The race leads either to pthread_mutex_destroy returning EBUSY
or triggering an assertion (See description in bugzilla).
This patch is fixing the race by ensuring that the elision path is
used in all cases if elision is enabled by the GLIBC_TUNABLES framework.
The __kind variable in struct __pthread_mutex_s is accessed concurrently.
Therefore we are now using the atomic macros.
The new testcase tst-mutex10 is triggering the race on s390x and intel.
Presumably also on power, but I don't have access to a power machine
with lock-elision. At least the code for power is the same as on the other
two architectures.
ChangeLog:
[BZ #23275]
* nptl/tst-mutex10.c: New File.
* nptl/Makefile (tests): Add tst-mutex10.
(tst-mutex10-ENV): New variable.
* sysdeps/unix/sysv/linux/s390/force-elision.h: (FORCE_ELISION):
Ensure that elision path is used if elision is available.
* sysdeps/unix/sysv/linux/powerpc/force-elision.h (FORCE_ELISION):
Likewise.
* sysdeps/unix/sysv/linux/x86/force-elision.h: (FORCE_ELISION):
Likewise.
* nptl/pthreadP.h (PTHREAD_MUTEX_TYPE, PTHREAD_MUTEX_TYPE_ELISION)
(PTHREAD_MUTEX_PSHARED): Use atomic_load_relaxed.
* nptl/pthread_mutex_consistent.c (pthread_mutex_consistent): Likewise.
* nptl/pthread_mutex_getprioceiling.c (pthread_mutex_getprioceiling):
Likewise.
* nptl/pthread_mutex_lock.c (__pthread_mutex_lock_full)
(__pthread_mutex_cond_lock_adjust): Likewise.
* nptl/pthread_mutex_setprioceiling.c (pthread_mutex_setprioceiling):
Likewise.
* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock): Likewise.
* nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock): Likewise.
* nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise.
* sysdeps/nptl/bits/thread-shared-types.h (struct __pthread_mutex_s):
Add comments.
* nptl/pthread_mutex_destroy.c (__pthread_mutex_destroy):
Use atomic_load_relaxed and atomic_store_relaxed.
* nptl/pthread_mutex_init.c (__pthread_mutex_init):
Use atomic_store_relaxed.
The bits/sem.h headers for architectures using the Linux kernel vary
in a few ways:
* x32 uses __syscall_ulong_t instead of unsigned long int.
* The x86 header uses padding after time fields unconditionally
(including for both x86_64 ABIs), not just for 32-bit time (unlike
in msqid_ds where there is only padding for 32-bit time). Because
this padding is present for x32, and is __syscall_ulong_t there, it
does have to be __syscall_ulong_t, not unsigned long int.
* The MIPS header never uses padding around time fields, even when
32-bit (unlike in msqid_ds where it has endian-dependent padding for
32-bit time).
* Some older 32-bit big-endian architectures have padding before
rather than after time fields, although the preferred generic
approach is padding after the time fields independent of endianness.
(There are also insubstantial differences such as use of unsigned int
for padding instead of unsigned long int, which makes no difference to
layout since the padding fields using unsigned int are only present on
32-bit architectures.)
For the first, __syscall_ulong_t can be used in the generic version as
it's the same as unsigned long int everywhere except x32. For the
other differences, this patch adds macros __SEM_PAD_BEFORE_TIME and
__SEM_PAD_AFTER_TIME in a new bits/sem-pad.h header, so that header is
the only one needing to be provided on architectures with differences
in this area, and everything else can go in a single common bits/sem.h
header.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
bits/sem-pad.h.
* sysdeps/unix/sysv/linux/bits/sem.h: Include <bits/sem-pad.h>
instead of <bits/wordsize.h>.
(__SEM_PAD_TIME): New macro, depending on [__SEM_PAD_BEFORE_TIME]
and [__SEM_PAD_AFTER_TIME].
(struct semid_ds): Define time fields using __SEM_PAD_TIME. Use
__syscall_ulong_t instead of unsigned long int.
* sysdeps/unix/sysv/linux/bits/sem-pad.h: New file.
* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h: Likewise.
* sysdeps/unix/sysv/linux/mips/bits/sem-pad.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/sem-pad.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/sem.h: Remove.
* sysdeps/unix/sysv/linux/mips/bits/sem.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sem.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sem.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/sem.h: Likewise.
The bits/msq.h headers for architectures using the Linux kernel vary
in a few ways:
* x32 uses __syscall_ulong_t instead of unsigned long int.
* x32 has 64-bit time_t, so no padding around time fields despite
__WORDSIZE == 32.
* Some older 32-bit big-endian architectures have padding before
rather than after time fields, although the preferred generic
approach is padding after the time fields independent of endianness.
(There are also insubstantial differences such as use of unsigned int
for padding instead of unsigned long int, which makes no difference to
layout since the padding fields using unsigned int are only present on
32-bit architectures.)
For the first, __syscall_ulong_t can be used in the generic version as
it's the same as unsigned long int everywhere except x32. For the
other two differences, this patch adds macros __MSQ_PAD_BEFORE_TIME
and __MSQ_PAD_AFTER_TIME in a new bits/msq-pad.h header, so that
header is the only one needing to be provided on architectures with
differences in this area, and everything else can go in a single
common bits/msq.h header. Once we have __TIMESIZE, the generic
bits/msq-pad.h can change to use that instead of __WORDSIZE, at which
point the x86 version of bits/msq-pad.h won't be needed either.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
bits/msq-pad.h.
* sysdeps/unix/sysv/linux/bits/msq.h: Include <bits/msq-pad.h>
instead of <bits/wordsize.h>.
(msgqnum_t): Define as __syscall_ulong_t.
(msglen_t): Likewise.
(__MSQ_PAD_TIME): New macro, depending on [__MSQ_PAD_BEFORE_TIME]
and [__MSQ_PAD_AFTER_TIME].
(struct msqid_ds): Define time fields using __MSQ_PAD_TIME. Use
__syscall_ulong_t instead of unsigned long int.
* sysdeps/unix/sysv/linux/bits/msq-pad.h: New file.
* sysdeps/unix/sysv/linux/hppa/bits/msq-pad.h: Likewise.
* sysdeps/unix/sysv/linux/mips/bits/msq-pad.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/msq-pad.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/msq-pad.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/msq-pad.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/msq.h: Remove.
* sysdeps/unix/sysv/linux/mips/bits/msq.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/msq.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/msq.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/msq.h: Likewise.
sysdeps/unix/sysv/linux/bits/shm.h has padding after time fields in
struct shmid_ds unconditionally, and thus is only suitable for 32-bit
architectures (no 64-bit configurations use this file);
sysdeps/unix/sysv/linux/generic/bits/shm.h is substantively the same,
except that the padding is conditioned on __WORDSIZE == 32, and so it
can be used for 64-bit architectures as well.
This patch adds the conditionals to
sysdeps/unix/sysv/linux/bits/shm.h. The linux/generic/ version is
then no longer needed and so is removed, as are the alpha and s390
versions which are also no longer needed. The other
architecture-specific versions have different padding, layout, types
or SHMLBA definitions and so are still needed after this change.
This is essentially the same change for bits/shm.h as the bits/msq.h
patch and the bits/sem.h patch. However, the details of the padding
variations for the architectures that aren't changed are not all the
same between msqid_ds, shmid_ds and semid_ds.
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/shm.h: Include <bits/wordsize.h>.
(struct shmid_ds): Condition padding after time fields on
[__WORDSIZE == 32].
* sysdeps/unix/sysv/linux/alpha/bits/shm.h: Remove file.
* sysdeps/unix/sysv/linux/generic/bits/shm.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/shm.h: Likewise.
sysdeps/unix/sysv/linux/bits/sem.h has padding after time fields in
struct semid_ds unconditionally, and thus is only suitable for 32-bit
architectures (no 64-bit configurations use this file);
sysdeps/unix/sysv/linux/generic/bits/sem.h is substantively the same,
except that the padding is conditioned on __WORDSIZE == 32, and so it
can be used for 64-bit architectures as well.
This patch adds the conditionals to
sysdeps/unix/sysv/linux/bits/sem.h. The linux/generic/ version is
then no longer needed and so is removed, as are the alpha, ia64 and
s390 versions which are also no longer needed. The other
architecture-specific versions have different padding or types and so
are still needed after this change.
This is essentially the same change for bits/sem.h as the bits/msq.h
patch. However, the details of the padding variations for the
architectures that aren't changed are not all the same between
msqid_ds and semid_ds.
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/sem.h: Include <bits/wordsize.h>.
(struct semid_ds): Condition padding after time fields on
[__WORDSIZE == 32].
* sysdeps/unix/sysv/linux/alpha/bits/sem.h: Remove file.
* sysdeps/unix/sysv/linux/generic/bits/sem.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/sem.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/sem.h: Likewise.
sysdeps/unix/sysv/linux/bits/msq.h has padding after time fields in
struct msqid_ds unconditionally, and thus is only suitable for 32-bit
architectures (no 64-bit configurations use this file);
sysdeps/unix/sysv/linux/generic/bits/msq.h is substantively the same,
except that the padding is conditioned on __WORDSIZE == 32, and so it
can be used for 64-bit architectures as well.
This patch adds the conditionals to
sysdeps/unix/sysv/linux/bits/msq.h. The linux/generic/ version is
then no longer needed and so is removed, as are the alpha, ia64 and
s390 versions which are also no longer needed. The other
architecture-specific versions have different padding or types and so
are still needed after this change.
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/msq.h: Include <bits/wordsize.h>.
(struct msqid_ds): Condition padding after time fields on
[__WORDSIZE == 32].
* sysdeps/unix/sysv/linux/alpha/bits/msq.h: Remove file.
* sysdeps/unix/sysv/linux/generic/bits/msq.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/msq.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/msq.h: Likewise.
hppa currently has a bits/mman.h that does not include
bits/mman-linux.h, unlike all other architectures using the Linux
kernel. This sort of variation between architectures is generally
unhelpful when making global changes for new constants added to new
Linux kernel releases.
This patch changes hppa to use bits/mman-linux.h, overriding constants
with different values as necessary (including with #undef after
bits/mman.h inclusion when needed, as already done for alpha). While
there could possibly be further improvements through e.g. splitting
more sets of definitions into separate bits/ headers, I think this is
still an improvement on the current state. diffstat shows 27 lines
added, 51 deleted (and some of that is actually existing lines moving
to a different place in the file).
Tested with build-many-glibcs.py for hppa-linux-gnu.
* sysdeps/unix/sysv/linux/hppa/bits/mman.h: Include
<bits/mman-linux.h>.
(PROT_READ): Don't define here.
(PROT_WRITE): Likewise.
(PROT_EXEC): Likewise.
(PROT_NONE): Likewise.
(PROT_GROWSDOWN): Likewise.
(PROT_GROWSUP): Likewise.
(MAP_SHARED): Likewise.
(MAP_PRIVATE): Likewise.
[__USE_MISC] (MAP_SHARED_VALIDATE): Likewise.
[__USE_MISC] (MAP_FILE): Likewise.
[__USE_MISC] (MAP_ANONYMOUS): Likewise.
[__USE_MISC] (MAP_ANON): Likewise.
[__USE_MISC] (MAP_HUGE_SHIFT): Likewise.
[__USE_MISC] (MAP_HUGE_MASK): Likewise.
(MCL_CURRENT): Likewise.
(MCL_FUTURE): Likewise.
(MCL_ONFAULT): Likewise.
[__USE_MISC] (MADV_NORMAL): Likewise.
[__USE_MISC] (MADV_RANDOM): Likewise.
[__USE_MISC] (MADV_SEQUENTIAL): Likewise.
[__USE_MISC] (MADV_WILLNEED): Likewise.
[__USE_MISC] (MADV_DONTNEED): Likewise.
[__USE_MISC] (MADV_FREE): Likewise.
[__USE_MISC] (MADV_REMOVE): Likewise.
[__USE_MISC] (MADV_DONTFORK): Likewise.
[__USE_MISC] (MADV_DOFORK): Likewise.
[__USE_MISC] (MADV_HWPOISON): Likewise.
[__USE_XOPEN2K] (POSIX_MADV_NORMAL): Likewise.
[__USE_XOPEN2K] (POSIX_MADV_RANDOM): Likewise.
[__USE_XOPEN2K] (POSIX_MADV_SEQUENTIAL): Likewise.
[__USE_XOPEN2K] (POSIX_MADV_WILLNEED): Likewise.
[__USE_XOPEN2K] (POSIX_MADV_DONTNEED): Likewise.
(__MAP_ANONYMOUS): New macro.
[__USE_MISC] (MAP_TYPE): Undefine and redefine after
<bits/mman-linux.h> inclusion.
(MAP_FIXED): Likewise.
(MS_SYNC): Likewise.
(MS_ASYNC): Likewise.
(MS_INVALIDATE): Likewise.
[__USE_MISC] (MADV_MERGEABLE): Likewise.
[__USE_MISC] (MADV_UNMERGEABLE): Likewise.
[__USE_MISC] (MADV_HUGEPAGE): Likewise.
[__USE_MISC] (MADV_NOHUGEPAGE): Likewise.
[__USE_MISC] (MADV_DONTDUMP): Likewise.
[__USE_MISC] (MADV_DODUMP): Likewise.
[__USE_MISC] (MADV_WIPEONFORK): Likewise.
[__USE_MISC] (MADV_KEEPONFORK): Likewise.
Since RTM intrinsics are supported in GCC 4.9, we can use them in
pthread mutex lock elision.
* sysdeps/unix/sysv/linux/x86/Makefile (CFLAGS-elision-lock.c):
Add -mrtm.
(CFLAGS-elision-unlock.c): Likewise.
(CFLAGS-elision-timed.c): Likewise.
(CFLAGS-elision-trylock.c): Likewise.
* sysdeps/unix/sysv/linux/x86/hle.h: Rewritten.
As POSIX states [1] a freopen call should first flush the stream as if by a
call fflush. C99 (n1256) and C11 (n1570) only states the function should
first close any file associated with the specific stream. Although current
implementation only follow C specification, current BSD and other libc
implementation (musl) are in sync with POSIX and fflush the stream.
This patch change freopen{64} to fflush the stream before actually reopening
it (or returning if the stream does not support reopen). It also changes the
Linux implementation to avoid a dynamic allocation on 'fd_to_filename'.
Checked on x86_64-linux-gnu.
[BZ #21037]
* libio/Makefile (tests): Add tst-memstream4 and tst-wmemstream4.
* libio/freopen.c (freopen): Sync stream before reopen and adjust to
new fd_to_filename interface.
* libio/freopen64.c (freopen64): Likewise.
* libio/tst-memstream.h: New file.
* libio/tst-memstream4.c: Likewise.
* libio/tst-wmemstream4.c: Likewise.
* sysdeps/generic/fd_to_filename.h (fd_to_filename): Change signature.
* sysdeps/unix/sysv/linux/fd_to_filename.h (fd_to_filename): Likewise
and remove internal dynamic allocation.
[1] http://pubs.opengroup.org/onlinepubs/9699919799/
The MREMAP_* flags are identical between bits/mman-linux.h and the
hppa bits/mman.h; thus, they should be in bits/mman-shared.h instead
to avoid unnecessary duplication. This patch moves them there.
Tested for x86_64, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/mman-linux.h [__USE_GNU]
(MREMAP_MAYMOVE): Do not define here.
[__USE_GNU] (MREMAP_FIXED): Likewise.
* sysdeps/unix/sysv/linux/bits/mman-shared.h [__USE_GNU]
(MREMAP_MAYMOVE): Define here instead.
[__USE_GNU] (MREMAP_FIXED): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/mman.h [__USE_GNU]
(MREMAP_MAYMOVE): Remove.
[__USE_GNU] (MREMAP_FIXED): Likewise.
The fallback code of Linux wrapper for preadv2/pwritev2 executes
regardless of the errno code for preadv2, instead of the case where
the syscall is not supported.
This fixes it by calling the fallback code iff errno is ENOSYS. The
patch also adds tests for both invalid file descriptor and invalid
iov_len and vector count.
The only discrepancy between preadv2 and fallback code regarding
error reporting is when an invalid flags are used. The fallback code
bails out earlier with ENOTSUP instead of EINVAL/EBADF when the syscall
is used.
Checked on x86_64-linux-gnu on a 4.4.0 and 4.15.0 kernel.
[BZ #23579]
* misc/tst-preadvwritev2-common.c (do_test_with_invalid_fd): New
test.
* misc/tst-preadvwritev2.c, misc/tst-preadvwritev64v2.c (do_test):
Call do_test_with_invalid_fd.
* sysdeps/unix/sysv/linux/preadv2.c (preadv2): Use fallback code iff
errno is ENOSYS.
* sysdeps/unix/sysv/linux/preadv64v2.c (preadv64v2): Likewise.
* sysdeps/unix/sysv/linux/pwritev2.c (pwritev2): Likewise.
* sysdeps/unix/sysv/linux/pwritev64v2.c (pwritev64v2): Likewise.
Continuing bits/mman.h unification between architectures using the
Linux kernel, this patch arranges for the common set of MAP_* flags to
be used by two more architectures. That common set is moved to
bits/mman-map-flags-generic.h, which is included by bits/mman.h, to
allow architectures to use that common set even if they also have
architecture-specific additions to it. As well as the generic
bits/mman.h, the versions for x86 and ia64 are also then made to
include bits/mman-map-flags-generic.h, so while they still need
architecture-specific bits/mman.h (for MAP_32BIT and MAP_GROWSUP
respectively), they do not need to duplicate the generic flag
definitions in there.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/mman-map-flags-generic.h: New
file. Most contents moved from ....
* sysdeps/unix/sysv/linux/bits/mman.h: ... here. Move contents to
and include <bits/mman-map-flags-generic.h>.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) = misc]
(sysdep_headers): Add bits/mman-map-flags-generic.h.
* sysdeps/unix/sysv/linux/ia64/bits/mman.h: Include
<bits/mman-map-flags-generic.h>.
[__USE_MISC] (MAP_GROWSUP): Only define this macro, not other
macros defined in <bits/mman-map-flags-generic.h>.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Include
<bits/mman-map-flags-generic.h>.
[__USE_MISC] (MAP_32BIT): Only define this macro, not other macros
defined in <bits/mman-map-flags-generic.h>.
This patch completes the process of unifying sys/procfs.h headers for
architectures using the Linux kernel by making alpha use the generic
version.
That was previously deferred because alpha has different definitions
of prgregset_t and prfpregset_t from other architectures, so changing
to the common definitions would change C++ name mangling. To avoid
such a change, a header bits/procfs-prregset.h is added, and alpha
gets its own version of that header.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/sys/procfs.h: Include
<bits/procfs-prregset.h>.
(prgregset_t): Define using __prgregset_t.
(prfpregset_t): Define using __prfpregset_t.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) = misc]
(sysdep_headers): Add bits/procfs-prregset.h.
* sysdeps/unix/sysv/linux/bits/procfs-prregset.h: New file.
* sysdeps/unix/sysv/linux/alpha/bits/procfs-prregset.h: Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/alpha/sys/procfs.h: Remove file.
This patch continues the process of unifying sys/procfs.h headers for
architectures using the Linux kernel.
A bits/procfs-id.h header is added to define __pr_uid_t and __pr_gid_t
for the types of pr_uid and pr_gid; the default version of this header
uses unsigned int. On some architectures, sys/procfs.h has copies of
32-bit structures for 64-bit builds; those move into a
bits/procfs-extra.h header (they can't go in bits/procfs.h because
they have to come *after* other declarations from sys/procfs.h).
Given appropriate versions of these headers, six more architectures
can then move to providing only bits/procfs*.h without duplicating the
rest of the contents of sys/procfs.h. Only alpha needs a further
bits/ header to be added before it can stop having its own
sys/procfs.h.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/sys/procfs.h: Include
<bits/procfs-id.h> and <bits/procfs-extra.h>.
(struct elf_prpsinfo): Use __pr_uid_t and __pr_gid_t as types of
pr_uid and pr_gid.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) = misc]
(sysdep_headers): Add bits/procfs-id.h and bits/procfs-extra.h.
* sysdeps/unix/sysv/linux/bits/procfs-extra.h: New file.
* sysdeps/unix/sysv/linux/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/arm/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/arm/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/m68k/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/m68k/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/procfs-extra.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/procfs-extra.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/procfs-id.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/arm/sys/procfs.h: Remove file.
* sysdeps/unix/sysv/linux/m68k/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/s390/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/sh/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/x86/sys/procfs.h: Likewise.
As per recent discussions, this patch unifies some of the sys/procfs.h
headers for architectures using the Linux kernel, producing a generic
version that can hopefully be used by all new architectures as well.
The new generic version is based on the AArch64 one. The register
definitions, the only part that generally needs to vary by
architecture, go in a new bits/procfs.h header (which each
architecture using the generic version needs to provide); that header
also has any #includes that were in the architecture-specific
sys/procfs.h, where those includes went beyond the generic set.
The generic version is used for eight architectures where the generic
definitions were the same as the architecture-specific ones. (Some of
those architectures had #if 0 fields, now removed; some defined types
or fields using different type names which were typedefs for the same
underlying types.)
Six of the remaining architectures with their own sys/procfs.h use
unsigned short for pr_uid / pr_gid in some cases; moving those to the
generic header will require a bits/ header to define a typedef for the
type of those fields. In the case of alpha, the generic sys/procfs.h
uses elf_gregset_t (= unsigned long int[33]) to define prgregset_t and
elf_fpregset_t (= double[32]) to define prfpregset_t, but the alpha
version uses gregset_t (= long int[33]) and fpregset_t (= long
int[32]), so avoiding unnecessarily changing the underlying types (and
thus C++ name mangling) again means a bits/ header will need to be
able to define a different choice for those typedefs.
bits/procfs.h is included outside the __BEGIN_DECLS / __END_DECLS pair
(whereas the definitions it contains were previously inside that pair
in various sys/procfs.h headers), because it sometimes includes other
headers and putting those other #includes inside that pair seems
risky. Because none of the declarations in bits/procfs.h are of
functions or variables or involve function types, I don't think it
makes any difference whether they are inside or outside an extern "C"
context.
Tested with build-many-glibcs.py (again, that does not provide much
validation for the correctness of this patch).
* sysdeps/unix/sysv/linux/sys/procfs.h: Replace with file based on
AArch64 version. Include <bits/procfs.h>.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) = misc]
(sysdep_headers): Add bits/procfs.h.
* sysdeps/unix/sysv/linux/bits/procfs.h: New file.
* sysdeps/unix/sysv/linux/aarch64/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/microblaze/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/mips/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/riscv/bits/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/aarch64/sys/procfs.h: Remove file.
* sysdeps/unix/sysv/linux/hppa/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/microblaze/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/mips/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/procfs.h: Likewise.
* sysdeps/unix/sysv/linux/riscv/sys/procfs.h: Likewise.
Linux from 3.9 through 4.2 does not abort HTM transaction on syscalls,
instead it suspend and resume it when leaving the kernel. The
side-effects of the syscall will always remain visible, even if the
transaction is aborted. This is an issue when transaction is used along
with futex syscall, on pthread_cond_wait for instance, where the futex
call might succeed but the transaction is rolled back leading the
pthread_cond object in an inconsistent state.
Glibc used to prevent it by always aborting a transaction before issuing
a syscall. Linux 4.2 also decided to abort active transaction in
syscalls which makes the glibc workaround superfluous. Worse, glibc
transaction abortion leads to a performance issue on recent kernels
where the HTM state is saved/restore lazily (v4.9). By aborting a
transaction on every syscalls, regardless whether a transaction has being
initiated before, GLIBS makes the kernel always save/restore HTM state
(it can not even lazily disable it after a certain number of syscall
iterations).
Because of this shortcoming, Transactional Lock Elision is just enabled
when it has been explicitly set (either by tunables of by a configure
switch) and if kernel aborts HTM transactions on syscalls
(PPC_FEATURE2_HTM_NOSC). It is reported that using simple benchmark [1],
the context-switch is about 5% faster by not issuing a tabort in every
syscall in newer kernels.
Checked on powerpc64le-linux-gnu with 4.4.0 kernel (Ubuntu 16.04).
* NEWS: Add note about new TLE support on powerpc64le.
* sysdeps/powerpc/nptl/tcb-offsets.sym (TM_CAPABLE): Remove.
* sysdeps/powerpc/nptl/tls.h (tcbhead_t): Rename tm_capable to
__ununsed1.
(TLS_INIT_TP, TLS_DEFINE_INIT_TP): Remove tm_capable setup.
(THREAD_GET_TM_CAPABLE, THREAD_SET_TM_CAPABLE): Remove macros.
* sysdeps/powerpc/powerpc32/sysdep.h,
sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION_IMPL,
ABORT_TRANSACTION): Remove macros.
* sysdeps/powerpc/sysdep.h (ABORT_TRANSACTION): Likewise.
* sysdeps/unix/sysv/linux/powerpc/elision-conf.c (elision_init): Set
__pthread_force_elision iff PPC_FEATURE2_HTM_NOSC is set.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h,
sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
sysdeps/unix/sysv/linux/powerpc/syscall.S (ABORT_TRANSACTION): Remove
usage.
* sysdeps/unix/sysv/linux/powerpc/not-errno.h: Remove file.
Reported-by: Breno Leitão <leitao@debian.org>
Many bits/mman.h headers for Linux architectures have exactly the same
contents, up to whitespace, comments and the number of leading 0s on
constants. Specifically, this applies to architectures that, in the
Linux kernel, either have no uapi/asm/mman.h, or have one that
includes asm-generic/mman.h without any changes or additions relevant
to glibc (this last case is the one that applies to Arm).
It's not useful to have to duplicate the set of MAP_* constants in
glibc for all such architectures and any new architectures with that
property. Thus, this patch creates a generic
sysdeps/unix/sysv/linux/bits/mman.h and removes all the
architecture-specific versions that become unnecessary.
Further unification remains possible after this patch. For example,
the new bits/mman.h could become bits/mman-map-flags-generic.h so that
it could also be used by architecture-specific bits/mman.h headers on
architectures that use the generic flags but add architecture-specific
ones to them. That would allow this common set of MAP_* definitions
to be used on ia64 and x86 as well (architectures that include
asm-generic/mman.h from their own uapi/asm/mman.h but define
additional MAP_* values of their own).
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/mman.h: New file.
* sysdeps/unix/sysv/linux/aarch64/bits/mman.h: Remove.
* sysdeps/unix/sysv/linux/arm/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/m68k/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/microblaze/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/riscv/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Likewise.
As of Linux 4.17, siginfo headers in the Linux kernel have been
largely unified across architectures (so various constants are defined
with common values in include/uapi/asm-generic/siginfo.h even if not
all architectures can generate those particular constants).
This patch makes glibc reflect that unification and the current set of
constants in that header as of Linux 4.18. Various constants are
added to bits/siginfo-consts.h (under the same feature test macro
conditions as the other constants with the same prefix), and removed
from the ia64 bits/siginfo-consts-arch.h where they were previously
there - this is not limited to constants added by the unification.
Nothing is done about macros that are defined in
include/uapi/asm-generic/siginfo.h with names with leading '__' (some
of those are ia64-specific ones that remain in the ia64
bits/siginfo-consts-arch.h without the leading '__' there).
A consequence of these changes is that TRAP_HWBKPT becomes available
on AArch64 and all other architectures as requested in bug 21286.
Tested for x86_64; tested with build-many-glibcs.py for ia64.
[BZ #21286]
* sysdeps/unix/sysv/linux/bits/siginfo-consts.h (SI_DETHREAD): New
constant.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (ILL_BADIADDR): Likewise.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (FPE_FLTUNK): Likewise.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (FPE_CONDTRAP): Likewise.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (SEGV_ACCADI): Likewise.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (SEGV_ADIDERR): Likewise.
[__USE_XOPEN_EXTENDED || __USE_XOPEN2K8] (SEGV_ADIPERR): Likewise.
[__USE_XOPEN_EXTENDED] (TRAP_BRANCH): Likewise.
[__USE_XOPEN_EXTENDED] (TRAP_HWBKPT): Likewise.
[__USE_XOPEN_EXTENDED] (TRAP_UNK): Likweise.
* sysdeps/unix/sysv/linux/ia64/bits/siginfo-consts-arch.h
(ILL_BADIADDR): Remove constant.
(TRAP_BRANCH): Likewise.
(TRAP_HWBKPT): Likewise.
As discussed at
<https://sourceware.org/ml/libc-alpha/2018-09/msg00191.html> and
followup discussions, the MIPS n32 definitions of pr_sigpend and
pr_sighold in struct elf_prstatus, and pr_flag in struct elf_prpsinfo,
are wrong to use unsigned long long int; actual n32 core dumps use a
32-bit type there, so userspace unsigned long int is correct for all
MIPS ABIs. This patch removes the conditionals (also thereby aligning
the structures with other architectures and so facilitating future
unification of different versions of this header).
Tested with build-many-glibcs.py for its MIPS configurations.
[BZ #23656]
* sysdeps/unix/sysv/linux/mips/sys/procfs.h (struct elf_prstatus):
Remove [_MIPS_SIM = _ABIN32] conditional case.
(struct elf_prpsinfo): Likewise.
As noted in
<https://sourceware.org/ml/libc-alpha/2018-09/msg00178.html>, glibc's
sys/procfs.h headers for microblaze, mips (n64), nios2 and riscv have
incorrect types for the pr_uid and pr_gid members of struct
elf_prpsinfo (as does the generic Linux version, but nothing uses
that).
This patch fixes those headers to use unsigned int. The generic Linux
version is also fixed, but I do *not* recommend making new
architectures use it yet. Rather, I think it should be reworked to
look more like a copy of the AArch64 version, but with a new
<bits/procfs.h> header included to provide register set definitions;
<bits/procfs.h> would then be architecture-specific while many
architectures could use the generic <sys/procfs.h>. This fix is
deliberately separate from any reworking to use a generic header more,
since it's possible there could be uses for backporting this fix but
not for backporting a subsequent cleanup.
Tested with build-many-glibcs.py. This of course doesn't provide much
validation of the structure layout; if the Linux kernel is fixed so
that "#include <linux/elfcore.h>" actually compiles with the headers
from "make headers_install" (and if the layout in both headers is
meant to be the same, whatever ABI we are building for), I have a test
that can be added to glibc to check the layout against that from the
Linux kernel.
[BZ #23649]
* sysdeps/unix/sysv/linux/microblaze/sys/procfs.h (struct
elf_prpsinfo): Use unsigned int for pr_uid and pr_gid.
* sysdeps/unix/sysv/linux/mips/sys/procfs.h (struct elf_prpsinfo):
Likewise.
* sysdeps/unix/sysv/linux/nios2/sys/procfs.h (struct
elf_prpsinfo): Likewise.
* sysdeps/unix/sysv/linux/riscv/sys/procfs.h (struct
elf_prpsinfo): Likewise.
* sysdeps/unix/sysv/linux/sys/procfs.h (struct elf_prpsinfo):
Likewise.
If glibc is built with gcc 8 and -march=z900,
the testcase posix/tst-spawn4-compat crashes with a segfault.
In function maybe_script_execute, the new_argv array is dynamically
initialized on stack with (argc + 1) elements.
The function wants to add _PATH_BSHELL as the first argument
and writes out of bounds of new_argv.
There is an off-by-one because maybe_script_execute fails to count
the terminating NULL when sizing new_argv.
ChangeLog:
* sysdeps/unix/sysv/linux/spawni.c (maybe_script_execute):
Increment size of new_argv by one.
This patch adds the PF_XDP, AF_XDP and SOL_XDP macros from Linux 4.18 to
sysdeps/unix/sysv/linux/bits/socket.h.
* sysdeps/unix/sysv/linux/bits/socket.h (PF_MAX): Set to 45.
(PF_XDP): New macro.
(AF_XDP): New macro.
(SOL_XDP): New macro.
This patch updates struct signalfd_siginfo in sys/signalfd.h with new
members from Linux 4.18 (plus ssi_addr_lsb, added to the kernel in
2.6.37 without being added to sys/signalfd.h at that time). The
__pad2 member name follows the kernel and the existing __pad name.
Tested for x86_64.
* sysdeps/unix/sysv/linux/sys/signalfd.h (struct
signalfd_siginfo): Add ssi_addr_lsb, ssi_syscall, ssi_call_addr
and ssi_arch members.
This patch updates sysdeps/unix/sysv/linux/syscall-names.list for
Linux 4.18. The io_pgetevents and rseq syscalls are added to the
kernel on various architectures, so need to be mentioned in this file.
Tested with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/syscall-names.list: Update kernel
version to 4.18.
(io_pgetevents): New syscall.
(rseq): Likewise.
Commit 298d0e3129 ("Consolidate Linux
getdents{64} implementation") broke the implementation because it does
not take into account struct offset differences.
The new implementation is close to the old one, before the
consolidation, but has been cleaned up slightly.
* Since __fentry__ is almost the same as _mcount, reuse the code by
#including it twice with different #defines around.
* Remove LA usages - they are needed in 31-bit mode to clear the top
bit, but in 64-bit they appear to do nothing.
* Add CFI rule for the nonstandard return register. This rule applies
to the current function (binutils generates a new CIE - see
gas/dw2gencfi.c:select_cie_for_fde()), so it is not necessary to put
__fentry__ into a new file.
* Fix CFI offset for %r14.
* Add CFI rule for %r0.
* Fix unwound value of %r15 being off by 244 bytes.
* Unwinding in __fentry__@plt does not work, no plan to fix it - it
would require asking linker to generate CFI for return address in
%r0. From functional perspective keeping it broken is fine, since
the callee did not have a chance to do anything yet. From
convenience perspective it would be possible to enhance GDB in the
future to treat __fentry__@plt in a special way.
* Fix whitespace.
* Fix offsets in comments, which were copied from 32-bit code.
* 32-bit version will not be implemented, since it's not compatible
with the corresponding PLT stubs: they assume %r12 points to GOT,
which is not the case for gcc-emitted __fentry__ stub, which runs
before the prolog.
This patch adds the runtime support in glibc for the -mfentry
gcc feature introduced in [1] and [2].
[1] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00784.html
[2] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00912.html
ChangeLog:
* sysdeps/s390/s390-64/Versions (__fentry__): Add.
* sysdeps/s390/s390-64/s390x-mcount.S: Move the common
code to s390x-mcount.h and #include it.
* sysdeps/s390/s390-64/s390x-mcount.h: New file.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
(__fentry__): Add.
The glibc.tune namespace is vaguely named since it is a 'tunable', so
give it a more specific name that describes what it refers to. Rename
the tunable namespace to 'cpu' to more accurately reflect what it
encompasses. Also rename glibc.tune.cpu to glibc.cpu.name since
glibc.cpu.cpu is weird.
* NEWS: Mention the change.
* elf/dl-tunables.list: Rename tune namespace to cpu.
* sysdeps/powerpc/dl-tunables.list: Likewise.
* sysdeps/x86/dl-tunables.list: Likewise.
* sysdeps/aarch64/dl-tunables.list: Rename tune.cpu to
cpu.name.
* elf/dl-hwcaps.c (_dl_important_hwcaps): Adjust.
* elf/dl-hwcaps.h (GET_HWCAP_MASK): Likewise.
* manual/README.tunables: Likewise.
* manual/tunables.texi: Likewise.
* sysdeps/powerpc/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/aarch64/cpu-features.c
(init_cpu_features): Likewise.
* sysdeps/x86/cpu-features.c: Likewise.
* sysdeps/x86/cpu-features.h: Likewise.
* sysdeps/x86/cpu-tunables.c: Likewise.
* sysdeps/x86_64/Makefile: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
GNU_PROPERTY_X86_FEATURE_1_AND may not be the first property item. We
need to check each property item until we reach the end of the property
or find GNU_PROPERTY_X86_FEATURE_1_AND.
This patch adds 2 tests. The first test checks if IBT is enabled and
the second test reads the output from the first test to check if IBT
is is enabled. The second second test fails if IBT isn't enabled
properly.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ #23467]
* sysdeps/unix/sysv/linux/x86/Makefile (tests): Add
tst-cet-property-1 and tst-cet-property-2 if CET is enabled.
(CFLAGS-tst-cet-property-1.o): New.
(ASFLAGS-tst-cet-property-dep-2.o): Likewise.
($(objpfx)tst-cet-property-2): Likewise.
($(objpfx)tst-cet-property-2.out): Likewise.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-1.c: New file.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-2.c: Likewise.
* sysdeps/unix/sysv/linux/x86/tst-cet-property-dep-2.S: Likewise.
* sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Parse
each property item until GNU_PROPERTY_X86_FEATURE_1_AND is found.
This patch make the OFD tests return unsupported if kernel does not
support OFD locks (it was added on 3.15).
Checked on a ia64-linux-gnu with Linux 3.14.
* sysdeps/unix/sysv/linux/tst-ofdlocks.c: Return unsupported if
kernel does not support OFD locks.
* sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Likewise.
Verify that setcontext works with gaps above and below the newly
allocated shadow stack.
* sysdeps/unix/sysv/linux/x86/Makefile (tests): Add
tst-cet-setcontext-1 if CET is enabled.
(CFLAGS-tst-cet-setcontext-1.c): Add -mshstk.
* sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c: New file.
This patch adds a field to ucontext_t to save shadow stack:
1. getcontext and swapcontext are updated to save the caller's shadow
stack pointer and return addresses.
2. setcontext and swapcontext are updated to restore shadow stack and
jump to new context directly.
3. makecontext is updated to allocate a new shadow stack and set the
caller's return address to __start_context.
Since makecontext allocates a new shadow stack when making a new
context and kernel allocates a new shadow stack for clone/fork/vfork
syscalls, we track the current shadow stack base. In setcontext and
swapcontext, if the target shadow stack base is the same as the current
shadow stack base, we unwind the shadow stack. Otherwise it is a stack
switch and we look for a restore token.
We enable shadow stack at run-time only if program and all used shared
objects, including dlopened ones, are shadow stack enabled, which means
that they must be compiled with GCC 8 or above and glibc 2.28 or above.
We need to save and restore shadow stack only if shadow stack is enabled.
When caller of getcontext, setcontext, swapcontext and makecontext is
compiled with smaller ucontext_t, shadow stack won't be enabled at
run-time. We check if shadow stack is enabled before accessing the
extended field in ucontext_t.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/x86/sys/ucontext.h (ucontext_t): Add
__ssp.
* sysdeps/unix/sysv/linux/x86_64/__start_context.S: Include
<asm/prctl.h> and "ucontext_i.h" when shadow stack is enabled.
(__push___start_context): New.
* sysdeps/unix/sysv/linux/x86_64/getcontext.S: Include
<asm/prctl.h>.
(__getcontext): Record the current shadow stack base. Save the
caller's shadow stack pointer and base.
* sysdeps/unix/sysv/linux/x86_64/makecontext.c: Include
<pthread.h>, <libc-pointer-arith.h> and <sys/prctl.h>.
(__push___start_context): New prototype.
(__makecontext): Call __push___start_context to allocate a new
shadow stack, push __start_context onto the new stack as well
as the new shadow stack.
* sysdeps/unix/sysv/linux/x86_64/setcontext.S: Include
<asm/prctl.h>.
(__setcontext): Restore the target shadow stack.
* sysdeps/unix/sysv/linux/x86_64/swapcontext.S: Include
<asm/prctl.h>.
(__swapcontext): Record the current shadow stack base. Save
the caller's shadow stack pointer and base. Restore the target
shadow stack.
* sysdeps/unix/sysv/linux/x86_64/sysdep.h
(STACK_SIZE_TO_SHADOW_STACK_SIZE_SHIFT): New.
* sysdeps/unix/sysv/linux/x86_64/ucontext_i.sym (oSSP): New.
CET arch_prctl bits should be defined in <asm/prctl.h> from Linux kernel
header files. Add x86 <include/asm/prctl.h> for pre-CET kernel header
files.
Note: sysdeps/unix/sysv/linux/x86/include/asm/prctl.h should be removed
if <asm/prctl.h> from the required kernel header files contains CET
arch_prctl bits.
/* CET features:
IBT: GNU_PROPERTY_X86_FEATURE_1_IBT
SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK
*/
/* Return CET features in unsigned long long *addr:
features: addr[0].
shadow stack base address: addr[1].
shadow stack size: addr[2].
*/
# define ARCH_CET_STATUS 0x3001
/* Disable CET features in unsigned int features. */
# define ARCH_CET_DISABLE 0x3002
/* Lock all CET features. */
# define ARCH_CET_LOCK 0x3003
/* Allocate a new shadow stack with unsigned long long *addr:
IN: requested shadow stack size: *addr.
OUT: allocated shadow stack address: *addr.
*/
# define ARCH_CET_ALLOC_SHSTK 0x3004
/* Return legacy region bitmap info in unsigned long long *addr:
address: addr[0].
size: addr[1].
*/
# define ARCH_CET_LEGACY_BITMAP 0x3005
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/x86/include/asm/prctl.h: New file.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Include
<sys/prctl.h> and <asm/prctl.h>.
(get_cet_status): Call arch_prctl with ARCH_CET_STATUS.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Include <sys/prctl.h>
and <asm/prctl.h>.
(dl_cet_allocate_legacy_bitmap): Call arch_prctl with
ARCH_CET_LEGACY_BITMAP.
(dl_cet_disable_cet): Call arch_prctl with ARCH_CET_DISABLE.
(dl_cet_lock_cet): Call arch_prctl with ARCH_CET_LOCK.
* sysdeps/x86/libc-start.c: Include <startup.h>.
This patch adds the thrd_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically thrd_create, thrd_curent, rhd_detach, thrd_equal,
thrd_exit, thrd_join, thrd_sleep, thrd_yield, and required types.
Mostly of the definitions are composed based on POSIX conterparts, such as
thrd_t (using pthread_t). For thrd_* function internally direct
POSIX pthread call are used with the exceptions:
1. thrd_start uses pthread_create internal implementation, but changes
how to actually calls the start routine. This is due the difference
in signature between POSIX and C11, where former return a 'void *'
and latter 'int'.
To avoid calling convention issues due 'void *' to int cast, routines
from C11 threads are started slight different than default pthread one.
Explicit cast to expected return are used internally on pthread_create
and the result is stored back to void also with an explicit cast.
2. thrd_sleep uses nanosleep internal direct syscall to avoid clobbering
errno and to handle expected standard return codes. It is a
cancellation entrypoint to be consistent with both thrd_join and
cnd_{timed}wait.
3. thrd_yield also uses internal direct syscall to avoid errno clobbering.
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/Makefile (conformtest-headers-ISO11): Add threads.h.
(linknamespace-libs-ISO11): Add libpthread.a.
* conform/data/threads.h-data: New file: add C11 thrd_* types and
functions.
* include/stdc-predef.h (__STDC_NO_THREADS__): Remove definition.
* nptl/Makefile (headers): Add threads.h.
(libpthread-routines): Add new C11 thread thrd_create, thrd_current,
thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and
thrd_yield.
* nptl/Versions (libpthread) [GLIBC_2.28]): Add new C11 thread
thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit,
thrd_join, thrd_sleep, and thrd_yield symbols.
* nptl/descr.h (struct pthread): Add c11 field.
* nptl/pthreadP.h (ATTR_C11_THREAD): New define.
* nptl/pthread_create.c (START_THREAD_DEFN): Call C11 thread start
routine with expected function prototype.
(__pthread_create_2_1): Add C11 threads check based on attribute
value.
* sysdeps/unix/sysdep.h (INTERNAL_SYSCALL_CANCEL): New macro.
* nptl/thrd_create.c: New file.
* nptl/thrd_current.c: Likewise.
* nptl/thrd_detach.c: Likewise.
* nptl/thrd_equal.c: Likewise.
* nptl/thrd_exit.c: Likewise.
* nptl/thrd_join.c: Likewise.
* nptl/thrd_priv.h: Likewise.
* nptl/thrd_sleep.c: Likewise.
* nptl/thrd_yield.c: Likewise.
* include/threads.h: Likewise.
The shadow stack prevents us from pushing the saved return PC onto
the stack and returning normally. Instead we pop the shadow stack
and return directly. This is the safest way to return and ensures
any stack manipulations done by the vfork'd child doesn't cause the
parent to terminate when CET is enabled.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/i386/vfork.S (SYSCALL_ERROR_HANDLER):
Redefine if shadow stack is enabled.
(SYSCALL_ERROR_LABEL): Likewise.
(__vfork): Pop shadow stack and jump back to to caller directly
when shadow stack is in use.
* sysdeps/unix/sysv/linux/x86_64/vfork.S (SYSCALL_ERROR_HANDLER):
Redefine if shadow stack is enabled.
(SYSCALL_ERROR_LABEL): Likewise.
(__vfork): Pop shadow stack and jump back to to caller directly
when shadow stack is in use.
Intel Control-flow Enforcement Technology (CET) instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en
forcement-technology-preview.pdf
includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK).
GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to
indicate that all executable sections are compatible with IBT when
ENDBR instruction starts each valid target where an indirect branch
instruction can land. Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on
output only if it is set on all relocatable inputs.
On an IBT capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable IBT and
lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable.
2. When loading an executable with an interpreter, enable IBT if
GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable,
disable IBT.
b. Lock IBT.
3. If IBT is enabled, when loading a shared object without
GNU_PROPERTY_X86_FEATURE_1_IBT:
a. If legacy interwork is allowed, then mark all pages in executable
PT_LOAD segments in legacy code page bitmap. Failure of legacy code
page bitmap allocation causes an error.
b. If legacy interwork isn't allowed, it causes an error.
GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to
indicate that all executable sections are compatible with SHSTK where
return address popped from shadow stack always matches return address
popped from normal stack. Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK
on output only if it is set on all relocatable inputs.
On a SHSTK capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable.
2. When loading an executable with an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable
or any shared objects loaded via the DT_NEEDED tag, disable SHSTK.
b. Otherwise lock SHSTK.
3. After SHSTK is enabled, it is an error to load a shared object
without GNU_PROPERTY_X86_FEATURE_1_SHSTK.
To enable CET support in glibc, --enable-cet is required to configure
glibc. When CET is enabled, both compiler and assembler must support
CET. Otherwise, it is a configure-time error.
To support CET run-time control,
1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate
if IBT or SHSTK are enabled at run-time. It should be initialized by
init_cpu_features.
2. For dynamic executables:
a. A l_cet field is added to struct link_map to indicate if IBT or
SHSTK is enabled in an ELF module. _dl_process_pt_note or
_rtld_process_pt_note is called to process PT_NOTE segment for
GNU program property and set l_cet.
b. _dl_open_check is added to check IBT and SHSTK compatibilty when
dlopening a shared object.
3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with
_dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if
SHSTK is enabled.
CET run-time control can be changed via GLIBC_TUNABLES with
$ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off]
$ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off]
1. permissive: SHSTK is disabled when dlopening a legacy ELF module.
2. on: IBT or SHSTK are always enabled, regardless if there are IBT or
SHSTK bits in GNU program property.
3. off: IBT or SHSTK are always disabled, regardless if there are IBT or
SHSTK bits in GNU program property.
<cet.h> from CET-enabled GCC is automatically included by assembly codes
to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
to GNU program property. _CET_ENDBR is added at the entrance of all
assembly functions whose address may be taken. _CET_NOTRACK is used to
insert NOTRACK prefix with indirect jump table to support IBT. It is
defined as notrack when _CET_NOTRACK is defined in <cet.h>.
[BZ #21598]
* configure.ac: Add --enable-cet.
* configure: Regenerated.
* elf/Makefille (all-built-dso): Add a comment.
* elf/dl-load.c (filebuf): Moved before "dynamic-link.h".
Include <dl-prop.h>.
(_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE
segment.
* elf/dl-open.c: Include <dl-prop.h>.
(dl_open_worker): Call _dl_open_check.
* elf/rtld.c: Include <dl-prop.h>.
(dl_main): Call _rtld_process_pt_note on PT_NOTE segment. Call
_rtld_main_check.
* sysdeps/generic/dl-prop.h: New file.
* sysdeps/i386/dl-cet.c: Likewise.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise.
* sysdeps/x86/cet-tunables.h: Likewise.
* sysdeps/x86/check-cet.awk: Likewise.
* sysdeps/x86/configure: Likewise.
* sysdeps/x86/configure.ac: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
* sysdeps/x86/dl-procruntime.c: Likewise.
* sysdeps/x86/dl-prop.h: Likewise.
* sysdeps/x86/libc-start.h: Likewise.
* sysdeps/x86/link_map.h: Likewise.
* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
(_dl_runtime_resolve_shstk): New.
(_dl_runtime_profile_shstk): Likewise.
* sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet
if CET is enabled.
(CFLAGS-.o): Add -fcf-protection if CET is enabled.
(CFLAGS-.os): Likewise.
(CFLAGS-.op): Likewise.
(CFLAGS-.oS): Likewise.
(asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET
is enabled.
(tests-special): Add $(objpfx)check-cet.out.
(cet-built-dso): New.
(+$(cet-built-dso:=.note)): Likewise.
(common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note).
($(objpfx)check-cet.out): New.
(generated): Add check-cet.out.
* sysdeps/x86/cpu-features.c: Include <dl-cet.h> and
<cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New prototype.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
(init_cpu_features): Call get_cet_status to check CET status
and update dl_x86_feature_1 with CET status. Call
TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK
(set_x86_shstk). Disable and lock CET in libc.a.
* sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New function.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
* sysdeps/x86/sysdep.h (_CET_NOTRACK): New.
(_CET_ENDBR): Define if not defined.
(ENTRY): Add _CET_ENDBR.
* sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and
x86_shstk.
* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
Since SHADOW_STACK_POINTER_OFFSET is defined in jmp_buf-ssp.h, we must
undef SHADOW_STACK_POINTER_OFFSET after including <jmp_buf-ssp.h>.
* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Undef
SHADOW_STACK_POINTER_OFFSET after including <jmp_buf-ssp.h>.
Save and restore shadow stack pointer in setjmp and longjmp to support
shadow stack in Intel CET. Use feature_1 in tcbhead_t to check if
shadow stack is enabled before saving and restoring shadow stack pointer.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>.
(_setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>.
(setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers):
Remove jmp_buf-ssp.sym.
* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/x86/Makefile (gen-as-const-headers): Add
jmp_buf-ssp.sym.
* sysdeps/x86/jmp_buf-ssp.sym: New dummy file.
* sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
As pointed out in a libc-alpha thread [1], the misc/tst-ofdlocks-compat
may fail in some specific Linux releases. This patch adds a comment
along with a link to discussion in the test source code.
No changes are expected.
* sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Add a comment about
a kernel issue which lead to test failure in some cases.
[1] https://sourceware.org/ml/libc-alpha/2018-07/msg00243.html
This enables searching shared libraries in atomics/ when the hardware
supports LSE atomics of armv8.1 so one can provide optimized variants
of libraries in a portable way.
LSE atomics does not affect library abi, the new instructions can
interoperate with old ones.
I considered the earlier comments on the patch
https://sourceware.org/ml/libc-alpha/2018-04/msg00400.htmlhttps://sourceware.org/ml/libc-alpha/2018-04/msg00625.html
It turns out that the way glibc dynamic linker decides on the search
path is not very flexible: it wants to use hwcap bits and associated
strings. So some targets reuse hwcap bits for glibc internal purposes
to affect the search logic. But hwcap is an interface with the kernel,
glibc should not allocate bits in it for its internal logic as that
limits future hwcap extensions and confusing to users who expect to see
hwcap bits in ifunc resolvers. Instead of rewriting the dynamic linker
path logic (which affects all targets) this patch just uses the existing
mechanism, however this means that the path name has to be the hwcap
name "atomics" and cannot be changed to something more meaningful to
users.
It is hard to tell how much performance benefit this can give, in
principle armv8.1 atomics can be better optimized in the hardware, so it
can make a difference for synchronization heavy code. On some systems
such multilib setup may be the only viable way to get optimized
libraries used.
* sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (HWCAP_IMPORTANT): Add
HWCAP_ATOMICS.
