Previously open(2) was allowed in capability mode, with a comment that
suggested this was likely the case to facilitate debugging. The system
call would still fail later on, but it's better to disallow the syscall
altogether.
We now have the kern.trap_enotcap sysctl or PROC_TRAPCAP_CTL proccontrol
to aid in debugging.
In any case libc has translated open() to the openat syscall since
r277032.
Reviewed by: kib, rwatson
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10850
kern_yield(0) effectively causes the calling thread to be rescheduled
immediately since it resets the thread's priority to the highest possible
value. This can cause livelocks when the pattern
"while (!trylock()) kern_yield(0);" is used since the thread holding the
lock may linger on the runqueue for the CPU on which the looping thread is
running.
MFC after: 1 week
CPU_FOREACH() is not available until SI_SUB_CPU at SI_ORDER_ANY
when the LinuxKPI is loaded as part of the kernel.
MFC after: 1 week
Sponsored by: Mellanox Technologies
The previous misuse of sys_sigqueue() was sending random register or
stack garbage to 64-bit targets. The freebsd32 implementation preserves
the sival_int member of value when signaling a 64-bit process.
Document the mixed ABI implementation of union sigval and the
incompability of sival_ptr with pointer integrity schemes.
Reviewed by: kib, wblock
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D10605
Background:
The same VM object might be shared by multiple processes and the
mm_struct is usually freed when a process exits.
Grab a reference on the mm_struct while the vmap is in the
linux_vma_head list in case the first process which inserted a VM
object has exited.
Tested by: kwm @
MFC after: 1 week
Sponsored by: Mellanox Technologies
linux_page_address() function in the LinuxKPI. This solves an issue
where the return value from linux_page_address() is passed to
kmem_free().
MFC after: 1 week
Sponsored by: Mellanox Technologies
kit, CK, in the LinuxKPI.
When threads are pinned to a CPU core or when there is only one CPU,
it can happen that a higher priority thread can call the CK
synchronize function while a lower priority thread holds the read
lock. Because the CK's synchronize is a simple wait loop this can lead
to a deadlock situation. To solve this problem use the recently
introduced CK's wait callback function.
When detecting a CK blocking condition figure out the lowest priority
among the blockers and update the calling thread's priority and
yield. If another CPU core is holding the read lock, pin the thread to
the blocked CPU core and update the priority. The calling threads
priority and CPU bindings are restored before return.
If a thread holding a CK read lock is detected to be sleeping, pause()
will be used instead of yield().
MFC after: 1 week
Sponsored by: Mellanox Technologies
CPUs when allocating a LinuxKPI workqueue. This also ensures that the
created taskqueue always have a non-zero number of worker threads.
MFC after: 1 week
Sponsored by: Mellanox Technologies
in place. To do per-cpu stats, convert all fields that previously were
maintained in the vmmeters that sit in pcpus to counter(9).
- Since some vmmeter stats may be touched at very early stages of boot,
before we have set up UMA and we can do counter_u64_alloc(), provide an
early counter mechanism:
o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter.
o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter,
so that at early stages of boot, before counters are allocated we already
point to a counter that can be safely written to.
o For sparc64 that required a whole dummy pcpu[MAXCPU] array.
Further related changes:
- Don't include vmmeter.h into pcpu.h.
- vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit,
to match kernel representation.
- struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion.
This is based on benno@'s 4-year old patch:
https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html
Reviewed by: kib, gallatin, marius, lidl
Differential Revision: https://reviews.freebsd.org/D10156
According to the C standard, it is invalid to copy beyond the end of an
object, even if that object is obviously a member of a larger object (a
struct, in this case).
Appease the standard and Coverity by refactoring the copy in a
straightforward way. No functional change.
Reported by: Coverity (CWE-120)
CIDs: 1007819, 1007820, 1007821, 1007822, 1009668, 1009669
Security: no (false positive detection)
Sponsored by: Dell EMC Isilon
This matches the getcwd() definition.
This is technically an ABI change, but that would only effect 64-bit
big-endian platforms that pass arguments on the stack. We have none of
those.
Reviewed by: jhb
Obtained from: CheriABI
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9428
- Move all bitmap related functions from bitops.h to bitmap.h, similar
to what Linux does.
- Apply some minor code cleanup and simplifications to optimize the
generated code when using static inline functions.
- Implement the following list of bitmap functions which are needed by
drm-next and ibcore:
- bitmap_find_next_zero_area_off()
- bitmap_find_next_zero_area()
- bitmap_or()
- bitmap_and()
- bitmap_xor()
- Add missing include directives to the qlnxe driver
(davidcs@ has been notified)
MFC after: 1 week
Sponsored by: Mellanox Technologies
In FreeBSD thread IDs and procedure IDs have distinct number
spaces. When asking for the group leader task ID in the LinuxKPI,
return the procedure ID and let this resolve to the first task in the
procedure having a valid LinuxKPI task structure pointer.
MFC after: 1 week
Sponsored by: Mellanox Technologies
like open, close and fault using the character device pager.
Some notes about the implementation:
1) Linux drivers set the vm_ops and vm_private_data fields during a
mmap() call to indicate that the driver wants to use the LinuxKPI VM
operations. Else these operations are not used.
2) The vm_private_data pointer is associated with a VM area structure
and inserted into an internal LinuxKPI list. If the vm_private_data
pointer already exists, the existing VM area structure is used instead
of the allocated one which gets freed.
3) The LinuxKPI's vm_private_data pointer is used as the callback
handle for the FreeBSD VM object. The VM subsystem in FreeBSD has a
similar list to identify equal handles and will only call the
character device pager's close function once.
4) All LinuxKPI VM operations are serialized through the mmap_sem
sempaphore, which is per procedure, which prevents simultaneous access
to the shared VM area structure when receiving page faults.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
tasks in the belonging procedure already have a valid mm_struct and
reference that instead.
The mm_struct in the LinuxKPI should be shared among all tasks
belonging to the same procedure. This has to do with with the mmap_sem
semaphore which should serialize all VM operations inside a given
procedure. Linux based drivers depend on this behaviour.
MFC after: 1 week
Sponsored by: Mellanox Technologies
Make sure the character device poll callback function does not return
an error code, but a POLLXXX value, in case of failure.
MFC after: 1 week
Sponsored by: Mellanox Technologies
so overflow can still occur. Fix that. Also remove the extra check for
tv_sec size as under COMPAT_LINUX32 it is always true.
Pointed out by: bde@
MFC after: 1 week
