Subtract stack by 24 bytes instead of 16 bytes so that stack is aligned
to 16 bytes when calling __gettimeofday.
[BZ #18661]
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
(__lll_timedwait_tid): Align stack to 16 bytes when calling
__gettimeofday.
Don't use pop to restore %rdi so that stack is aligned to 16 bytes
when calling __setcontext.
[BZ #18661]
* sysdeps/unix/sysv/linux/x86_64/__start_context.S
(__start_context): Don't use pop to restore %rdi so that stack
is aligned to 16 bytes when calling __setcontext.
{memcpy,strcmp}-sse2-unaligned.S aren't needed in ld.so.
* sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: Compile
only for libc.
* sysdeps/x86_64/multiarch/strcmp-sse2-unaligned.S: Likewise.
on bench-strncpy is 1.9-2.1x faster on average. I tried several variations, and using a tailcall and
calling memset conditionally gave the best overall results.
It uses the same logic as the ARM version. The common case removes 1 FPSR
and 1 FPCR read. For FE_DFL_ENV and FE_NOMASK_ENV a FPCR read is avoided in
case the FPCR does not change.
_nl_load_locale_from_archive (int category, const char **namep)
has
for (cnt = 0; cnt < __LC_LAST; ++cnt)
if (cnt != LC_ALL)
{
lia->data[cnt] = _nl_intern_locale_data (cnt,
results[cnt].addr,
results[cnt].len);
if (__glibc_likely (lia->data[cnt] != NULL))
{
...
}
}
lia->data[cnt] can be NULL, which happens to en_US.UTF-8 with
LC_COLLATE. But this won't happen if glibc is configured with
--enable-hardcoded-path-in-tests. We should also check
dead->data[category] != NULL.
* locale/loadarchive.c (_nl_archive_subfreeres): Also check
dead->data[category] != NULL.
The flt-32 implementation of powf wrongly uses x-1 instead of |x|-1
when computing log (x) for the case where |x| is close to 1 and y is
large. This patch fixes the logic accordingly. Relevant tests
existed for x close to 1, and corresponding tests are added for x
close to -1, as well as for some new variant cases.
Tested for x86_64 and x86.
[BZ #18647]
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): For large y
and |x| close to 1, use absolute value of x when computing log.
* math/auto-libm-test-in: Add more tests of pow.
* math/auto-libm-test-out: Regenerated.
as discussed in the thread starting at
https://sourceware.org/ml/libc-alpha/2015-06/msg00098.html
it looks like the best options is to remove locale timezone information
from locales which currently provide it (in incomplete or incorrect
fashion) rather than to start duplicating tzdata info in glibc.
This patch adds __nonnull annotations for wcscat, wcsncat, wcscmp and wcsncmp.
These added annotations match the annoations for strcat, strncat, strcmp, strncmp in glibc.
I keep trying to run tests with --help and then remembering that does
nothing when it throws an error. That means I have to dig into the
source when I want to refer to flags or env vars and re-read a good
amount of code to find the nested locations.
Make this all much more user friendly with a usage screen that gets
printed out whenever an unknown option is specified.
On arches that set _STACK_GROWS_UP, the stacktop variable is declared
and set, but never actually used. Refactor the code a bit so that the
variable is only declared/set under _STACK_GROWS_DOWN settings.
<regexp.h> (not to be confused with <regex.h>) is an obsolete and
frankly horrible regular expression-matching API. It was part of SVID
but was withdrawn in Issue 5 (for reference, we're on Issue 7 now).
It doesn't do anything you can't do with <regex.h>, and using it
involves defining a bunch of macros before including the header.
Moreover, the code in regexp.h that uses those macros has been buggy
since its creation (in 1996) and no one has noticed, which indicates
to me that there are no users. (Specifically, RETURN() is used in a
whole bunch of cases where it should have been ERROR().)
The header is given a warning and marked deprecated for 2.22.
See:
https://sourceware.org/ml/libc-alpha/2015-07/msg00862.html and
https://sourceware.org/ml/libc-alpha/2015-07/msg00871.html.
The semi-recent SYSCALL_CANCEL macro imposes a slight nuance on the
implementation of INLINE_SYSCALL: the nr argument cannot be expanded
directly but must be passed on to another macro which may expand it.
Most arches don't notice because INLINE_SYSCALL is defined in terms
of INTERNAL_SYSCALL which has the additional layer of expansion, but
on hppa, it was attempting to expand it directly. That causes build
errors like so:
../sysdeps/unix/sysv/linux/sigsuspend.c: In function '__sigsuspend':
../sysdeps/unix/sysv/linux/sigsuspend.c:31:62: error:
implicit declaration of function 'LOAD_ARGS___SYSCALL_NARGS'
../sysdeps/unix/sysv/linux/sigsuspend.c:31:304: error:
called object 'LOAD_ARGS___SYSCALL_NARGS(set, 8)' is not a function
So rewrite hppa's INLINE_SYSCALL to use INTERNAL_SYSCALL like other
arches do. This is also a nice clean up as the two macros had quite
a bit of duplicated logic.
On x86, linker in binutils 2.26 and newer consolidates R_*_JUMP_SLOT with
R_*_GLOB_DAT relocation against the same symbol. This patch extends
local PLT reference check to support alternate relocations.
[BZ #18078]
* scripts/check-localplt.awk: Support alternate relocations.
* scripts/localplt.awk: Also check relocations in DT_RELA/DT_REL
sections.
* sysdeps/unix/sysv/linux/i386/localplt.data: Mark free and
malloc entries with + REL R_386_GLOB_DAT.
* sysdeps/x86_64/localplt.data: New file.
Way back in 2005 the atomic_exchange_and_add function was cleaned up to
avoid the explicit size checking and instead let gcc handle things itself.
Unfortunately that change ended up leaving beyond a cast to int, even when
the incoming value was a long. This has flown under the radar for a long
time due to the function not being heavily used in the tree (especially as
a full 64bit field), but a recent change to semaphores made some nptl tests
fail reliably. This is due to the code packing two 32bit values into one
64bit variable (where the high 32bits contained the number of waiters), and
then the whole variable being atomically updated between threads. On ia64,
that meant we never atomically updated the count, so sometimes the sem_post
would not wake up the waiters.
This define made more sense in the pre-sanitized kernel headers days,
but since we require kernel versions that are sanitized, we don't need
this hack anymore.
This function actually checks for NULL arguments and the API has been
tenatively documented as using EINVAL in that case. We can debate
leaving it this way, but it should be done after the pending release.
Changes in support of -fno-plt also cause the elf/tst-audit* tests to
start passing on MIPS. This patch duly marks the relevant bug as
fixed in ChangeLog and NEWS.
The recently introduced TLS variables in the thread-local destructor
implementation (__cxa_thread_atexit_impl) used the default GD access
model, resulting in a call to __tls_get_addr. This causes a deadlock
with recent changes to the way TLS is initialized because DTV
allocations are delayed and hence despite knowing the offset to the
variable inside its TLS block, the thread has to take the global rtld
lock to safely update the TLS offset.
This causes deadlocks when a thread is instantiated and joined inside
a destructor of a dlopen'd DSO. The correct long term fix is to
somehow not take the lock, but that will need a lot deeper change set
to alter the way in which the big rtld lock is used.
Instead, this patch just eliminates the call to __tls_get_addr for the
thread-local variables inside libc.so, libpthread.so and rtld by
building all of their units with -mtls-model=initial-exec.
There were concerns that the static storage for TLS is limited and
hence we should not be using it. Additionally, dynamically loaded
modules may result in libc.so looking for this static storage pretty
late in static binaries. Both concerns are valid when using TLSDESC
since that is where one may attempt to allocate a TLS block from
static storage for even those variables that are not IE. They're not
very strong arguments for the traditional TLS model though, since it
assumes that the static storage would be used sparingly and definitely
not by default. Hence, for now this would only theoretically affect
ARM architectures.
The impact is hence limited to statically linked binaries that dlopen
modules that in turn load libc.so, all that on arm hardware. It seems
like a small enough impact to justify fixing the larger problem that
currently affects everything everywhere.
This still does not solve the original problem completely. That is,
it is still possible to deadlock on the big rtld lock with a small
tweak to the test case attached to this patch. That problem is
however not a regression in 2.22 and hence could be tackled as a
separate project. The test case is picked up as is from Alex's patch.
This change has been tested to verify that it does not cause any
issues on x86_64.
ChangeLog:
[BZ #18457]
* nptl/Makefile (tests): New test case tst-join7.
(modules-names): New test case module tst-join7mod.
* nptl/tst-join7.c: New file.
* nptl/tst-join7mod.c: New file.
* Makeconfig (tls-model): Pass -ftls-model=initial-exec for
all translation units in libc.so, libpthread.so and rtld.
