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* Reorganize static TLS memory for ELF TLSRyan Prichard2019-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For ELF TLS "local-exec" accesses, the static linker assumes that an executable's TLS segment is located at a statically-known offset from the thread pointer (i.e. "variant 1" for ARM and "variant 2" for x86). Because these layouts are incompatible, Bionic generally needs to allocate its TLS slots differently between different architectures. To allow per-architecture TLS slots: - Replace the TLS_SLOT_xxx enumerators with macros. New ARM slots are generally negative, while new x86 slots are generally positive. - Define a bionic_tcb struct that provides two things: - a void* raw_slots_storage[BIONIC_TLS_SLOTS] field - an inline accessor function: void*& tls_slot(size_t tpindex); For ELF TLS, it's necessary to allocate a temporary TCB (i.e. TLS slots), because the runtime linker doesn't know how large the static TLS area is until after it has loaded all of the initial solibs. To accommodate Golang, it's necessary to allocate the pthread keys at a fixed, small, positive offset from the thread pointer. This CL moves the pthread keys into bionic_tls, then allocates a single mapping per thread that looks like so: - stack guard - stack [omitted for main thread and with pthread_attr_setstack] - static TLS: - bionic_tcb [exec TLS will either precede or succeed the TCB] - bionic_tls [prefixed by the pthread keys] - [solib TLS segments will be placed here] - guard page As before, if the new mapping includes a stack, the pthread_internal_t is allocated on it. At startup, Bionic allocates a temporary bionic_tcb object on the stack, then allocates a temporary bionic_tls object using mmap. This mmap is delayed because the linker can't currently call async_safe_fatal() before relocating itself. Later, Bionic allocates a stack-less thread mapping for the main thread, and copies slots from the temporary TCB to the new TCB. (See *::copy_from_bootstrap methods.) Bug: http://b/78026329 Test: bionic unit tests Test: verify that a Golang app still works Test: verify that a Golang app crashes if bionic_{tls,tcb} are swapped Change-Id: I6543063752f4ec8ef6dc9c7f2a06ce2a18fc5af3
* pthread_key.cpp: factor out get_thread_key_dataRyan Prichard2019-01-111-3/+7
| | | | | | | | | | This change makes it easier to move the location of the pthread keys (e.g. into the bionic_tls struct). Bug: http://b/78026329 Test: bionic unit tests Test: disassembly of libc.so doesn't change Change-Id: Ib75d9dab8726de96856af91ec3daa2c5cdbc2178
* Modernize codebase by replacing NULL with nullptrYi Kong2018-08-021-6/+6
| | | | | | | | Fixes -Wzero-as-null-pointer-constant warning. Test: m Bug: 68236239 Change-Id: I5b4123bc6709641315120a191e36cc57541349b2
* Mark __BIONIC_WEAK_FOR_NATIVE_BRIDGE symbolsdimitry2017-10-271-0/+5
| | | | | | | | | To make it easier for Native Bridge implementations to override these symbols. Bug: http://b/67993967 Test: make Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
* Prevent using static-allocated pthread keys before creation.Yabin Cui2015-04-141-6/+18
| | | | | | Bug: 19993460 Change-Id: I244dea7f5df3c8384f88aa48d635348fafc9cbaf
* Refactor pthread_key.cpp to be lock-free.Yabin Cui2015-03-031-172/+97
| | | | Change-Id: I20dfb9d3cdc40eed10ea12ac34f03caaa94f7a49
* Remove t->tls==NULL check in pthread_key_delete.Yabin Cui2014-12-191-10/+0
| | | | Change-Id: I6c0c71d30fe9d5b888752a4204abd95d5149bb96
* Move some pthread functions to signal.h.Dan Albert2014-11-211-0/+1
| | | | | | | | | | | | | POSIX specifies that pthread_kill(3) and pthread_sigmask(3) are supposed to live in signal.h rather than pthread.h. Since signal.h now needs pthread_t and pthread_attr_t, I've moved those defintions into include/machine/pthread_types.h to keep the namespace clean. I also sorted some includes. The combination of these two things seems to have exploded into a cascade of missing includes, so this patch also cleans up all those. Change-Id: Icfa92a39432fe83f542a797e5a113289d7e4ad0c
* Switch to g_ for globals.Elliott Hughes2014-05-141-3/+3
| | | | | | | That's what the Google style guide recommends, and we're starting to get a mix. Change-Id: Ib0c53a890bb5deed5c679e887541a715faea91fc
* Fix pthread_join.Elliott Hughes2013-11-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Clean up the pthread_create trampoline.Elliott Hughes2013-11-151-1/+1
| | | | | | Bug: 8206355 Bug: 11693195 Change-Id: I35cc024d5b6ebd19d1d2e45610db185addaf45df
* Fix x86_64 build, clean up intermediate libraries.Elliott Hughes2013-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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
* Fix __errno for LP64 and clean up __get_tls.Elliott Hughes2013-10-091-4/+3
| | | | | | | | | | | If __get_tls has the right type, a lot of confusing casting can disappear. It was probably a mistake that __get_tls was exposed as a function for mips and x86 (but not arm), so let's (a) ensure that the __get_tls function always matches the macro, (b) that we have the function for arm too, and (c) that we don't have the function for any 64-bit architecture. Change-Id: Ie9cb989b66e2006524ad7733eb6e1a65055463be
* Remove more assumptions that pointers are 32-bit.Elliott Hughes2013-10-011-2/+3
| | | | Change-Id: I2157e2fc4db7692b746c697982c3d028a056462a
* Handles spurious wake-ups in pthread_join()msg5552013-06-121-6/+3
| | | | | | | | | | | | | | | | | | | 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
* Hide various symbols that shouldn't be exposed.Elliott Hughes2013-03-151-2/+2
| | | | | | | A mangled symbol in libc.so is a symbol that shouldn't be exported by libc.so. Change-Id: Id92d1e1968b3d11d111a5d9ef692adb1ac7694a1
* Revert "Revert "More pthreads cleanup.""Elliott Hughes2013-02-121-24/+1
| | | | | | | | | This reverts commit 6f94de3ca49e4ea147b1c59e5818fa175846518f (Doesn't try to increase the number of TLS slots; that leads to an inability to boot. Adds more tests.) Change-Id: Ia7d25ba3995219ed6e686463dbba80c95cc831ca
* Revert "More pthreads cleanup."Elliott Hughes2013-02-121-1/+24
| | | | | | This reverts commit 2a1bb4e64677b9abbc17173c79768ed494565047 Change-Id: Ia443d0748015c8e9fc3121e40e68258616767b51
* More pthreads cleanup.Elliott Hughes2013-02-111-24/+1
| | | | | | | | | | | | | | | | | | | | 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
* Revert "Revert "Pull the pthread_key_t functions out of pthread.c.""Elliott Hughes2013-02-111-0/+280
| | | | | | | | This reverts commit 6260553d48f6fd87ca220270bea8bafdde5726ec (Removing the accidental libm/Android.mk change.) Change-Id: I6cddd9857c31facc05636e8221505b3d2344cb75
* Revert "Pull the pthread_key_t functions out of pthread.c."Elliott Hughes2013-02-111-280/+0
| | | | | | | | This reverts commit ad59322ae432d11ff36dcf046016af8cfe45fbe4 somehow my unfinished libm/Android.mk change got into here. Change-Id: I46be626c5269d60fb1ced9862f2ebaa380b4e0af
* Pull the pthread_key_t functions out of pthread.c.Elliott Hughes2013-02-111-0/+280
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
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