Add a GNU_STACK marker to crtend* files. This tells the linker
that these files do not require an executable stack.
When linking, a missing GNU_STACK marker in any .o file can prevent
the compiler from automatically marking the final executable as NX
safe (executable stack not required). In Android, we normally work
around this by adding -Wa,--noexecstack / -Wl,-z,noexecstack.
For files like crtend.S / crtend_so.S, which are included in every
executable / shared library, it's better to add the GNU_STACK note
directly to the assembly file. This allows the compiler to
automatically mark the final executable as NX safe without any
special command line options.
References: http://www.gentoo.org/proj/en/hardened/gnu-stack.xml
Change-Id: I07bd058f9f60ddd8b146e0fb36ba26ff84c0357d
Move the stackpointer so a captured signal does not corrupt
stack variables needed for __thread_entry.
Change-Id: I3e1e7b94a6d7cd3a07081f849043262743aa8064
Rewrite
crtbegin.S -> crtbegin.c
crtbegin_so.S -> crtbegin_so.c
This change allows us to generate PIC code without relying
on text relocations.
As a consequence of this rewrite, also rewrite
__dso_handle.S -> __dso_handle.c
__dso_handle_so.S -> __dso_handle_so.c
atexit.S -> atexit.c
In crtbegin.c _start, place the __PREINIT_ARRAY__, __INIT_ARRAY__,
__FINI_ARRAY__, and __CTOR_LIST__ variables onto the stack, instead of
passing a pointer to the text section of the binary.
This change appears sorta wonky, as I attempted to preserve,
as much as possible, the structure of the original assembly.
As a result, you have C files including other C files, and other
programming uglyness.
Result: This change reduces the number of files with text-relocations
from 315 to 19 on my Android build.
Before:
$ scanelf -aR $OUT/system | grep TEXTREL | wc -l
315
After:
$ scanelf -aR $OUT/system | grep TEXTREL | wc -l
19
Change-Id: Ib9f98107c0eeabcb606e1ddc7ed7fc4eba01c9c4
crtbegin_dynamic and crtbegin_static are essentially identical,
minus a few trivial differences (comments and whitespace).
Eliminate duplicates.
Change-Id: Ic9fae6bc9695004974493b53bfc07cd3bb904480
Some SoCs that support NEON nevertheless perform better with a non-NEON than a
NEON memcpy(). This patch adds build variable ARCH_ARM_USE_NON_NEON_MEMCPY,
which can be set in BoardConfig.mk. When ARCH_ARM_USE_NON_NEON_MEMCPY is
defined, we compile in the non-NEON optimized memcpy() even if the SoC supports
NEON.
Change-Id: Ia0e5bee6bad5880ffc5ff8f34a1382d567546cf9
So that we can always get the full stack trace regardless of gcc's handling
of the "noreturn" attribute associated with abort().
[cherry-picked from master]
BUG:6455193
Change-Id: I0102355f5bf20e636d3feab9d1424495f38e39e2
ARM Cortex A8 use 64 bytes and ARM Cortex A9 use 32 bytes cache line
size.
The following patch:
Adds code to adjust memcpy cache line size to match A9 cache line
size.
Adds a flag to select between 32 bytes and 64 bytes cache line
size.
Copyright (C) ST-Ericsson SA 2010
Modified neon implementation to fit Cortex A9 cache line size
Author: Henrik Smiding henrik.smiding@stericsson.com for
ST-Ericsson.
Change-Id: I8a55946bfb074e6ec0a14805ed65f73fcd0984a3
Signed-off-by: Christian Bejram <christian.bejram@stericsson.com>
The END macro was put too far down which made the linker complain about
it. Move up to the end of the code.
Change-Id: Ica71a9c6083b437d2213c7cefe34b0083c78f16b
Marking segments read-only was pushing the alignment of __on_dlclose by
2 bytes making it unaligned. This change makes sure the ARM code is
aligned to the 4 byte boundary.
Bug: 6313309
Change-Id: Ic2bf475e120dd61225ec19e5d8a9a8b1d0b7f081
This change fixes a segmentation fault in the libc unwinder when it goes
past __libc_init.
Unwind instructions for __libc_init direct it to grab the return address from
the stack frame. Without this change, the unwinder gets a wild address and
looks up further unwind instructions for the routine at that address. If it's
unlucky enough to hit an existing function, it will try to unwind it. Bad
things happen then.
With this change, the return address always points to the _start function,
which does not have unwind instructions associated with it. This stop the
unwind process.
__libc_init never returns, so this does not affect program execution, other
than adding 4 bytes on the main thread stack.
Change-Id: Id58612172e8825c8729cccd081541a13bff96bd0
Use the same pattern in atexit.S to reference __dso_handle in a way that
doesn't require a TEXTREL flag to be set.
Change-Id: Id69d20863ee203d2b2f7ef0db230f9b548657741
Some platform libraries built for ICS do not work with master
because of some refactoring in frameworks/base.
Make sure that these libgcc symbols are always present in our libc
Change-Id: Ib8d345878be0ba711f051082a778f5cc1f1b3a19
Signed-off-by: Dima Zavin <dima@android.com>
This patch defines a few new macros that can be used to control the
visibility of symbols exported by the C library:
- ENTRY_PRIVATE() can be used in assembly sources to indicate
that an assembler function should have "hidden" visibility, i.e.
will never be exported by the C library's shared library.
This is the equivalent of using __LIBC_HIDDEN__ for a C function,
but ENTRY_PRIVATE() works like ENTRY(), and must be used with
END() to tag the end of the function.
- __LIBC_ABI_PUBLIC__ can be used to tag a C functions as being
part of the C library's public ABI. This is important for a
few functions that must be exposed by the NDK to maintain
binary compatibility.
Once a symbol has been tagged with this macro, it shall
*never* be removed from the library, even if it becomes
directly unused due to implementation changes
(e.g. __is_threaded).
- __LIBC_ABI_PRIVATE__ can be used for C functions that should
always be exported by the C library because they are used by
other libraries in the platform, but should not be exposed
by the NDK. It is possible to remove such symbols from the
implementation if all callers are also modified.
+ Add missing END() assembly macro for x86
Change-Id: Ia96236ea0dbec41d57bea634b39d246b30e5e234
The xattr system calls are required for the SE Android userspace in
order to get and set file security contexts. In particular, libselinux
requires these calls.
Change-Id: I78f5eb3d8f3384aed0a5e7c6a6f001781d982017
Add bionic libc to support readahead system call.
This is needed to enable sreadahead to work.
Change-Id: I3856e1a3833db82e6cf42fd34af7631bd40cc723
Author: Winson Yung <winson.w.yung@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
The function must be named __atomic_cmpxchg, not __android_cmpxchg.
This typo broke existing prebuilt binaries (they couldn't be loaded
at runtime anymore).
Change-Id: I25ca7d18329817f0056e616a0409113269ad7b1f
Use tgkill instead of tkill to implement pthread_kill.
This is safer in the event that the thread has already terminated
and its id has been reused by a different process.
Change-Id: Ied715e11d7eadeceead79f33db5e2b5722954ac9
__atomic_cmpxchg and other related atomic operations did not
provide memory barriers, which can be a problem for non-platform
code that links against them when it runs on multi-core devices.
This patch does two things to fix this:
- It modifies the existing implementation of the functions
that are exported by the C library to always provide
full memory barriers. We need to keep them exported by
the C library to prevent breaking existing application
machine code.
- It also modifies <sys/atomics.h> to only export
always-inlined versions of the functions, to ensure that
any application code compiled against the new header will
not rely on the platform version of the functions.
This ensure that said machine code will run properly on
all multi-core devices.
This is based on the GCC built-in sync primitives.
The end result should be only slightly slower than the
previous implementation.
Note that the platform code does not use these functions
at all. A previous patch completely removed their usage in
the pthread and libstdc++ code.
+ rename arch-arm/bionic/atomics_arm.S to futex_arm.S
+ rename arch-x86/bionic/atomics_x86.S to futex_x86.S
+ remove arch-x86/include/sys/atomics.h which already
provided inlined functions to the x86 platform.
Change-Id: I752a594475090cf37fa926bb38209c2175dda539
Modify the dynamic linker so that executables can be loaded
at locations other than 0x00000000.
Modify crtbegin* so that non-PIC compilant "thumb interwork
veneers" are not created by the linker.
Bug: 5323301
Change-Id: Iece0272e2b708c79034f302c20160e1fe9029588
Without this change strcmp size is zero (not set), and it gets
ignored by Valgrind. Changes to memcpy and atexit don't affect the
generated binary in any way.
Change-Id: I05818cb5951f75901dc8c0eef02807a2e83a9231
This patch ensure that __aeabi_f2uiz is embedded in our C library.
This is needed to avoid breaking certain applications when they are
loaded in ICS. It is likely that the issue is due to mis-linked
binaries generated with the stand-alone toolchain (the problem
should not exist if you use ndk-build), but this fix is easier
than asking all app developers to fix their custom build system.
If you want more technical details, read the comments inside
libgcc_compat.c
Change-Id: I59ac1fc781ecb70b90b5573c5a3c67560ca8f270
Unfortunately, legacy .so files for ARM don't have a correct crtbegin file.
Consequently, we have to grandfather the old __dso_handle behaviour.
Add some ifdefs for ARM to allow it to use the old code until we can work
out a transition.
Change-Id: I6a28f368267d792c94e1d985d8344023bc632f6f
Author: H.J. Lu <hongjiu.lu@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Reference results of the experiments on TI OMAP3430 at 600 MHz
$ bench_strcmp -N "strcmp_1k" -s 1k -I 200
[original C code]
prc thr usecs/call samples errors cnt/samp size
strcmp_1k 1 1 10.38000 102 0 15000 1024
[ARM optimized code]
prc thr usecs/call samples errors cnt/samp size
strcmp_1k 1 1 3.08840 88 0 15000 1024
The work was derived from ARM Ltd, contributed to newlib, and reworked
for Android by Linaro.
Change-Id: Ib0d5755e1eb9adb07d80ef0252f57a5c4c57a425
Signed-off-by: Jim Huang <jserv@0xlab.org>
The kernel has supported this syscall for quite some time now,
but bionic did not. Now that there is a need for it, let's
add it to bionic.
Change-Id: Ifcef3e46f1438d79435b600c4e6063857ab16903
Used the new gensyscalls.py script to update the ARM syscalls with the
BEGIN(x) and END(x) macros to give size information for the code of the
syscall. Useful for valgrind.
Change-Id: I8c481c8928401ac110fd19b087f7d67e4db39326
Add a macro to annotate function end and start using both ENTRY and END
for each function. This allows valgrind (and presumably other debugging
tools) to use the debug symbols to trace the functions.
Change-Id: I5f09cef8e22fb356eb6f5cee952b031e567599b6
