A new syscall sigfastblock(2) is added which registers a uint32_t
variable as containing the count of blocks for signal delivery. Its
content is read by kernel on each syscall entry and on AST processing,
non-zero count of blocks is interpreted same as the signal mask
blocking all signals.
The biggest downside of the feature that I see is that memory
corruption that affects the registered fast sigblock location, would
cause quite strange application misbehavior. For instance, the process
would be immune to ^C (but killable by SIGKILL).
With consumers (rtld and libthr added), benchmarks do not show a
slow-down of the syscalls in micro-measurements, and macro benchmarks
like buildworld do not demonstrate a difference. Part of the reason is
that buildworld time is dominated by compiler, and clang already links
to libthr. On the other hand, small utilities typically used by shell
scripts have the total number of syscalls cut by half.
The syscall is not exported from the stable libc version namespace on
purpose. It is intended to be used only by our C runtime
implementation internals.
Tested by: pho
Disscussed with: cem, emaste, jilles
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D12773
Submitted by: Bora Özarslan <borako.ozarslan@gmail.com>
Submitted by: Yang Wang <2333@outlook.jp>
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19917
- handle the CLOCK_{PROCESS,THREAD}_CPUTIME_ID specified directly;
- fix thread id calculation as in the Linuxulator we should
convert the user supplied thread id to struct thread * by linux_tdfind();
- fix CPUCLOCK_SCHED case by using kern_{process,thread}_cputime()
directly as native get_cputime() used by kern_clock_gettime() uses
native tdfind()/pfind() to find proccess/thread.
PR: 240990
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23341
MFC after: 2 weeks
so don't initialize nwhich in declaration and remove stale comment from r161304.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D23339
MFC after: 2 weeks
for missing IP_RECVERR setsockopt(2) support. Without it, DNS
resolution is broken for glibc >= 2.30 (glibc BZ #24047).
From the user point of view this fixes "yum update" on recent
CentOS 8.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23234
This unbreaks Mono (mono-devel-4.6.2.7+dfsg-1ubuntu1 from Ubuntu Bionic);
previously would crash on "amd64_is_imm32" assert.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23306
This unbreaks Mono (mono-devel-4.6.2.7+dfsg-1ubuntu1 from Ubuntu Bionic);
previously would crash on "amd64_is_imm32" assert.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
The Linux32 system call argument fetcher places each argument (passed in
registers in the Linux x86 system call convention) into an entry in the
generic system call args array. Each member of this array is 8 bytes
wide, so this approach is broken for system calls that take off_t
arguments.
Fix the problem by splitting l_loff_t arguments in the 32-bit system
call descriptions, the same as we do for FreeBSD32. Change entry points
to handle this using the PAIR32TO64 macro.
Move linux_ftruncate64() into compat/linux.
PR: 243155
Reported by: Alex S <iwtcex@gmail.com>
Reviewed by: kib (previous version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23210
r355473 vastly improved the readability and cleanliness of these Makefiles.
Every single one of them follows the same pattern and duplicates the exact
same logic.
Now that we have GENERATED/SRCS, split SRCS up into the two parameters we'll
use for ${MAKESYSCALLS} rather than assuming a specific ordering of SRCS and
include a common sysent.mk to handle the rest. This makes it less tedious to
make sweeping changes.
Some default values are provided for GENERATED/SYSENT_*; almost all of these
just use a 'syscalls.master' and 'syscalls.conf' in cwd, and they all use
effectively the same filenames with an arbitrary prefix. Most ABIs will be
able to get away with just setting GENERATED_PREFIX and including
^/sys/conf/sysent.mk, while others only need light additions. kern/Makefile
is the notable exception, as it doesn't take a SYSENT_CONF and the generated
files are spread out between ^/sys/kern and ^/sys/sys, but it otherwise fits
the pattern enough to use the common version.
Reviewed by: brooks, imp
Nice!: emaste
Differential Revision: https://reviews.freebsd.org/D23197
This can happen if a file is closed during unix socket GC. The same bug
was fixed for devfs descriptors in r228361.
PR: 242913
Reported and tested by: iz-rpi03@hs-karlsruhe.de
Reviewed by: hselasky, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23178
sys_setsockopt. Just a cleanup; no functional changes.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22812
When either makesyscalls.lua or syscalls.master changes, all of the
${GENERATED} targets are now out-of-date. With make jobs > 1, this means we
will run the makesyscalls script in parallel for the same ABI, generating
the same set of output files.
Prior to r356603 , there is a large window for interlacing output for some
of the generated files that we were generating in-place rather than staging
in a temp dir. After that, we still should't need to run the script more
than once per-ABI as the first invocation should update all of them. Add
.ORDER to do so cleanly.
Reviewed by: brooks
Discussed with: sjg
Differential Revision: https://reviews.freebsd.org/D23099
- Export the offset into the backing object, not the object size.
- Fix a bug where we would print the previous entry's "offset" when a
map_entry has no object.
- Try to identify shared mappings. Linux prints "s" when the mapping
"may be shared". This attempt is not perfect, for example, we print
"p" for anonymous memory that may be shared via
minherit(INHERIT_SHARE).
PR: 240992
Reviewed by: kib
MFC after: 1 week
MFC note: no OBJ_ANON in stable/12
Differential Revision: https://reviews.freebsd.org/D23062
The previous behavior of leaving VI_OWEINACT vnodes on the active list without
a hold count is eliminated. Hold count is kept and inactive processing gets
explicitly deferred by setting the VI_DEFINACT flag. The syncer is then
responsible for vdrop.
Reviewed by: kib (previous version)
Tested by: pho (in a larger patch, previous version)
Differential Revision: https://reviews.freebsd.org/D23036
When file sealing and shm_open2 were introduced, we should have grown a new
kern_shm_open2 helper that did the brunt of the work with the new interface
while kern_shm_open remains the same. Instead, more complexity was
introduced to kern_shm_open to handle the additional features and consumers
had to keep changing in somewhat awkward ways, and a kern_shm_open2 was
added to wrap kern_shm_open.
Backpedal on this and correct the situation- kern_shm_open returns to the
interface it had prior to file sealing being introduced, and neither
function needs an initial_seals argument anymore as it's handled in
kern_shm_open2 based on the shmflags.
Linux mmap rejects mmap() on a write-only file with EACCES.
linux_mmap_common currently does a fun dance to grab the fp associated with
the passed in fd, validates it, then drops the reference and calls into
kern_mmap(). Doing so is perhaps both fragile and premature; there's still
plenty of chance for the request to get rejected with a more appropriate
error, and it's prone to a race where the file we ultimately mmap has
changed after it drops its referenced.
This change alleviates the need to do this by providing a kern_mmap variant
that allows the caller to inspect the fp just before calling into the fileop
layer. The callback takes flags, prot, and maxprot as one could imagine
scenarios where any of these, in conjunction with the file itself, may
influence a caller's decision.
The file type check in the linux compat layer has been removed; EINVAL is
seemingly not an appropriate response to the file not being a vnode or
device. The fileop layer will reject the operation with ENODEV if it's not
supported, which more closely matches the common linux description of
mmap(2) return values.
If we discover that we're allowing an mmap() on a file type that Linux
normally wouldn't, we should restrict those explicitly.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22977
Filesystems which want to use it in limited capacity can employ the
VOP_UNLOCK_FLAGS macro.
Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D21427
Its use of the page lock is incorrect, and it is not used by the DRM
modules.
Reviewed by: hselasky
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D23002
syscall is to query the CPU number and the NUMA domain the calling
thread is currently running on. The third argument is ignored.
It doesn't do anything regarding scheduling - it's literally
just a way to query the current state, without any guarantees
you won't get rescheduled an opcode later.
This unbreaks Java from CentOS 8
(java-11-openjdk-11.0.5.10-0.el8_0.x86_64).
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22972
copy_file_range(2) is implemented natively since r350315, make it available
for Linux binaries too.
Reviewed by: kib (mentor), trasz (previous version)
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D22959
devices. It's required for LTP, among other things. It's not
complete, but good enough for now.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22950
srandom(9) is meaningless on SMP systems or any system with, say,
interrupts. One could never rely on random(9) to produce a reproducible
sequence of outputs on the basis of a specific srandom() seed because the
global state was shared by all kernel contexts. As such, removing it is
literally indistinguishable to random(9) consumers (as compared with
retaining it).
Mark random(9) as deprecated and slated for quick removal. This is not to
say we intend to remove all fast, non-cryptographic PRNG(s) in the kernel.
It/they just won't be random(9), as it exists today, in either name or
implementation.
Before random(9) is removed, a replacement will be provided and in-tree
consumers will be converted.
Note that despite the name, the random(9) interface does not bear any
resemblance to random(3). Instead, it is the same crummy 1988 Park-Miller
LCG used in libc rand(3).
removed from objects including calls to free. Pages must not be xbusy
when freed and not on an object. Strengthen assertions to match these
expectations. In practice very little code had to change busy handling
to meet these rules but we can now make stronger guarantees to busy
holders and avoid conditionally dropping busy in free.
Refine vm_page_remove() and vm_page_replace() semantics now that we have
stronger guarantees about busy state. This removes redundant and
potentially problematic code that has proliferated.
Discussed with: markj
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22822
than "/compat/linux". Useful when you have several compat directories
with different Linux versions and you don't want to clash with files
installed by linux-c7 packages.
Reviewed by: bcr (manpages)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22574
Don't hold the scheduler lock while doing context switches. Instead we
unlock after selecting the new thread and switch within a spinlock
section leaving interrupts and preemption disabled to prevent local
concurrency. This means that mi_switch() is entered with the thread
locked but returns without. This dramatically simplifies scheduler
locking because we will not hold the schedlock while spinning on
blocked lock in switch.
This change has not been made to 4BSD but in principle it would be
more straightforward.
Discussed with: markj
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22778
