svn commit: r189959 - head/libexec/rtld-elf
Konstantin Belousov
kib at FreeBSD.org
Wed Mar 18 06:40:38 PDT 2009
Author: kib
Date: Wed Mar 18 13:40:37 2009
New Revision: 189959
URL: http://svn.freebsd.org/changeset/base/189959
Log:
Implement the dynamic string token substitution in the rpath and
soneeded pathes. The $ORIGIN, $OSNAME, $OSREL and $PLATFORM tokens
are supported. Enabling the substitution requires DF_ORIGIN flag in
DT_FLAGS or DF_1_ORIGIN if DF_FLAGS_1, that may be set with -z origin
gnu ld flag. Translation is unconditionally disabled for setuid/setgid
processes.
The $ORIGIN translation relies on the AT_EXECPATH auxinfo supplied
by kernel.
Requested by: maho
Tested by: maho, pho
Reviewed by: kan
Modified:
head/libexec/rtld-elf/map_object.c
head/libexec/rtld-elf/rtld.c
head/libexec/rtld-elf/rtld.h
Modified: head/libexec/rtld-elf/map_object.c
==============================================================================
--- head/libexec/rtld-elf/map_object.c Wed Mar 18 13:19:46 2009 (r189958)
+++ head/libexec/rtld-elf/map_object.c Wed Mar 18 13:40:37 2009 (r189959)
@@ -348,6 +348,8 @@ obj_free(Obj_Entry *obj)
free(obj->vertab);
if (obj->origin_path)
free(obj->origin_path);
+ if (obj->z_origin)
+ free(obj->rpath);
if (obj->priv)
free(obj->priv);
if (obj->path)
Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c Wed Mar 18 13:19:46 2009 (r189958)
+++ head/libexec/rtld-elf/rtld.c Wed Mar 18 13:40:37 2009 (r189959)
@@ -41,6 +41,7 @@
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/uio.h>
+#include <sys/utsname.h>
#include <sys/ktrace.h>
#include <dlfcn.h>
@@ -118,6 +119,7 @@ static void objlist_remove_unref(Objlist
static void *path_enumerate(const char *, path_enum_proc, void *);
static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
static int rtld_dirname(const char *, char *);
+static int rtld_dirname_abs(const char *, char *);
static void rtld_exit(void);
static char *search_library_path(const char *, const char *);
static const void **get_program_var_addr(const char *);
@@ -134,6 +136,9 @@ static void unlink_object(Obj_Entry *);
static void unload_object(Obj_Entry *);
static void unref_dag(Obj_Entry *);
static void ref_dag(Obj_Entry *);
+static int origin_subst_one(char **res, const char *real, const char *kw,
+ const char *subst, char *may_free);
+static char *origin_subst(const char *real, const char *origin_path);
static int rtld_verify_versions(const Objlist *);
static int rtld_verify_object_versions(Obj_Entry *);
static void object_add_name(Obj_Entry *, const char *);
@@ -412,7 +417,25 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_
die();
}
- obj_main->path = xstrdup(argv0);
+ if (aux_info[AT_EXECPATH] != 0) {
+ char *kexecpath;
+ char buf[MAXPATHLEN];
+
+ kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
+ dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
+ if (kexecpath[0] == '/')
+ obj_main->path = kexecpath;
+ else if (getcwd(buf, sizeof(buf)) == NULL ||
+ strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
+ strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
+ obj_main->path = xstrdup(argv0);
+ else
+ obj_main->path = xstrdup(buf);
+ } else {
+ dbg("No AT_EXECPATH");
+ obj_main->path = xstrdup(argv0);
+ }
+ dbg("obj_main path %s", obj_main->path);
obj_main->mainprog = true;
/*
@@ -614,6 +637,83 @@ basename(const char *name)
return p != NULL ? p + 1 : name;
}
+static struct utsname uts;
+
+static int
+origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
+ char *may_free)
+{
+ const char *p, *p1;
+ char *res1;
+ int subst_len;
+ int kw_len;
+
+ res1 = *res = NULL;
+ p = real;
+ subst_len = kw_len = 0;
+ for (;;) {
+ p1 = strstr(p, kw);
+ if (p1 != NULL) {
+ if (subst_len == 0) {
+ subst_len = strlen(subst);
+ kw_len = strlen(kw);
+ }
+ if (*res == NULL) {
+ *res = xmalloc(PATH_MAX);
+ res1 = *res;
+ }
+ if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
+ _rtld_error("Substitution of %s in %s cannot be performed",
+ kw, real);
+ if (may_free != NULL)
+ free(may_free);
+ free(res);
+ return (false);
+ }
+ memcpy(res1, p, p1 - p);
+ res1 += p1 - p;
+ memcpy(res1, subst, subst_len);
+ res1 += subst_len;
+ p = p1 + kw_len;
+ } else {
+ if (*res == NULL) {
+ if (may_free != NULL)
+ *res = may_free;
+ else
+ *res = xstrdup(real);
+ return (true);
+ }
+ *res1 = '\0';
+ if (may_free != NULL)
+ free(may_free);
+ if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
+ free(res);
+ return (false);
+ }
+ return (true);
+ }
+ }
+}
+
+static char *
+origin_subst(const char *real, const char *origin_path)
+{
+ char *res1, *res2, *res3, *res4;
+
+ if (uts.sysname[0] == '\0') {
+ if (uname(&uts) != 0) {
+ _rtld_error("utsname failed: %d", errno);
+ return (NULL);
+ }
+ }
+ if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
+ !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
+ !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
+ !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
+ return (NULL);
+ return (res4);
+}
+
static void
die(void)
{
@@ -790,11 +890,8 @@ digest_dynamic(Obj_Entry *obj, int early
#endif
case DT_FLAGS:
- if (dynp->d_un.d_val & DF_ORIGIN) {
- obj->origin_path = xmalloc(PATH_MAX);
- if (rtld_dirname(obj->path, obj->origin_path) == -1)
- die();
- }
+ if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
+ obj->z_origin = true;
if (dynp->d_un.d_val & DF_SYMBOLIC)
obj->symbolic = true;
if (dynp->d_un.d_val & DF_TEXTREL)
@@ -826,6 +923,15 @@ digest_dynamic(Obj_Entry *obj, int early
break;
#endif
+ case DT_FLAGS_1:
+ if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
+ obj->z_origin = true;
+ if (dynp->d_un.d_val & DF_1_GLOBAL)
+ /* XXX */;
+ if (dynp->d_un.d_val & DF_1_BIND_NOW)
+ obj->bind_now = true;
+ break;
+
default:
if (!early) {
dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
@@ -844,8 +950,17 @@ digest_dynamic(Obj_Entry *obj, int early
obj->pltrelsize = 0;
}
- if (dyn_rpath != NULL)
- obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
+ if (obj->z_origin && obj->origin_path == NULL) {
+ obj->origin_path = xmalloc(PATH_MAX);
+ if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
+ die();
+ }
+
+ if (dyn_rpath != NULL) {
+ obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
+ if (obj->z_origin)
+ obj->rpath = origin_subst(obj->rpath, obj->origin_path);
+ }
if (dyn_soname != NULL)
object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
@@ -1003,7 +1118,10 @@ find_library(const char *xname, const Ob
xname);
return NULL;
}
- return xstrdup(xname);
+ if (refobj->z_origin)
+ return origin_subst(xname, refobj->origin_path);
+ else
+ return xstrdup(xname);
}
if (libmap_disable || (refobj == NULL) ||
@@ -2309,6 +2427,23 @@ rtld_dirname(const char *path, char *bna
return (0);
}
+static int
+rtld_dirname_abs(const char *path, char *base)
+{
+ char base_rel[PATH_MAX];
+
+ if (rtld_dirname(path, base) == -1)
+ return (-1);
+ if (base[0] == '/')
+ return (0);
+ if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
+ strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
+ strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
+ return (-1);
+ strcpy(base, base_rel);
+ return (0);
+}
+
static void
linkmap_add(Obj_Entry *obj)
{
Modified: head/libexec/rtld-elf/rtld.h
==============================================================================
--- head/libexec/rtld-elf/rtld.h Wed Mar 18 13:19:46 2009 (r189958)
+++ head/libexec/rtld-elf/rtld.h Wed Mar 18 13:40:37 2009 (r189959)
@@ -195,7 +195,7 @@ typedef struct Struct_Obj_Entry {
const Elf_Hashelt *chains; /* Hash table chain array */
unsigned long nchains; /* Number of chains */
- const char *rpath; /* Search path specified in object */
+ char *rpath; /* Search path specified in object */
Needed_Entry *needed; /* Shared objects needed by this one (%) */
STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we
@@ -216,6 +216,7 @@ typedef struct Struct_Obj_Entry {
bool init_done : 1; /* Already have added object to init list */
bool tls_done : 1; /* Already allocated offset for static TLS */
bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */
+ bool z_origin : 1; /* Process rpath and soname tokens */
struct link_map linkmap; /* for GDB and dlinfo() */
Objlist dldags; /* Object belongs to these dlopened DAGs (%) */
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