The system call returns the head of the robust futex list. The list head is stored
in the location pointed to by the head argument. When copying data between address
spaces use proper head storage size as it depends on an emulated ABI.
PR: 267616
MFC after: 3 days
Follow the 11a6ecd4. Check and handle the case when the ll/sc casu fails
even when the compare succeeds.
For more details PR/263825, https://reviews.freebsd.org/D35150.
Obtained from: Andrew@
MFC after: 2 weeks
There are many places where we copyin Linux timespec from the userspace
and then convert it to the kernel timespec. To avoid code duplication
add a tiny halper for doing this.
MFC after: 2 weeks
As no more NetBSD code in futexes exists replace NetBSD copyrights by
standard FreeBSD 2 clause license.
Add Roman Divacky's copyrights as an author of the robust futexes.
Differential revision: https://reviews.freebsd.org/D31347
MFC after: 2 weeks
FUTEX_LOCK_PI2 was added to support clock selection as FUTEX_LOCK_PI uses a
CLOCK_REALTIME based absolute value since it was implemented, but it does not
require that the FUTEX_CLOCK_REALTIME bit is set, because that was introduced
later.
MFC after: 2 weeks
In the Linux emulation layer linux_tdfind() has a special purpose to
handle glibc specific TID mangling and we should use it instead of tdfind().
MFC after: 2 weeks
Handle some races in handle_futex_death() which can prevents a wakeup of
potential waiters which can cause these waiters to block forever.
Differential Revision: https://reviews.freebsd.org/D31280
MFC after: 2 weeks
Linux futex documentation explicitly states that EINVAL is returned if
the futex is not 4-byte aligned. Check futex alignment as a Linux do
and return EINVAL.
Differential Revision: https://reviews.freebsd.org/D31279
MFC after: 2 weeks
Follow the r349951 (30b3018d), add check to react to stops and requests
to terminate between retries.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31254
MFC after: 2 weeks
According to fetch(9) fueword facility designed to fetch atomically
small amount of data from user space.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31239
MFC after: 2 weeks
To prevent umtx.h polluting by future changes split it on two headers:
umtx.h - ABI header for userspace;
umtxvar.h - the kernel staff.
While here fix umtx_key_match style.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D31248
MFC after: 2 weeks
In the futex_atomic_op() the encoded_op is a user-supplied parameter.
If the user specifies an incorrect value for this parameter paired with a valid
*uaddr parameter the caller will go into the endless loop. To prevent this check
futex_atomic_op() result and break the loop in case of ENOSYS.
MFC after: 2 weeks
For the caller is no need for access checking here, as the caller must take care
of EFAULT handling. Moreover, this check would be superfluous, since EFAULT is
extremily rare, and we prefer the fast path.
MFC after: 2 weeks
Initial patch from submitter was adapted by me to prevent unconditional
FUTEX_REQUEUE use.
PR: 255947
Submitted by: Philippe Michaud-Boudreault
Differential Revision: https://reviews.freebsd.org/D30332
Move flags and rtclock to the struct linux_futex_args. This will be used when
I split linux_futex() into separate futex op functions.
MFC after: 2 weeks
Remove all the 'entry' and 'return' probes; they clutter up the source
and are redundant to FBT.
Reviewed By: dchagin
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30040
Move futex_mtx to linux_common.ko for amd64 and aarch64 along
with respective list/mutex init/destroy.
PR: 240989
Reported by: Alex S <iwtcex@gmail.com>
Move futex_list definition to linux.c which is included once
in linux.ko (i386) and in linux_common.ko (amd64 and aarch64)
allowing 32/64 bit linux programs to access the same futexes
in the latter case.
PR: 240989
Reviewed by: dchagin
Differential Revision: https://reviews.freebsd.org/D22073
The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have grown at least 28 syscalls that use timespecs in some
way, leading many programs both inside and outside of the base system to
redefine those macros. It's better just to make the definitions public.
Our kernel currently defines two-argument versions of timespecadd and
timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define
three-argument versions. Solaris also defines a three-argument version, but
only in its kernel. This revision changes our definition to match the
common three-argument version.
Bump _FreeBSD_version due to the breaking KPI change.
Discussed with: cem, jilles, ian, bde
Differential Revision: https://reviews.freebsd.org/D14725
Use proper method to access userspace. For now, only the slow copyout
path is implemented.
Reported and tested by: tijl (previous version)
Sponsored by: The FreeBSD Foundation
