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
The memchr implementation for 64 bit fails if these conditions occur:
- The buffer is 32 byte aligned.
- The buffer contains the character in the first byte.
- The count sent in is zero.
The function should return NULL, but it's not.
Bug: 16676625
Change-Id: Iab33cc7a8b79920350c72f054dff0e0a3cde69ce
Also fix a few formatting issues in copyright headers that were confusing
the script (though obviously it would be better if the script were smarter).
Change-Id: I7f561bef4f84fdcbd84f375ee226bd65db0e507b
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
Add 64-bit bionic implementation for denver. memcpy/memset are
denver-specific optimized. Use generic version of other routines.
Change-Id: I44a830e07b82b2986001d73d1540b4080aaa839b
vfork() was removed from POSIX 2008, so this replaces its implementation
with a call to fork().
Bug: 13935372
Change-Id: I6d99ac9e52a2efc5ee9bda1cab908774b830cedc
This patch removes the frame record created on svc calls.
Change-Id: I67cf926ba59540e824fb9749d30538e332df7c1e
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
This function has been removed from POSIX.
Unfortunately, we can't leave #define index(a, b) strchr((a), (b)) in its place
because defining a preprocessor macro for index() breaks a whole lot of code.
Bug: 13935372
Change-Id: Ifda348acde06da61c12e7ee2f8fe6950a3174dd1
These symbols are still defined for LP32 for binary compatibility, but
the declarations have been replaced with the POSIX recommended #defines.
Bug: 13935372
Change-Id: Ief7e6ca012db374588ba5839f11e8f3a13a20467
System calls can be pretty slow. This is mako, which has one of our
lowest latencies:
iterations ns/op
BM_unistd_getpid 10000000 209
BM_unistd_gettid 200000000 8
Bug: 15297299 (kernel panic from too many gettid calls)
Bug: 15315766 (excessive gettid overhead in liblogd)
Change-Id: I49656c0fc5b5d092390264a59e4f2c0d8a8b1aeb
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 reverts commit ced906c849.
Causes issues on art / dalvik due to a broken return value
check and other undiagnosed issues.
bug: 15195455
Change-Id: I5d6bbb389ecefb0e33a5237421a9d56d32a9317c
Add optimized versions of bcopy and wmemmove for AArch64 based on the
memmove implementation
Change-Id: I82fbe8a7221ce224c567ffcfed7a94a53640fca8
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
This reverts commit 8167dd7cb9.
For some reason I thought the bcopy change was bzero. The bcopy code doesn't pass our tests, so reverting until I can figure out what's wrong.
Change-Id: Id89fe959ea5105cd58dff6bba8d91a30cc4bcb07
Add optimized versions of bcopy and wmemmove for AArch64 based on the
memmove implementation
Change-Id: Ie43d0ff4f8ec4edba5b4fb5ccacd941f81ac6557
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
Since __bionic_clone uses tail-call to invoke __bionic_clone_entry,
at runtime the unwinder will reach the stack of the clone() function,
which belongs to the parent thread, if the link register is not cleared.
BUG: 14270816
Change-Id: Ia3711c87f8b619debe73748c28b9fb8691ea698e
glibc doesn't have tkill or tgkill and says "use syscall(3) instead".
I've left tgkill since it's quite widely used, but there's no reason
to have tkill as well.
Bug: 11156955
Change-Id: Ifc0af750320086f829bc9914551c172b501f3b60
Also hide part of the system properties compatibility code, since
we needed to touch that to keep it building.
I'll remove __futex_syscall4 and futex in a later patch.
Bug: 11156955
Change-Id: Ibbf42414c5bb07fb9f1c4a169922844778e4eeae
Fix syscall generator to add cfi directives and add the directives
for all arm64 assembler.
Bug: 15138290
Change-Id: I7f0e4a16c141ac624e5276917a3a1ed45778e057
