The #ifdef FSOPEN_CLOEXEC check did not work because the macro
was always defined in this header prior to the check, so that
the <linux/mount.h> contents did not matter.
Fixes commit 774058d729
("linux: Fix sys/mount.h usage with kernel headers").
I.e. from sysdeps/unix/sysv/linux/bits/in.h to netinet/in.h
It is following both the BSD and Linux definitions.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Now that kernel exports linux/mount.h and includes it on linux/fs.h,
its definitions might clash with glibc exports sys/mount.h. To avoid
the need to rearrange the Linux header to be always after glibc one,
the glibc sys/mount.h is changed to:
1. Undefine the macros also used as enum constants. This covers prior
inclusion of <linux/mount.h> (for instance MS_RDONLY).
2. Include <linux/mount.h> based on the usual __has_include check
(needs to use __has_include ("linux/mount.h") to paper over GCC
bugs.
3. Define enum fsconfig_command only if FSOPEN_CLOEXEC is not defined.
(FSOPEN_CLOEXEC should be a very close proxy.)
4. Define struct mount_attr if MOUNT_ATTR_SIZE_VER0 is not defined.
(Added in the same commit on the Linux side.)
This patch also adds some tests to check if including linux/fs.h and
linux/mount.h after and before sys/mount.h does work.
Checked on x86_64-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
So far this test checks if pidfd_open-syscall is supported,
which was introduced with linux 5.3.
The process_madvise-syscall was introduced with linux 5.10.
Thus you'll get FAILs if you are running a kernel in between.
This patch adds a check if the first process_madvise-syscall
returns ENOSYS and in this case will fail with UNSUPPORTED.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
The older libc versions are obsolete for over twenty years now.
This patch removes the special flags for libc5 and libc4 and assumes
that all libraries cached are libc6 compatible and use FLAG_ELF_LIBC6.
Checked with a build for all affected architectures.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
exit only terminates the current thread, not the whole process, so it
is the wrong fallback system call in this context. All supported
Linux versions implement the exit_group system call anyway.
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 5.18. (There are no
new constants covered by these tests in 5.19, or in 5.17 or 5.18 in
the case of tst-mount-consts.py that previously used version 5.16,
that need any other header changes.)
Tested with build-many-glibcs.py.
Linux 5.19 has no new syscalls, but enables memfd_secret in the uapi
headers for RISC-V. Update the version number in syscall-names.list
to reflect that it is still current for 5.19 and regenerate the
arch-syscall.h headers with build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
The inline and library functions that the CMSG_NXTHDR macro may expand
to increment the pointer to the header before checking the stride of
the increment against available space. Since C only allows incrementing
pointers to one past the end of an array, the increment must be done
after a length check. This commit fixes that and includes a regression
test for CMSG_FIRSTHDR and CMSG_NXTHDR.
The Linux, Hurd, and generic headers are all changed.
Tested on Linux on armv7hl, i686, x86_64, aarch64, ppc64le, and s390x.
[BZ #28846]
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
pidfd_getfd can fail for a valid pidfd with errno EPERM for various
reasons in a restricted environment. Use FAIL_UNSUPPORTED in that case.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Rather than buffering 16 MiB of entropy in userspace (by way of
chacha20), simply call getrandom() every time.
This approach is doubtlessly slower, for now, but trying to prematurely
optimize arc4random appears to be leading toward all sorts of nasty
properties and gotchas. Instead, this patch takes a much more
conservative approach. The interface is added as a basic loop wrapper
around getrandom(), and then later, the kernel and libc together can
work together on optimizing that.
This prevents numerous issues in which userspace is unaware of when it
really must throw away its buffer, since we avoid buffering all
together. Future improvements may include userspace learning more from
the kernel about when to do that, which might make these sorts of
chacha20-based optimizations more possible. The current heuristic of 16
MiB is meaningless garbage that doesn't correspond to anything the
kernel might know about. So for now, let's just do something
conservative that we know is correct and won't lead to cryptographic
issues for users of this function.
This patch might be considered along the lines of, "optimization is the
root of all evil," in that the much more complex implementation it
replaces moves too fast without considering security implications,
whereas the incremental approach done here is a much safer way of going
about things. Once this lands, we can take our time in optimizing this
properly using new interplay between the kernel and userspace.
getrandom(0) is used, since that's the one that ensures the bytes
returned are cryptographically secure. But on systems without it, we
fallback to using /dev/urandom. This is unfortunate because it means
opening a file descriptor, but there's not much of a choice. Secondly,
as part of the fallback, in order to get more or less the same
properties of getrandom(0), we poll on /dev/random, and if the poll
succeeds at least once, then we assume the RNG is initialized. This is a
rough approximation, as the ancient "non-blocking pool" initialized
after the "blocking pool", not before, and it may not port back to all
ancient kernels, though it does to all kernels supported by glibc
(≥3.2), so generally it's the best approximation we can do.
The motivation for including arc4random, in the first place, is to have
source-level compatibility with existing code. That means this patch
doesn't attempt to litigate the interface itself. It does, however,
choose a conservative approach for implementing it.
Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Cristian Rodríguez <crrodriguez@opensuse.org>
Cc: Paul Eggert <eggert@cs.ucla.edu>
Cc: Mark Harris <mark.hsj@gmail.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Commit a06b40cdf5 updated stat.h to use
__USE_XOPEN2K8 instead of __USE_MISC to add the st_atim, st_mtim and
st_ctim members to struct stat. However, for microblaze, there are two
definitions of struct stat, depending on the __USE_FILE_OFFSET64 macro.
The second one was not updated.
Change __USE_MISC to __USE_XOPEN2K8 in the __USE_FILE_OFFSET64 version
of struct stat for microblaze.
The hppa port starts libc at GLIBC_2.2, but has earlier symbol
versions in other shared objects. This means that the compat
symbol for readdir64 is not actually present in libc even though
have-GLIBC_2.1.3 is defined as yes at the make level.
Fixes commit 15e50e6c96 ("Linux:
dirent/tst-readdir64-compat can be a regular test") by mostly
reverting it.
The implementation is based on scalar Chacha20 with per-thread cache.
It uses getrandom or /dev/urandom as fallback to get the initial entropy,
and reseeds the internal state on every 16MB of consumed buffer.
To improve performance and lower memory consumption the per-thread cache
is allocated lazily on first arc4random functions call, and if the
memory allocation fails getentropy or /dev/urandom is used as fallback.
The cache is also cleared on thread exit iff it was initialized (so if
arc4random is not called it is not touched).
Although it is lock-free, arc4random is still not async-signal-safe
(the per thread state is not updated atomically).
The ChaCha20 implementation is based on RFC8439 [1], omitting the final
XOR of the keystream with the plaintext because the plaintext is a
stream of zeros. This strategy is similar to what OpenBSD arc4random
does.
The arc4random_uniform is based on previous work by Florian Weimer,
where the algorithm is based on Jérémie Lumbroso paper Optimal Discrete
Uniform Generation from Coin Flips, and Applications (2013) [2], who
credits Donald E. Knuth and Andrew C. Yao, The complexity of nonuniform
random number generation (1976), for solving the general case.
The main advantage of this method is the that the unit of randomness is not
the uniform random variable (uint32_t), but a random bit. It optimizes the
internal buffer sampling by initially consuming a 32-bit random variable
and then sampling byte per byte. Depending of the upper bound requested,
it might lead to better CPU utilization.
Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.
Co-authored-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
[1] https://datatracker.ietf.org/doc/html/rfc8439
[2] https://arxiv.org/pdf/1304.1916.pdf
Before this the test fails if run in a chroot by a non-root user:
warning: could not become root outside namespace (Operation not permitted)
../sysdeps/unix/sysv/linux/tst-mount.c:36: numeric comparison failure
left: 1 (0x1); from: errno
right: 19 (0x13); from: ENODEV
error: ../sysdeps/unix/sysv/linux/tst-mount.c:39: not true: fd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:46: not true: r != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:48: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:52: numeric comparison failure
left: 1 (0x1); from: errno
right: 9 (0x9); from: EBADF
error: ../sysdeps/unix/sysv/linux/tst-mount.c:55: not true: mfd != -1
../sysdeps/unix/sysv/linux/tst-mount.c:58: numeric comparison failure
left: 1 (0x1); from: errno
right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:61: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:65: numeric comparison failure
left: 1 (0x1); from: errno
right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:68: not true: pfd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:75: not true: fd_tree != -1
../sysdeps/unix/sysv/linux/tst-mount.c:88: numeric comparison failure
left: 1 (0x1); from: errno
right: 38 (0x26); from: ENOSYS
error: 12 test failures
Checking that the test can enter a new mount namespace is more correct
than just checking the return value of support_become_root() as the test
code changes the mount namespace it runs in so running it as root on a
system that does not support mount namespaces should still skip.
Also change the test to remove the unnecessary fork.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Starting with commit e070501d12
"Replace __libc_multiple_threads with __libc_single_threaded"
the testcases nptl/tst-cancel-self and
nptl/tst-cancel-self-cancelstate are failing.
This is fixed by only defining SINGLE_THREAD_BY_GLOBAL on s390x,
but not on s390.
Starting with commit 09c76a7409
"Linux: Consolidate {RTLD_}SINGLE_THREAD_P definition",
SINGLE_THREAD_BY_GLOBAL was defined in
sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h.
Lateron the commit 9a973da617
"s390: Consolidate Linux syscall definition" consolidates the sysdep.h files
from s390-32/s390-64 subdirectories. Unfortunately the macro is now always
defined instead of only on s390-64.
As information:
TLS_MULTIPLE_THREADS_IN_TCB is also only defined for s390.
See: sysdeps/s390/nptl/tls.h
This change provides implementations for the mbrtoc8 and c8rtomb
functions adopted for C++20 via WG21 P0482R6 and for C2X via WG14
N2653. It also provides the char8_t typedef from WG14 N2653.
The mbrtoc8 and c8rtomb functions are declared in uchar.h in C2X
mode or when the _GNU_SOURCE macro or C++20 __cpp_char8_t feature
test macro is defined.
The char8_t typedef is declared in uchar.h in C2X mode or when the
_GNU_SOURCE macro is defined and the C++20 __cpp_char8_t feature
test macro is not defined (if __cpp_char8_t is defined, then char8_t
is a builtin type).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
since header inclusion single-thread.h is in the wrong order, the define
needs to come before including sysdeps/unix/sysdep.h. The macro
is now moved to a per-arch single-threade.h header.
The SINGLE_THREAD_P is used on some more places.
Checked on aarch64-linux-gnu and x86_64-linux-gnu.
It was added on Linux 5.12 (2a1867219c7b27f928e2545782b86daaf9ad50bd)
to allow change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The new mount API was added on Linux 5.2 with six new syscalls:
fsopen, fsconfig, fsmount, move_mount, fspick, and open_tree.
The new test verifies minimal functionality along with error paths
for specific arguments and their corner cases.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.2 (a07b20004793d8926f78d63eb5980559f7813404)
to return a O_PATH-opened file descriptor to an existing mountpoint.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.2 (cf3cba4a429be43e5527a3f78859b1bfd9ebc5fb)
that can be used to pick an existing mountpoint into an filesystem
context which can thereafter be used to reconfigure a superblock
with fsconfig syscall.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.2 (ecdab150fddb42fe6a739335257949220033b782)
as a way to a configure filesystem creation context and trigger
actions upon it, to be used in conjunction with fsopen, fspick and
fsmount.
The fsconfig_command commands are currently only defined as an enum,
so they can't be checked on tst-mount-consts.py with current test
support.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The main drive is to optimize the internal usage and required size
when sigset_t is embedded in other data structures. On Linux, the
current supported signal set requires up to 8 bytes (16 on mips),
was lower than the user defined sigset_t (128 bytes).
A new internal type internal_sigset_t is added, along with the
functions to operate on it similar to the ones for sigset_t. The
internal-signals.h is also refactored to remove unused functions
Besides small stack usage on some functions (posix_spawn, abort)
it lower the struct pthread by about 120 bytes (112 on mips).
Checked on x86_64-linux-gnu.
Reviewed-by: Arjun Shankar <arjun@redhat.com>
The new asymmetric mode is available when HWCAP2_MTE3 is set (support is
available), bit2 is set in the tunable (user request per application),
and the system is configured such that the asymmetric mode is preferred over
sync or async (per-cpu system-wide setting).
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
On success, mq_receive() and mq_timedreceive() return the number of
bytes in the received message, so it requires to check if the value
is larger than 0.
Checked on i686-linux-gnu.
These files simply include the sysdeps/posix implementations which would
be used even in the absence of the files. They have been unnecessary
since 7b17aeda0c when nice and signal were removed from the
syscalls.list file.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This maintains compatibility between <sys/mman.h> and <linux/uio.h>.
Before that, the addition of process_madvise made those two header
files incompatible. This has been observed resulting in a build
failure in LLDB's Process/Linux/NativeRegisterContextLinux_s390x.cpp
source file.
Fixes commit d19ee3473d
("linux: Add process_madvise").
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It was added on Linux 5.2 (2db154b3ea8e14b04fee23e3fdfd5e9d17fbc6ae)
as way t move a mount from one place to another and, in the next
commit, allow to attach an unattached mount tree.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
It was added on 5.2 (93766fbd2696c2c4453dd8e1070977e9cd4e6b6d) to
provide a way by which a filesystem opened with fsopen and configured
by a series of fsconfig calls can have a detached mount object
created for it.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.2 (24dcb3d90a1f67fe08c68a004af37df059d74005)
to start the process of preparing to create a superblock that will
then be mountable, using an fd as a context handle.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Added in Linux 5.15 (884a7e5964e06ed93c7771c0d7cf19c09a8946f1), the new
syscalls allows a caller to free the memory of a dying target process.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.10 (ecb8ac8b1f146915aa6b96449b66dd48984caacc)
with the same functionality as madvise but using a pidfd of the target
process.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This definition is only used as a fallback with old kernel headers.
The change follows kernel commit bfdf4e6208051ed7165b2e92035b4bf11
("rseq: Remove broken uapi field layout on 32-bit little endian").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
