A BPF descriptor only has an associated interface descriptor once it is
attached to an interface, e.g., with BIOCSETIF. Avoid dereferencing a
NULL pointer in filt_bpfwrite() if the BPF descriptor is not attached.
Reviewed by: ae
Reported by: syzbot+ae45d5166afe15a5a21d@syzkaller.appspotmail.com
Fixes: ded77e0237a8 ("Allow the BPF to be select for write.")
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32561
for state control over TRACE, TRAPCAP, ASLR, PROTMAX, STACKGAP,
NO_NEWPRIVS, and WXMAP.
Reported by: emaste
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32513
These calls do operate on vnodes only, not file contents.
This is useful for e.g. the xdg-document-portal fuse filesystem.
Reviewed by: kib, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D32438
When this flag is set, operations that update an existing kevent will
not change the udata field. This can be used to NOTE_TRIGGER or
EV_{EN,DIS}ABLE events without overwriting the stashed pointer.
Reviewed by: Domagoj Stolfa <domagoj.stolfa@gmail.com>
Obtained from: CheriBSD
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D30286
It allows to override kern.elf{32,64}.allow_wx on per-process basis.
In particular, it makes it possible to run binaries without PT_GNU_STACK
and without elfctl note while allow_wx = 0.
Reviewed by: brooks, emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31779
On case-insensitive file systems (most likely to be seen on macOS, where
it is the default), _Fork.o for the new POSIX _Fork function conflicts
with _fork.o for the PSEUDO file. This results in non-determinsitic
behaviour in terms of which ends up being present; if _Fork.o wins then
the build fails to link libc.so due to missing __sys_fork, and if
_fork.o wins then libc silently fails to include the implementation of
_Fork. A similar issue occurred in the past for C99's _Exit conflicting
with exit(2) and was fixed in cb1cb6a2a83f, so this adds a fix based on
that.
As a longer-term solution it might be better to instead make the
generated files use a different prefix that's less likely to conflict
with other things (such as __sys_foo.o given they always contain that)
but that's a rather more invasive change.
Fixes: 49ad342cc10c ("Add _Fork()")
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D31895
Unlike the other syscalls these two symbols were missing from the
version script. I noticed this while looking into the compiler-rt
runtime libraries for CHERI.
Reviewed by: brooks
Obtained from: https://github.com/CTSRD-CHERI/cheribsd/pull/1063
MFC after: 3 days
The new wording for standard flags is losely based on the POSIX
description.
Make it clearer that PROT_MAX() is a local extension.
Reviewed by: alc, mckusick, imp, kib, markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D31777
This text dates to the BSD 4.4 import and is misleading. The mprotect
syscall acts on page granularity and breaks up mappings as required to
do so.
Note that with the addition of non-transparent superpages (aka
largepages) the size of a page at a given address may vary. This
commit does not attempt to address the lack of documentation of this
feature.
Sponsored by: DARPA
Reviewed by: alc, mckusick, imp, kib, markj
Differential Revision: https://reviews.freebsd.org/D31776
rmsr.r_offset now is set to rqsr.r_offset plus the number of bytes
zeroed before hitting the end-of-file. After this change rmsr.r_offset
no longer contains the EOF when the requested operation range is
completely beyond the end-of-file. Instead in such case rmsr.r_offset is
equal to rqsr.r_offset. Callers can obtain the number of bytes zeroed
by subtracting rqsr.r_offset from rmsr.r_offset.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31677
rmacklem@ spotted two things in the system call:
- Upon returning from a successful operation, vop_stddeallocate can
update rmsr.r_offset to a value greater than file size. This behavior,
although being harmless, can be confusing.
- The EINVAL return value for rqsr.r_offset + rqsr.r_len > OFF_MAX is
undocumented.
This commit has the following changes:
- vop_stddeallocate and shm_deallocate to bound the the affected area
further by the file size.
- The EINVAL case for rqsr.r_offset + rqsr.r_len > OFF_MAX is
documented.
- The fspacectl(2), vn_deallocate(9) and VOP_DEALLOCATE(9)'s return
len is explicitly documented the be the value 0, and the return offset
is restricted to be the smallest of off + len and current file size
suggested by kib@. This semantic allows callers to interact better
with potential file size growth after the call.
Sponsored by: The FreeBSD Foundation
Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D31604
Add missing wrapper code to librt for these new functions so that
SIGEV_THREAD works. Without machinery to convert it to SIGEV_THREAD_ID,
you got EINVAL.
Reviewed by: asomers
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D31618
Allow multiple vector IOs to be started with one system call.
aio_readv() and aio_writev() already used these opcodes under the
covers. This commit makes them available to user space.
Being non-standard extensions, they're only visible if __BSD_VISIBLE is
defined, like the functions.
Reviewed by: asomers, kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D31627
Add fflush(stdout) as the common idiom. Explain the need to use exit()
but advise against it.
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D31425
_PC_MIN_HOLE_SIZE and _PC_DEALLOC_PRESENT were mixed somehow before this
fix.
Sponsored by: The FreeBSD Foundation
Reviewed by: delphij
Differential Revision: https://reviews.freebsd.org/D31436
fspacectl(2) is a system call to provide space management support to
userspace applications. VOP_DEALLOCATE(9) is a VOP call to perform the
deallocation. vn_deallocate(9) is a public KPI for kmods' use.
The purpose of proposing a new system call, a KPI and a VOP call is to
allow bhyve or other hypervisor monitors to emulate the behavior of SCSI
UNMAP/NVMe DEALLOCATE on a plain file.
fspacectl(2) comprises of cmd and flags parameters to specify the
space management operation to be performed. Currently cmd has to be
SPACECTL_DEALLOC, and flags has to be 0.
fo_fspacectl is added to fileops.
VOP_DEALLOCATE(9) is added as a new VOP call. A trivial implementation
of VOP_DEALLOCATE(9) is provided.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D28347
Current POSIX standard requires fork() to be async-signal safe. Neither
our implementation, nor implementations in other operating systems are,
and practically it is impossible to make fork() async-signal safe without
too much efforts. Also, that would put undue requirement that all atfork
handlers should be async-signal safe as well, which contradicts its main
use.
As result, Austin Group dropped the requirement, and added a new function
_Fork() that should be async-signal safe, but it does not call atfork
handlers. Basically, _Fork() can be implemented as a raw syscall.
Release of glibc 2.34 added _Fork(), do the same for FreeBSD.
Clarify threading behavior for fork() in the manpage.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D31378
Linux standardized what we call CLOCK_{REALTIME,MONOTONIC}_FAST as
CLOCK_{REALTIME,MONOTONIC}_COARSE. In addition, Linux spells
CLOCK_UPTIME as CLOCK_BOOTTIME.
Add aliases to time.h and document these new aliases in
clock_gettime(2).
Reviewed by: vangyzen, kib (prior), dchagin (prior)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D30988
SO_RERROR indicates that receive buffer overflows should be handled as
errors. Historically receive buffer overflows have been ignored and
programs could not tell if they missed messages or messages had been
truncated because of overflows. Since programs historically do not
expect to get receive overflow errors, this behavior is not the
default.
This is really really important for programs that use route(4) to keep
in sync with the system. If we loose a message then we need to reload
the full system state, otherwise the behaviour from that point is
undefined and can lead to chasing bogus bug reports.
Reviewed by: philip (network), kbowling (transport), gbe (manpages)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26652
The early environment is typically cleared, so these new options
need the PRESERVE_EARLY_KENV kernel config(8) option. These environments
are reported as missing by kenv(1) if the option is not present in the
running kernel.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30835
The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.
This reapplies 3a522ba1bc852c3d4660a4fa32e4a94999d09a47 with a fix for
the static assertion failure on i386.
Approved by: markj (mentor)
Reviewed by: kib, bcr (manpages)
Differential Revision: https://reviews.freebsd.org/D29185
The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.
Approved by: markj (mentor)
Reviewed by: kib, bcr (manpages)
Differential Revision: https://reviews.freebsd.org/D29185
This introduces a new, per-process flag, "NO_NEW_PRIVS", which
is inherited, preserved on exec, and cannot be cleared. The flag,
when set, makes subsequent execs ignore any SUID and SGID bits,
instead executing those binaries as if they not set.
The main purpose of the flag is implementation of Linux
PROC_SET_NO_NEW_PRIVS prctl(2), and possibly also unpriviledged
chroot.
Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30939
When debugging POSIX shared memory issues, it's really
useful to learn that there is a command line tool now
to manipulate shared memory segments.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30896
so that libc vdso and kernel syscall give closer results.
Reported by: dchagin
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30873
Call binuptime inside switch statement, instead of pre-calculating
the abs argument.
Change the type of the abs argument to bool.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30873
Previously, a negative change list length would be treated the same as
an empty change list. A negative event list length would result in
bogus copyouts. Make kevent(2) return EINVAL for both cases so that
application bugs are more easily found, and to be more robust against
future changes to kevent internals.
Reviewed by: imp, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30480
There are still references to timed(8) and timedc(8) in the base system,
which were removed in 2018.
PR: 255425
Reported by: Ceri Davies <ceri at submonkey dot net>
Reviewed by: ygy, gbe
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D30232
It reopens the passed file descriptor, checking the file backing vnode'
current access rights against open mode. In particular, this flag allows
to convert file descriptor opened with O_PATH, into operable file
descriptor, assuming permissions allow that.
Reviewed by: markj
Tested by: Andrew Walker <awalker@ixsystems.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30148
It writes the core of live stopped process to the file descriptor
provided as an argument.
Based on the initial version from https://reviews.freebsd.org/D29691,
submitted by Michał Górny <mgorny@gentoo.org>.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29955
Teach poll(2) to support Linux-style POLLRDHUP events for sockets, if
requested. Triggered when the remote peer shuts down writing or closes
its end.
Reviewed by: kib
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D29757
It seems to be a nice idea to show how fork() is usually used in
practice. This may act as a guide to developers who want to quickly
recall how to use the fork() function.
Reviewed by: bcr, yuripv
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D27626
if VREAD access is checked as allowed during open
Requested by: wulf
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29323
