aboutsummaryrefslogtreecommitdiff
path: root/lib/libc/sys/interposing_table.c
diff options
context:
space:
mode:
authorKonstantin Belousov <kib@FreeBSD.org>2015-01-03 18:38:46 +0000
committerKonstantin Belousov <kib@FreeBSD.org>2015-01-03 18:38:46 +0000
commit8495e8b1e9e13fb707296a486acf7538dbfa12b2 (patch)
treee381919bf3f754392eb9a47b256135a1dbb2b2b1 /lib/libc/sys/interposing_table.c
parent0e521992a44f909675127096f51621326c540481 (diff)
downloadsrc-8495e8b1e9e13fb707296a486acf7538dbfa12b2.tar.gz
src-8495e8b1e9e13fb707296a486acf7538dbfa12b2.zip
Fix known issues which blow up the process after dlopen("libthr.so")
(or loading a dso linked to libthr.so into process which was not linked against threading library). - Remove libthr interposers of the libc functions, including __error(). Instead, functions calls are indirected through the interposing table, similar to how pthread stubs in libc are already done. Libc by default points either to syscall trampolines or to existing libc implementations. On libthr load, libthr rewrites the pointers to the cancellable implementations already in libthr. The interposition table is separate from pthreads stubs indirection table to not pull pthreads stubs into static binaries. - Postpone the malloc(3) internal mutexes initialization until libthr is loaded. This avoids recursion between calloc(3) and static pthread_mutex_t initialization. - Reinstall signal handlers with wrapper on libthr load. The _rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2) when libthr is statically referenced from the main binary. In the process, fix openat(2), swapcontext(2) and setcontext(2) interposing. The libc symbols were exported at different versions than libthr interposers. Export both libc and libthr versions from libc now, with default set to the higher version from libthr. Remove unused and disconnected swapcontext(3) userspace implementation from libc/gen. No objections from: deischen Tested by: pho, antoine (exp-run) (previous versions) Sponsored by: The FreeBSD Foundation MFC after: 1 week
Notes
Notes: svn path=/head/; revision=276630
Diffstat (limited to 'lib/libc/sys/interposing_table.c')
-rw-r--r--lib/libc/sys/interposing_table.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/libc/sys/interposing_table.c b/lib/libc/sys/interposing_table.c
new file mode 100644
index 000000000000..9987bf057a6c
--- /dev/null
+++ b/lib/libc/sys/interposing_table.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice(s), this list of conditions and the following disclaimer as
+ * the first lines of this file unmodified other than the possible
+ * addition of one or more copyright notices.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice(s), this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include "libc_private.h"
+
+#define SLOT(a, b) \
+ [INTERPOS_##a] = (interpos_func_t)b
+interpos_func_t __libc_interposing[INTERPOS_MAX] = {
+ SLOT(accept, __sys_accept),
+ SLOT(accept4, __sys_accept4),
+ SLOT(aio_suspend, __sys_aio_suspend),
+ SLOT(close, __sys_close),
+ SLOT(connect, __sys_connect),
+ SLOT(creat, __libc_creat),
+ SLOT(fcntl, __fcntl_compat),
+ SLOT(fsync, __sys_fsync),
+ SLOT(fork, __sys_fork),
+ SLOT(msync, __sys_msync),
+ SLOT(nanosleep, __sys_nanosleep),
+ SLOT(open, __sys_open),
+ SLOT(openat, __sys_openat),
+ SLOT(poll, __sys_poll),
+ SLOT(pselect, __sys_pselect),
+ SLOT(raise, __libc_raise),
+ SLOT(read, __sys_read),
+ SLOT(readv, __sys_readv),
+ SLOT(recvfrom, __sys_recvfrom),
+ SLOT(recvmsg, __sys_recvmsg),
+ SLOT(select, __sys_select),
+ SLOT(sendmsg, __sys_sendmsg),
+ SLOT(sendto, __sys_sendto),
+ SLOT(setcontext, __sys_setcontext),
+ SLOT(sigaction, __sys_sigaction),
+ SLOT(sigprocmask, __sys_sigprocmask),
+ SLOT(sigsuspend, __sys_sigsuspend),
+ SLOT(sigwait, __libc_sigwait),
+ SLOT(sigtimedwait, __sys_sigtimedwait),
+ SLOT(sigwaitinfo, __sys_sigwaitinfo),
+ SLOT(swapcontext, __sys_swapcontext),
+ SLOT(system, __libc_system),
+ SLOT(sleep, __libc_sleep),
+ SLOT(tcdrain, __libc_tcdrain),
+ SLOT(usleep, __libc_usleep),
+ SLOT(pause, __libc_pause),
+ SLOT(wait, __libc_wait),
+ SLOT(wait3, __libc_wait3),
+ SLOT(wait4, __sys_wait4),
+ SLOT(waitpid, __libc_waitpid),
+ SLOT(write, __sys_write),
+ SLOT(writev, __sys_writev),
+ SLOT(_pthread_mutex_init_calloc_cb, _pthread_mutex_init_calloc_cb_stub),
+};
+#undef SLOT
+
+interpos_func_t *
+__libc_interposing_slot(int interposno)
+{
+
+ return (&__libc_interposing[interposno]);
+}