diff options
author | CoprDistGit <infra@openeuler.org> | 2024-08-03 06:28:41 +0000 |
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committer | CoprDistGit <infra@openeuler.org> | 2024-08-03 06:28:41 +0000 |
commit | d20db0561a6a36f914fde030512503b114ef9a0c (patch) | |
tree | d4e5e3494d95c269a1cee6195f11bf3201bcadbf /elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch | |
parent | 016343d99b1b269d7246ef1e143d4b54914433d4 (diff) |
automatic import of glibcopeneuler22.03_LTS_SP4openeuler22.03_LTS_SP3openeuler20.03
Diffstat (limited to 'elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch')
-rw-r--r-- | elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch b/elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch new file mode 100644 index 0000000..da70902 --- /dev/null +++ b/elf-Avoid-deadlock-between-pthread_create-and-ctors-.patch @@ -0,0 +1,482 @@ +From 83b5323261bb72313bffcf37476c1b8f0847c736 Mon Sep 17 00:00:00 2001 +From: Szabolcs Nagy <szabolcs.nagy@arm.com> +Date: Wed, 15 Sep 2021 15:16:19 +0100 +Subject: [PATCH] elf: Avoid deadlock between pthread_create and ctors [BZ + #28357] + +The fix for bug 19329 caused a regression such that pthread_create can +deadlock when concurrent ctors from dlopen are waiting for it to finish. +Use a new GL(dl_load_tls_lock) in pthread_create that is not taken +around ctors in dlopen. + +The new lock is also used in __tls_get_addr instead of GL(dl_load_lock). + +The new lock is held in _dl_open_worker and _dl_close_worker around +most of the logic before/after the init/fini routines. When init/fini +routines are running then TLS is in a consistent, usable state. +In _dl_open_worker the new lock requires catching and reraising dlopen +failures that happen in the critical section. + +The new lock is reinitialized in a fork child, to keep the existing +behaviour and it is kept recursive in case malloc interposition or TLS +access from signal handlers can retake it. It is not obvious if this +is necessary or helps, but avoids changing the preexisting behaviour. + +The new lock may be more appropriate for dl_iterate_phdr too than +GL(dl_load_write_lock), since TLS state of an incompletely loaded +module may be accessed. If the new lock can replace the old one, +that can be a separate change. + +Fixes bug 28357. + +Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> +--- + elf/dl-close.c | 6 ++ + elf/dl-open.c | 35 +++++++++++- + elf/dl-support.c | 7 +++ + elf/dl-tls.c | 16 +++--- + elf/rtld.c | 1 + + posix/fork.c | 3 + + sysdeps/generic/ldsodefs.h | 9 ++- + sysdeps/pthread/Makefile | 10 +++- + sysdeps/pthread/tst-create1.c | 119 +++++++++++++++++++++++++++++++++++++++ + sysdeps/pthread/tst-create1mod.c | 41 ++++++++++++++ + 10 files changed, 235 insertions(+), 12 deletions(-) + create mode 100644 sysdeps/pthread/tst-create1.c + create mode 100644 sysdeps/pthread/tst-create1mod.c + +diff --git a/elf/dl-close.c b/elf/dl-close.c +index 93ff5c9..cfe0f1c 100644 +--- a/elf/dl-close.c ++++ b/elf/dl-close.c +@@ -549,6 +549,9 @@ _dl_close_worker (struct link_map *map, bool force) + size_t tls_free_end; + tls_free_start = tls_free_end = NO_TLS_OFFSET; + ++ /* Protects global and module specitic TLS state. */ ++ __rtld_lock_lock_recursive (GL(dl_load_tls_lock)); ++ + /* We modify the list of loaded objects. */ + __rtld_lock_lock_recursive (GL(dl_load_write_lock)); + +@@ -784,6 +787,9 @@ _dl_close_worker (struct link_map *map, bool force) + GL(dl_tls_static_used) = tls_free_start; + } + ++ /* TLS is cleaned up for the unloaded modules. */ ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); ++ + #ifdef SHARED + /* Auditing checkpoint: we have deleted all objects. */ + if (__glibc_unlikely (do_audit)) +diff --git a/elf/dl-open.c b/elf/dl-open.c +index 5295e93..6ea5dd2 100644 +--- a/elf/dl-open.c ++++ b/elf/dl-open.c +@@ -66,6 +66,9 @@ struct dl_open_args + libc_map value in the namespace in case of a dlopen failure. */ + bool libc_already_loaded; + ++ /* Set to true if the end of dl_open_worker_begin was reached. */ ++ bool worker_continue; ++ + /* Original parameters to the program and the current environment. */ + int argc; + char **argv; +@@ -482,7 +485,7 @@ call_dl_init (void *closure) + } + + static void +-dl_open_worker (void *a) ++dl_open_worker_begin (void *a) + { + struct dl_open_args *args = a; + const char *file = args->file; +@@ -774,6 +777,36 @@ dl_open_worker (void *a) + _dl_call_libc_early_init (libc_map, false); + } + ++ args->worker_continue = true; ++} ++ ++static void ++dl_open_worker (void *a) ++{ ++ struct dl_open_args *args = a; ++ ++ args->worker_continue = false; ++ ++ { ++ /* Protects global and module specific TLS state. */ ++ __rtld_lock_lock_recursive (GL(dl_load_tls_lock)); ++ ++ struct dl_exception ex; ++ int err = _dl_catch_exception (&ex, dl_open_worker_begin, args); ++ ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); ++ ++ if (__glibc_unlikely (ex.errstring != NULL)) ++ /* Reraise the error. */ ++ _dl_signal_exception (err, &ex, NULL); ++ } ++ ++ if (!args->worker_continue) ++ return; ++ ++ int mode = args->mode; ++ struct link_map *new = args->map; ++ + /* Run the initializer functions of new objects. Temporarily + disable the exception handler, so that lazy binding failures are + fatal. */ +diff --git a/elf/dl-support.c b/elf/dl-support.c +index 02e2ed7..d99c1f1 100644 +--- a/elf/dl-support.c ++++ b/elf/dl-support.c +@@ -228,6 +228,13 @@ __rtld_lock_define_initialized_recursive (, _dl_load_lock) + list of loaded objects while an object is added to or removed from + that list. */ + __rtld_lock_define_initialized_recursive (, _dl_load_write_lock) ++ /* This lock protects global and module specific TLS related data. ++ E.g. it is held in dlopen and dlclose when GL(dl_tls_generation), ++ GL(dl_tls_max_dtv_idx) or GL(dl_tls_dtv_slotinfo_list) are ++ accessed and when TLS related relocations are processed for a ++ module. It was introduced to keep pthread_create accessing TLS ++ state that is being set up. */ ++__rtld_lock_define_initialized_recursive (, _dl_load_tls_lock) + + + #ifdef HAVE_AUX_VECTOR +diff --git a/elf/dl-tls.c b/elf/dl-tls.c +index d554ae4..9260d2d 100644 +--- a/elf/dl-tls.c ++++ b/elf/dl-tls.c +@@ -532,7 +532,7 @@ _dl_allocate_tls_init (void *result) + size_t maxgen = 0; + + /* Protects global dynamic TLS related state. */ +- __rtld_lock_lock_recursive (GL(dl_load_lock)); ++ __rtld_lock_lock_recursive (GL(dl_load_tls_lock)); + + /* Check if the current dtv is big enough. */ + if (dtv[-1].counter < GL(dl_tls_max_dtv_idx)) +@@ -606,7 +606,7 @@ _dl_allocate_tls_init (void *result) + listp = listp->next; + assert (listp != NULL); + } +- __rtld_lock_unlock_recursive (GL(dl_load_lock)); ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); + + /* The DTV version is up-to-date now. */ + dtv[0].counter = maxgen; +@@ -745,7 +745,7 @@ _dl_update_slotinfo (unsigned long int req_modid) + + Here the dtv needs to be updated to new_gen generation count. + +- This code may be called during TLS access when GL(dl_load_lock) ++ This code may be called during TLS access when GL(dl_load_tls_lock) + is not held. In that case the user code has to synchronize with + dlopen and dlclose calls of relevant modules. A module m is + relevant if the generation of m <= new_gen and dlclose of m is +@@ -867,11 +867,11 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map) + if (__glibc_unlikely (the_map->l_tls_offset + != FORCED_DYNAMIC_TLS_OFFSET)) + { +- __rtld_lock_lock_recursive (GL(dl_load_lock)); ++ __rtld_lock_lock_recursive (GL(dl_load_tls_lock)); + if (__glibc_likely (the_map->l_tls_offset == NO_TLS_OFFSET)) + { + the_map->l_tls_offset = FORCED_DYNAMIC_TLS_OFFSET; +- __rtld_lock_unlock_recursive (GL(dl_load_lock)); ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); + } + else if (__glibc_likely (the_map->l_tls_offset + != FORCED_DYNAMIC_TLS_OFFSET)) +@@ -883,7 +883,7 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map) + #else + # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" + #endif +- __rtld_lock_unlock_recursive (GL(dl_load_lock)); ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); + + dtv[GET_ADDR_MODULE].pointer.to_free = NULL; + dtv[GET_ADDR_MODULE].pointer.val = p; +@@ -891,7 +891,7 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map) + return (char *) p + GET_ADDR_OFFSET; + } + else +- __rtld_lock_unlock_recursive (GL(dl_load_lock)); ++ __rtld_lock_unlock_recursive (GL(dl_load_tls_lock)); + } + struct dtv_pointer result = allocate_and_init (the_map); + dtv[GET_ADDR_MODULE].pointer = result; +@@ -962,7 +962,7 @@ _dl_tls_get_addr_soft (struct link_map *l) + return NULL; + + dtv_t *dtv = THREAD_DTV (); +- /* This may be called without holding the GL(dl_load_lock). Reading ++ /* This may be called without holding the GL(dl_load_tls_lock). Reading + arbitrary gen value is fine since this is best effort code. */ + size_t gen = atomic_load_relaxed (&GL(dl_tls_generation)); + if (__glibc_unlikely (dtv[0].counter != gen)) +diff --git a/elf/rtld.c b/elf/rtld.c +index 8d2bba3..9642eb9 100644 +--- a/elf/rtld.c ++++ b/elf/rtld.c +@@ -322,6 +322,7 @@ struct rtld_global _rtld_global = + #ifdef _LIBC_REENTRANT + ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, + ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, ++ ._dl_load_tls_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, + #endif + ._dl_nns = 1, + ._dl_ns = +diff --git a/posix/fork.c b/posix/fork.c +index c471f7b..021691b 100644 +--- a/posix/fork.c ++++ b/posix/fork.c +@@ -99,6 +99,9 @@ __libc_fork (void) + /* Reset the lock the dynamic loader uses to protect its data. */ + __rtld_lock_initialize (GL(dl_load_lock)); + ++ /* Reset the lock protecting dynamic TLS related data. */ ++ __rtld_lock_initialize (GL(dl_load_tls_lock)); ++ + reclaim_stacks (); + + /* Run the handlers registered for the child. */ +diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h +index d49529d..9ec1511 100644 +--- a/sysdeps/generic/ldsodefs.h ++++ b/sysdeps/generic/ldsodefs.h +@@ -369,6 +369,13 @@ struct rtld_global + list of loaded objects while an object is added to or removed + from that list. */ + __rtld_lock_define_recursive (EXTERN, _dl_load_write_lock) ++ /* This lock protects global and module specific TLS related data. ++ E.g. it is held in dlopen and dlclose when GL(dl_tls_generation), ++ GL(dl_tls_max_dtv_idx) or GL(dl_tls_dtv_slotinfo_list) are ++ accessed and when TLS related relocations are processed for a ++ module. It was introduced to keep pthread_create accessing TLS ++ state that is being set up. */ ++ __rtld_lock_define_recursive (EXTERN, _dl_load_tls_lock) + + /* Incremented whenever something may have been added to dl_loaded. */ + EXTERN unsigned long long _dl_load_adds; +@@ -1268,7 +1275,7 @@ extern int _dl_scope_free (void *) attribute_hidden; + + /* Add module to slot information data. If DO_ADD is false, only the + required memory is allocated. Must be called with GL +- (dl_load_lock) acquired. If the function has already been called ++ (dl_load_tls_lock) acquired. If the function has already been called + for the link map L with !do_add, then this function will not raise + an exception, otherwise it is possible that it encounters a memory + allocation failure. */ +diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile +index 0af9c59..df8943f 100644 +--- a/sysdeps/pthread/Makefile ++++ b/sysdeps/pthread/Makefile +@@ -152,15 +152,17 @@ tests += tst-cancelx2 tst-cancelx3 tst-cancelx6 tst-cancelx8 tst-cancelx9 \ + tst-cleanupx0 tst-cleanupx1 tst-cleanupx2 tst-cleanupx3 + + ifeq ($(build-shared),yes) +-tests += tst-atfork2 tst-pt-tls4 tst-_res1 tst-fini1 ++tests += tst-atfork2 tst-pt-tls4 tst-_res1 tst-fini1 tst-create1 + tests-nolibpthread += tst-fini1 + endif + + modules-names += tst-atfork2mod tst-tls4moda tst-tls4modb \ +- tst-_res1mod1 tst-_res1mod2 tst-fini1mod ++ tst-_res1mod1 tst-_res1mod2 tst-fini1mod \ ++ tst-create1mod + test-modules = $(addprefix $(objpfx),$(addsuffix .so,$(modules-names))) + + tst-atfork2mod.so-no-z-defs = yes ++tst-create1mod.so-no-z-defs = yes + + ifeq ($(build-shared),yes) + # Build all the modules even when not actually running test programs. +@@ -279,4 +281,8 @@ LDFLAGS-tst-join7mod.so = -Wl,-soname,tst-join7mod.so + + CFLAGS-tst-unwind-thread.c += -funwind-tables + ++LDFLAGS-tst-create1 = -Wl,-export-dynamic ++$(objpfx)tst-create1: $(shared-thread-library) ++$(objpfx)tst-create1.out: $(objpfx)tst-create1mod.so ++ + endif +diff --git a/sysdeps/pthread/tst-create1.c b/sysdeps/pthread/tst-create1.c +new file mode 100644 +index 0000000..932586c +--- /dev/null ++++ b/sysdeps/pthread/tst-create1.c +@@ -0,0 +1,119 @@ ++/* Verify that pthread_create does not deadlock when ctors take locks. ++ Copyright (C) 2021 Free Software Foundation, Inc. ++ This file is part of the GNU C Library. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <stdio.h> ++#include <support/xdlfcn.h> ++#include <support/xthread.h> ++ ++/* ++Check if ctor and pthread_create deadlocks in ++ ++thread 1: dlopen -> ctor -> lock(user_lock) ++thread 2: lock(user_lock) -> pthread_create ++ ++or in ++ ++thread 1: dlclose -> dtor -> lock(user_lock) ++thread 2: lock(user_lock) -> pthread_create ++*/ ++ ++static pthread_barrier_t bar_ctor; ++static pthread_barrier_t bar_dtor; ++static pthread_mutex_t user_lock = PTHREAD_MUTEX_INITIALIZER; ++ ++void ++ctor (void) ++{ ++ xpthread_barrier_wait (&bar_ctor); ++ dprintf (1, "thread 1: in ctor: started.\n"); ++ xpthread_mutex_lock (&user_lock); ++ dprintf (1, "thread 1: in ctor: locked user_lock.\n"); ++ xpthread_mutex_unlock (&user_lock); ++ dprintf (1, "thread 1: in ctor: unlocked user_lock.\n"); ++ dprintf (1, "thread 1: in ctor: done.\n"); ++} ++ ++void ++dtor (void) ++{ ++ xpthread_barrier_wait (&bar_dtor); ++ dprintf (1, "thread 1: in dtor: started.\n"); ++ xpthread_mutex_lock (&user_lock); ++ dprintf (1, "thread 1: in dtor: locked user_lock.\n"); ++ xpthread_mutex_unlock (&user_lock); ++ dprintf (1, "thread 1: in dtor: unlocked user_lock.\n"); ++ dprintf (1, "thread 1: in dtor: done.\n"); ++} ++ ++static void * ++thread3 (void *a) ++{ ++ dprintf (1, "thread 3: started.\n"); ++ dprintf (1, "thread 3: done.\n"); ++ return 0; ++} ++ ++static void * ++thread2 (void *a) ++{ ++ pthread_t t3; ++ dprintf (1, "thread 2: started.\n"); ++ ++ xpthread_mutex_lock (&user_lock); ++ dprintf (1, "thread 2: locked user_lock.\n"); ++ xpthread_barrier_wait (&bar_ctor); ++ t3 = xpthread_create (0, thread3, 0); ++ xpthread_mutex_unlock (&user_lock); ++ dprintf (1, "thread 2: unlocked user_lock.\n"); ++ xpthread_join (t3); ++ ++ xpthread_mutex_lock (&user_lock); ++ dprintf (1, "thread 2: locked user_lock.\n"); ++ xpthread_barrier_wait (&bar_dtor); ++ t3 = xpthread_create (0, thread3, 0); ++ xpthread_mutex_unlock (&user_lock); ++ dprintf (1, "thread 2: unlocked user_lock.\n"); ++ xpthread_join (t3); ++ ++ dprintf (1, "thread 2: done.\n"); ++ return 0; ++} ++ ++static void ++thread1 (void) ++{ ++ dprintf (1, "thread 1: started.\n"); ++ xpthread_barrier_init (&bar_ctor, NULL, 2); ++ xpthread_barrier_init (&bar_dtor, NULL, 2); ++ pthread_t t2 = xpthread_create (0, thread2, 0); ++ void *p = xdlopen ("tst-create1mod.so", RTLD_NOW | RTLD_GLOBAL); ++ dprintf (1, "thread 1: dlopen done.\n"); ++ xdlclose (p); ++ dprintf (1, "thread 1: dlclose done.\n"); ++ xpthread_join (t2); ++ dprintf (1, "thread 1: done.\n"); ++} ++ ++static int ++do_test (void) ++{ ++ thread1 (); ++ return 0; ++} ++ ++#include <support/test-driver.c> +diff --git a/sysdeps/pthread/tst-create1mod.c b/sysdeps/pthread/tst-create1mod.c +new file mode 100644 +index 0000000..62c9006 +--- /dev/null ++++ b/sysdeps/pthread/tst-create1mod.c +@@ -0,0 +1,41 @@ ++/* Verify that pthread_create does not deadlock when ctors take locks. ++ Copyright (C) 2021 Free Software Foundation, Inc. ++ This file is part of the GNU C Library. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <stdio.h> ++ ++/* Require TLS setup for the module. */ ++__thread int tlsvar; ++ ++void ctor (void); ++void dtor (void); ++ ++static void __attribute__ ((constructor)) ++do_init (void) ++{ ++ dprintf (1, "constructor started: %d.\n", tlsvar++); ++ ctor (); ++ dprintf (1, "constructor done: %d.\n", tlsvar++); ++} ++ ++static void __attribute__ ((destructor)) ++do_end (void) ++{ ++ dprintf (1, "destructor started: %d.\n", tlsvar++); ++ dtor (); ++ dprintf (1, "destructor done: %d.\n", tlsvar++); ++} +-- +1.8.3.1 + |