At the cost of two flag bits for what POSIX thinks should be a boolean
choice, plus somewhat confusing behavior from pthread_attr_getinheritsched
depending on when you call it/what specific scheduler attributes you've
set in the pthread_attr_t, we can emulate the old behavior exactly and
prevent annoying SELinux denial spam caused by calls to sched_setscheduler.
Bug: http://b/68391226
Test: adb logcat on boot contains no sys_nice avc denials
Change-Id: I4f759c2c4fd1d80cceb0912d7da09d35902e2e5e
To make it easier for Native Bridge implementations
to override these symbols.
Bug: http://b/67993967
Test: make
Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
Historically, Android defaulted to EXPLICIT but with a special case
because SCHED_NORMAL/priority 0 was awkward. Because the code couldn't
actually tell whether SCHED_NORMAL/priority 0 was a genuine attempt to
explicitly set those attributes (because the parent thread is SCHED_FIFO,
say) or just because the pthread_attr_t was left at its defaults.
Now we support INHERIT, we could call sched_getscheduler to see whether
we actually need to call sched_setscheduler, but since the major cost
is the fixed syscall overhead, we may as well just conservatively
call sched_setscheduler and let the kernel decide whether it's a
no-op. (Especially because we'd then have to add both sched_getscheduler
and sched_setscheduler to any seccomp filter.)
Platform code (or app code that only needs to support >= P) can actually
add a call to pthread_attr_setinheritsched to say that they just want
to inherit (if they know that none of their threads actually mess with
scheduler attributes at all), which will save them a sched_setscheduler
call except in the doubly-special case of SCHED_RESET_ON_FORK (which we
do handle).
An alternative would be "make pthread_attr_setschedparams and
pthread_attr_setschedprio set EXPLICIT and change the platform default
to INHERIT", but even though I can only think of weird pathological
examples where anyone would notice that change, that behavior -- of
pthread_attr_setschedparams/pthread_attr_setschedprio overriding an
earlier call to pthread_attr_setinheritsched -- isn't allowed by POSIX
(whereas defaulting to EXPLICIT is).
If we have a lot of trouble with this change in the app compatibility
testing phase, though, we'll want to reconsider this decision!
-*-
This change also removes a comment about setting the scheduler attributes
in main_thread because we'd have to actually keep them up to date,
and it's not clear that doing so would be worth the trouble.
Also make async_safe_format_log preserve errno so we don't have to be
so careful around it.
Bug: http://b/67471710
Test: ran tests
Change-Id: Idd026c4ce78a536656adcb57aa2e7b2c616eeddf
This also fixes a long-standing bug where the guard region would be taken
out of the stack itself, rather than being -- as POSIX demands -- additional
space after the stack. Historically a 128KiB stack with a 256KiB guard would
have given you an immediate crash.
Bug: http://b/38413813
Test: builds, boots
Change-Id: Idd12a3899be1d92fea3d3e0fa6882ca2216bd79c
(Where errno is relevant.)
Also consistently use -1 as the fd for anonymous mmaps. (It doesn't matter,
but it's more common, and potentially more intention-revealing.)
Bug: http://b/65608572
Test: ran tests
Change-Id: Ie9a207632d8242f42086ba3ca862519014c3c102
This library is used by a number of different libraries in the system.
Make it easy for platform libraries to use this library and create
an actual exported include file.
Change the names of the functions to reflect the new name of the library.
Run clang_format on the async_safe_log.cpp file since the formatting is
all over the place.
Bug: 31919199
Test: Compiled for angler/bullhead, and booted.
Test: Ran bionic unit tests.
Test: Ran the malloc debug tests.
Change-Id: I8071bf690c17b0ea3bc8dc5749cdd5b6ad58478a
For previous way to get the stack using the [stack] string from
/proc/self/task/<pid>/maps is not enough. On x86/x86_64, if an
alternative signal stack is used while a task switch happens,
the [stack] indicator may no longer be correct.
Instead, stack_start from /proc/self/stat which is always inside
the main stack, is used to find the main stack in /proc/self/maps.
Change-Id: Ieb010e71518b57560d541cd3b3563e5aa9660750
Signed-off-by: Nitzan Mor-sarid <nitzan.mor-sarid@intel.com>
Signed-off-by: Mingwei Shi <mingwei.shi@intel.com>
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
valgrind seems to mess with the stack enough that the kernel will
report "[stack:pid]" rather than "[stack]" in /proc/self/maps, so
switch to the task-specific file instead to force "[stack]". (There
are two conditions in the kernel code that decides which form to
output.)
Bug: 17897476
Change-Id: Iff85ceb6d52e8716251fab4e45d95a27184c5529
...rather than just what's already mapped in. This seems somewhat
contrary to POSIX's "All pages within the stack described by stackaddr
and stacksize shall be both readable and writable by the thread", but
it's what glibc does.
Bug: 17111575
Change-Id: If9e2dfad9a603c0d0615a8123aacda4946e95b2c
On most architectures the kernel subtracts a random offset to the stack
pointer in create_elf_tables by calling arch_align_stack before writing
the auxval table and so on. On all but x86 this doesn't cause a problem
because the random offset is less than a page, but on x86 it's up to two
pages. This means that our old technique of rounding the stack pointer
doesn't work. (Our old implementation of that technique was wrong too.)
It's also incorrect to assume that the main thread's stack base and size
are constant. Likewise to assume that the main thread has a guard page.
The main thread is not like other threads.
This patch switches to reading /proc/self/maps (and checking RLIMIT_STACK)
whenever we're asked.
Bug: 17111575
Signed-off-by: Fengwei Yin <fengwei.yin@intel.com>
Change-Id: I1d4dbffe7bc7bda1d353c3a295dbf68d29f63158
Functions protected with !defined(__LP64__) will be get build as C++
symbols for X64 build. This is not the desired work. So protect the
implementation with !defined(__LP64__) as well.
Change-Id: I4ef50ec36e46289ab308063e24f6c5ac61a6ca8d
<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
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
We notify debuggerd of problems by installing signal handlers. That's
fine except for when the signal is caused by us running off the end of
a thread's stack and into the guard page.
Bug: 8557703
Change-Id: I1ef65b4bb3bbca7e9a9743056177094921e60ed3
pthread_getattr_np was reporting the values supplied to us, not the values we
actually used, which is kinda the whole point of pthread_getattr_np.
pthread_attr_setguardsize and pthread_attr_setstacksize were reporting EINVAL
for any size that wasn't a multiple of the system page size. This is
unnecessary. We can just round like POSIX suggests and glibc already does.
Also improve the error reporting for pthread_create failures.
Change-Id: I7ebc518628a8a1161ec72e111def911d500bba71
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
