Constraints in libmap(32).conf do not work as expected, possible bug in rtld-elf
Konstantin Belousov
kostikbel at gmail.com
Fri Sep 21 13:48:46 UTC 2018
On Tue, Sep 11, 2018 at 10:47:58PM +0200, Andreas Longwitz wrote:
> Thanks very much for answer !
>
> Now I use the following libmap32.conf:
>
> ## php52
> [/usr/local/php52/lib/php/20060613/mysql.so]
> /usr/local/lib/mysql /usr/local/lib32/mysql
> [/usr/local/php52/]
> /usr/local/lib /usr/local/lib32
>
> > I am having problem understanding what do you mean by step1/step2. The
> > refobj reference that you cache in the patch, comes into load_object()
> > as the pointer to the object which initiate the load_object() call. It
> > is NULL for preloaded objects, otherwise it is not.
> > So, could you, please, explain where does it get passed as NULL in your
> > case ?
>
> Ok, I try to explain better:
>
> step1 means: call of lm_find() in rtld.c (line 1500) and first argument
> is refobj->path, which is used in libmap.c to find the correct entry in
> the lmp_list.
>
> step2 means: call of lm_findn() in rtld.c (line 2834) when called from
> search_library_path(). In this case the first argument is NULL and in
> libmap.c this means "$DEFAULT" entry in the lmp_list. Please notice that
> after reading libmap32.conf in lm_init() the entry $DEFAULT in the
> lmp_list does not exist, when all mappings are defined with constraints.
Can you try this instead ?
diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index dfd0388478f..83d5e28e287 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -125,7 +125,7 @@ static void objlist_remove(Objlist *, Obj_Entry *);
static int open_binary_fd(const char *argv0, bool search_in_path);
static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp);
static int parse_integer(const char *);
-static void *path_enumerate(const char *, path_enum_proc, void *);
+static void *path_enumerate(const char *, path_enum_proc, const char *, void *);
static void print_usage(const char *argv0);
static void release_object(Obj_Entry *);
static int relocate_object_dag(Obj_Entry *root, bool bind_now,
@@ -140,7 +140,8 @@ static int rtld_dirname(const char *, char *);
static int rtld_dirname_abs(const char *, char *);
static void *rtld_dlopen(const char *name, int fd, int mode);
static void rtld_exit(void);
-static char *search_library_path(const char *, const char *, int *);
+static char *search_library_path(const char *, const char *, const char *,
+ int *);
static char *search_library_pathfds(const char *, const char *, int *);
static const void **get_program_var_addr(const char *, RtldLockState *);
static void set_program_var(const char *, const void *);
@@ -1576,8 +1577,7 @@ gnu_hash(const char *s)
static char *
find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
{
- char *pathname;
- char *name;
+ char *name, *pathname, *refobj_path;
bool nodeflib, objgiven;
objgiven = refobj != NULL;
@@ -1597,6 +1597,7 @@ find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
}
dbg(" Searching for \"%s\"", name);
+ refobj_path = objgiven ? refobj->path : NULL;
/*
* If refobj->rpath != NULL, then refobj->runpath is NULL. Fall
@@ -1605,52 +1606,61 @@ find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
* nodeflib.
*/
if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
- pathname = search_library_path(name, ld_library_path, fdp);
+ pathname = search_library_path(name, ld_library_path,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
if (refobj != NULL) {
- pathname = search_library_path(name, refobj->rpath, fdp);
+ pathname = search_library_path(name, refobj->rpath,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
}
pathname = search_library_pathfds(name, ld_library_dirs, fdp);
if (pathname != NULL)
return (pathname);
- pathname = search_library_path(name, gethints(false), fdp);
+ pathname = search_library_path(name, gethints(false),
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
- pathname = search_library_path(name, ld_standard_library_path, fdp);
+ pathname = search_library_path(name, ld_standard_library_path,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
} else {
nodeflib = objgiven ? refobj->z_nodeflib : false;
if (objgiven) {
- pathname = search_library_path(name, refobj->rpath, fdp);
+ pathname = search_library_path(name, refobj->rpath,
+ refobj->path, fdp);
if (pathname != NULL)
return (pathname);
}
if (objgiven && refobj->runpath == NULL && refobj != obj_main) {
- pathname = search_library_path(name, obj_main->rpath, fdp);
+ pathname = search_library_path(name, obj_main->rpath,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
}
- pathname = search_library_path(name, ld_library_path, fdp);
+ pathname = search_library_path(name, ld_library_path,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
if (objgiven) {
- pathname = search_library_path(name, refobj->runpath, fdp);
+ pathname = search_library_path(name, refobj->runpath,
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
}
pathname = search_library_pathfds(name, ld_library_dirs, fdp);
if (pathname != NULL)
return (pathname);
- pathname = search_library_path(name, gethints(nodeflib), fdp);
+ pathname = search_library_path(name, gethints(nodeflib),
+ refobj_path, fdp);
if (pathname != NULL)
return (pathname);
if (objgiven && !nodeflib) {
pathname = search_library_path(name,
- ld_standard_library_path, fdp);
+ ld_standard_library_path, refobj_path, fdp);
if (pathname != NULL)
return (pathname);
}
@@ -1845,8 +1855,9 @@ gethints(bool nostdlib)
hargs.request = RTLD_DI_SERINFOSIZE;
hargs.serinfo = &hmeta;
- path_enumerate(ld_standard_library_path, fill_search_info, &sargs);
- path_enumerate(hints, fill_search_info, &hargs);
+ path_enumerate(ld_standard_library_path, fill_search_info, NULL,
+ &sargs);
+ path_enumerate(hints, fill_search_info, NULL, &hargs);
SLPinfo = xmalloc(smeta.dls_size);
hintinfo = xmalloc(hmeta.dls_size);
@@ -1864,8 +1875,9 @@ gethints(bool nostdlib)
hargs.serpath = &hintinfo->dls_serpath[0];
hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
- path_enumerate(ld_standard_library_path, fill_search_info, &sargs);
- path_enumerate(hints, fill_search_info, &hargs);
+ path_enumerate(ld_standard_library_path, fill_search_info, NULL,
+ &sargs);
+ path_enumerate(hints, fill_search_info, NULL, &hargs);
/*
* Now calculate the difference between two sets, by excluding
@@ -2974,7 +2986,8 @@ rtld_exit(void)
* callback on the result.
*/
static void *
-path_enumerate(const char *path, path_enum_proc callback, void *arg)
+path_enumerate(const char *path, path_enum_proc callback,
+ const char *refobj_path, void *arg)
{
const char *trans;
if (path == NULL)
@@ -2986,7 +2999,7 @@ path_enumerate(const char *path, path_enum_proc callback, void *arg)
char *res;
len = strcspn(path, ":;");
- trans = lm_findn(NULL, path, len);
+ trans = lm_findn(refobj_path, path, len);
if (trans)
res = callback(trans, strlen(trans), arg);
else
@@ -3045,7 +3058,8 @@ try_library_path(const char *dir, size_t dirlen, void *param)
}
static char *
-search_library_path(const char *name, const char *path, int *fdp)
+search_library_path(const char *name, const char *path,
+ const char *refobj_path, int *fdp)
{
char *p;
struct try_library_args arg;
@@ -3059,7 +3073,7 @@ search_library_path(const char *name, const char *path, int *fdp)
arg.buflen = PATH_MAX;
arg.fd = -1;
- p = path_enumerate(path, try_library_path, &arg);
+ p = path_enumerate(path, try_library_path, refobj_path, &arg);
*fdp = arg.fd;
free(arg.buffer);
@@ -3776,12 +3790,12 @@ do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
_info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
_info.dls_cnt = 0;
- path_enumerate(obj->rpath, fill_search_info, &args);
- path_enumerate(ld_library_path, fill_search_info, &args);
- path_enumerate(obj->runpath, fill_search_info, &args);
- path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
+ path_enumerate(obj->rpath, fill_search_info, NULL, &args);
+ path_enumerate(ld_library_path, fill_search_info, NULL, &args);
+ path_enumerate(obj->runpath, fill_search_info, NULL, &args);
+ path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args);
if (!obj->z_nodeflib)
- path_enumerate(ld_standard_library_path, fill_search_info, &args);
+ path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args);
if (request == RTLD_DI_SERINFOSIZE) {
@@ -3801,25 +3815,25 @@ do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
args.flags = LA_SER_RUNPATH;
- if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
+ if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL)
return (-1);
args.flags = LA_SER_LIBPATH;
- if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
+ if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL)
return (-1);
args.flags = LA_SER_RUNPATH;
- if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
+ if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL)
return (-1);
args.flags = LA_SER_CONFIG;
- if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
+ if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args)
!= NULL)
return (-1);
args.flags = LA_SER_DEFAULT;
- if (!obj->z_nodeflib &&
- path_enumerate(ld_standard_library_path, fill_search_info, &args) != NULL)
+ if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path,
+ fill_search_info, NULL, &args) != NULL)
return (-1);
return (0);
}
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