim;  rela++) {
 	Elf_Addr *where, target;
 	const Elf_Sym *def;
@@ -392,8 +394,9 @@
 /* Fixup the jump slot at "where" to transfer control to "target". */
 Elf_Addr
 reloc_jmpslot(Elf_Addr *where, Elf_Addr target,
-    const struct Struct_Obj_Entry *obj, const struct Struct_Obj_Entry *refobj,
-    const Elf_Rel *rel)
+    const struct Struct_Obj_Entry *obj  __unused,
+    const struct Struct_Obj_Entry *refobj  __unused,
+    const Elf_Rel *rel  __unused)
 {
 #ifdef dbg
 	dbg("reloc_jmpslot: *%p = %p", where, (void *)target);
@@ -411,7 +414,7 @@
 
     if (!obj->irelative)
 	return (0);
-    relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+    relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
     for (rela = obj->pltrela;  rela < relalim;  rela++) {
 	Elf_Addr *where, target, *ptr;
 
@@ -441,7 +444,7 @@
 
     if (!obj->gnu_ifunc)
 	return (0);
-    relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize);
+    relalim = (const Elf_Rela *)((const char *)obj->pltrela + obj->pltrelasize);
     for (rela = obj->pltrela;  rela < relalim;  rela++) {
 	Elf_Addr *where, target;
 	const Elf_Sym *def;
Index: libexec/rtld-elf/libmap.c
===================================================================
--- libexec/rtld-elf/libmap.c
+++ libexec/rtld-elf/libmap.c
@@ -44,8 +44,8 @@
 static int lm_count;
 
 static void lmc_parse(char *, size_t);
-static void lmc_parse_file(char *);
-static void lmc_parse_dir(char *);
+static void lmc_parse_file(const char *);
+static void lmc_parse_dir(const char *);
 static void lm_add(const char *, const char *, const char *);
 static void lm_free(struct lm_list *);
 static char *lml_find(struct lm_list *, const char *);
@@ -96,7 +96,7 @@
 }
 
 static void
-lmc_parse_file(char *path)
+lmc_parse_file(const char *path)
 {
 	struct lmc *p;
 	char *lm_map;
@@ -149,7 +149,7 @@
 }
 
 static void
-lmc_parse_dir(char *idir)
+lmc_parse_dir(const char *idir)
 {
 	DIR *d;
 	struct dirent *dp;
Index: libexec/rtld-elf/map_object.c
===================================================================
--- libexec/rtld-elf/map_object.c
+++ libexec/rtld-elf/map_object.c
@@ -301,7 +301,7 @@
 	    _rtld_error("%s: cannot allocate program header", path);
 	    goto error1;
 	}
-	memcpy((char *)obj->phdr, (char *)hdr + hdr->e_phoff, phsize);
+	memcpy(__DECONST(char *, obj->phdr), (char *)hdr + hdr->e_phoff, phsize);
 	obj->phdr_alloc = true;
     }
     obj->phsize = phsize;
@@ -430,13 +430,13 @@
     if (obj->origin_path)
 	free(obj->origin_path);
     if (obj->z_origin)
-	free(obj->rpath);
+	free(__DECONST(void*, obj->rpath));
     if (obj->priv)
 	free(obj->priv);
     if (obj->path)
 	free(obj->path);
     if (obj->phdr_alloc)
-	free((void *)obj->phdr);
+	free(__DECONST(void *, obj->phdr));
     free(obj);
 }
 
Index: libexec/rtld-elf/paths.h
===================================================================
--- libexec/rtld-elf/paths.h
+++ libexec/rtld-elf/paths.h
@@ -69,10 +69,10 @@
 #define	SOFT_STANDARD_LIBRARY_PATH "/usr/libsoft"
 #define	LD_SOFT_		"LD_SOFT_"
 
-extern char *ld_elf_hints_default;
-extern char *ld_path_libmap_conf;
-extern char *ld_path_rtld;
-extern char *ld_standard_library_path;
-extern char *ld_env_prefix;
+extern const char *ld_elf_hints_default;
+extern const char *ld_path_libmap_conf;
+extern const char *ld_path_rtld;
+extern const char *ld_standard_library_path;
+extern const char *ld_env_prefix;
 
 #endif /* PATHS_H */
Index: libexec/rtld-elf/rtld.h
===================================================================
--- libexec/rtld-elf/rtld.h
+++ libexec/rtld-elf/rtld.h
@@ -211,12 +211,12 @@
     Elf32_Word maskwords_bm_gnu;  	/* Bloom filter words - 1 (bitmask) */
     Elf32_Word shift2_gnu;		/* Bloom filter shift count */
     Elf32_Word dynsymcount;		/* Total entries in dynsym table */
-    Elf_Addr *bloom_gnu;		/* Bloom filter used by GNU hash func */
+    const Elf_Addr *bloom_gnu;		/* Bloom filter used by GNU hash func */
     const Elf_Hashelt *buckets_gnu;	/* GNU hash table bucket array */
     const Elf_Hashelt *chain_zero_gnu;	/* GNU hash table value array (Zeroed) */
 
-    char *rpath;		/* Search path specified in object */
-    char *runpath;		/* Search path with different priority */
+    const char *rpath;		/* Search path specified in object */
+    const char *runpath;	/* Search path with different priority */
     Needed_Entry *needed;	/* Shared objects needed by this one (%) */
     Needed_Entry *needed_filtees;
     Needed_Entry *needed_aux_filtees;
Index: libexec/rtld-elf/rtld.c
===================================================================
--- libexec/rtld-elf/rtld.c
+++ libexec/rtld-elf/rtld.c
@@ -158,7 +158,7 @@
 static void ref_dag(Obj_Entry *);
 static char *origin_subst_one(Obj_Entry *, char *, const char *,
     const char *, bool);
-static char *origin_subst(Obj_Entry *, char *);
+static char *origin_subst(Obj_Entry *, const char *);
 static bool obj_resolve_origin(Obj_Entry *obj);
 static void preinit_main(void);
 static int  rtld_verify_versions(const Objlist *);
@@ -195,8 +195,8 @@
 static char *ld_library_dirs;	/* Environment variable for library descriptors */
 static char *ld_preload;	/* Environment variable for libraries to
 				   load first */
-static char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
-static char *ld_tracing;	/* Called from ldd to print libs */
+static const char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
+static const char *ld_tracing;	/* Called from ldd to print libs */
 static char *ld_utrace;		/* Use utrace() to log events. */
 static struct obj_entry_q obj_list;	/* Queue of all loaded objects */
 static Obj_Entry *obj_main;	/* The main program shared object */
@@ -276,11 +276,11 @@
 /*
  * Globals for path names, and such
  */
-char *ld_elf_hints_default = _PATH_ELF_HINTS;
-char *ld_path_libmap_conf = _PATH_LIBMAP_CONF;
-char *ld_path_rtld = _PATH_RTLD;
-char *ld_standard_library_path = STANDARD_LIBRARY_PATH;
-char *ld_env_prefix = LD_;
+const char *ld_elf_hints_default = _PATH_ELF_HINTS;
+const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF;
+const char *ld_path_rtld = _PATH_RTLD;
+const char *ld_standard_library_path = STANDARD_LIBRARY_PATH;
+const char *ld_env_prefix = LD_;
 
 /*
  * Fill in a DoneList with an allocation large enough to hold all of
@@ -362,7 +362,8 @@
     RtldLockState lockstate;
     struct stat st;
     Elf_Addr *argcp;
-    char **argv, *argv0, **env, **envp, *kexecpath, *library_path_rpath;
+    char **argv, **env, **envp, *kexecpath, *library_path_rpath;
+    const char *argv0;
     caddr_t imgentry;
     char buf[MAXPATHLEN];
     int argc, fd, i, phnum, rtld_argc;
@@ -796,9 +797,9 @@
     if (sigsetjmp(lockstate.env, 0) != 0)
 	    lock_upgrade(rtld_bind_lock, &lockstate);
     if (obj->pltrel)
-	rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
+	rel = (const Elf_Rel *) ((const char*) obj->pltrel + reloff);
     else
-	rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
+	rel = (const Elf_Rel *) ((const char*) obj->pltrela + reloff);
 
     where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
     def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT,
@@ -943,7 +944,7 @@
 }
 
 static char *
-origin_subst(Obj_Entry *obj, char *real)
+origin_subst(Obj_Entry *obj, const char *real)
 {
 	char *res1, *res2, *res3, *res4;
 
@@ -955,7 +956,9 @@
 			return (NULL);
 		}
 	}
-	res1 = origin_subst_one(obj, real, "$ORIGIN", NULL, false);
+	/* __DECONST is safe here since without may_free real is unchanged */
+	res1 = origin_subst_one(obj, __DECONST(char*, real), "$ORIGIN", NULL,
+	    false);
 	res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true);
 	res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true);
 	res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true);
@@ -1102,7 +1105,7 @@
 		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
 		obj->maskwords_bm_gnu = nmaskwords - 1;
 		obj->shift2_gnu = hashtab[3];
-		obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
+		obj->bloom_gnu = (const Elf_Addr *) (hashtab + 4);
 		obj->buckets_gnu = hashtab + 4 + bloom_size32;
 		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
 		  obj->symndx_gnu;
@@ -1217,7 +1220,7 @@
 	case DT_DEBUG:
 	    if (!early)
 		dbg("Filling in DT_DEBUG entry");
-	    ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
+	    (__DECONST(Elf_Dyn*, dynp))->d_un.d_ptr = (Elf_Addr) &r_debug;
 	    break;
 #endif
 
@@ -1336,10 +1339,10 @@
 		rtld_die();
 
 	if (dyn_runpath != NULL) {
-		obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
+		obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val;
 		obj->runpath = origin_subst(obj, obj->runpath);
 	} else if (dyn_rpath != NULL) {
-		obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
+		obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val;
 		obj->rpath = origin_subst(obj, obj->rpath);
 	}
 	if (dyn_soname != NULL)
@@ -1379,7 +1382,7 @@
 
 	obj->phdr = phdr;
 	obj->phsize = ph->p_memsz;
-	obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
+	obj->relocbase = __DECONST(char*, phdr) - ph->p_vaddr;
 	break;
     }
 
@@ -1586,14 +1589,14 @@
 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
 {
 	char *pathname;
-	char *name;
+	const char *name;
 	bool nodeflib, objgiven;
 
 	objgiven = refobj != NULL;
 
 	if (libmap_disable || !objgiven ||
 	    (name = lm_find(refobj->path, xname)) == NULL)
-		name = (char *)xname;
+		name = xname;
 
 	if (strchr(name, '/') != NULL) {	/* Hard coded pathname */
 		if (name[0] != '/' && !trust) {
@@ -1772,7 +1775,8 @@
 static const char *
 gethints(bool nostdlib)
 {
-	static char *hints, *filtered_path;
+	static char *filtered_path;
+	static const char *hints;
 	static struct elfhints_hdr hdr;
 	struct fill_search_info_args sargs, hargs;
 	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
@@ -3201,11 +3205,11 @@
  */
 void
 dllockinit(void *context,
-	   void *(*lock_create)(void *context),
-           void (*rlock_acquire)(void *lock),
-           void (*wlock_acquire)(void *lock),
-           void (*lock_release)(void *lock),
-           void (*lock_destroy)(void *lock),
+	   void *(*lock_create)(void *context) __unused,
+           void (*rlock_acquire)(void *lock) __unused,
+           void (*wlock_acquire)(void *lock)  __unused,
+           void (*lock_release)(void *lock) __unused,
+           void (*lock_destroy)(void *lock) __unused,
 	   void (*context_destroy)(void *context))
 {
     static void *cur_context;
@@ -3244,7 +3248,7 @@
 	rlock_acquire(rtld_bind_lock, &lockstate);
 	if (sigsetjmp(lockstate.env, 0) != 0)
 	    lock_upgrade(rtld_bind_lock, &lockstate);
-	environ = (char **)*get_program_var_addr("environ", &lockstate);
+	environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate));
 	lock_release(rtld_bind_lock, &lockstate);
     }
     lo_flags = RTLD_LO_DLOPEN;
@@ -3957,7 +3961,7 @@
  *  +0   RetAddr
  */
 void
-r_debug_state(struct r_debug* rd, struct link_map *m)
+r_debug_state(struct r_debug* rd __unused, struct link_map *m  __unused)
 {
     /*
      * The following is a hack to force the compiler to emit calls to
@@ -3975,7 +3979,7 @@
  * main is not available in the symbol table.
  */
 void
-_r_debug_postinit(struct link_map *m)
+_r_debug_postinit(struct link_map *m __unused)
 {
 
 	/* See r_debug_state(). */
@@ -4466,7 +4470,7 @@
 static void
 trace_loaded_objects(Obj_Entry *obj)
 {
-    char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
+    const char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
     int		c;
 
     if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL)
@@ -4482,7 +4486,7 @@
 
     for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
 	Needed_Entry		*needed;
-	char			*name, *path;
+	const char			*name, *path;
 	bool			is_lib;
 
 	if (obj->marker)
@@ -4498,7 +4502,7 @@
 	    } else
 		path = "not found";
 
-	    name = (char *)obj->strtab + needed->name;
+	    name = obj->strtab + needed->name;
 	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
 
 	    fmt = is_lib ? fmt1 : fmt2;
@@ -4900,7 +4904,7 @@
 }
 
 void
-free_tls(void *tls, size_t tcbsize, size_t tcbalign)
+free_tls(void *tls, size_t tcbsize  __unused, size_t tcbalign)
 {
     Elf_Addr* dtv;
     size_t size, ralign;
@@ -5116,13 +5120,13 @@
 	}
 	if (vna->vna_hash == vd->vd_hash) {
 	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
-		((char *)vd + vd->vd_aux);
+		((const char *)vd + vd->vd_aux);
 	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
 		return (0);
 	}
 	if (vd->vd_next == 0)
 	    break;
-	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
+	vd = (const Elf_Verdef *) ((const char *)vd + vd->vd_next);
     }
     if (vna->vna_flags & VER_FLG_WEAK)
 	return (0);
@@ -5158,18 +5162,18 @@
 		obj->path, vn->vn_version);
 	    return (-1);
 	}
-	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
+	vna = (const Elf_Vernaux *) ((const char *)vn + vn->vn_aux);
 	for (;;) {
 	    vernum = VER_NEED_IDX(vna->vna_other);
 	    if (vernum > maxvernum)
 		maxvernum = vernum;
 	    if (vna->vna_next == 0)
 		 break;
-	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
+	    vna = (const Elf_Vernaux *) ((const char *)vna + vna->vna_next);
 	}
 	if (vn->vn_next == 0)
 	    break;
-	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
+	vn = (const Elf_Verneed *) ((const char *)vn + vn->vn_next);
     }
 
     vd = obj->verdef;
@@ -5184,7 +5188,7 @@
 		maxvernum = vernum;
 	if (vd->vd_next == 0)
 	    break;
-	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
+	vd = (const Elf_Verdef *) ((const char *)vd + vd->vd_next);
     }
 
     if (maxvernum == 0)
@@ -5203,7 +5207,7 @@
 	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
 	    vernum = VER_DEF_IDX(vd->vd_ndx);
 	    assert(vernum <= maxvernum);
-	    vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
+	    vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux);
 	    obj->vertab[vernum].hash = vd->vd_hash;
 	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
 	    obj->vertab[vernum].file = NULL;
@@ -5211,7 +5215,7 @@
 	}
 	if (vd->vd_next == 0)
 	    break;
-	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
+	vd = (const Elf_Verdef *) ((const char *)vd + vd->vd_next);
     }
 
     vn = obj->verneed;
@@ -5219,7 +5223,7 @@
 	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
 	if (depobj == NULL)
 	    return (-1);
-	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
+	vna = (const Elf_Vernaux *) ((const char *)vn + vn->vn_aux);
 	for (;;) {
 	    if (check_object_provided_version(obj, depobj, vna))
 		return (-1);
@@ -5232,11 +5236,11 @@
 		VER_INFO_HIDDEN : 0;
 	    if (vna->vna_next == 0)
 		 break;
-	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
+	    vna = (const Elf_Vernaux *) ((const char *)vna + vna->vna_next);
 	}
 	if (vn->vn_next == 0)
 	    break;
-	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
+	vn = (const Elf_Verneed *) ((const char *)vn + vn->vn_next);
     }
     return 0;
 }
@@ -5563,7 +5567,7 @@
  * No unresolved symbols for rtld.
  */
 void
-__pthread_cxa_finalize(struct dl_phdr_info *a)
+__pthread_cxa_finalize(struct dl_phdr_info *a __unused)
 {
 }