The errors are introduced in "Make pthread join_state not protected by g_thread_list_lock".
Bug: 19636317
Change-Id: I58ae9711da94bfbac809abfd81311eeb70301a4b
1. Move the representation of thread join_state from pthread.attr.flag
to pthread.join_state. This clarifies thread state change.
2. Use atomic operations for pthread.join_state. So we don't need to
protect it by g_thread_list_lock. g_thread_list_lock will be reduced
to only protect g_thread_list or even removed in further changes.
Bug: 19636317
Change-Id: I31fb143a7c69508c7287307dd3b0776993ec0f43
Make this change because I think it is more reasonable to check stack info
in pthread_getattr_np. I believe pthread_attr_t is not tied with any thread,
and can't have a flag saying who using it is the main thread.
This change also helps refactor of g_thread_list_lock.
Bug: 19636317
Change-Id: Iedbb85a391ac3e1849dd036d01445dac4bc63db9
If pthread_detach() is called while the thread is in pthread_exit(),
it takes the risk that no one can free the pthread_internal_t.
So I add PTHREAD_ATTR_FLAG_ZOMBIE to detect this, maybe very rare, but
both glibc and netbsd libpthread have similar function.
Change-Id: Iaa15f651903b8ca07aaa7bd4de46ff14a2f93835
Unfortunately, this change provokes random crashes for ART, and
I have seen libc crashes on the device that might be related to it.
Reverting it fixes the ART crashes. there is unfortunately no
stack trace for the crashes, but just a "Segmentation fault" message.
This reverts commit cc5f6543e3.
Change-Id: I68dca8e1e9b9edcce7eb84596e8db619e40e8052
A lot of third-party code calls the private __get_thread symbol,
often as part of a backport of bionic's pthread_rwlock implementation.
Hopefully this will go away for LP64 (since you're guaranteed the
real implementation there), but there are still APIs that take a tid
and no way to convert between a pthread_t and a tid. pthread_gettid_np
is a public API for that. To aid the transition, make __get_thread
available again for LP32.
(cherry-pick of 27efc48814b8153c55cbcd0af5d9add824816e69.)
Bug: 14079438
Change-Id: I43fabc7f1918250d31d4665ffa4ca352d0dbeac1
In practice, with this implementation we never need to make a system call.
We get the main thread's tid (which is the same as our pid) back from
the set_tid_address system call we have to make during initialization.
A new pthread will have the same pid as its parent, and a fork child's
main (and only) thread will have a pid equal to its tid, which we get for
free from the kernel before clone returns.
The only time we'd actually have to make a getpid system call now is if
we take a signal during fork and the signal handler calls getpid. (That,
or we call getpid in the dynamic linker while it's still dealing with its
own relocations and hasn't even set up the main thread yet.)
Bug: 15387103
Change-Id: I6d4718ed0a5c912fc75b5f738c49a023dbed5189
The problem with the original patch was that using syscall(3) means that
errno can be set, but pthread_create(3) was abusing the TLS errno slot as
a pthread_mutex_t for the thread startup handshake.
There was also a mistake in the check for syscall failures --- it should
have checked against -1 instead of 0 (not just because that's the default
idiom, but also here because futex(2) can legitimately return values > 0).
This patch stops abusing the TLS errno slot and adds a pthread_mutex_t to
pthread_internal_t instead. (Note that for LP64 sizeof(pthread_mutex_t) >
sizeof(uintptr_t), so we could potentially clobber other TLS slots too.)
I've also rewritten the LP32 compatibility stubs to directly reuse the
code from the .h file.
This reverts commit 75c55ff84e.
Bug: 15195455
Change-Id: I6ffb13e5cf6a35d8f59f692d94192aae9ab4593d
This is a much simpler implementation that lets the kernel
do as much as possible.
Co-authored-by: Jörgen Strand <jorgen.strand@sonymobile.com>
Co-authored-by: Snild Dolkow <snild.dolkow@sonymobile.com>
Change-Id: Iad19f155de977667aea09410266d54e63e8a26bf
This replaces the non-standard pthread_mutex_lock_timeout_np, which we have
to keep around on LP32 for binary compatibility.
Change-Id: I098dc7cd38369f0c1bec1fac35687fbd27392e00
The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.
Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
Let the kernel keep pthread_internal_t::tid updated, including
across forks and for the main thread. This then lets us fix
pthread_join to only return after the thread has really exited.
Also fix the thread attributes of the main thread so we don't
unmap the main thread's stack (which is really owned by the
dynamic linker and contains things like environment variables),
which fixes crashes when joining with an exited main thread
and also fixes problems reported publicly with accessing environment
variables after the main thread exits (for which I've added a new
unit test).
In passing I also fixed a bug where if the clone(2) inside
pthread_create(3) fails, we'd unmap the child's stack and TLS (which
contains the mutex) and then try to unlock the mutex. Boom! It wasn't
until after I'd uploaded the fix for this that I came across a new
public bug reporting this exact failure.
Bug: 8206355
Bug: 11693195
Bug: https://code.google.com/p/android/issues/detail?id=57421
Bug: https://code.google.com/p/android/issues/detail?id=62392
Change-Id: I2af9cf6e8ae510a67256ad93cad891794ed0580b
<pthread.h> was missing nonnull attributes, noreturn on pthread_exit,
and had incorrect cv qualifiers for several standard functions.
I've also marked the non-standard stuff (where I count glibc rather
than POSIX as "standard") so we can revisit this cruft for LP64 and
try to ensure we're compatible with glibc.
I've also broken out the pthread_cond* functions into a new file.
I've made the remaining pthread files (plus ptrace) part of the bionic code
and fixed all the warnings.
I've added a few more smoke tests for chunks of untested pthread functionality.
We no longer need the libc_static_common_src_files hack for any of the
pthread implementation because we long since stripped out the rest of
the armv5 support, and this hack was just to ensure that __get_tls in libc.a
went via the kernel if necessary.
This patch also finishes the job of breaking up the pthread.c monolith, and
adds a handful of new tests.
Change-Id: Idc0ae7f5d8aa65989598acd4c01a874fe21582c7
Also remove the SIGSEGV special case, which was probably because
hand-written __exit_with_stack_teardown stubs used to try to cause
SIGSEGV if the exit system call returned (which it never does, so
that dead code disappeared).
Also move the sigprocmask into the only case where it's necessary ---
the one where we unmap the stack that would be used by a signal
handler.
Change-Id: Ie40d20c1ae2f5e7125131b6b492cba7a2c6d08e9
The x86_64 build was failing because clone.S had a call to __thread_entry which
was being added to a different intermediate .a on the way to making libc.so,
and the linker couldn't guarantee statically that such a relocation would be
possible.
ld: error: out/target/product/generic_x86_64/obj/STATIC_LIBRARIES/libc_common_intermediates/libc_common.a(clone.o): requires dynamic R_X86_64_PC32 reloc against '__thread_entry' which may overflow at runtime; recompile with -fPIC
This patch addresses that by ensuring that the caller and callee end up in the
same intermediate .a. While I'm here, I've tried to clean up some of the mess
that led to this situation too. In particular, this removes libc/private/ from
the default include path (except for the DNS code), and splits out the DNS
code into its own library (since it's a weird special case of upstream NetBSD
code that's diverged so heavily it's unlikely ever to get back in sync).
There's more cleanup of the DNS situation possible, but this is definitely a
step in the right direction, and it's more than enough to get x86_64 building
cleanly.
Change-Id: I00425a7245b7a2573df16cc38798187d0729e7c4
This reverts commits eb1b07469f and
d14dc3b87f, and fixes the bug where
we were calling mmap (which might cause errno to be set) before
__set_tls (which is required to implement errno).
Bug: 8557703
Change-Id: I2c36d00240c56e156e1bb430d8c22a73a068b70c
Removed 'join_count' from pthread_internal_t and switched to using the flag
PTHREAD_ATTR_FLAG_JOINED to indicate if a thread is being joined. Combined with
a switch to a while loop in pthread_join, this fixes spurious wake-ups but
prevents a thread from being joined multiple times. This is fine for
two reasons:
1) The pthread_join specification allows for undefined behavior when multiple
threads try to join a single thread.
2) There is no thread safe way to allow multiple threads to join a single
thread with the pthread interface. The second thread calling pthread_join
could be pre-empted until the thread is destroyed and its handle reused for
a different thread. Therefore multi-join is always an error.
Bug: https://code.google.com/p/android/issues/detail?id=52255
Change-Id: I8b6784d47620ffdcdbfb14524e7402e21d46c5f7
imgtec pointed out that pthread_kill(3) was broken, but most of the
other functions that ought to return ESRCH for invalid/exited threads
were equally broken.
Change-Id: I96347f6195549aee0c72dc39063e6c5d06d2e01f
Fix the pthread_setname_np test to take into account that emulator kernels are
so old that they don't support setting the name of other threads.
The CLONE_DETACHED thread is obsolete since 2.5 kernels.
Rename kernel_id to tid.
Fix the signature of __pthread_clone.
Clean up the clone and pthread_setname_np implementations slightly.
Change-Id: I16c2ff8845b67530544bbda9aa6618058603066d
This reverts commit 6f94de3ca4
(Doesn't try to increase the number of TLS slots; that leads to
an inability to boot. Adds more tests.)
Change-Id: Ia7d25ba3995219ed6e686463dbba80c95cc831ca
POSIX says pthread_create returns EAGAIN, not ENOMEM.
Also pull pthread_attr_t functions into their own file.
Also pull pthread_setname_np into its own file.
Also remove unnecessary #includes from pthread_key.cpp.
Also account for those pthread keys used internally by bionic,
so they don't count against the number of keys available to user
code. (They do with glibc, but glibc's limit is the much more
generous 1024.)
Also factor out the common errno-restoring idiom to reduce gotos.
Bug: 6702535
Change-Id: I555e66efffcf2c1b5a2873569e91489156efca42
This was originally motivated by noticing that we were setting the
wrong bits for the well-known tls entries. That was a harmless bug
because none of the well-known tls entries has a destructor, but
it's best not to leave land mines lying around.
Also add some missing POSIX constants, a new test, and fix
pthread_key_create's return value when we hit the limit.
Change-Id: Ife26ea2f4b40865308e8410ec803b20bcc3e0ed1
...and don't pass a non-heap pointer to free(3), either.
This patch replaces the "node** prev" with the clearer "node* prev"
style and fixes the null pointer dereference in the old code. That's
not sufficient to fix the reporter's bug, though. The pthread_internal_t*
for the main thread isn't heap-allocated --- __libc_init_tls causes a
pointer to a statically-allocated pthread_internal_t to be added to
the thread list.
Bug: http://code.google.com/p/android/issues/detail?id=37410
Change-Id: I112b7f22782fc789d58f9c783f7b323bda8fb8b7
The first NULL pointer check against `attr' suggests that `attr' can
be NULL. Then later `attr' is directly dereferenced, suggesting the
opposite.
if (attr == NULL) {
...
} else {
...
}
...
if (attr->stack_base == ...) { ... }
The public API pthread_create(3) allows NULL, and interprets it as "default".
Our implementation actually swaps in a pointer to the global default
pthread_attr_t, so we don't need any NULL checks in _init_thread. (The other
internal caller passes its own pthread_attr_t.)
Change-Id: I0a4e79b83f5989249556a07eed1f2887e96c915e
Signed-off-by: Xi Wang <xi.wang@gmail.com>
I gave up trying to use the usual thread-local buffer idiom; calls to
calloc(3) and free(3) from any of the "dl" functions -- which live in
the dynamic linker -- end up resolving to the dynamic linker's stubs.
I tried to work around that, but was just making things more complicated.
This alternative costs us a well-known TLS slot (instead of the
dynamically-allocated TLS slot we'd have used otherwise, so no difference
there), plus an extra buffer inside every pthread_internal_t.
Bug: 5404023
Change-Id: Ie9614edd05b6d1eeaf7bf9172792d616c6361767
Several previous changes conspired to make a mess of the thread list
in static binaries. This was most obvious when trying to call
pthread_key_delete(3) on the main thread.
Bug: http://code.google.com/p/android/issues/detail?id=36893
Change-Id: I2a2f553114d8fb40533c481252b410c10656da2e
The creation of a thread succeeds even if the requested scheduling
parameters can not be set. This is not POSIX compliant, and even
worse, it leads to a wrong behavior. Let pthread_create() fail in this
case.
Change-Id: Ice66e2a720975c6bde9fe86c2cf8f649533a169c
Signed-off-by: Christian Bejram <christian.bejram@stericsson.com>
