Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.
Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/
Sponsored by: Netflix
For the uncommon items: Go through the tree and remove sccs tags that
didn't fit any nice pattern. If in the neighborhood, other SCM tags were
removed when they were detritis of long-ago CVS somehow in the early
mists of the project. Some adjacent copyrights stringswere removed (they
duplicated the copyright notices in the file). This also removed
non-standard formations of omission of SCCS tags (usually by adding an
extra #if 0 somewhere.
After this commit, a number of strings tagged with the 'what' @(#)
prefix remain, but they are primarily copyright notices.
Sponsored by: Netflix
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.
Sponsored by: Netflix
This is built into a test so needs the BTI elf note for the rest of the
test to be built with BTI support enabled.
As the assembly uses the ENTRY macro it already supports BTI, so mark
it as such.
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D42595
crc32_tab[] is only exposed as a global in <sys/gsb_crc32.h> for the
kernel, not for userland.
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D40614
These are poorly optimized (linear search), and we now prefer the
compiler-provided routines on all platforms. These files can be removed.
Reviewed by: emaste, dougm
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40699
The sign of the remainder matches the sign of the numerator in C.
Reported by: jrtc27
Reviewed by: jrtc27
Differential Revision: https://reviews.freebsd.org/D40832
GCC 12 uses these in several places when building the i386 kernel.
They are very similar to [u]divdiv3 except that they return both
the quotient and the remainder.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D40817
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
Division by zero triggers an arithmetic exception and should not be very
common. Predict this.
No functional change intended.
MFC after: 1 week
Sponsored by: NVIDIA Networking
glibc-based interface.
Unfortunately, the glibc maintainers, despite knowing the existence
of the FreeBSD qsort_r(3) interface in 2004 and refused to add the
same interface to glibc based on grounds of the lack of standardization
and portability concerns, has decided it was a good idea to introduce
their own qsort_r(3) interface in 2007 as a GNU extension with a
slightly different and incompatible interface.
With the adoption of their interface as POSIX standard, let's switch
to the same prototype, there is no need to remain incompatible.
C++ and C applications written for the historical FreeBSD interface
get source level compatibility when building in C++ mode, or when
building with a C compiler with C11 generics support, provided that
the caller passes a fifth parameter of qsort_r() that exactly matches
the historical FreeBSD comparator function pointer type and does not
redefine the historical qsort_r(3) prototype in their source code.
Symbol versioning is used to keep old binaries working.
MFC: never
Relnotes: yes
Reviewed by: cem, imp, hps, pauamma
Differential revision: https://reviews.freebsd.org/D17083
Unused since ba96f37758 ("Use __builtin for various mem* and b* (e.g. bzero)
routines.")
File name remains to reduce churn.
Sponsored by: Rubicon Communications, LLC ("Netgate")
The kernel was migrated to memcmp in ba96f37758 ("Use __builtin
for various mem* and b* (e.g. bzero) routines.") and there are no
remaining architectures using the file.
Sponsored by: Rubicon Communications, LLC ("Netgate")
If code calls arc4random(), and our RNG is not yet seeded and
random_bypass_before_seeding is true, we'll compute a key using the
SHA256 hash of some hopefully hard-to-predict data, including the
contents of an uninitialized stack buffer (which is also the output
buffer).
When KMSAN is enabled, this use of uninitialized state propagtes through
to the arc4random() output, resulting in false positives. To address
this, lie to KMSAN and explicitly mark the buffer as initialized.
Reviewed by: cem (previous version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31510
These ones were unambiguous cases where the Foundation was the only
listed copyright holder (in the associated license block).
Sponsored by: The FreeBSD Foundation
There is no need to read the same variable to check if the CPU supports
crc32c instructions.
Reviewed by: arichardson, kib, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31274
strcspn should never have had the __restrict keywords. While both of
these strings are const, it may have unindended side effects. While this
is the kernel, the POSIX definition also omits restrict.
Reviewed by: imp@
Pull Request: https://github.com/freebsd/freebsd-src/pull/497
documention.
Commit SVN r364219 / Git 8a0edc914f changed random(9) to be a shim around
prng32(9) and inadvertently caused random(9) to begin returning numbers in the
range [0,2^32-1] instead of [0,2^31-1], where the latter has been the documented
range for decades.
The increased output range has been identified as the source of numerous bugs in
code written against the historical output range e.g. ipfw "prob" rules and
stats(3) are known to be affected, and a non-exhaustive audit of the tree
identified other random(9) consumers which are also likely affected.
As random(9) is deprecated and slated for eventual removal in 14.0, consumers
should gradually be audited and migrated to prng(9).
Submitted by: Loic Prylli <lprylli@netflix.com>
Obtained from: Netflix
Reviewed by: cem, delphij, imp
MFC after: 1 day
MFC to: stable/13, releng/13.0
Differential Revision: https://reviews.freebsd.org/D29385
This reverts commit 710e45c4b8.
It breaks for some corner cases on big endian ppc64.
Given the stage of the release process it is best to revert for now.
Reported by: jhibbits
This avoids a SIGILL when running these tests on QEMU (which
defaults to a basic amd64 CPU without SSE4.2).
This commit also tests the table-based implementations in addition to
testing the hw-accelerated crc32 versions.
Reviewed By: cem, kib, markj
Differential Revision: https://reviews.freebsd.org/D28395
The previous code neglected to use primitives which can find the end
of the string without having to branch on every character.
While here augment the somewhat misleading commentary -- strlen as
implemented here leaves performance on the table, especially so for
userspace. Every arch should get a dedicated variant instead.
In the meantime this commit lessens the problem.
Tested with glibc test suite.
Naive test just calling strlen in a loop on Haswell (ops/s):
$(perl -e "print 'A' x 3"):
before: 211198039
after: 338626619
$(perl -e "print 'A' x 100"):
before: 83151997
after: 98285919
This is all code only run on ARMv4 and ARMv5. Support for these have
been dropped from FreeBSD.
Differential Revision: https://reviews.freebsd.org/D28314
There is no functional change for the existing Fortuna random(4)
implementation, which remains the default in GENERIC.
In the FenestrasX model, when the root CSPRNG is reseeded from pools due to
an (infrequent) timer, child CSPRNGs can cheaply detect this condition and
reseed. To do so, they just need to track an additional 64-bit value in the
associated state, and compare it against the root seed version (generation)
on random reads.
This revision integrates arc4random(9) into that model without substantially
changing the design or implementation of arc4random(9). The motivation is
that arc4random(9) is immediately reseeded when the backing random(4)
implementation has additional entropy. This is arguably most important
during boot, when fenestrasX is reseeding at 1, 3, 9, 27, etc., second
intervals. Today, arc4random(9) has a hardcoded 300 second reseed window.
Without this mechanism, if arc4random(9) gets weak entropy during initial
seed (and arc4random(9) is used early in boot, so this is quite possible),
it may continue to emit poorly seeded output for 5 minutes. The FenestrasX
push-reseed scheme corrects consumers, like arc4random(9), as soon as
possible.
Reviewed by: markm
Approved by: csprng (markm)
Differential Revision: https://reviews.freebsd.org/D22838
Doing it this way eliminates the assumption about homogeneous support
for the feature, since HWCAP values are only set if support is present
on all CPUs.
Reviewed by: tuexen, markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26032
Save 7k of text space by using simpler crc32 for standalone case. we
don't need all that fancy optimization in the boot loader, so use a
simplified version of the CRC function. We could save more by doing it
one bit at a time rather than 32, but this is the biggest savings at
the smallest performance hit.
With LUA and verfied exec, gptboot, gptzfsboot and friends are pushing
the ~530k limit and every little bit helps.
Reviewed By: allanjude
Differential Revision: https://reviews.freebsd.org/D24225
Add prng(9) as a replacement for random(9) in the kernel.
There are two major differences from random(9) and random(3):
- General prng(9) APIs (prng32(9), etc) do not guarantee an
implementation or particular sequence; they should not be used for
repeatable simulations.
- However, specific named API families are also exposed (for now: PCG),
and those are expected to be repeatable (when so-guaranteed by the named
algorithm).
Some minor differences from random(3) and earlier random(9):
- PRNG state for the general prng(9) APIs is per-CPU; this eliminates
contention on PRNG state in SMP workloads. Each PCPU generator in an
SMP system produces a unique sequence.
- Better statistical properties than the Park-Miller ("minstd") PRNG
(longer period, uniform distribution in all bits, passes
BigCrush/PractRand analysis).
- Faster than Park-Miller ("minstd") PRNG -- no division is required to
step PCG-family PRNGs.
For now, random(9) becomes a thin shim around prng32(). Eventually I
would like to mechanically switch consumers over to the explicit API.
Reviewed by: kib, markj (previous version both)
Discussed with: markm
Differential Revision: https://reviews.freebsd.org/D25916
This variant get a random number up to the limit passed as the argument.
This is simply a copy of the libc version.
Sponsored-by: The FreeBSD Foundation
Reviewed by: cem, hselasky (previous version)
Differential Revision: https://reviews.freebsd.org/D24962
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
srandom(9) is meaningless on SMP systems or any system with, say,
interrupts. One could never rely on random(9) to produce a reproducible
sequence of outputs on the basis of a specific srandom() seed because the
global state was shared by all kernel contexts. As such, removing it is
literally indistinguishable to random(9) consumers (as compared with
retaining it).
Mark random(9) as deprecated and slated for quick removal. This is not to
say we intend to remove all fast, non-cryptographic PRNG(s) in the kernel.
It/they just won't be random(9), as it exists today, in either name or
implementation.
Before random(9) is removed, a replacement will be provided and in-tree
consumers will be converted.
Note that despite the name, the random(9) interface does not bear any
resemblance to random(3). Instead, it is the same crummy 1988 Park-Miller
LCG used in libc rand(3).
Update the NetBSD Kernel Concurrency Sanitizer (KCSAN) runtime to work in
the FreeBSD kernel. It is a useful tool for finding data races between
threads executing on different CPUs.
This can be enabled by enabling KCSAN in the kernel config, or by using the
GENERIC-KCSAN amd64 kernel. It works on amd64 and arm64, however the later
needs a compiler change to allow -fsanitize=thread that KCSAN uses.
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22315
