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.
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.
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.
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.
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.
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.
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>
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.
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>
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>
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.
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.
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>
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>
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 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.
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.
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.
It removes all the arch-specific assembly implementation. The
outliers are alpha, where its kernel ABI explict return -ENOMEM
in case of failure; and i686, where it can't use
"call *%gs:SYSINFO_OFFSET" during statup in static PIE.
Also some ABIs exports an additional ___brk_addr symbol and to
handle it an internal HAVE_INTERNAL_BRK_ADDR_SYMBOL is added.
Checked on x86_64-linux-gnu, i686-linux-gnu, adn with builsd for
the affected ABIs.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This reverts commit 81b83ff61f to move
__xmknod{at} back to default symbols. ABIs with default symbol version
of 2.33 or newer (such as riscv32) continue to just provide the mknod*
symbols.
The idea is to not force static libraries built against old glibc
to update against new glibcs (since they reference the the
xmknod{at} symbols).
Checked on x86_64-linux-gnu and i686-linux-gnu.
This reverts commit 20b39d5946 to move
{f}xstat{at} back to default symbols. ABIs with default symbol version
of 2.33 or newer (such as riscv32) continue to just provide the stat
symbols.
The idea is to not force static libraries built against old glibc
to update against new glibcs (since they reference the old
{f}xstat{at} symbols).
Checked on x86_64-linux-gnu and i686-linux-gnu.
The commit 605f38177d (sh: Split BE/LE abilist) did not take in
consideration the SH4 fpu support.
Checked with a build for sh4-linux-gnu and manually checked that
the implementations at sysdeps/sh/sh4/fpu/ are selected.
John Paul Adrian Glaubitz also confirmed it fixes the build issues
he encontered.
On ports with __TIMESIZE != 64 the remaining time argument always receives
pointer to struct __timespec64 instance. This is the different behavior
when compared to 64 bit versions of clock_nanosleep and nanosleep
functions, which receive NULL.
To avoid any potential issues, we also pass NULL when *rem pointer is
NULL.
Reported-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The thrd_sleep function has been converted to support 64 bit time.
It was also necessary to provide Linux specific copy of it to avoid
problems on i686-gnu (i.e. HURD) port, which is not providing
clock_nanosleep() supporting 64 bit time.
The thrd_sleep is a wrapper on POSIX threads to provide C11 standard
threads interface. It directly calls __clock_nanosleep64().
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The mtx_timedlock function has been converted to support 64 bit time.
It was also necessary to provide Linux specific copy of it to avoid
problems on i686-gnu (i.e. HURD) port, which is not providing
pthread_mutex_timedlock() supporting 64 bit time.
The mtx_timedlock is a wrapper on POSIX threads to provide C11 standard
threads interface. It directly calls __pthread_mutex_timedlock64().
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The cnd_timedwait function has been converted to support 64 bit time.
It was also necessary to provide Linux specific copy of it to avoid
problems on i686-gnu (i.e. HURD) port, which is not providing
pthread_cond_timedwait() supporting 64 bit time.
Moreover, a linux specific copy of thrd_priv.h header file has been
added as well.
The cnd_timedwait is a wrapper on POSIX threads to provide C11 standard
threads interface. It directly calls __pthread_cond_timedwait64().
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The tls.h inclusion is not really required and limits possible
definition on more arch specific headers.
This is a cleanup to allow inline functions on sysdep.h, more
specifically on i386 and ia64 which requires to access some tls
definitions its own.
No semantic changes expected, checked with a build against all
affected ABIs.
Most systems are SMP, so optimizing for the UP case is no longer
approriate. A dynamic check based on the kernel identification
has been only implemented for i386 anyway.
To disable adaptive mutexes on sh, define DEFAULT_ADAPTIVE_COUNT
as zero for this architecture.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add support to query cache information on RISC-V through sysconf()
function. The cache information had been added in AUX vector of RISC-V
architecture in Linux kernel v.5.10-rc1.
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
The adjtime interface allows return the amount of time remaining
from any previous adjustment that has not yet been completed by
passing a NULL as first argument. This was introduced with y2038
support 0308077e3a.
Checked on i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The #include <sys/msg.h> is redundant as we do not use message specific
types for issuing syscalls to handle msg and shm. Only msgctl requires
this header.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
