Date: Thu, 22 Dec 2016 17:44:27 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r310422 - head/libexec/rtld-elf Message-ID: <201612221744.uBMHiRFW059462@repo.freebsd.org>
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Author: markj Date: Thu Dec 22 17:44:27 2016 New Revision: 310422 URL: https://svnweb.freebsd.org/changeset/base/310422 Log: rtld: Fix a couple of bugs around the unloading of ELF filters. - Pass the correct object to unload_filtees(). - Use a marker to restart iteration after unload_filtees() has returned. It calls dlclose() and may recursively remove entries from the global object list, so TAILQ_FOREACH_SAFE is not sufficient. Reviewed by: kib MFC after: 2 weeks Sponsored by: Dell EMC Isilon Modified: head/libexec/rtld-elf/rtld.c Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Thu Dec 22 17:41:32 2016 (r310421) +++ head/libexec/rtld-elf/rtld.c Thu Dec 22 17:44:27 2016 (r310422) @@ -90,6 +90,7 @@ static const char *gethints(bool); static void hold_object(Obj_Entry *); static void unhold_object(Obj_Entry *); static void init_dag(Obj_Entry *); +static void init_marker(Obj_Entry *); static void init_pagesizes(Elf_Auxinfo **aux_info); static void init_rtld(caddr_t, Elf_Auxinfo **); static void initlist_add_neededs(Needed_Entry *, Objlist *); @@ -1829,6 +1830,14 @@ init_dag(Obj_Entry *root) root->dag_inited = true; } +static void +init_marker(Obj_Entry *marker) +{ + + bzero(marker, sizeof(*marker)); + marker->marker = true; +} + Obj_Entry * globallist_curr(const Obj_Entry *obj) { @@ -3566,8 +3575,7 @@ dl_iterate_phdr(__dl_iterate_hdr_callbac RtldLockState bind_lockstate, phdr_lockstate; int error; - bzero(&marker, sizeof(marker)); - marker.marker = true; + init_marker(&marker); error = 0; wlock_acquire(rtld_phdr_lock, &phdr_lockstate); @@ -4419,7 +4427,7 @@ trace_loaded_objects(Obj_Entry *obj) static void unload_object(Obj_Entry *root) { - Obj_Entry *obj, *obj1; + Obj_Entry marker, *obj, *next; assert(root->refcount == 0); @@ -4430,7 +4438,8 @@ unload_object(Obj_Entry *root) unlink_object(root); /* Unmap all objects that are no longer referenced. */ - TAILQ_FOREACH_SAFE(obj, &obj_list, next, obj1) { + for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { + next = TAILQ_NEXT(obj, next); if (obj->marker || obj->refcount != 0) continue; LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, @@ -4444,7 +4453,16 @@ unload_object(Obj_Entry *root) TAILQ_REMOVE(&obj_list, obj, next); obj_count--; - unload_filtees(root); + if (obj->filtees_loaded) { + if (next != NULL) { + init_marker(&marker); + TAILQ_INSERT_BEFORE(next, &marker, next); + unload_filtees(obj); + next = TAILQ_NEXT(&marker, next); + TAILQ_REMOVE(&obj_list, &marker, next); + } else + unload_filtees(obj); + } release_object(obj); } }
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