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
Merged-In: I6543063752f4ec8ef6dc9c7f2a06ce2a18fc5af3
Change-Id: I6543063752f4ec8ef6dc9c7f2a06ce2a18fc5af3
(cherry picked from commit 1e660b70da)
This slot will replace TLS_SLOT_TSAN, which needs to be removed for ELF
TLS compatibility. The platform has both slots reserved until compiler-rt
can be updated. See:
- https://reviews.llvm.org/D53906
- discussion on AOSP change Idf25d2ee457a5d26d0bdd6281cee72c345c8b755
Bug: http://b/78026329
Test: m
Change-Id: Ifd5aeb5711dc88266e7350cb022146dd87cfd7be
This change is intended to allow native-bridge to use independent
TLS memory for host and guest environments, while still sharing a
thread-local errno between the two.
Bug: http://b/78026329
Test: bionic unit tests
Change-Id: I838cd321e159add60760bc12a8aa7e9ddc960c33
Merged-In: I838cd321e159add60760bc12a8aa7e9ddc960c33
(cherry picked from commit a9c7c55462)
Instead of passing the address of a KernelArgumentBlock to libc.so for
initialization, use __loader_shared_globals() to initialize globals.
Most of the work happened in the previous CLs. This CL switches a few
KernelArgumentBlock::getauxval calls to [__bionic_]getauxval and stops
routing the KernelArgumentBlock address through the libc init functions.
Bug: none
Test: bionic unit tests
Change-Id: I96c7b02c21d55c454558b7a5a9243c682782f2dd
Merged-In: I96c7b02c21d55c454558b7a5a9243c682782f2dd
(cherry picked from commit 746ad15912)
Split __libc_init_main_thread into __libc_init_main_thread_early and
__libc_init_main_thread_late. The early function is called very early in
the startup of the dynamic linker and static executables. It initializes
the global auxv pointer and enough TLS memory to do system calls, access
errno, and run -fstack-protector code (but with a zero cookie because the
code for generating a cookie is complex).
After the linker is relocated, __libc_init_main_thread_late finishes
thread initialization.
Bug: none
Test: bionic unit tests
Change-Id: I6fcd8d7587a380f8bd649c817b40a3a6cc1d2ee0
Merged-In: I6fcd8d7587a380f8bd649c817b40a3a6cc1d2ee0
(cherry picked from commit 39bc44bb0e)
While this was never an inline, this function alone has caused most of
the bug reports related to _FILE_OFFSET_BITS=64. Providing an inline
for it should allow a lot more code to build with _FILE_OFFSET_BITS=64
when targeting pre-L.
Test: make checkbuild
Test: built trivial cc_binary for LP32 against API 14 with
_FILE_OFFSET_BITS=64 set
Bug: lots
Change-Id: I8479d34af4da358c11423bee43d45b59e9d4143e
Thread local buffers were using pthread_setspecific for storage with
lazy initialization. pthread_setspecific shares TLS slots between the
linker and libc.so, so thread local buffers being initialized in a
different order between libc.so and the linker meant that bad things
would happen (manifesting as snprintf not working because the
locale was mangled)
Bug: http://b/20464031
Test: /data/nativetest64/bionic-unit-tests/bionic-unit-tests
everything passes
Test: /data/nativetest/bionic-unit-tests/bionic-unit-tests
thread_local tests are failing both before and after (KUSER_HELPERS?)
Test: /data/nativetest64/bionic-unit-tests-static/bionic-unit-tests-static
no additional failures
Change-Id: I9f445a77c6e86979f3fa49c4a5feecf6ec2b0c3f
Exactly which functions get a stack protector is up to the compiler, so
let's separate the code that sets up the environment stack protection
requires and explicitly build it with -fno-stack-protector.
Bug: http://b/26276517
Change-Id: I8719e23ead1f1e81715c32c1335da868f68369b5
Found by the toybox id(1) which calls both getpwuid(3) and getgrgid(3) before
looking at either result. The use of a shared buffer in this code meant that
even on a single thread, the data for any of the passwd functions would be
clobbered by the data for any of the group functions (or vice versa).
This might seem like an insufficient fix, but POSIX explicitly says (for
getpwnam) that the result "might be overwritten by a subsequent call to
getpwent(), getpwnam(), or getpwuid()" and likewise for other members of
that group, plus equivalent text for the group-related functions.
Change-Id: I2272f47e91f72e043fdaf7c169fa9f6978ff4370
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
To use jemalloc, add MALLOC_IMPL = jemalloc in a board config file
and you get the new version automatically.
Update the pthread_create_key tests since jemalloc uses a few keys.
Add a new test to verify memalign works as expected.
Bug: 981363
Change-Id: I16eb152b291a95bd2499e90492fc6b4bd7053836
pthread_once is nice for decoupling, but it makes resource availability less
predictable, which is a bad thing.
This fixes a test failure if uselocale(3) is called before
pthread.pthread_key_create_lots runs.
Change-Id: Ie2634f986a50e7965582d4bd6e5aaf48cf0d55c8
I fixed this bug a while back, but didn't remove it from the list,
could have added a better test, and could have written clearer code
that didn't require a comment.
Change-Id: Iebdf0f9a54537a7d5cbca254a5967b1543061f3d
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
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
Although 'register' is deprecated, we need to use v1, and there's
no way to do that through register constraints on the assembler
fragment itself.
Change-Id: Ib5b12c4c3652513d10cc61d4a4b11314ece25663
In c++11, register has been deprecated, and
libc is now built as gnu++11
From the documentation:
A register specifier is a hint to the implementation
that the variable so declared will be heavily used.
[ Note: The hint can be ignored and in most implementations
it will be ignored if the address of the variable is taken.
This use is deprecated (see D.2)
Change-Id: I459dc3f5f9de63fc09eeda3bc6700f31bdf20f6f
KernelArgumentBlock is defined as a class in KernelArgumentBlock.h, but
forward declarations refer to it as a struct.
While this is essentially the same, the mismatch causes a compiler
warning in clang (and may cause warnings in future versions of gcc) in
code that is supposed to be compiled with -Werror.
Change-Id: I4ba49d364c44d0a42c276aff3a8098300dbdcdf0
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
Also make sysconf use PTHREAD_STACK_MIN rather than redefining its
own, different, constant.
Bug: 9997352
Change-Id: I9a8e7d2b18e691439abfb45533e82c36eee9e81d
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
There's now only one place where we deal with this stuff, it only needs to
be parsed once by the dynamic linker (rather than by each recipient), and it's
now easier for us to get hold of auxv data early on.
Change-Id: I6314224257c736547aac2e2a650e66f2ea53bef5
