ARM now supports loading unmarked objects from
the dynamic loader cache. Unmarked objects can
be used with the hard-float or soft-float ABI.
We must support loading unmarked objects during
the transition period from a binutils that does
not mark objects to one that does mark them with
the correct ELF flags.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
That convention requires the instruction immediately preceding SYSCALL
to initialize $v0 with the syscall number. Then if a restart triggers,
$v0 will have been clobbered by the syscall interrupted, and needs to be
reinititalized. The kernel will decrement the PC by 4 before switching
back to the user mode so that $v0 has been reloaded before SYSCALL is
executed again. This implies the place $v0 is loaded from must be
preserved across a syscall, e.g. an immediate, static register, stack
slot, etc.
The restriction was lifted with Linux 2.6.36 kernel release and no
special requirements are placed around the SYSCALL instruction anymore,
however we still support older kernel binaries.
Previously, we would see a bad frame in the gdb backtrace output, e.g.:
(gdb) bt
#0 foo () at foo.c:5
#1 0x000000aaaab68ee8 in start_thread () from /lib/libpthread.so.0
#2 0x000000aaaad01c88 in clone () from /lib/libc.so.6
#3 0x0000000000000000 in ?? ()
With this change the bogus frame #3 is gone and we have the
same output as x86 does for the same program.
In bdd7898a58 we added self-definitions
of __isnan and friends in order to indicate specialized architecture
support, and avoid redefinitions within various generic math_private.h.
There is no generic math_private.h that concerns ldbl-128, and while
we provide __isnanl in the alpha math_private.h there's no need to
protect the function against redefinition.
In bdd7898a58 we added self-definitions
of __isnan and friends in order to indicate specialized architecture
support, and avoid redefinitions within various generic math_private.h.
There is no generic math_private.h that concerns ldbl-128, and while
we provide __isnanl in the alpha math_private.h there's no need to
protect the function against redefinition.
* sysdeps/unix/sysv/linux/aarch64/ldconfig.h: Add entries
for /lib/ld-linux.so.3 and /lib/ld-linux-armhf.so.3.
Signed-off-by: Steve McIntyre <steve.mcintyre@linaro.org>
Since we no longer support __ASSUME_POSIX_CPU_TIMERS, the ia64 code
no longer needs to override HAS_CPUCLOCK in the common file. Drop
the ia64 shim as well.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Use the new FLAG_AARCH64_LIB64 ldconfig cache tag for AArch64,
similarly to the way tags are handled for other architectures.
Signed-off-by: Steve McIntyre <steve.mcintyre@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
Signed-off-by: Marcus Shawcroft <marcus.shawcroft@linaro.org>
Atomic ops are issued directly from the core, rather than
potentially sitting in the write buffer, so can improve the
performance of other waiters. In addition, if we didn't end
up pulling a copy of the cache line where the lock is into cache,
by using an atomic op we don't have to acquire the cache line
before we can unlock.
With gcc 4.8 tilegx has support for -mcmodel=large, to tolerate very
large shared objects. This option changes the compiler output to
not include direct jump instructions, which have a range of only
2^30, i.e +/- 512MB. Instead the compiler marshalls the target PCs
into registers and then uses jump- or call-to-register instructions.
For glibc, the upshot is that we need to arrange for a few functions
to tolerate the possibility of a large range between the PC and
the target. In particular, the crti.S and start.S code needs
to be able to reach from .init to the PLT, as does gmon-start.c.
The elf-init.c code has the reverse problem, needing to call from
libc_nonshared.a (linked at the end of shared objects) back to the
_init section at the beginning.
No other functions in *_nonshared.a need to be built this way, as
they only call the PLT (or potentially each other), but all of that
code is linked at the very end of the shared object.
We don't build the standard -static archives with this option as the
performance cost is high enough and the use case is rare enough that
it doesn't seem worthwhile. Instead, we would encourage developers
who need the -static model with huge executables to build a private
copy of glibc and configure it with -mcmodel=large.
Note that libc.so et al don't need any changes; the only changes
are for code that is statically linked into user code built with
-mcmodel=large.
For the assembly code, I just rewrote it so that it unconditionally
uses the large model. To be able to pass -mcmodel=large to
csu/elf-init.c and csu/gmon-start.c, I need to check to see if the
compiler supports that flag, since gcc 4.7 doesn't; I added the
support by creating a small Makefile fragment that just runs the
compiler to check.
Normally, the simulator is notified of absolute pathnames by the
_dl_load_hook hook. However, when a relative pathname is used, the
simulator may not know that the relative path matches a path that
it could figure out in the file system that it has access to.
Instead we provide a simplified version of the realpath function
so we can pass a plausible absolute pathname to the simulator.
Since we're now doing more work at object load time, we also add
a guard so we do no work at all if we're not running on the simulator.
- Override <memcopy.h> so we use full 8-byte word copies on tilegx32
for memmove, then use op_t in memcpy instead of the previous
locally-defined word_t just to avoid proliferating identical types.
- Fix bug in memcpy prefetch that caused us to never prefetch past
the first cache line.
- Optimize misaligned memcpy by inlining _wordcopy_fwd_dest_aligned
instead of just doing a dumb word-at-a-time copy.
- Make memcpy safe for forward copies by doing all the loads from
a given cache line prior to doing a wh64 (cache line zero-fill)
on the destination. Remove now-redundant src == dst check.
- Copy and optimize the generic wordcopy.c routines to use the tile
"double align" instruction instead of the MERGE macro; to avoid
offset addressing mode (which tile doesn't have) by rewriting the
pointer math to load and store with a zero index; and to use
post-increment addresses in the inner loops to improve scheduling.
This hook is useful for any arch-specific functionality that
should be done on loaded objects. For the tile architecture,
the hook is already provided (though we switch to using the new
macro name with this commit) and implements a simulator notifier
so that the simulator can load Elf symbols to match the object
and generate better error messages for PC's.
Also, remove a spurious definition of DL_UNMAP in dl-runtime.c
We must save and restore r19 in both PIC and non-PIC
situations since the kernel paths that clobber r19
are independent of that PIC-ness of userspace.
In addition we choose r4 as the temporary register over
r3 which is being used by recent gcc's as the frame
pointer.
