PIPE_MINDIRECT determines at what (blocking) write size one-copy
optimizations are applied in pipe(2) I/O. That threshold hasn't
been tuned since the 1990s when this code was originally
committed, and allowing run-time reconfiguration will make it
easier to assess whether contemporary microarchitectures would
prefer a different threshold.
(On our local RPi4 baords, the 8k default would ideally be at least
32k, but it's not clear how generalizable that observation is.)
MFC after: 3 weeks
Reviewers: jrtc27, arichardson
Differential Revision: https://reviews.freebsd.org/D29819
This reverts a portion of 274579831b ("capsicum: Limit socket
operations in capability mode") as at least rtsol and dhcpcd rely on
being able to configure network interfaces while in capability mode.
Reported by: bapt, Greg V
Sponsored by: The FreeBSD Foundation
"i" is not used in this loop at all. There's no need to initialize and
increment it.
Reviewed by: markj@
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D29898
If VOP_ADD_WRITECOUNT() or adv locking failed, so VOP_CLOSE() needs to
be called, we cannot use fp fo_close() when there is no fp. This occurs
when e.g. kernel code directly calls vn_open() instead of the open(2)
syscall.
In this case, VOP_CLOSE() can be called directly, after possible lock
upgrade.
Reported by: nvass@gmx.com
PR: 255119
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29830
For anonymous objects, provide a handle kvo_me naming the object,
and report the handle of the backing object. This allows userspace
to deconstruct the shadow chain. Right now the handle is the address
of the object in KVA, but this is not guaranteed.
For the same anonymous objects, report the swap space used for actually
swapped out pages, in kvo_swapped field. I do not believe that it is
useful to report full 64bit counter there, so only uint32_t value is
returned, clamped to the max.
For kinfo_vmentry, report anonymous object handle backing the entry,
so that the shadow chain for the specific mapping can be deconstructed.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29771
In particular, this avoids malloc(9) calls when from early tunable handling,
with no working malloc yet.
Reported and tested by: mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Fix a few 'if(' to be 'if (' in a few places, per style(9) and
overwhelming usage in the rest of the kernel / tree.
MFC After: 3 days
Sponsored by: Netflix
We prefer 'while (0)' to 'while(0)' according to grep and stlye(9)'s
space after keyword rule. Remove a few stragglers of the latter.
Many of these usages were inconsistent within the file.
MFC After: 3 days
Sponsored by: Netflix
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
When O_NOFOLLOW is specified, namei() returns the symlink itself. In
this case, open(O_PATH) should be allowed, to denote the location of symlink
itself.
Prevent O_EXEC in this case, execve(2) code is not ready to try to execute
symlinks.
Reported by: wulf
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29323
by only keeping hold count on the vnode, instead of the use count.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29323
It is currently allowed to fchownat(2), fchmodat(2), fchflagsat(2),
utimensat(2), fstatat(2), and linkat(2).
For linkat(2), PRIV_VFS_FHOPEN privilege is required to exercise the flag.
It allows to link any open file.
Requested by: trasz
Tested by: pho, trasz
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D29111
Add global definitions for first-touch and interleave policies. The
former may be useful for UMA, which implements a similar policy without
using domainset iterators.
No functional change intended.
Reviewed by: mav
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29104
Found by: syzkaller
Reported and reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29746
It is fine to drop the process lock there, process cannot exit until its
timers are cleared.
Found by: syzkaller
Reported and reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29746
and length should be not less than SBUF_MINSIZE
Reported and tested by: pho
Noted and reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29752
- Reuse some REDZONE bits to keep track of the requested and allocated
sizes, and use that to provide red zones.
- As in UMA, disable memory trashing to avoid unnecessary CPU overhead.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29461
We cache mapped execve argument buffers to avoid the overhead of TLB
shootdowns. Mark them invalid when they are freed to the cache.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29460
vnodes are a bit special in that they may exist on per-CPU lists even
while free. Add a KASAN-only destructor that poisons regions of each
vnode that are not expected to be accessed after a free.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29459
The idea behind KASAN is to use a region of memory to track the validity
of buffers in the kernel map. This region is the shadow map. The
compiler inserts calls to the KASAN runtime for every emitted load
and store, and the runtime uses the shadow map to decide whether the
access is valid. Various kernel allocators call kasan_mark() to update
the shadow map.
Since the shadow map tracks only accesses to the kernel map, accesses to
other kernel maps are not validated by KASAN. UMA_MD_SMALL_ALLOC is
disabled when KASAN is configured to reduce usage of the direct map.
Currently we have no mechanism to completely eliminate uses of the
direct map, so KASAN's coverage is not comprehensive.
The shadow map uses one byte per eight bytes in the kernel map. In
pmap_bootstrap() we create an initial set of page tables for the kernel
and preloaded data.
When pmap_growkernel() is called, we call kasan_shadow_map() to extend
the shadow map. kasan_shadow_map() uses pmap_kasan_enter() to allocate
memory for the shadow region and map it.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29417
KASAN enables the use of LLVM's AddressSanitizer in the kernel. This
feature makes use of compiler instrumentation to validate memory
accesses in the kernel and detect several types of bugs, including
use-after-frees and out-of-bounds accesses. It is particularly
effective when combined with test suites or syzkaller. KASAN has high
CPU and memory usage overhead and so is not suited for production
environments.
The runtime and pmap maintain a shadow of the kernel map to store
information about the validity of memory mapped at a given kernel
address.
The runtime implements a number of functions defined by the compiler
ABI. These are prefixed by __asan. The compiler emits calls to
__asan_load*() and __asan_store*() around memory accesses, and the
runtime consults the shadow map to determine whether a given access is
valid.
kasan_mark() is called by various kernel allocators to update state in
the shadow map. Updates to those allocators will come in subsequent
commits.
The runtime also defines various interceptors. Some low-level routines
are implemented in assembly and are thus not amenable to compiler
instrumentation. To handle this, the runtime implements these routines
on behalf of the rest of the kernel. The sanitizer implementation
validates memory accesses manually before handing off to the real
implementation.
The sanitizer in a KASAN-configured kernel can be disabled by setting
the loader tunable debug.kasan.disable=1.
Obtained from: NetBSD
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29416
Allows for duplicate locks to be acquired without witness complaining.
Similar flags exists already for rwlock(9) and sx(9).
Reviewed by: markj
MFC after: 3 days
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
NetApp PR: 52
Differential Revision: https://reviews.freebsd.org/D29683n
types.h defines device_t as a typedef of struct device *. struct device
is defined in subr_bus.c and almost all of the kernel uses device_t.
The LinuxKPI also defines a struct device, so type confusion can occur.
This causes bugs and ambiguity for debugging tools. Rename the FreeBSD
struct device to struct _device.
Reviewed by: gbe (man pages)
Reviewed by: rpokala, imp, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29676
This is intended to be used with memory mapped IO, e.g. from
bus_space_map with no flags, or pmap_mapdev.
Use this new memory type in the map request configured by
resource_init_map_request, and in pciconf.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D29692
This way, even if the process specified very tight reschedule
intervals, it should be stoppable/killable.
Reported and reviewed by: markj
Tested by: markj, pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D29106
Capsicum did not prevent certain privileged networking operations,
specifically creation of raw sockets and network configuration ioctls.
However, these facilities can be used to circumvent some of the
restrictions that capability mode is supposed to enforce.
Add capability mode checks to disallow network configuration ioctls and
creation of sockets other than PF_LOCAL and SOCK_DGRAM/STREAM/SEQPACKET
internet sockets.
Reviewed by: oshogbo
Discussed with: emaste
Reported by: manu
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D29423
After e7a5b3bd05, the la->delay value was adjusted after
being set by the starvation_limit code block, which is wrong.
Reported By: avg
Reviewed By: avg
Fixes: e7a5b3bd05
Sponsored By: NetApp, Inc.
Sponsored By: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D29513
While sbuf_drain was an internal function, two
KASSERTS checked the sanity of it being called.
However, an external caller may be ignorant if
there is any data to drain, or if an error has
already accumulated. Be nice and return immediately
with the accumulated error.
MFC after: 2 weeks
Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D29544
Allow the calculation of the mu adjustment factor to underflow instead of
rejecting the VOI sample from the digest and logging an error. This trades off
some (currently unquantified) additional centroid error in exchange for better
fidelity of the distribution's density, which is the right trade off at the
moment until follow up work to better handle and track accumulated error can be
undertaken.
Obtained from: Netflix
MFC after: immediately
