Author: kib
Date: Thu Mar 16 15:13:28 2017
New Revision: 315416
URL: https://svnweb.freebsd.org/changeset/base/315416
Log:
MFC r314973:
Avoid bind lock recursion.
Modified:
stable/11/libexec/rtld-elf/rtld.c
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/libexec/rtld-elf/rtld.c
==============================================================================
--- stable/11/libexec/rtld-elf/rtld.c Thu Mar 16 15:10:04 2017
(r315415)
+++ stable/11/libexec/rtld-elf/rtld.c Thu Mar 16 15:13:28 2017
(r315416)
@@ -77,6 +77,7 @@ static void digest_dynamic2(Obj_Entry *,
static void digest_dynamic(Obj_Entry *, int);
static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
static Obj_Entry *dlcheck(void *);
+static int dlclose_locked(void *, RtldLockState *);
static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
int lo_flags, int mode, RtldLockState *lockstate);
static Obj_Entry *do_load_object(int, const char *, char *, struct stat *,
int);
@@ -98,7 +99,7 @@ static void initlist_add_objects(Obj_Ent
static void linkmap_add(Obj_Entry *);
static void linkmap_delete(Obj_Entry *);
static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
-static void unload_filtees(Obj_Entry *);
+static void unload_filtees(Obj_Entry *, RtldLockState *);
static int load_needed_objects(Obj_Entry *, int);
static int load_preload_objects(void);
static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
@@ -142,7 +143,7 @@ static int symlook_obj1_sysv(SymLook *,
static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
static void trace_loaded_objects(Obj_Entry *);
static void unlink_object(Obj_Entry *);
-static void unload_object(Obj_Entry *);
+static void unload_object(Obj_Entry *, RtldLockState *lockstate);
static void unref_dag(Obj_Entry *);
static void ref_dag(Obj_Entry *);
static char *origin_subst_one(Obj_Entry *, char *, const char *,
@@ -2099,13 +2100,13 @@ initlist_add_objects(Obj_Entry *obj, Obj
#endif
static void
-free_needed_filtees(Needed_Entry *n)
+free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate)
{
Needed_Entry *needed, *needed1;
for (needed = n; needed != NULL; needed = needed->next) {
if (needed->obj != NULL) {
- dlclose(needed->obj);
+ dlclose_locked(needed->obj, lockstate);
needed->obj = NULL;
}
}
@@ -2116,14 +2117,14 @@ free_needed_filtees(Needed_Entry *n)
}
static void
-unload_filtees(Obj_Entry *obj)
+unload_filtees(Obj_Entry *obj, RtldLockState *lockstate)
{
- free_needed_filtees(obj->needed_filtees);
- obj->needed_filtees = NULL;
- free_needed_filtees(obj->needed_aux_filtees);
- obj->needed_aux_filtees = NULL;
- obj->filtees_loaded = false;
+ free_needed_filtees(obj->needed_filtees, lockstate);
+ obj->needed_filtees = NULL;
+ free_needed_filtees(obj->needed_aux_filtees, lockstate);
+ obj->needed_aux_filtees = NULL;
+ obj->filtees_loaded = false;
}
static void
@@ -3010,15 +3011,23 @@ search_library_pathfds(const char *name,
int
dlclose(void *handle)
{
+ RtldLockState lockstate;
+ int error;
+
+ wlock_acquire(rtld_bind_lock, &lockstate);
+ error = dlclose_locked(handle, &lockstate);
+ lock_release(rtld_bind_lock, &lockstate);
+ return (error);
+}
+
+static int
+dlclose_locked(void *handle, RtldLockState *lockstate)
+{
Obj_Entry *root;
- RtldLockState lockstate;
- wlock_acquire(rtld_bind_lock, &lockstate);
root = dlcheck(handle);
- if (root == NULL) {
- lock_release(rtld_bind_lock, &lockstate);
+ if (root == NULL)
return -1;
- }
LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
root->path);
@@ -3030,19 +3039,18 @@ dlclose(void *handle)
* The object will be no longer referenced, so we must unload it.
* First, call the fini functions.
*/
- objlist_call_fini(&list_fini, root, &lockstate);
+ objlist_call_fini(&list_fini, root, lockstate);
unref_dag(root);
/* Finish cleaning up the newly-unreferenced objects. */
GDB_STATE(RT_DELETE,&root->linkmap);
- unload_object(root);
+ unload_object(root, lockstate);
GDB_STATE(RT_CONSISTENT,NULL);
} else
unref_dag(root);
LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
- lock_release(rtld_bind_lock, &lockstate);
return 0;
}
@@ -3118,13 +3126,13 @@ rtld_dlopen(const char *name, int fd, in
}
static void
-dlopen_cleanup(Obj_Entry *obj)
+dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate)
{
obj->dl_refcount--;
unref_dag(obj);
if (obj->refcount == 0)
- unload_object(obj);
+ unload_object(obj, lockstate);
}
static Obj_Entry *
@@ -3173,7 +3181,7 @@ dlopen_object(const char *name, int fd,
(mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
(lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
lockstate) == -1) {
- dlopen_cleanup(obj);
+ dlopen_cleanup(obj, lockstate);
obj = NULL;
} else if (lo_flags & RTLD_LO_EARLY) {
/*
@@ -3230,7 +3238,7 @@ dlopen_object(const char *name, int fd,
(lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
lockstate) == -1) {
objlist_clear(&initlist);
- dlopen_cleanup(obj);
+ dlopen_cleanup(obj, lockstate);
if (lockstate == &mlockstate)
lock_release(rtld_bind_lock, lockstate);
return (NULL);
@@ -4424,7 +4432,7 @@ trace_loaded_objects(Obj_Entry *obj)
* reference count of 0.
*/
static void
-unload_object(Obj_Entry *root)
+unload_object(Obj_Entry *root, RtldLockState *lockstate)
{
Obj_Entry marker, *obj, *next;
@@ -4456,11 +4464,11 @@ unload_object(Obj_Entry *root)
if (next != NULL) {
init_marker(&marker);
TAILQ_INSERT_BEFORE(next, &marker, next);
- unload_filtees(obj);
+ unload_filtees(obj, lockstate);
next = TAILQ_NEXT(&marker, next);
TAILQ_REMOVE(&obj_list, &marker, next);
} else
- unload_filtees(obj);
+ unload_filtees(obj, lockstate);
}
release_object(obj);
}
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