It is not implemented anywhere. There is an osf_sstk system call on
alpha, but it is not used to implement sstk, and the system call
is not implemented on Linux, either.
New threads inherit the signal mask from the current thread. This
means that signal handlers can run on the newly created thread
immediately after the kernel has created the userspace thread, even
before glibc has initialized the TCB. Consequently, new threads can
observe uninitialized ctype data, among other things.
To address this, block all signals before starting the thread, and
pass the original signal mask to the start routine wrapper. On the
new thread, first perform all thread initialization, and then unblock
signals.
The cost of doing this is two rt_sigprocmask system calls on the old
thread, and one rt_sigprocmask system call on the new thread. (If
there was a way to clone a new thread with a signals disabled, this
could be brought down to one system call each.) The thread descriptor
increases in size, too, and sigset_t is fairly large. This increase
could be brought down by reusing space the in the descriptor which is
not needed before running user code, or by switching to an internal
sigset_t definition which only covers the signals supported by the
kernel definition. (Part of the thread descriptor size increase is
already offset by reduced stack usage in the thread start wrapper
routine after this commit.)
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
During testing of localedef running in a minimal container
there were several error cases which were hard to diagnose
since they appeared as strerror (errno) values printed by the
higher level functions. This change adds three new verbose
messages for potential failure paths. The new messages give
the user the opportunity to use -v and display additional
information about why localedef might be failing. I found
these messages useful myself while writing a localedef
container test for --no-hard-links.
Since the changes cleanup the code that handle codeset
normalization we add tst-localedef-path-norm which contains
many sub-tests to verify the correct expected normalization of
codeset strings both when installing to default paths (the
only time normalization is enabled) and installing to absolute
paths. During the refactoring I created at least one
buffer-overflow which valgrind caught, but these tests did not
catch because the exec in the container had a very clean heap
with zero-initialized memory. However, between valgrind and
the tests the results are clean.
The new tst-localedef-path-norm passes without regression on
x86_64.
Change-Id: I28b9f680711ff00252a2cb15625b774cc58ecb9d
Most gmp-mparam.h headers in glibc define various macros to the same
values they would be defined to by the generic version of that header,
plus macros IEEE_DOUBLE_BIG_ENDIAN or IEEE_DOUBLE_MIXED_ENDIAN related
to the representation of double. The latter macros are in turn only
used in gmp-impl.h to define union ieee_double_extract, which is not
used in glibc. Thus all of these headers, except for the generic one
and those that define _LONG_LONG_LIMB for ILP32 configurations with
64-bit registers, are redundant, and this patch removes them.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.
This function is defined in libc.so, and the dynamic loader calls
right after relocation has been finished, before any ELF constructors
or the preinit function is invoked. It is also used in the static
build for initializing parts of the static libc.
To locate __libc_early_init, a direct symbol lookup function is used,
_dl_lookup_direct. It does not search the entire symbol scope and
consults merely a single link map. This function could also be used
to implement lookups in the vDSO (as an optimization).
A per-namespace variable (libc_map) is added for locating libc.so,
to avoid repeated traversals of the search scope. It is similar to
GL(dl_initfirst). An alternative would have been to thread a context
argument from _dl_open down to _dl_map_object_from_fd (where libc.so
is identified). This could have avoided the global variable, but
the change would be larger as a result. It would not have been
possible to use this to replace GL(dl_initfirst) because that global
variable is used to pass the function pointer past the stack switch
from dl_main to the main program. Replacing that requires adding
a new argument to _dl_init, which in turn needs changes to the
architecture-specific libc.so startup code written in assembler.
__libc_early_init should not be used to replace _dl_var_init (as
it exists today on some architectures). Instead, _dl_lookup_direct
should be used to look up a new variable symbol in libc.so, and
that should then be initialized from the dynamic loader, immediately
after the object has been loaded in _dl_map_object_from_fd (before
relocation is run). This way, more IFUNC resolvers which depend on
these variables will work.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
MIPS needs to ignore certain existing symbols during symbol lookup.
The old scheme uses the ELF_MACHINE_SYM_NO_MATCH macro, with an
inline function, within its own header, with a sysdeps override for
MIPS. This allows re-use of the function from another file (without
having to include <dl-machine.h> or providing the default definition
for ELF_MACHINE_SYM_NO_MATCH).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Add a test to pass 64-bit long arguments to syscall with undefined upper
32 bits on x32.
Tested on i386, x86-64 and x32 as well as with build-many-glibcs.py.
GNU ld and gold's -Map include a line like:
path/to/build/libc_pic.a(check_fds.os)
lld -Map does not have the archive member list, but we can still derive the
members from the following output
VMA LMA Size Align Out In Symbol
...
1a1c0 1a1c0 e2 16 path/to/build/libc_pic.a(check_fds.os):(.text)
The upper bits of the sigset_t s not fully initialized in the signal
mask calls that return information from kernel (sigprocmask,
sigpending, and pthread_sigmask), since the exported sigset_t size
(1024 bits) is larger than Linux support one (64 or 128 bits).
It might make sigisemptyset/sigorset/sigandset fail if the mask
is filled prior the call.
This patch changes the internal signal function to handle up to
supported Linux signal number (_NSIG), the remaining bits are
untouched.
Checked on x86_64-linux-gnu and i686-linux-gnu.
It is required because __libc_unwind_longjmp (used on thread
cancellation) calls __sigprocmask. Replace with a direct call.
They are required because __libc_unwind_longjmp (used for thread
cancellation) calls __sigprocmask. Replace this with a direct call.
The sigblock function is not exported and is not used internally, so
it can be removed.
Checked on cross build for ia64-linux-gnu.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
A new symbol version is added on libc to force loading failure
instead of lazy binding one for newly binaries with old loaders.
Checked with a build against all affected ABIs.
Unicode 13.0.0 Support: Character encoding, character type info, and
transliteration tables are all updated to Unicode 13.0.0, using
the generator scripts contributed by Mike FABIAN (Red Hat).
Total added characters in newly generated CHARMAP: 5930
Total added characters in newly generated WIDTH: 5536
The __sfp_handle_exceptions is not fully correct regarding raising
exceptions, since there is no direct way to raise only FP_EX_OVERFLOW
nor FP_EX_UNDERFLOW for SSE mode. Both libgcc and feraiseexcept rely
on x87 mode to accomplish it.
This reverts commit 460ee50de0.
Checked on x86_64.
These will be used by upcoming RV32 and ARC ports and any future ports.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The exported x86_64 fenv.h functions operate on both i387 and SSE (since
they should work on both float, double, and long double) while the
internal libc_fe* set either SSE (float, double, and float128) or
i387 (long double).
The libgcc __sfp_handle_exceptions (used on float128 implementation),
however, will set either SEE or i387 exception depending of the
exception to raise. This broke the internal assumption of float128
where only SSE operations will be used.
This patch reimplements the libgcc __sfp_handle_exceptions to use only
SSE operations and sets libgcc to use it instead of its own
implementation.
And I think we should fix libgcc in a similar manner, since checking on
config/i386/64/sfp-machine.h it already only supports SSE rounding mode
and x86_64 ABI also expectes float128 to use SSE registers [1]
(although it is not clear on how future implementation might implement
it).
Checked on x86_64-linux-gnu.
[1] https://github.com/hjl-tools/x86-psABI/wiki/X86-psABI
It is required for i686 BZ#12683 support when building with -Os
or -fno-omit-frame-pointer on some gcc versions. It is not used
on current code.
Check on i686-linux-gnu.
An input BIG5-HKSCS character may be converted into at most 2 wchar_t
characters. After outputting the second whcar_t character (which was
saved in the converter state) we must reset the state. If we fail
to reset the state we will be stuck continually copying that
character to the output even if we have further input to consider.
We add a new test case that covers the 4 BIG5-HKSCS characters
that may become 2 wchar_t characters.
Reviewed-by: Tom Honermann <tom@honermann.net>
Linux 5.5 remove the system call in commit
61a47c1ad3a4dc6882f01ebdc88138ac62d0df03 ("Linux: Remove
<sys/sysctl.h>"). Therefore, the compat function is just a stub that
sets ENOSYS.
Due to SHLIB_COMPAT, new ports will not add the sysctl function anymore
automatically.
x32 already lacks the sysctl function, so an empty sysctl.c file is
used to suppress it. Otherwise, a new compat symbol would be added.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Patch 600f00b "linux: Use long time_t for wait4/getrusage" introduced
two bugs:
- The usage32 struct was set if the wait4 syscall had an error.
- For 32-bit systems the usage struct was set even if it was specified
as NULL.
This patch fixes the two issues.
X32 has 32-bit long and pointer with 64-bit off_t. Since x32 psABI
requires that pointers passed in registers must be zero-extended to
64bit, x32 can share many syscall interfaces with LP64. When a LP64
syscall with long and unsigned long arguments is used for x32, these
arguments must be properly extended to 64-bit. Otherwise if the upper
32 bits of the register have undefined value, such a syscall will be
rejected by kernel.
Enforce zero-extension for pointers and array system call arguments.
For integer types, extend to int64_t (the full register) using a
regular cast, resulting in zero or sign extension based on the
signedness of the original type.
For
void *mmap(void *addr, size_t length, int prot, int flags,
int fd, off_t offset);
we now generate
0: 41 f7 c1 ff 0f 00 00 test $0xfff,%r9d
7: 75 1f jne 28 <__mmap64+0x28>
9: 48 63 d2 movslq %edx,%rdx
c: 89 f6 mov %esi,%esi
e: 4d 63 c0 movslq %r8d,%r8
11: 4c 63 d1 movslq %ecx,%r10
14: b8 09 00 00 40 mov $0x40000009,%eax
19: 0f 05 syscall
That is
1. addr is unchanged.
2. length is zero-extend to 64 bits.
3. prot is sign-extend to 64 bits.
4. flags is sign-extend to 64 bits.
5. fd is sign-extend to 64 bits.
6. offset is unchanged.
For int arguments, since kernel uses only the lower 32 bits and ignores
the upper 32 bits in 64-bit registers, these work correctly.
Tested on x86-64 and x32. There are no code changes on x86-64.
This patch adds the GRND_INSECURE constant from Linux 5.6 to glibc's
sys/random.h. This is also added to the documentation. The constant
acts as a no-op for the Hurd implementation (as that doesn't check
whether the flags are known), which is semantically fine, while older
Linux kernels reject unknown flags with an EINVAL error.
Tested for x86_64.
This patch updates the kernel version in the test tst-mman-consts.py
to 5.6. (There are no new constants covered by this test in 5.6 that
need any other header changes.)
Tested with build-many-glibcs.py.
There are 2 new input values that require to be marked as
xfail-rounding:ibm128-libgcc as they're known to fail because of libgcc
issues with different rounding modes.
Otherwise, the other tests just need an increase in ULP.
Since GCC 6.2 or later is required to build glibc, remove build support
for GCC older than GCC 6.
Testd with GCC 6.4 and GCC 9.3.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Confirmed by CLDR and a native speaker: "abril" is more often used even
if "abrial" is also correct. Both nominative (alt_mon) and genitive (mon)
cases are updated.
This patch provides new __mq_timedreceive_time64 explicit 64 bit function for
receiving messages with absolute timeout.
Moreover, a 32 bit version - __mq_timedreceive has been refactored to
internally use __mq_timedreceive_time64.
The __mq_timedreceive is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64 from struct timespec.
The new mq_timedsend_time64 syscall available from Linux 5.1+ has been used,
when applicable.
As this wrapper function is also used internally in the glibc, to e.g. provide
mq_receive implementation, an explicit check for abs_timeout being NULL has been
added due to conversions between struct timespec and struct __timespec64.
Before this change the Linux kernel handled this NULL pointer.
Build tests:
- ./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Linux kernel, headers and minimal kernel version for glibc build test matrix:
- Linux v5.1 (with mq_timedreceive_time64) and glibc built with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
mq_timedreceive_time64 syscall.
- Linux v4.19 (no mq_timedreceive_time64 support) with default minimal kernel
version for contemporary glibc (3.2.0)
This kernel doesn't support mq_timedreceive_time64 syscall, so the fallback to
mq_timedreceive is tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides new __mq_timedsend_time64 explicit 64 bit function for
sending messages with absolute timeout.
Moreover, a 32 bit version - __mq_timedsend has been refactored to internally
use __mq_timedsend_time64.
The __mq_timedsend is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64 from struct timespec.
The new __mq_timedsend_time64 syscall available from Linux 5.1+ has been used,
when applicable.
As this wrapper function is also used internally in the glibc, to e.g. provide
mq_send implementation, an explicit check for abs_timeout being NULL has been
added due to conversions between struct timespec and struct __timespec64.
Before this change the Linux kernel handled this NULL pointer.
Build tests:
- ./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Linux kernel, headers and minimal kernel version for glibc build test matrix:
- Linux v5.1 (with mq_timedsend_time64) and glibc built with v5.1 as a
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
mq_timedsend_time64 syscall.
- Linux v4.19 (no mq_timedsend_time64 support) with default minimal kernel
version for contemporary glibc (3.2.0)
This kernel doesn't support mq_timedsend_time64 syscall, so the fallback to
mq_timedsend is tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The struct __timespec64's definition has been moved from ./include/time.h to
./include/struct___timespec64.h.
This change would prevent from polluting other glibc namespaces (when
headers are modified to support 64 bit time on architectures with
__WORDSIZE==32).
Now it is possible to just include definition of this particular structure
when needed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The code for set_max_fast() stores an "impossibly small value"
instead of zero, when the parameter is zero. However, for
small values of the parameter (ex: 1 or 2) the computation
results in a zero being stored anyway.
This patch checks for the parameter being small enough for the
computation to result in zero instead, so that a zero is never
stored.
key values which result in zero being stored:
x86-64: 1..7 (or other 64-bit)
i686: 1..11
armhfp: 1..3 (or other 32-bit)
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
We turn off this feature to avoid polluting our shared libary with
a specific value. However, static libgcc is not under our control,
and has enabled this for ibm128 routines. This pollutes the
resulting shared libraries with it.
Attach a post-linking hook to replace this section with one crafted
as hard-float + indeterminate ldbl. This allows IEEE ldbl users to
avoid having to disable the gnu attributes feature which should
protect them from linking ibm ldbl libraries using the gnu attributes
feature.
Currently, this only replaces libc and libm which support both ldbl
formats and rely on application code to explicitly determine which
is to be used.
Strictly speaking, the section could be deleted with minimal lost value.
However correctly set attributes could prove useful for some future change,
and similarly missing attributes.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
-mabi=ieeelongdouble triggers the stdc++ libraries _Float128
support, which then breaks if algorithm is included. For now,
explicitly disable _Float128 for such tests.
I have opened up GCC BZ 94080 to track this.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
I have observed a bug on 7.4.0 whereby __mulkc3 calls are
swapped with __multc3 depending on ABI selection. For the
sake of being overly cautious, build all _Float128 files
with ibm128 to workaround these compilers. This has been
noted in GCC BZ 84914, and will not be fixed for GCC 7.
Likewise, non-math files built with _Float128 are assumed
to have ibm long double. Explicilty preserve this
assumption.
Finally, add some bootstrapping code to avoid applying
these options until IEEE long double is enabled as they
require GCC 7 and above.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
The test for enabling _Float128 or IEEE 128 long double can be
greatly simplified knowing that there is no ibm128, thus we require
no special cases, and everything is canonical.
This reverts the changes to ldbl-128ibm iscanonical.h from commit
8dbfea3a20 and extends the check
for __NO_LONG_DOUBLE_MATH to include a check for float128 redirects
to long double.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
check_consistency should be disabled for GCC 5 and above since there is
no fixed PIC register in GCC 5 and above. Check __GNUC_PREREQ (5,0)
instead OPTIMIZE_FOR_GCC_5 since OPTIMIZE_FOR_GCC_5 is false with
-fno-omit-frame-pointer.
