Some Linux filesystems might not fully support 64 bit timestamps [1],
which make some Linux specific tests to fail when they check for the
functionality.
This patch adds a new libsupport function, support_path_support_time64,
that returns whether the target file supports or not 64 bit timestamps.
The support is checked by issuing a utimensat and verifying both the
last access and last modification time against a statx call.
The tests that might fail are also adjusted to check the file support
as well:
$ dd if=/dev/zero of=loopbackfile.img bs=100M count=1
1+0 records in
1+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 0,0589568 s, 1,8 GB/s
$ sudo losetup -fP loopbackfile.img
$ mkfs.xfs loopbackfile.img
meta-data=loopbackfile.img isize=512 agcount=4, agsize=6400 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=25600, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=1368, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
$ mkdir loopfs
$ sudo mount -o loop /dev/loop0 loopfs/
$ sudo chown -R azanella:azanella loopfs
$ TMPDIR=loopfs/ ./testrun.sh misc/tst-utimes
error: ../sysdeps/unix/sysv/linux/tst-utimes.c:55: File loopfs//utimesfECsK1 does not support 64-bit timestamps
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1795576
Previous commit was missing deleted files in sysdeps/ieee754/dbl-64.
Finally remove all mpa related files, headers, declarations, probes, unused
tables and update makefiles.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Finally remove all mpa related files, headers, declarations, probes, unused
tables and update makefiles.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Remove slow paths in tan. Add ULP annotations. Merge 'number' into 'mynumber'.
Remove unused entries from tan constants.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
This patch series removes all remaining slow paths and related code.
First asin/acos, tan, atan, atan2 implementations are updated, and the final
patch removes the unused mpa files, headers and probes. Passes buildmanyglibc.
Remove slow paths from asin/acos. Add ULP annotations based on previous slow
path checks (which are approximate). Update AArch64 and x86_64 libm-test-ulps.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Now that fstat is implemented on top fstatat we need to handle negative
inputs. The implementation now rejects AT_FDCWD, which would otherwise
be accepted by the kernel.
Checked on x86_64-linux-gnu and on i686-linux-gnu.
This patch updates the kernel version in the test tst-mman-consts.py
to 5.11. (There are no new MAP_* constants covered by this test in
5.11 that need any other header changes.)
Tested with build-many-glibcs.py.
Now that compat_symbol_reference works in non-internal tests.
Also do not build and run the test at all on architectures which
do not have the pre-2.28 symbol version of fcntl.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
compat_symbol_reference works in non-internal tests now. Also
avoid building the test for unsupported configurations at all.
I verified by building with build-many-glibcs.py that GLIBC_2.1.3
works as the predecessor of GLIBC_2.2. (Symbol versions in
the early days are complex.)
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
__nss_database_lookup2's extra arguments were left unused in the
nsswitch reloading patch set; this broke compat (default config
ignored) and shadow files (secondary name ignored) which relies on
these fallbacks.
This patch adds in the previous behavior by correcting the
initialization of the database list to reflect the fallbacks. This
means that the nss_database_lookup2 interface no longer needs to be
passed the fallback info, so API and callers were adjusted.
Since all callers needed to be edited anyway, the calls were changed
from __nss_database_lookup2 to the faster __nss_database_get. This
was an intended optimization which was deferred during the initial
lookup changes to avoid touching so many files.
The test case verifies that compat targets work (passwd) and that the
default configuration works (group). Tested on x86-64.
This code privides test to check if time on target machine is properly
adjusted.
The time is altered only when cross-test-ssh.sh is executed with
--allow-time-setting flag.
As the delta added to CLOCK_REALTIME is only 1 sec the original time is
not restored and further tests are executed with this bias.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Since the full ISA set used in an ELF binary is unknown to compiler,
an x86-64 ISA level marker indicates the minimum, not maximum, ISA set
required to run such an ELF binary. We never guarantee a library with
an x86-64 ISA level v3 marker doesn't contain other ISAs beyond x86-64
ISA level v3, like AVX VNNI. We check the x86-64 ISA level marker for
the minimum ISA set. Since -march=sandybridge enables only some ISAs
in x86-64 ISA level v3, we should set the needed ISA marker to v2.
Otherwise, libc is compiled with -march=sandybridge will fail to run on
Sandy Bridge:
$ ./elf/ld.so ./libc.so
./libc.so: (p) CPU ISA level is lower than required: needed: 7; got: 3
Set the minimum, instead of maximum, x86-64 ISA level marker should have
no impact on the glibc-hwcaps directory assignment logic in ldconfig nor
ld.so.
This is another attempt at making pthread_once handle throwing exceptions
from the init routine callback. As the new testcases show, just switching
to the cleanup attribute based cleanup does fix the tst-once5 test, but
breaks the new tst-oncey3 test. That is because when throwing exceptions,
only the unwind info registered cleanups (i.e. C++ destructors or cleanup
attribute), when cancelling threads and there has been unwind info from the
cancellation point up to whatever needs cleanup both unwind info registered
cleanups and THREAD_SETMEM (self, cleanup, ...) registered cleanups are
invoked, but once we hit some frame with no unwind info, only the
THREAD_SETMEM (self, cleanup, ...) registered cleanups are invoked.
So, to stay fully backwards compatible (allow init routines without
unwind info which encounter cancellation points) and handle exception throwing
we actually need to register the pthread_once cleanups in both unwind info
and in the THREAD_SETMEM (self, cleanup, ...) way.
If an exception is thrown, only the former will happen and we in that case
need to also unregister the THREAD_SETMEM (self, cleanup, ...) registered
handler, because otherwise after catching the exception the user code could
call deeper into the stack some cancellation point, get cancelled and then
a stale cleanup handler would clobber stack and probably crash.
If a thread calling init routine is cancelled and unwind info ends before
the pthread_once frame, it will be cleaned up through self->cleanup as
before. And if unwind info is present, unwind_stop first calls the
self->cleanup registered handler for the frame, then it will call the
unwind info registered handler but that will already see __do_it == 0
and do nothing.
There were following problems discovered for tst-timerfd test:
1. Do not set the struct itimerspec's it_interval tv_sec to 2 seconds.
After this change the timerfd will trigger only once (the it_value is
only set in this case).
2. The 'val1' variable (including the call to timerfd_gettime) is not
needed anymore, as it is just enough to read the struct itimerspec
after sleep. As a consequence the 'val2' has been renamed to 'val'.
3. After calling timerfd_gettime, the value of struct itimerspec time,
when timer is running, is the remaining time. In the case of this test
it would be less than 1 second.
As a result the TEST_COMPARE macro logic had to be adjusted.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides test for utimes. It uses wrapper to read
access and modification times to compare them with ones written by
utimes.
Moreover, access and modification times beyond the Y2038 threshold
date (i.e. 32 bit time_t overflow) are also checked.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides test for utime. It uses wrapper to read access
and modification times to compare them with ones written by utime.
Moreover, access and modification times beyond the Y2038 threshold
date (i.e. 32 bit time_t overflow) are also checked.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides test for futimens. It uses wrapper, which
reads access and modification time to compare them with ones
written by futimens.
Moreover, access and modification times beyond the Y2038 threshold
date (i.e. 32 bit time_t overflow) are also checked.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Do not define these macros if they do nothing in a particular
compilation, otherwise they can easily be used accidentally, while
not actually achieving anything.
Temporarily move the arm _Unwind_Resume implementation to the file
used by libpthread. It will be ported to <unwind-link.h> along with
the rest of nptl.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This will be used to consolidate the libgcc_s access for backtrace
and pthread_cancel.
Unlike the existing backtrace implementations, it provides some
hardening based on pointer mangling.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR"). These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker. However, the dynamic
linker skipped the main program for some reason. For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.
For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.
A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
The elision interfaces are closely aligned between the targets that
implement them, so declare them in the generic <lowlevellock.h>
file.
Empty .c stubs are provided, so that fewer makefile updates
under sysdeps are needed. Also simplify initialization via
__libc_early_init.
The symbols __lll_clocklock_elision, __lll_lock_elision,
__lll_trylock_elision, __lll_unlock_elision, __pthread_force_elision
move into libc. For the time being, non-hidden references are used
from libpthread to access them, but once that part of libpthread
is moved into libc, hidden symbols will be used again. (Hidden
references seem desirable to reduce the likelihood of transactions
aborts.)
This moves __futex_abstimed_wait64 and
__futex_abstimed_wait_cancelable64 and exports these functions as
GLIBC_PRIVATE.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This was likely a mistake in the original aarch64 port copied over
from arm: on aarch64 tpidr_el0 register is always available.
The __read_tp symbol is visible with static linking, but it's not
part of the public ABI so it should be safe to remove.
Linux 5.11 has one new syscall, epoll_pwait2. Update
syscall-names.list and regenerate the arch-syscall.h headers with
build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
If the linux asm/ptrace.h is included before sys/ptrace.h that
breaks the newly added declarations there, so undef the names
that may be defined as macros in the linux header.
Remove the extra space between "# endif" left over from
commit f380868f6d
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Dec 24 15:43:34 2020 -0800
Remove _ISOMAC check from <cpu-features.h>
It was added by 1bfbaf7130 where it added a libc_hidden_proto for
__fstatfs but it didn't update the Hurd version as well.
Checked with a build for i686-gnu.
The check is moved to LFS fstatat implementation (since it is the
code that actually implements the syscall).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Remove the internal_statvfs64.c and open code the implementation
on internal_statvfs.c. The alpha is now unrequired, the generic
implementation also handles it.
Also, remove unused includes on internal_statvfs.c, and remove
unused arguments on __internal_statvfs{64}.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
There is no need to handle ENOSYS on fstatfs64 call, required only
for alpha (where is already fallbacks to fstatfs).
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
There is no need to handle ENOSYS on fstatfs64 call, required only
for alpha (where is already fallbacks to fstatfs). The wordsize
internal_statvfs64.c is removed, since how the LFS support is
provided by fstatvfs64.c (used on 64-bit architectures as well).
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The __NR_statfs64 syscall is supported on all architectures but
aarch64, mips64, riscv64, and x86_64. And newer ABIs also uses
the new statfs64 interface (where the struct size is used as
second argument).
So the default implementation now uses:
1. __NR_statfs64 for non-LFS call and handle overflow directly
There is no need to handle __NR_statfs since all architectures
that only support are LFS only.
2. __NR_statfs if defined or __NR_statfs64 otherwise for LFS
call.
Alpha is the only outlier, since it is a 64-bit architecture which
provides non-LFS interface and only provides __NR_statfs64 on
newer kernels (v5.1+).
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The __NR_fstatfs64 syscall is supported on all architectures but
aarch64, mips64, riscv64, and x86_64. And newer ABIs also uses
the new fstatfs64 interface (where the struct size is used as
first argument).
So the default implementation now uses:
1. __NR_fstatfs64 for non-LFS call and handle overflow directly
There is no need to handle __NR_fstatfs since all architectures
that only support are LFS only.
2. __NR_fstatfs if defined or __NR_fstatfs64 otherwise for LFS
call.
Alpha is the only outlier, it is a 64-bit architecture which
provides non-LFS interface and only provides __NR_fstatfs64 on
newer kernels (5.1+).
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Currently glibc has three different struct statfs{64} definitions:
1. Non-LFS support where non-LFS and LFS struct have different
size: alpha, arm, hppa, i686, m68k, microblaze, mips (all abis),
powerpc32, s390, sh4, and sparc.
2. Non-LFS support where non-LFS and LFS struct have the same
size: csky and nios2.
3. Only LFS support (where both struct have the same size): arc,
ia64, powerpc64 (including LE), riscv (both 32 and 64 bits),
s390x, sparc64, and x86 (including x32).
The STATFS_IS_STATFS64/__STATFS_MATCHES_STATFS64 does not tell apart
between 1. and 2. since for both the only difference is the struct
size (for 2. both non-LFS and LFS uses the same syscall, where for
1. the old non-LFS is used for [f]statfs).
This patch move the generic statfs.h for both csky and nios2, and
make the default definitions for newer ABIs to assume that only
LFS will be support (so there is no need to keep no-LFS and LFS
struct statfs with the same size, it will be implicit).
This patch does not change the code generation.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The XSTAT_IS_XSTAT64 and STAT_IS_KERNEL_STAT flags are now set to 1 and
STATFS_IS_STATFS64 is set to __STATFS_MATCHES_STATFS64. This makes the
default ABI for newer ports to provide only LFS calls.
A copy of non-LFS support is provided to 32-bit ABIS with non-LFS
support (arm, csky, i386, m68k, nios2, s390, and sh). Is also allows
to remove the 64-bit ports, which already uses the default values.
This patch does not change the code generation.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
aarch64, arc, ia64, mips64, powerpc64, riscv32, riscv64, s390x, sparc64,
and x86_64 defines STATFS_IS_STATFS64 to 0, but all of them alias
statfs to statfs64 and the struct statfs has the same and layout of
struct statfs64.
The correct definition will be used on the [f]statfs[64] consolidation.
This patch does not change code generation since the symbols are
implemented using the auto-generation syscall for all the aforementioned
ABIs.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The TUNABLE_SET interface took a primitive C type argument, which
resulted in inconsistent type conversions internally due to incorrect
dereferencing of types, especialy on 32-bit architectures. This
change simplifies the TUNABLE setting logic along with the interfaces.
Now all numeric tunable values are stored as signed numbers in
tunable_num_t, which is intmax_t. All calls to set tunables cast the
input value to its primitive type and then to tunable_num_t for
storage. This relies on gcc-specific (although I suspect other
compilers woul also do the same) unsigned to signed integer conversion
semantics, i.e. the bit pattern is conserved. The reverse conversion
is guaranteed by the standard.
Take in consideration the trailling NULL since sem_search uses
strcmp to compare entries.
Checked on x86_64-linux-gnu and powerpc-linux-gnu (where it triggered
a nptl/tst-sem7 regression).
Linux 5.10 adds PTRACE_PEEKMTETAGS and PTRACE_POKEMTETAGS for AArch64.
Adding those shows up that glibc is also missing PTRACE_SYSEMU and
PTRACE_SYSEMU_SINGLESTEP, for AArch64 (where they were added to Linux
in 5.3) and for PowerPC (where they were added in Linux 4.20); it
already has those two defines for x86. Add all those defines to
glibc's headers.
Tested with build-many-glibcs.py for aarch64-linux-gnu and
powerpc-linux-gnu.
No bug. Just seemed the performance could be improved a bit. Observed
and expected behavior are unchanged. Optimized body of main
loop. Updated page cross logic and optimized accordingly. Made a few
minor instruction selection modifications. No regressions in test
suite. Both test-strchrnul and test-strchr passed.
sem_open already returns EINVAL for input names larger than NAME_MAX,
so it can assume the largest name length with tfind.
Checked on x86_64-linux-gnu.
The internal semaphore list code is moved to a specific file,
sem_routine.c, and the internal usage is simplified to only two
functions (one to insert a new semaphore and one to remove it
from the internal list). There is no need to expose the
internal locking, neither how the semaphore mapping is implemented.
No functional or semantic change is expected, tested on
x86_64-linux-gnu.
Previously, glibc would pick an arbitrary tmpfs file system from
/proc/mounts if /dev/shm was not available. This could lead to
an unsuitable file system being picked for the backing storage for
shm_open, sem_open, and related functions.
This patch introduces a new function, __shm_get_name, which builds
the file name under the appropriate (now hard-coded) directory. It is
called from the various shm_* and sem_* function. Unlike the
SHM_GET_NAME macro it replaces, the callers handle the return values
and errno updates. shm-directory.c is moved directly into the posix
subdirectory because it can be implemented directly using POSIX
functionality. It resides in libc because it is needed by both
librt and nptl/htl.
In the sem_open implementation, tmpfname is initialized directly
from a string constant. This happens to remove one alloca call.
Checked on x86_64-linux-gnu.
This change adds new test to assess ppoll()'s timeout related
functionality (the struct pollfd does not provide valid fd to wait
for - just wait for timeout).
To be more specific - two use cases are checked:
- if ppoll() times out immediately when passed struct timespec has zero
values of tv_nsec and tv_sec.
- if ppoll() times out after timeout specified in passed argument
This change adds new test to assess functionality of timerfd_*
functions.
It creates new timer (operates on its file descriptor) and checks
if time before and after sleep is between expected values.
1. Add CPUID_INDEX_14_ECX_0 for CPUID leaf 0x14 to detect PTWRITE feature
in EBX of CPUID leaf 0x14 with ECX == 0.
2. Add PTWRITE detection to CPU feature tests.
3. Add 2 static CPU feature tests.
It is effectively used, unexcept for pthread_cond_destroy, where we do
not want it; see bug 27304. The internal locks do not support a
process-shared mode.
This fixes commit dc6cfdc934 ("nptl:
Move pthread_cond_destroy implementation into libc").
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The shmmax expected value is tricky to check because kernel clamps it
to INT_MAX in two cases:
1. Compat symbols with IPC_64, i.e, 32-bit binaries running on 64-bit
kernels.
2. Default symbol without IPC_64 (defined as IPC_OLD within Linux) and
glibc always use IPC_64 for 32-bit ABIs (to support 64-bit time_t).
It means that 32-bit binaries running on 32-bit kernels will not see
shmmax being clamped.
And finding out whether the compat symbol is used would require checking
the underlying kernel against the current ABI. The shmall and shmmni
already provided enough coverage.
Checked on x86_64-linux-gnu and i686-linux-gnu. It should fix the
tst-sysvshm-linux failures on 32-bit kernels.
In the process of optimizing memcpy for AMD machines, we have found the
vector move operations are outperforming enhanced REP MOVSB for data
transfers above the L2 cache size on Zen3 architectures.
To handle this use case, we are adding an upper bound parameter on
enhanced REP MOVSB:'__x86_rep_movsb_stop_threshold'.
As per large-bench results, we are configuring this parameter to the
L2 cache size for AMD machines and applicable from Zen3 architecture
supporting the ERMS feature.
For architectures other than AMD, it is the computed value of
non-temporal threshold parameter.
Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
Add _SC_MINSIGSTKSZ for the minimum signal stack size derived from
AT_MINSIGSTKSZ, which is the minimum number of bytes of free stack
space required in order to gurantee successful, non-nested handling
of a single signal whose handler is an empty function, and _SC_SIGSTKSZ
which is the suggested minimum number of bytes of stack space required
for a signal stack.
If AT_MINSIGSTKSZ isn't available, sysconf (_SC_MINSIGSTKSZ) returns
MINSIGSTKSZ. On Linux/x86 with XSAVE, the signal frame used by kernel
is composed of the following areas and laid out as:
------------------------------
| alignment padding |
------------------------------
| xsave buffer |
------------------------------
| fsave header (32-bit only) |
------------------------------
| siginfo + ucontext |
------------------------------
Compute AT_MINSIGSTKSZ value as size of xsave buffer + size of fsave
header (32-bit only) + size of siginfo and ucontext + alignment padding.
If _SC_SIGSTKSZ_SOURCE or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ
are redefined as
/* Default stack size for a signal handler: sysconf (SC_SIGSTKSZ). */
# undef SIGSTKSZ
# define SIGSTKSZ sysconf (_SC_SIGSTKSZ)
/* Minimum stack size for a signal handler: SIGSTKSZ. */
# undef MINSIGSTKSZ
# define MINSIGSTKSZ SIGSTKSZ
Compilation will fail if the source assumes constant MINSIGSTKSZ or
SIGSTKSZ.
The reason for not simply increasing the kernel's MINSIGSTKSZ #define
(apart from the fact that it is rarely used, due to glibc's shadowing
definitions) was that userspace binaries will have baked in the old
value of the constant and may be making assumptions about it.
For example, the type (char [MINSIGSTKSZ]) changes if this #define
changes. This could be a problem if an newly built library tries to
memcpy() or dump such an object defined by and old binary.
Bounds-checking and the stack sizes passed to things like sigaltstack()
and makecontext() could similarly go wrong.
BSD 4.1 did not have an argument for TIOCFLUSH, BSD 4.2 added it. There
are still a lot of applications out there that pass a NULL argument to
TIOCFLUSH, so we should rather cope with it.
commit 94cd37ebb2
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Sep 16 05:27:32 2020 -0700
x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625]
broke
GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with:
1. Revert commit 94cd37ebb2.
2. Clears the usable CET feature bits if kernel doesn't support CET.
3. Add GLIBC_TUNABLES tests without dlopen.
4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches
_get_ssp.
5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled
with GLIBC_TUNABLES.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
brk used by statup before TCB is properly set, so we can't use
IA64_USE_NEW_STUB.
This patch fixes a regression introduced by 720480934a.
Checked on ia64-linux-gnu.
A not so recent kernel change[1] changed how the trampoline
`__kernel_sigtramp_rt64` is used to call signal handlers.
This was exposed on the test misc/tst-sigcontext-get_pc
Before kernel 5.9, the kernel set LR to the trampoline address and
jumped directly to the signal handler, and at the end the signal
handler, as any other function, would `blr` to the address set. In
other words, the trampoline was executed just at the end of the signal
handler and the only thing it did was call sigreturn. But since
kernel 5.9 the kernel set CTRL to the signal handler and calls to the
trampoline code, the trampoline then `bctrl` to the address in CTRL,
setting the LR to the next instruction in the middle of the
trampoline, when the signal handler returns, the rest of the
trampoline code executes the same code as before.
Here is the full trampoline code as of kernel 5.11.0-rc5 for
reference:
V_FUNCTION_BEGIN(__kernel_sigtramp_rt64)
.Lsigrt_start:
bctrl /* call the handler */
addi r1, r1, __SIGNAL_FRAMESIZE
li r0,__NR_rt_sigreturn
sc
.Lsigrt_end:
V_FUNCTION_END(__kernel_sigtramp_rt64)
This new behavior breaks how `backtrace()` uses to detect the
trampoline frame to correctly reconstruct the stack frame when it is
called from inside a signal handling.
This workaround rely on the fact that the trampoline code is at very
least two (maybe 3?) instructions in size (as it is in the 32 bits
version, only on `li` and `sc`), so it is safe to check the return
address be in the range __kernel_sigtramp_rt64 .. + 4.
[1] subject: powerpc/64/signal: Balance return predictor stack in signal trampoline
commit: 0138ba5783ae0dcc799ad401a1e8ac8333790df9
url: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0138ba5783ae0dcc799ad401a1e8ac8333790df9
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Some IFUNC variants are not compatible with BTI and MTE so don't
set them as usable for testing and benchmarking on a BTI or MTE
enabled system.
As far as IFUNC selectors are concerned a system is BTI enabled if
the cpu supports it and glibc was built with BTI branch protection.
Most IFUNC variants are BTI compatible, but thunderx2 memcpy and
memmove use a jump table with indirect jump, without a BTI j.
Fixes bug 26818.
The hwcap value is now in linux 5.10 and in glibc bits/hwcap.h, so use
that definition.
Move the definition to init-arch.h so all ifunc selectors can use it
and expose an "mte" shorthand for mte enabled runtime.
For now we allow user code to enable tag checks and use PROT_MTE
mappings without libc involvment, this is not guaranteed ABI, but
can be useful for testing and debugging with MTE.
GCC mainline shows the following error:
../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c: In function '__getdents64':
../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c:121:7: error: 'memcpy' forming offset [4, 7] is out of the bounds [0, 4] [-Werror=array-bounds]
121 | memcpy (((char *) dp + offsetof (struct dirent64, d_ino)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
122 | KDP_MEMBER (kdp, d_ino), sizeof ((struct dirent64){0}.d_ino));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c:123:7: error: 'memcpy' forming offset [4, 7] is out of the bounds [0, 4] [-Werror=array-bounds]
123 | memcpy (((char *) dp + offsetof (struct dirent64, d_off)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
124 | KDP_MEMBER (kdp, d_off), sizeof ((struct dirent64){0}.d_off));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The issue is due both d_ino and d_off fields for mips64-n32
kernel_dirent are 32-bits, while this is using memcpy to copy 64 bits
from it into the glibc dirent64.
The fix is to use a temporary buffer to read the correct type
from kernel_dirent.
Checked with a build-many-glibcs.py for mips64el-linux-gnu and I
also checked the tst-getdents64 on mips64el 4.1.4 kernel with
and without fallback enabled (by manually setting the
getdents64_supported).
It is not available with the baseline ISA.
Fixes commit 68ab82f566
("powerpc: Runtime selection between sc and scv for syscalls").
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Check ifunc resolver with CPU_FEATURE_USABLE and tunables in dynamic and
static executables to verify that CPUID features are initialized early in
static PIE.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This reverts commit 20b39d5946 for static
library. This avoids the need to rebuild the world for the case where
libstdc++ (and potentially other libraries) are linked to a old glibc.
To avoid requering to provide xstat symbols for newer ABIs (such as
riscv32) a new LIB_COMPAT macro is added. It is similar to SHLIB_COMPAT
but also works for static case (thus evaluating similar to SHLIB_COMPAT
for both shared and static case).
Checked with a check-abi on all affected ABIs. I also check if the
static library does contains the xstat symbols.
In commit 863d775c48, kunpeng920 is added to default memcpy version,
however, there is performance degradation when the copy size is some large bytes, eg: 100k.
This is the result, tested in glibc-2.28:
before backport after backport Performance improvement
memcpy_1k 0.005 0.005 0.00%
memcpy_10k 0.032 0.029 10.34%
memcpy_100k 0.356 0.429 -17.02%
memcpy_1m 7.470 11.153 -33.02%
This is the demo
#include "stdio.h"
#include "string.h"
#include "stdlib.h"
char a[1024*1024] = {12};
char b[1024*1024] = {13};
int main(int argc, char *argv[])
{
int i = atoi(argv[1]);
int j;
int size = atoi(argv[2]);
for (j = 0; j < i; j++)
memcpy(b, a, size*1024);
return 0;
}
# gcc -g -O0 memcpy.c -o memcpy
# time taskset -c 10 ./memcpy 100000 1024
Co-authored-by: liqingqing <liqingqing3@huawei.com>
Extern symbol access in position independent code usually involves GOT
indirection which needs RELATIVE reloc in a static linked PIE. (On
some targets this is avoided e.g. because the linker can relax a GOT
access to a pc-relative access, but this is not generally true.) Code
that runs before static PIE self relocation must avoid relying on
dynamic relocations which can be ensured by using hidden visibility.
However we cannot just make all symbols hidden:
On i386, all calls to IFUNC functions must go through PLT and calls to
hidden functions CANNOT go through PLT in PIE since EBX used in PIE PLT
may not be set up for local calls to hidden IFUNC functions.
This patch aims to make symbol references hidden in code that is used
before and by _dl_relocate_static_pie when building a static PIE libc.
Note: for an object that is used in the startup code, its references
and definition may not have consistent visibility: it is only forced
hidden in the startup code.
This is needed for fixing bug 27072.
Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add SUPPORT_STATIC_PIE that targets can define if they support
static PIE. This requires PI_STATIC_AND_HIDDEN support and various
linker features as described in
commit 9d7a3741c9
Add --enable-static-pie configure option to build static PIE [BZ #19574]
Currently defined on x86_64, i386 and aarch64 where static PIE is
known to work.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In <sys/platform/x86.h>, define CPU features as enum instead of using
the C preprocessor magic to make it easier to wrap this functionality
in other languages. Move the C preprocessor magic to internal header
for better GCC codegen when more than one features are checked in a
single expression as in x86-64 dl-hwcaps-subdirs.c.
1. Rename COMMON_CPUID_INDEX_XXX to CPUID_INDEX_XXX.
2. Move CPUID_INDEX_MAX to sysdeps/x86/include/cpu-features.h.
3. Remove struct cpu_features and __x86_get_cpu_features from
<sys/platform/x86.h>.
4. Add __x86_get_cpuid_feature_leaf to <sys/platform/x86.h> and put it
in libc.
5. Make __get_cpu_features() private to glibc.
6. Replace __x86_get_cpu_features(N) with __get_cpu_features().
7. Add _dl_x86_get_cpu_features to GLIBC_PRIVATE.
8. Use a single enum index for each CPU feature detection.
9. Pass the CPUID feature leaf to __x86_get_cpuid_feature_leaf.
10. Return zero struct cpuid_feature for the older glibc binary with a
smaller CPUID_INDEX_MAX [BZ #27104].
11. Inside glibc, use the C preprocessor magic so that cpu_features data
can be loaded just once leading to more compact code for glibc.
256 bits are used for each CPUID leaf. Some leaves only contain a few
features. We can add exceptions to such leaves. But it will increase
code sizes and it is harder to provide backward/forward compatibilities
when new features are added to such leaves in the future.
When new leaves are added, _rtld_global_ro offsets will change which
leads to race condition during in-place updates. We may avoid in-place
updates by
1. Rename the old glibc.
2. Install the new glibc.
3. Remove the old glibc.
NB: A function, __x86_get_cpuid_feature_leaf , is used to avoid the copy
relocation issue with IFUNC resolver as shown in IFUNC resolver tests.
Since __libc_init_secure is called before ARCH_SETUP_TLS, it must use
"int $0x80" for system calls in i386 static PIE. Add startup_getuid,
startup_geteuid, startup_getgid and startup_getegid to <startup.h>.
Update __libc_init_secure to use them.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add extra-test-objs to test-extras so that they are compiled with
-DMODULE_NAME=testsuite instead of -DMODULE_NAME=libc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
1. Move x86 processor cache info to _dl_x86_cpu_features in ld.so.
2. Update tunable bounds with TUNABLE_SET_WITH_BOUNDS.
3. Move x86 cache info initialization to dl-cacheinfo.h and initialize
x86 cache info in init_cpu_features ().
4. Put x86 cache info for libc in cacheinfo.h, which is included in
libc-start.c in libc.a and is included in cacheinfo.c in libc.so.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Store ISA level in the portion of the unused upper 32 bits of the hwcaps
field in cache and the unused pad field in aux cache. ISA level is stored
and checked only for shared objects in glibc-hwcaps subdirectories. The
shared objects in the default directories aren't checked since there are
no fallbacks for these shared objects.
Tested on x86-64-v2, x86-64-v3 and x86-64-v4 machines with
--disable-hardcoded-path-in-tests and --enable-hardcoded-path-in-tests.
The first getrandom is used only for __GT_NOCREATE, which is inherently
insecure and can use the entropy as a small improvement. On the
second and later attempts it might help against DoS attacks.
It sync with gnulib commit 854fbb81d91f7a0f2b463e7ace2499dee2f380f2.
Checked on x86_64-linux-gnu.
It syncs with gnulib commit b1268f22f443e8e4b9e. The try_tempname_len
now uses getrandom on each iteration to get entropy and only uses the
clock plus ASLR as source of entropy if getrandom fails.
Checked on x86_64-linux-gnu and i686-linux-gnu.
POSIX states that system returned code for failure to execute the shell
shall be as if the shell had terminated using _exit(127). This
behaviour was removed with 5fb7fc9635.
Checked on x86_64-linux-gnu.
The $gp register may be used to access the global variable in
the PDE program, so the $gp register should be initialized before
executing the IFUNC resolver of PDE program to avoid unexpected
error occurs.
AArch64 always uses pc relative access to static and hidden object
symbols, but the config setting was previously missing.
This affects ld.so start up code.
GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
levels:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250
and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
GNU_PROPERTY_X86_ISA_1_V[234] marker:
https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13
Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by
commit b0ab06937385e0ae25cebf1991787d64f439bf12
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Oct 30 06:49:57 2020 -0700
x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker
and
commit 32930e4edbc06bc6f10c435dbcc63131715df678
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Oct 9 05:05:57 2020 -0700
x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
micro-architecture ISA level required to execute the binary. The marker
must be added by programmers explicitly in one of 3 ways:
1. Pass -mneeded to GCC.
2. Add the marker in the linker inputs as this patch does.
3. Pass -z x86-64-v[234] to the linker.
Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker support to ld.so if binutils 2.32 or newer is used to build glibc:
1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
markers to elf.h.
2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker to abi-note.o based on the ISA level used to compile abi-note.o,
assuming that the same ISA level is used to compile the whole glibc.
3. Add isa_1 to cpu_features to record the supported x86 ISA level.
4. Rename _dl_process_cet_property_note to _dl_process_property_note and
add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
5. Update _rtld_main_check and _dl_open_check to check loaded objects
with the incompatible ISA level.
6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
on lesser platforms.
7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.
Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
x86-64-v4 machines.
Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
and got:
[hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
./elf/tst-isa-level-1: CPU ISA level is lower than required
[hjl@gnu-cfl-2 build-x86_64-linux]$
Remove the wordsize-64 implementations by merging them into the main dbl-64
directory. The second patch just moves all wordsize-64 files and removes a
few wordsize-64 uses in comments and Implies files.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Remove the wordsize-64 implementations by merging them into the main dbl-64
directory. The first patch adds special cases needed for 32-bit targets
(FIX_INT_FP_CONVERT_ZERO and FIX_DBL_LONG_CONVERT_OVERFLOW) to the
wordsize-64 versions. This has no effect on 64-bit targets since they don't
define these macros.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It sync with gnulib version ae9fb3d66. The testcase for BZ#23741
(stdlib/test-bz22786.c) is adjusted to check also for ENOMEM.
The patch fixes multiple realpath issues:
- Portability fixes for errno clobbering on free (BZ#10635). The
function does not call free directly anymore, although it might be
done through scratch_buffer_free. The free errno clobbering is
being tracked by BZ#17924.
- Pointer arithmetic overflows in realpath (BZ#26592).
- Realpath cyclically call __alloca(path_max) to consume too much
stack space (BZ#26341).
- Realpath mishandles EOVERFLOW; stat not needed anyway (BZ#24970).
The check is done through faccessat now.
Checked on x86_64-linux-gnu and i686-linux-gnu.
This ia regression from 09153638cf, versioned_symbol acts as
weak_alias for !SHARED but it is undefined to avoid non versioned
alias from the generic implementation.
Checked with a build for alpha-linux-gnu.
Calling an IFUNC function defined in unrelocated executable also leads to
segfault. Issue a fatal error message when calling IFUNC function defined
in the unrelocated executable from a shared library.
In the !MAP_FIXED case, when a bogus address is given mmap should pick up a
valide address rather than returning EINVAL: Posix only talks about
EINVAL for the MAP_FIXED case.
This fixes long-running ghc processes.
When copying with "rep movsb", if the distance between source and
destination is N*4GB + [1..63] with N >= 0, performance may be very
slow. This patch updates memmove-vec-unaligned-erms.S for AVX and
AVX512 versions with the distance in RCX:
cmpl $63, %ecx
// Don't use "rep movsb" if ECX <= 63
jbe L(Don't use rep movsb")
Use "rep movsb"
Benchtests data with bench-memcpy, bench-memcpy-large, bench-memcpy-random
and bench-memcpy-walk on Skylake, Ice Lake and Tiger Lake show that its
performance impact is within noise range as "rep movsb" is only used for
data size >= 4KB.
After sp is updated, the CFA offset should be set before next instruction.
Tested in glibc-2.28:
Thread 2 "xxxxxxx" hit Breakpoint 1, _dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:149
149 stp x1, x2, [sp, #-32]!
Missing separate debuginfos, use: dnf debuginfo-install libgcc-7.3.0-20190804.h24.aarch64
(gdb) bt
#0 _dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:149
#1 0x0000ffffbe4fbb44 in OurFunction (threadId=3194870184)
at /home/test/test_function.c:30
#2 0x0000000000400c08 in initaaa () at thread.c:58
#3 0x0000000000400c50 in thread_proc (param=0x0) at thread.c:71
#4 0x0000ffffbf6918bc in start_thread (arg=0xfffffffff29f) at pthread_create.c:486
#5 0x0000ffffbf5669ec in thread_start () at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78
(gdb) ni
_dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:150
150 stp x3, x4, [sp, #16]
(gdb) bt
#0 _dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:150
#1 0x0000ffffbe4fbb44 in OurFunction (threadId=3194870184)
at /home/test/test_function.c:30
#2 0x0000000000000000 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) ni
_dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:157
157 mrs x4, tpidr_el0
(gdb) bt
#0 _dl_tlsdesc_dynamic () at ../sysdeps/aarch64/dl-tlsdesc.S:157
#1 0x0000ffffbe4fbb44 in OurFunction (threadId=3194870184)
at /home/test/test_function.c:30
#2 0x0000000000400c08 in initaaa () at thread.c:58
#3 0x0000000000400c50 in thread_proc (param=0x0) at thread.c:71
#4 0x0000ffffbf6918bc in start_thread (arg=0xfffffffff29f) at pthread_create.c:486
#5 0x0000ffffbf5669ec in thread_start () at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78
Signed-off-by: liqingqing <liqingqing3@huawei.com>
Signed-off-by: Shuo Wang <wangshuo47@huawei.com>
Make the tests use TEST_COND_intel96 to decide on whether to build the
unnormal tests instead of the macro in nan-pseudo-number.h and then
drop the header inclusion. This unbreaks test runs on all
architectures that do not have ldbl-96.
Also drop the HANDLE_PSEUDO_NUMBERS macro since it is not used
anywhere.
I've updated copyright dates in glibc for 2021. This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files. As well as the usual annual
updates, mainly dates in --version output (minus csu/version.c which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a small change to the copyright notice
in NEWS which should let NEWS get updated automatically next year.
Please remember to include 2021 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
DELOUSE was added to asm code to make them compatible with non-LP64
ABIs, but it is an unfortunate name and the code was not compatible
with ABIs where pointer and size_t are different. Glibc currently
only supports the LP64 ABI so these macros are not really needed or
tested, but for now the name is changed to be more meaningful instead
of removing them completely.
Some DELOUSE macros were dropped: clone, strlen and strnlen used it
unnecessarily.
The out of tree ILP32 patches are currently not maintained and will
likely need a rework to rebase them on top of the time64 changes.
clone already uses r31 to temporarily save input arguments before doing the
syscall, so we use a different register to read from the TCB. We can also avoid
allocating another stack frame, which is not needed since we can simply extend
the usage of the red zone.
Tested-by: Lucas A. M. Magalhães <lamm@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Linux kernel v5.9 added support for system calls using the scv
instruction for POWER9 and later. The new codepath provides better
performance (see below) if compared to using sc. For the
foreseeable future, both sc and scv mechanisms will co-exist, so this
patch enables glibc to do a runtime check and use scv when it is
available.
Before issuing the system call to the kernel, we check hwcap2 in the TCB
for PPC_FEATURE2_SCV to see if scv is supported by the kernel. If not,
we fallback to sc and keep the old behavior.
The kernel implements a different error return convention for scv, so
when returning from a system call we need to handle the return value
differently depending on the instruction we used to enter the kernel.
For syscalls implemented in ASM, entry and exit are implemented by
different macros (PSEUDO and PSEUDO_RET, resp.), which may be used in
sequence (e.g. for templated syscalls) or with other instructions in
between (e.g. clone). To avoid accessing the TCB a second time on
PSEUDO_RET to check which instruction we used, the value read from
hwcap2 is cached on a non-volatile register.
This is not needed when using INTERNAL_SYSCALL macro, since entry and
exit are bundled into the same inline asm directive.
The dynamic loader may issue syscalls before the TCB has been setup
so it always uses sc with no extra checks. For the static case, there
is no compile-time way to determine if we are inside startup code,
so we also check the value of the thread pointer before effectively
accessing the TCB. For such situations in which the availability of
scv cannot be determined, sc is always used.
Support for scv in syscalls implemented in their own ASM file (clone and
vfork) will be added later. For now simply use sc as before.
Average performance over 1M calls for each syscall "type":
- stat: C wrapper calling INTERNAL_SYSCALL
- getpid: templated ASM syscall
- syscall: call to gettid using syscall function
Standard:
stat : 1.573445 us / ~3619 cycles
getpid : 0.164986 us / ~379 cycles
syscall : 0.162743 us / ~374 cycles
With scv:
stat : 1.537049 us / ~3535 cycles <~ -84 cycles / -2.32%
getpid : 0.109923 us / ~253 cycles <~ -126 cycles / -33.25%
syscall : 0.116410 us / ~268 cycles <~ -106 cycles / -28.34%
Tested on powerpc, powerpc64, powerpc64le (with and without scv)
Tested-by: Lucas A. M. Magalhães <lamm@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Add support to treat pseudo-numbers specially and implement x86
version to consider all of them as signaling.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
With xmknod wrapper functions removed (589260cef8), the mknod functions
are now properly exported, and version is done using symbols versioning
instead of the extra _MKNOD_* argument.
It also allows us to consolidate Linux and Hurd mknod implementation.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
With xstat wrapper functions removed (8ed005daf0), the stat functions
are now properly exported, and version is done using symbols versioning
instead of the extra _STAT_* argument.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The new __proc_waitid RPC now expects WEXITED to be passed, allowing to
properly implement waitid, and thus define the missing W* macros
(according to FreeBSD values).
Instead of having the arch-specific trampoline setup code detect whether
preemption happened or not, we'd rather pass it the sigaction. In the
future, this may also allow to change sa_flags from post_signal().
Do not attempt to fix the significand top bit in long double input
received in printf. The code should never reach here because isnan
should now detect unnormals as NaN. This is already a NOP for glibc
since it uses the gcc __builtin_isnan, which detects unnormals as NaN.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This syncs up isnanl behaviour with gcc. Also move the isnanl
implementation to sysdeps/x86 and remove the sysdeps/x86_64 version.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Also move sysdeps/i386/fpu/s_fpclassifyl.c to
sysdeps/x86/fpu/s_fpclassifyl.c and remove
sysdeps/x86_64/fpu/s_fpclassifyl.c
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add Intel Linear Address Masking (LAM) support to <sys/platform/x86.h>.
HAS_CPU_FEATURE (LAM) can be used to detect if LAM is enabled in CPU.
LAM modifies the checking that is applied to 64-bit linear addresses,
allowing software to use of the untranslated address bits for metadata.
Add various defines and stubs for enabling MTE on AArch64 sysv-like
systems such as Linux. The HWCAP feature bit is copied over in the
same way as other feature bits. Similarly we add a new wrapper header
for mman.h to define the PROT_MTE flag that can be used with mmap and
related functions.
We add a new field to struct cpu_features that can be used, for
example, to check whether or not certain ifunc'd routines should be
bound to MTE-safe versions.
Finally, if we detect that MTE should be enabled (ie via the glibc
tunable); we enable MTE during startup as required.
Support in the Linux kernel was added in version 5.10.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Older versions of the Linux kernel headers obviously lack support for
memory tagging, but we still want to be able to build in support when
using those (obviously it can't be enabled on such systems).
The linux kernel extensions are made to the platform-independent
header (linux/prctl.h), so this patch takes a similar approach.
This patch adds the basic support for memory tagging.
Various flavours are supported, particularly being able to turn on
tagged memory at run-time: this allows the same code to be used on
systems where memory tagging support is not present without neededing
a separate build of glibc. Also, depending on whether the kernel
supports it, the code will use mmap for the default arena if morecore
does not, or cannot support tagged memory (on AArch64 it is not
available).
All the hooks use function pointers to allow this to work without
needing ifuncs.
Reviewed-by: DJ Delorie <dj@redhat.com>
This is clever, but it confuses downstream detection in at least zstd
and GNOME's glib. zstd has preprocessor tests for the 'st_mtime' macro,
which is not provided by the path using the anonymous union; glib checks
for the presence of 'st_mtimensec' in struct stat but then tries to
access that field in struct statx (which might be a bug on its own).
Checked with a build for alpha-linux-gnu.
setjmp() uses C code to store current registers into jmp_buf
environment. -fstack-protector-all places canary into setjmp()
prologue and clobbers 'a5' before it gets saved.
The change inhibits stack canary injection to avoid clobber.
When SA_SIGINFO is available, sysdeps/posix/s?profil.c use it, so we have to
fix the __profil_counter function accordingly, using sigcontextinfo.h's
sigcontext_get_pc.
SA_SIGINFO is actually just another way of expressing what we were
already passing over with struct sigcontext. This just introduces the
SIGINFO interface and fixes the posix values when that interface is
requested by the application.
asin and acos have slow paths for rounding the last bit that cause some
calls to be 500-1500x slower than average calls.
These slow paths are rare, a test of a trillion (1.000.000.000.000)
random inputs between -1 and 1 showed 32870 slow calls for acos and 4473
for asin, with most occurrences between -1.0 .. -0.9 and 0.9 .. 1.0.
The slow paths claim correct rounding and use __sin32() and __cos32()
(which compare two result candidates and return the closest one) as the
final step, with the second result candidate (res1) having a small offset
applied from res. This suggests that res and res1 are intended to be 1
ULP apart (which makes sense for rounding), barring bugs, allowing us to
pick either one and still remain within 1 ULP of the exact result.
Remove the slow paths as the accuracy is better than 1 ULP even without
them, which is enough for glibc.
Also remove code comments claiming correctly rounded results.
After slow path removal, checking the accuracy of 14.400.000.000 random
asin() and acos() inputs showed only three incorrectly rounded
(error > 0.5 ULP) results:
- asin(-0x1.ee2b43286db75p-1) (0.500002 ULP, same as before)
- asin(-0x1.f692ba202abcp-4) (0.500003 ULP, same as before)
- asin(-0x1.9915e876fc062p-1) (0.50000000001 ULP, previously exact)
The first two had the same error even before this commit, and they did
not use the slow path at all.
Checking 4934 known randomly found previously-slow-path asin inputs
shows 25 calls with incorrectly rounded results, with a maximum error of
0.500000002 ULP (for 0x1.fcd5742999ab8p-1). The previous slow-path code
rounded all these inputs correctly (error < 0.5 ULP).
The observed average speed increase was 130x.
Checking 36240 known randomly found previously-slow-path acos inputs
shows 42 calls with incorrectly rounded results, with a maximum error of
0.500000008 ULP (for 0x1.f63845056f35ep-1). The previous "exact"
slow-path code showed 34 calls with incorrectly rounded results, with the
same maximum error of 0.500000008 ULP (for 0x1.f63845056f35ep-1).
The observed average speed increase was 130x.
The functions could likely be trimmed more while keeping acceptable
accuracy, but this at least gets rid of the egregiously slow cases.
Tested on x86_64.
This patch updates the kernel version in the test tst-mman-consts.py
to 5.10. (There are no new MAP_* constants covered by this test in
5.10 that need any other header changes.)
Tested with build-many-glibcs.py.
GCC 6.5 fails to correctly build ldconfig with recent ld.so.cache
commits, e.g.:
785969a047
elf: Implement a string table for ldconfig, with tail merging
If glibc is build with gcc 6.5.0:
__builtin_add_overflow is used in
<glibc>/elf/stringtable.c:stringtable_finalize()
which leads to ldconfig failing with "String table is too large".
This is also recognizable in following tests:
FAIL: elf/tst-glibc-hwcaps-cache
FAIL: elf/tst-glibc-hwcaps-prepend-cache
FAIL: elf/tst-ldconfig-X
FAIL: elf/tst-ldconfig-bad-aux-cache
FAIL: elf/tst-ldconfig-ld_so_conf-update
FAIL: elf/tst-stringtable
See gcc "Bug 98269 - gcc 6.5.0 __builtin_add_overflow() with small
uint32_t values incorrectly detects overflow"
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269)
Change sbrk to fail for !__libc_initial (in the generic
implementation). As a result, sbrk is (relatively) safe to use
for the __libc_initial case (from the main libc). It is therefore
no longer necessary to avoid using it in that case (or updating the
brk cache), and the __libc_initial flag does not need to be updated
as part of dlmopen or static dlopen.
As before, direct brk system calls on Linux may lead to memory
corruption.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Linux 5.10 has one new syscall, process_madvise. Update
syscall-names.list and regenerate the arch-syscall.h headers with
build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
This symbol is not in the implementation reserved namespace for static
linking and it was never used: it seems it was mistakenly added in the
orignal strlen_asimd commit 436e4d5b96
Since we can't tell if the tunable value is set by user or not:
https://sourceware.org/bugzilla/show_bug.cgi?id=27069
remove the default REP MOVSB threshold tunable value so that the correct
default value will be set correctly by init_cacheinfo ().
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Re-mmap executable segments if possible instead of using mprotect
to add PROT_BTI. This allows using BTI protection with security
policies that prevent mprotect with PROT_EXEC.
If the fd of the ELF module is not available because it was kernel
mapped then mprotect is used and failures are ignored. To protect
the main executable even when mprotect is filtered the linux kernel
will have to be changed to add PROT_BTI to it.
The delayed failure reporting is mainly needed because currently
_dl_process_gnu_properties does not propagate failures such that
the required cleanups happen. Using the link_map_machine struct for
error propagation is not ideal, but this seemed to be the least
intrusive solution.
Fixes bug 26831.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To handle GNU property notes on aarch64 some segments need to
be mmaped again, so the fd of the loaded ELF module is needed.
When the fd is not available (kernel loaded modules), then -1
is passed.
The fd is passed to both _dl_process_pt_gnu_property and
_dl_process_pt_note for consistency. Target specific note
processing functions are updated accordingly.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Handle unaligned executable load segments (the bfd linker is not
expected to produce such binaries, but other linkers may).
Computing the mapping bounds follows _dl_map_object_from_fd more
closely now.
Fixes bug 26988.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The _dl_open_check and _rtld_main_check hooks are not called on the
dependencies of a loaded module, so BTI protection was missed on
every module other than the main executable and directly dlopened
libraries.
The fix just iterates over dependencies to enable BTI.
Fixes bug 26926.
