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>
Since e19d702b8e, dlsym and friends use recursive mutexes that
require the current thread id, which is not available before the libc
constructor. This prevents us from using dlsym() in .preinit_array.
This change moves TLS initialization from libc constructor to the earliest
possible point - immediately after linker itself is relocated. As a result,
pthread_internal_t for the initial thread is available from the start.
As a bonus, values stored in TLS in .preinit_array are not lost when libc is
initialized.
Change-Id: Iee5a710ee000173bff63e924adeb4a4c600c1e2d
The problem was due to the fact that, in the case of dynamic executables,
the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
constructors when loading shared libraries and dynamic executables,
*before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
The latter did call these constructors array again, mistakenly.
The patch also updates the documentation of many related functions.
Also adds a new section to linker/README.TXT explaining restrictions on
C library usage.
The patch has been tested on a Dream for stability issues with
proprietary blobs:
- H264 decoding works
- Camera + Video recording works
- GPS works
- Sensors work
The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
run and shows the static C++ constructor being called only once.
