This lets us do two things:
1) Make setjmp and longjmp compatible with shadow call stack.
To avoid leaking the shadow call stack address into memory, only the
lower log2(SCS_SIZE) bits of x18 are stored to jmp_buf. This requires
allocating an additional guard page so that we're guaranteed to be
able to allocate a sufficiently aligned SCS.
2) SCS overflow detection. Overflows now result in a SIGSEGV instead
of corrupting the allocation that comes after it.
Change-Id: I04d6634f96162bf625684672a87fba8b402b7fd1
Test: bionic-unit-tests
HWASan needs to re-tag the newly unallocated stack space to match SP.
Bug: 112438058
Test: SANITIZE_TARGET=hwaddress
Change-Id: I4dddef542d802d63bdea59e32a03425a2c4f870b
To make it easier for Native Bridge implementations
to override these symbols.
Bug: http://b/67993967
Test: make
Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
Using __builtin_frame_address was clever, but didn't work for arm64 (for
reasons which were never investigated) and the ChromeOS folks claim it
causes trouble for x86 with ARC++ (though without a reproduceable test case).
Naked functions turn out to be quite unevenly supported: some architectures
do the right thing, others don't; some architectures warn, others don't (and
the warnings don't always match the platforms that _actually_ have problems).
Inline assembler also removes the guessing games: everyone knows what the
couple of instructions _ought_ to be, and now we don't have to reason about
what the compiler will actually do (yet still keep the majority of the code
in C).
Bug: N/A
Test: builds, boots
Change-Id: I14207ef50ca46b6eca273c3cb7509c311146a3ca
The visibility control in pthread_atfork.h is incorrect.
It breaks 64bit libc.so by hiding pthread_atfork.
This reverts commit 6df122f852.
Change-Id: I21e4b344d500c6f6de0ccb7420b916c4e233dd34
Apparently clang really doesn't want you to take the address of a builtin.
Since this is only a temporary hack, let's just shrug and accept that
clang-built volantis images won't work until we have new NVIDIA blobs.
Bug: http://b/20065774
Change-Id: I4c8e893b15a1af8f9c54d3f89bfef112b63d09b4
NVIDIA binary blobs are assuming that __cache_clear, _Unwind_Backtrace,
and _Unwind_GetIP are all in some library that they link, but now we've
cleaned up this leakage, they're no longer getting it. Deliberately leak
the symbols from libc.so until we get new blobs.
Bug: http://b/20065774
Change-Id: I92ef07b2bce8d1ad719bf40dab41d745cd6904d4
Specifically, use the argument to sigsetjmp as a flag in the buffer
to indicate whether or not the signal mask is valid.
Bug: 16918359
Change-Id: I5bb1f1220f14c105c6bc57e0c28c1dc366d1438f
Note that this doesn't address the fact that we don't save/restore the
real-time signals. But it does let us pass the tests we currently fail.
Bug: 16918359
Change-Id: I063a6926164289a71026a412da7f5dd2ca9a74b3
gdb was happy with what we had, but libgcc and libunwind weren't.
libgcc is happy with the kernel's restorer (because of the extra nop),
though libunwind looks like it's going to need code changes regardless.
We could make our restorer more like the kernel's one, but why bother
when we can just let the kernel supply the canonical one?
Bug: 17436734
Change-Id: I330fa5e68f23b1cf8133aa552896657b0b873ed3
* LP32 should use sa_restorer too. gdb expects this, and future (>= 3.15) x86
kernels will apparently stop supporting the case where SA_RESTORER isn't
set.
* gdb and libunwind care about the exact instruction sequences, so we need to
modify the code slightly in a few cases to match what they're looking for.
* gdb also cares about the exact function names (for some architectures),
so we need to use __restore and __restore_rt rather than __sigreturn and
__rt_sigreturn.
* It's possible that we don't have a VDSO; dl_iterate_phdr shouldn't assume
that getauxval(AT_SYSINFO_EHDR) will return a non-null pointer.
This fixes unwinding through a signal handler in gdb for all architectures.
It doesn't fix libunwind for arm and arm64. I'll keep investigating that...
Bug: 17436734
Change-Id: Ic1ea1184db6655c5d96180dc07bcc09628e647cb
The use of the .hidden directive to avoid going via the PLT for
__set_errno had the side-effect of actually making __set_errno
hidden (which is odd because assembler directives don't usually
affect symbols defined in a different file --- you can't even
create a weak reference to a symbol that's defined in a different
file).
This change switches the system call stubs over to a new always-hidden
__set_errno_internal and has a visible __set_errno on LP32 just for
binary compatibility with old NDK apps.
(cherry-pick of 7efad83d430f4d824f2aaa75edea5106f6ff8aae.)
Bug: 17423135
Change-Id: I6b6d7a05dda85f923d22e5ffd169a91e23499b7b
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
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>
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
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
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
