Arjun Shankar 52a103e237 Fix deadlock when pthread_atfork handler calls pthread_atfork or dlclose ... In multi-threaded programs, registering via pthread_atfork, de-registering implicitly via dlclose, or running pthread_atfork handlers during fork was protected by an internal lock. This meant that a pthread_atfork handler attempting to register another handler or dlclose a dynamically loaded library would lead to a deadlock. This commit fixes the deadlock in the following way: During the execution of handlers at fork time, the atfork lock is released prior to the execution of each handler and taken again upon its return. Any handler registrations or de-registrations that occurred during the execution of the handler are accounted for before proceeding with further handler execution. If a handler that hasn't been executed yet gets de-registered by another handler during fork, it will not be executed. If a handler gets registered by another handler during fork, it will not be executed during that particular fork. The possibility that handlers may now be registered or deregistered during handler execution means that identifying the next handler to be run after a given handler may register/de-register others requires some bookkeeping. The fork_handler struct has an additional field, 'id', which is assigned sequentially during registration. Thus, handlers are executed in ascending order of 'id' during 'prepare', and descending order of 'id' during parent/child handler execution after the fork. Two tests are included: * tst-atfork3: Adhemerval Zanella <adhemerval.zanella@linaro.org> This test exercises calling dlclose from prepare, parent, and child handlers. * tst-atfork4: This test exercises calling pthread_atfork and dlclose from the prepare handler. [BZ #24595, BZ #27054] Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>		2022-05-25 11:27:31 +02:00
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arpa	resolv: Move ns_samename into its own file, and into libc	2021-07-19 07:56:21 +02:00
bits	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
gnu	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
net
netinet
programs	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
protocols
rpc	Handle out-of-memory case in svc_tcp.c/svc_unix.c:rendezvous_request.	2020-12-10 11:11:20 +01:00
rpcsvc
sys	Linux: Only generate 64 bit timestamps for 64 bit time_t recvmsg/recvmmsg	2022-01-28 18:18:27 -03:00
aio.h	Linux: Move aio_suspend, aio_suspend64, __aio_suspend_time64 to libc	2021-06-25 11:55:27 +02:00
aliases.h
alloc_buffer.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
alloca.h
allocate_once.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
ar.h
argp-fmtstream.h
argp.h
argz.h
array_length.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
assert.h
atomic_wide_counter.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
atomic.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
byteswap.h
clone_internal.h	Add an internal wrapper for clone, clone2 and clone3	2021-07-14 06:33:58 -07:00
complex.h
cpio.h
crypt.h
ctype.h
des.h
dirent.h	Use 64 bit time_t stat internally	2021-06-22 12:09:52 -03:00
dlfcn.h	elf: Add _dl_find_object function	2021-12-28 22:52:56 +01:00
dso_handle.h
elf.h
endian.h
envz.h
err.h
errno.h	Remove tls.h inclusion from internal errno.h	2020-11-13 12:59:19 -03:00
error.h
execinfo.h
fcntl.h
features-time64.h	y2038: Add support for 64-bit time on legacy ABIs	2021-06-15 10:42:11 -03:00
features.h	Prepare for glibc 2.35 release.	2022-02-03 00:23:26 -05:00
fenv.h
file_change_detection.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
filename.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
float.h
fmtmsg.h
fnmatch.h
fpu_control.h
fstab.h
fts.h	io: Add fts64 with 64-bit time_t support	2021-06-15 10:42:11 -03:00
ftw.h	io: Add ftw64 with 64-bit time_t support	2021-06-15 10:42:11 -03:00
gconv.h
getopt_int.h
getopt.h
glob.h	Fix extra PLT reference in libc.so due to __glob64_time64 if build with gcc 7.5 on 32bit.	2021-07-01 16:46:59 +02:00
gmp.h
gnu-versions.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
grp-merge.h
grp.h
gshadow.h
iconv.h
idx.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
ifaddrs.h
ifreq.h
ifunc-impl-list.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
inline-hashtab.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
intprops.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
inttypes.h	Make strtoimax, strtoumax, wcstoimax, wcstoumax into aliases	2020-12-08 18:15:27 +00:00
langinfo.h
lastlog.h
libc-diag.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
libc-internal.h	elf: Remove __libc_init_secure	2022-04-19 15:52:27 -07:00
libc-pointer-arith.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
libc-symbols.h	Add declare_object_symbol_alias for assembly codes (BZ #28128)	2022-05-13 10:54:41 -03:00
libgen.h
libintl.h
limits.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
link.h	Add GLIBC_ABI_DT_RELR for DT_RELR support	2022-04-26 10:16:11 -07:00
list_t.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
list.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
locale.h
loop_unroll.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
malloc.h	Simplify __malloc_initialized	2021-07-22 18:38:04 +05:30
math-narrow-eval.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
math.h	Redirect fma calls to __fma in libm	2021-09-15 22:57:35 +00:00
mcheck.h	mcheck: Wean away from malloc hooks [BZ #23489]	2021-07-22 18:38:02 +05:30
memory.h
mntent.h
monetary.h
mqueue.h	Linux: Move mq_send, mq_timedsend, __mq_timedsend_time64 to libc	2021-06-25 12:21:12 +02:00
netdb.h	nss_files: Move into libc	2021-07-07 18:33:52 +02:00
netgroup.h
nl_types.h
nss_dns.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
nss_files.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
nss.h
nsswitch.h
obstack.h
plural-exp.h
poll.h
printf.h	stdio-common: Move union printf_arg int <printf.h>	2022-05-24 08:03:11 +02:00
pthread.h	Linux: Move mq_notify from librt to libc	2021-06-25 12:20:47 +02:00
pty.h	login: Move libutil into libc	2021-06-30 08:43:37 +02:00
pwd.h
random-bits.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
re_comp.h
regex.h	regex: copy back from Gnulib	2021-09-21 08:00:44 -07:00
regexp.h
register-atfork.h	Fix deadlock when pthread_atfork handler calls pthread_atfork or dlclose	2022-05-25 11:27:31 +02:00
resolv.h	resolv: Move res_queriesmatch to its own file and into libc	2021-07-19 07:56:21 +02:00
rounding-mode.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
rtld-malloc.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
sched.h
scratch_buffer.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
search.h
set-hooks.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
setjmp.h	setjmp: Replace jmp_buf-macros.h with jmp_buf-macros.sym	2021-11-22 13:43:22 -03:00
sgtty.h
shadow.h
shlib-compat.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
shm-directory.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
signal.h	stdio: Remove the usage of $(fno-unit-at-a-time) for siglist.c	2022-05-13 10:54:41 -03:00
spawn.h
stab.h
stackinfo.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
stap-probe.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
stdc-predef.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
stdint.h
stdio_ext.h
stdio.h	stdio: Remove the usage of $(fno-unit-at-a-time) for errlist.c	2022-05-13 10:54:41 -03:00
stdlib.h	Remove __morecore and __default_morecore	2021-07-22 18:37:57 +05:30
string.h	String: Add hidden defs for __memcmpeq() to enable internal usage	2021-10-26 16:51:29 -05:00
strings.h
struct___timeb64.h	time: Add 64-bit time_t support for ftime	2020-10-27 09:54:50 -03:00
struct___timespec64.h
struct___timeval64.h
stubs-prologue.h
syscall.h
sysexits.h
syslog.h
tar.h
termios.h
tgmath.h
time.h	clock_settime/clock_gettime: Use __nonnull to avoid null pointer	2022-05-05 17:48:04 +05:30
ttyent.h
uchar.h
ucontext.h
ulimit.h
unistd.h	elf: Remove __libc_init_secure	2022-04-19 15:52:27 -07:00
utime.h
utmp.h	login: Move libutil into libc	2021-06-30 08:43:37 +02:00
values.h	Update copyright dates with scripts/update-copyrights	2022-01-01 11:40:24 -08:00
verify.h
wait.h
wchar.h	wcrtomb: Make behavior POSIX compliant	2022-05-13 19:15:46 +05:30
wctype.h
wordexp.h