Such processes will be reparented to the reaper when the current
parent is done with them (i.e., ptrace detached), so p_oppid must be
updated accordingly.
Add a regression test to exercise this code path. Previously it
would not be possible to reap an orphan with a stale oppid.
Reviewed by: kib, mjg
Tested by: pho
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19825
'tos' is an index into an array and never holds a negative value. Correct
its signedness to match PCTRIE_LIMIT, which it is compared to in assertions.
No functional change (kills a warning).
the file associated with the given file descriptor.
Reviewed by: kib, asomers
Reviewed by: cem, jilles, brooks (they reviewed previous version)
Discussed with: pjd, and many others
Differential Revision: https://reviews.freebsd.org/D14567
It performs BUS_RESET_CHILD() on the parental bus and the specified
device.
Reviewed by: imp (previous version), jhb (previous version)
Sponsored by: Mellanox Technologies
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D19646
The methods BUS_RESET_PREPARE(), BUS_RESET(), and BUS_RESET_POST()
should be implemented by bus which can provide reset to a device. The
methods are described in inline doxygen comments.
Code only provides BUS_RESET_PREPARE() and BUS_RESET_POST() helpers
instead of default implementation, because actual bus needs to handle
device state around reset, while helpers provide the other half of
typical prepare/post code.
Reviewed by: imp (previous version), jhb (previous version)
Sponsored by: Mellanox Technologies
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D19646
Otherwise we might miss the last iteration where EOF appears below
unaligned noff.
Reported and reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19811
In particular, elf32 FreeBSD binaries were not executed on LP64 hosts.
The interp_name_len value should account for the nul terminator. This
is needed for strncmp()s in brand checking code to work.
Reported by: andreast
Sponsored by: The FreeBSD Foundation
MFC after: 12 days (together with r345661)
In most cases kernel.bootfile is populated from the information
provided by loader(8). There are certain scenarios when loader
is not available, for instance when kernel is loaded by u-boot
or some other BootROM directly. In this case the default value
"/kernel" points to invalid location and breaks some functinality,
like using installkernel on self-hosted system or dtrace's CTF
lookup. This can be fixed by setting the value manually but the
default that reflects correct location is better than default that
points to invalid one.
Current default was set around FreeBSD 1, when "/kernel" was the
actual path. Transition to /boot/kernel/kernel happened circa FreeBSD 3.
PR: 221550
Reviewed by: ian, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18902
It makes the code slightly easier to follow, and might make
it easier to fix the resouce accounting to also account for
the interpreter.
The PROC_UNLOCK() is moved earlier - I don't see anything
it should protect; the lim_max() is a wrapper around lim_rlimit(),
and that, differently from lim_rlimit_proc(), doesn't require
the proc lock to be held.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19689
A sysid of 0 denotes the local system, and some handlers for remote
locking commands do not attempt to deal with local locks. Note that
F_SETLK_REMOTE is only available to privileged users as it is intended
to be used as a testing interface.
Reviewed by: kib
Reported by: syzbot+9c457a6ae014a3281eb8@syzkaller.appspotmail.com
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19702
There are only 19 bytes available for the name of an interrupt plus the
name(s) of handlers/drivers using it. There is a mechanism from the days of
shared interrupts that replaces some of the handler names with '+' when they
don't all fit into 19 bytes.
In modern times there is typically only one device on an interrupt, but long
device names are the norm, especially with embedded systems. Also, in systems
with multiple interrupt controllers, the names of the interrupts themselves
can be long. For example, 'gic0,s54: imx6_anatop0' doesn't fit, and
replacing the device driver name with a '+' provides no useful info at all.
When there is only one handler but its name was too long to fit, this
change truncates enough leading chars of the handler name (replacing them
with a '-' char to indicate that some chars are missing) to use all 19
bytes, preserving the unit number typically on the end of the name. Using
the prior example, this results in: 'gic0,s54:-6_anatop0' which provides
plenty of info to figure out which device is involved.
PR: 211946
Reviewed by: gonzo@ (prior version without the '-' char)
Differential Revision: https://reviews.freebsd.org/D19675
r343532 noted the difference between "hw.realmem" and "hw.physmem", which I
was previously unaware of. I discovered that neither sysctl had a
description visible via `sysctl -d', so I found where they were defined and
added suitable descriptions. While in the file, I went ahead and added
descriptions for all the others which lacked them. I also updated sysctl.3
accordingly
Reviewed by: kib, bcr
MFC after: 1 weeks
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D19007
The line was misedited to change tt to st instead of
changing ut to st.
The use of st as the denominator in mul64_by_fraction() will lead
to an integer divide fault in the intr proc (the process holding
ithreads) where st will be 0. This divide by 0 happens after
the total runtime for all ithreads exceeds 76 hours.
Submitted by: bde
Add the infrastructure to allow MD procctl(2) commands, and use it to
introduce amd64 PTI control and reporting. PTI mode cannot be
modified for existing pmap, the knob controls PTI of the new vmspace
created on exec.
Requested by: jhb
Reviewed by: jhb, markj (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19514
PTI mode for the process pmap on exec is activated iff P_MD_PTI is set.
On exec, the existing vmspace can be reused only if pti mode of the
pmap matches the P_MD_PTI flag of the process. Add MD
cpu_exec_vmspace_reuse() callback for exec_new_vmspace() which can
vetoed reuse of the existing vmspace.
MFC note: md_flags change struct proc KBI.
Reviewed by: jhb, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19514
extended attributes, the kernel can panic with either "ffs_truncate3"
or with "softdep_deallocate_dependencies: dangling deps".
The problem arises because the flushbuflist() function which is
called to clear out buffers is passed either the V_NORMAL flag to
indicate that it should flush buffer associated with the contents
of the file or the V_ALT flag to indicate that it should flush the
buffers associated with the extended attribute data. The buffers
containing the extended attribute data are identified by having
their BX_ALTDATA flag set in the buffer's b_xflags field. The
BX_ALTDATA flag is set on the buffer when the extended attribute
block is first allocated or when its contents are read in from the
disk.
On a busy system, a buffer may be reused for another purpose, but
the contents of the block that it contained continues to be held
in the main page cache. Each physical page is identified as holding
the contents of a logical block within a specified file (identified
by a vnode). When a request is made to read a file, the kernel first
looks for the block in the existing buffers. If it is not found
there, it checks the page cache to see if it is still there. If
it is found in the page cache, then it is remapped into a new
buffer thus avoiding the need to read it in from the disk.
The bug is that when a buffer request made for an extended attribute
is fulfilled by reconstituting a buffer from the page cache rather
than reading it in from disk, the BX_ALTDATA flag was not being
set. Thus the flushbuflist() function would never clear it out and
the "ffs_truncate3" panic would occur because the vnode being cleared
still had buffers on its clean-buffer list. If the extended attribute
was being updated, it is first read, then updated, and finally
written. If the read is fulfilled by reconstituting the buffer
from the page cache the BX_ALTDATA flag was not set and thus the
dirty buffer would never be flushed by flushbuflist(). Eventually
the buffer would be recycled. Since it was never written it would
have an unfinished dependency which would trigger the
"softdep_deallocate_dependencies: dangling deps" panic.
The fix is to ensure that the BX_ALTDATA flag is set when a buffer
has been reconstituted from the page cache.
PR: 230962
Reported by: 2t8mr7kx9f@protonmail.com
Reviewed by: kib
Tested by: Peter Holm
MFC after: 1 week
Sponsored by: Netflix
When merging from Netflix's tree, resetting the carsize was dropped
accidentally. This fix fixes that revision by properly resetting how
many are in the car.
Noticed by: mav@
Research Unix, 7th Edition introduced TIMEZONE and DSTFLAG
compile-time constants in sys/param.h to communicate these values for
the machine. 4.2BSD moved from the compile-time to run-time and
introduced these variables and used for localtime() to return the
right offset from UTC (sometimes referred to as GMT, for this purpose
is the same). 4.4BSD migrated to using the tzdata code/database and
these variables were basically unused.
FreeBSD removed the real need for these with adjkerntz in
1995. However, some RTC clocks continued to use these variables,
though they were largely unused otherwise. Later, phk centeralized
most of the uses in utc_offset, but left it using both tz_minuteswest
and adjkerntz.
POSIX (IEEE Std 1003.1-2017) states in the gettimeofday specification
"If tzp is not a null pointer, the behavior is unspecified" so there's
no standards reason to retain it anymore. In fact, gettimeofday has
been marked as obsolecent, meaning it could be removed from a future
release of the standard. It is the only interface defined in POSIX
that references these two values. All other references come from the
tzdata database via tzset().
These were used to more faithfully implement early unix ABIs which
have been removed from FreeBSD. NetBSD has completely eliminated
these variables years ago. Linux has migrated to tzdata as well,
though these variables technically still exist for compatibility
with unspecified older programs.
So, there's no real reason to have them these days. They are a
historical vestige that's no longer used in any meaningful way.
Reviewed By: jhb@, brooks@
Differential Revision: https://reviews.freebsd.org/D19550
vnode pointer (b_vp). The value of b_vp can be used by "show vnode"
to print the vnode and "show vnodebufs" to print all the clean and
dirty buffers associated with the vnode (which should include this
buffer).
Sponsored by: Netflix
Note that only entries wired by userspace are shown as such. In
particular, entries transiently wired by sysctl_wire_old_buffer() are
not flagged as wired in procstat -v output.
Reviewed by: kib (previous version)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D19461
to call soabort() on a newborn socket created by sonewconn() in case
if further setup of PCB failed. Code in sofree() handles such socket
correctly.
Submitted by: jtl, rrs
MFC after: 3 weeks
In all of the architectures we have today, we always use PAGE_SIZE.
While in theory one could define different things, none of the
current architectures do, even the ones that have transitioned from
32-bit to 64-bit like i386 and arm. Some ancient mips binaries on
other systems used 8k instead of 4k, but we don't support running
those and likely never will due to their age and obscurity.
Reviewed by: imp (who also contributed the commit message)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19280
When the device is in attaching state, detach should return
EBUSY instead of success. In other case, there could be race
between attach and detach during the driver unloading.
If driver goes sleep and releases GIANT lock during attaching,
unloading module could start. In such case when attach continues
after module unload, page fault "supervisor read instruction,
page not present" occurred.
This patch works around the real issue, which is a locking
deficiency of the busses.
Submitted by: Rafal Kozik <rk@semihalf.com>
Reviewed by: imp
Obtained from: Semihalf
MFC after: 2 weeks
Sponsored by: Amazon, Inc.
Differential Revision: https://reviews.freebsd.org/D19375
They have no effect, as with filesystem file descriptors.
This improves compatibility with some existing userspace code.
Submitted by: Greg V <greg@unrelenting.technology>
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D19330
Linux generates the content of procfs files using a mechanism prefixed with
seq_*. This in particular came up with recent gcov import.
Sponsored by: The FreeBSD Foundation
On platforms without a direct map (i.e., platforms without
UMA_MD_SMALL_ALLOC defined), the boundary tag allocator reserves a
number of tags for use when allocating a new slab of boundary tags,
as such platforms require free boundary tags in order to allocate
boundary tags. r327899 increased the number of boundary tags required
for a KVA allocation in the worst case, and the aforementioned
reservation was not updated accordingly. In some cases, this could
lead to a system hang. Fix the problem by increasing this reservation.
Also reduce KVA_QUANTUM on systems lacking superpage support.
The previous import quantum (4MB with a 4KB page size) was quite large
for systems with limited KVA, and fragmentation in kernel_arena could
cause kernel memory allocation failures even with a substantial amount
of free KVA.
Reported and tested by: jhibbits
Reviewed by: alc, kib
No objections: jeff
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19337
If an interrupt fires while writing the cmp entry we may have a partial
entry. Work around this by using atomic_cmpset to set the new index. If it
fails we need to set the previous index value and try again as the entry
may be in an inconsistent state.
This fixes messages similar to the following from syzkaller:
bad comp 224 type 2163727253
Reviewed by: tuexen
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19287
Some consumers may be loosely coupled with the lkpi.
This allows them to call linux_alloc_current without
having a static dependency.
Reviewed by: hps@
MFC after: 1 week
Sponsored by: iX Systems
Differential Revision: https://reviews.freebsd.org/D19257
Without this the physical memory will not be returned to the kernel.
While here call vm_object_reference on the object when mmapping the buffer.
This removed the need for buggy tracking of if it has been mapped or not.
This fixes issues where kcov could use all the system memory.
Reported by: tuexen
Reviewed by: kib
Sponsored by: DARPA, AFTL
Differential Revision: https://reviews.freebsd.org/D19252
This removes the need to allocate a buffer to hold the vm_page_t objects
at the cost of extra IPIs on some architectures.
Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19252
The data structure implements non-intersecting intervals over the [0,
UINT64_MAX] range, and supports fast insert, predicated clearing of
subrange, and lookup of an interval containing the specified address.
Internally it is a pctrie over the interval start addresses.
Implementation provides additional guarantees over the structure state
in case of memory allocation failures.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D18893
EVFILT_WRITE knotes for pipes live on the knlist for the other end of the
pipe. Since they do not hold a reference on the corresponding file
structure, they may be removed from the knlist by pipeclose() while still
remaining active. In this case, there is no knlist lock acquired before
filt_pipewrite() is called, so the assertion fails.
Fix the problem by first checking whether that end of the pipe has been
closed. These checks are memory safe since the knote holds a reference
on one end of the pipe, and the pipe structure is not freed until both
ends are closed. The checks are not racy since PIPE_EOF is never cleared
after being set, and pipe_present is never set back to PIPE_ACTIVE after
pipeclose() has been called.
PR: 235640
Reported and tested by: pho
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19224
The previous fix was unnecessarily very slow up to 105 hours where the
simple formula used previously worked, and unnecessarily slow by a factor
of about 5/3 up to 388 days, and didn't work above 388 days. 388 days is
not a long time, since it is a reasonable uptime, and for processes the
times being calculated are aggregated over all threads, so with N CPUs
running the same thread a runtime of 388 days is reachable after only
388 / N physical days.
The PRs document overflow at 388 days, but don't try to fix it.
Use the simple formula up to 76 hours. Then use a complicated general
method that reduces to the simple formula up to a bit less than 105
hours, then reduces to the previous method without its extra work up
to almost 388 days, then does more complicated reductions, usually
many bits at a time so that this is not slow. This works up to half
of maximum representable time (292271 years), with accumulated rounding
errors of at most 32 usec.
amd64 can do all this with no avoidable rounding errors in an inline
asm with 2 instructions, but this is too special to use. __uint128_t
can do the same with 100's of instructions on 64-bit arches. Long
doubles with at least 64 bits of precision are the easiest method to
use on i386 userland, but are hard to use in the kernel.
PR: 76972 and duplicates
Reviewed by: kib
So far, intr_{g,s}etaffinity(9) take a single int for identifying
a device interrupt. This approach doesn't work on all architectures
supported, as a single int isn't sufficient to globally specify a
device interrupt. In particular, with multiple interrupt controllers
in one system as found on e. g. arm and arm64 machines, an interrupt
number as returned by rman_get_start(9) may be only unique relative
to the bus and, thus, interrupt controller, a certain device hangs
off from.
In turn, this makes taskqgroup_attach{,_cpu}(9) and - internal to
the gtaskqueue implementation - taskqgroup_attach_deferred{,_cpu}()
not work across architectures. Yet in turn, iflib(4) as gtaskqueue
consumer so far doesn't fit architectures where interrupt numbers
aren't globally unique.
However, at least for intr_setaffinity(..., CPU_WHICH_IRQ, ...) as
employed by the gtaskqueue implementation to bind an interrupt to a
particular CPU, using bus_bind_intr(9) instead is equivalent from
a functional point of view, with bus_bind_intr(9) taking the device
and interrupt resource arguments required for uniquely specifying a
device interrupt.
Thus, change the gtaskqueue implementation to employ bus_bind_intr(9)
instead and intr_{g,s}etaffinity(9) to take the device and interrupt
resource arguments required respectively. This change also moves
struct grouptask from <sys/_task.h> to <sys/gtaskqueue.h> and wraps
struct gtask along with the gtask_fn_t typedef into #ifdef _KERNEL
as userland likes to include <sys/_task.h> or indirectly drags it
in - for better or worse also with _KERNEL defined -, which with
device_t and struct resource dependencies otherwise is no longer
as easily possible now.
The userland inclusion problem probably can be improved a bit by
introducing a _WANT_TASK (as well as a _WANT_MOUNT) akin to the
existing _WANT_PRISON etc., which is orthogonal to this change,
though, and likely needs an exp-run.
While at it:
- Change the gt_cpu member in the grouptask structure to be of type
int as used elswhere for specifying CPUs (an int16_t may be too
narrow sooner or later),
- move the gtaskqueue_enqueue_fn typedef from <sys/gtaskqueue.h> to
the gtaskqueue implementation as it's only used and needed there,
- change the GTASK_INIT macro to use "gtask" rather than "task" as
argument given that it actually operates on a struct gtask rather
than a struct task, and
- let subr_gtaskqueue.c consistently use __func__ to print functions
names.
Reported by: mmel
Reviewed by: mmel
Differential Revision: https://reviews.freebsd.org/D19139
PR: 76972 and duplicates
Reported by: Dr. Christopher Landauer <cal AT aero.org>,
Steinar Haug <sthaug AT nethelp.no>
Submitted by: Andrey Zonov <andrey AT zonov.org> (earlier version)
MFC after: 2 weeks
With this change, randomization can be enabled for all non-fixed
mappings. It means that the base address for the mapping is selected
with a guaranteed amount of entropy (bits). If the mapping was
requested to be superpage aligned, the randomization honours the
superpage attributes.
Although the value of ASLR is diminshing over time as exploit authors
work out simple ASLR bypass techniques, it elimintates the trivial
exploitation of certain vulnerabilities, at least in theory. This
implementation is relatively small and happens at the correct
architectural level. Also, it is not expected to introduce
regressions in existing cases when turned off (default for now), or
cause any significant maintaince burden.
The randomization is done on a best-effort basis - that is, the
allocator falls back to a first fit strategy if fragmentation prevents
entropy injection. It is trivial to implement a strong mode where
failure to guarantee the requested amount of entropy results in
mapping request failure, but I do not consider that to be usable.
I have not fine-tuned the amount of entropy injected right now. It is
only a quantitive change that will not change the implementation. The
current amount is controlled by aslr_pages_rnd.
To not spoil coalescing optimizations, to reduce the page table
fragmentation inherent to ASLR, and to keep the transient superpage
promotion for the malloced memory, locality clustering is implemented
for anonymous private mappings, which are automatically grouped until
fragmentation kicks in. The initial location for the anon group range
is, of course, randomized. This is controlled by vm.cluster_anon,
enabled by default.
The default mode keeps the sbrk area unpopulated by other mappings,
but this can be turned off, which gives much more breathing bits on
architectures with small address space, such as i386. This is tied
with the question of following an application's hint about the mmap(2)
base address. Testing shows that ignoring the hint does not affect the
function of common applications, but I would expect more demanding
code could break. By default sbrk is preserved and mmap hints are
satisfied, which can be changed by using the
kern.elf{32,64}.aslr.honor_sbrk sysctl.
ASLR is enabled on per-ABI basis, and currently it is only allowed on
FreeBSD native i386 and amd64 (including compat 32bit) ABIs. Support
for additional architectures will be added after further testing.
Both per-process and per-image controls are implemented:
- procctl(2) adds PROC_ASLR_CTL/PROC_ASLR_STATUS;
- NT_FREEBSD_FCTL_ASLR_DISABLE feature control note bit makes it possible
to force ASLR off for the given binary. (A tool to edit the feature
control note is in development.)
Global controls are:
- kern.elf{32,64}.aslr.enable - for non-fixed mappings done by mmap(2);
- kern.elf{32,64}.aslr.pie_enable - for PIE image activation mappings;
- kern.elf{32,64}.aslr.honor_sbrk - allow to use sbrk area for mmap(2);
- vm.cluster_anon - enables anon mapping clustering.
PR: 208580 (exp runs)
Exp-runs done by: antoine
Reviewed by: markj (previous version)
Discussed with: emaste
Tested by: pho
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D5603
