Commit Graph

326 Commits

Author SHA1 Message Date
Conrad Meyer
10b1a17594 arc4random(9): Integrate with RANDOM_FENESTRASX push-reseed
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
2020-10-10 21:48:06 +00:00
Mitchell Horne
66245bc536 arm64: check for CRC32 support via HWCAP
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
2020-09-08 15:39:19 +00:00
Mateusz Guzik
1060326fb6 libkern: clean up empty lines in .c and .h files 2020-09-01 21:25:23 +00:00
Warner Losh
cffca129a9 Smaller crc for the boot loader.
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
2020-09-01 04:37:55 +00:00
Conrad Meyer
8a0edc914f Add prng(9) API
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
2020-08-13 20:48:14 +00:00
Emmanuel Vadot
353d02e927 libkern: Add arc4random_uniform
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
2020-05-23 17:51:06 +00:00
Pawel Biernacki
7029da5c36 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)
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
2020-02-26 14:26:36 +00:00
Conrad Meyer
f3bae413e9 random(9): Deprecate random(9), remove meaningless srandom(9)
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).
2019-12-26 19:41:09 +00:00
Andrew Turner
849aef496d Port the NetBSD KCSAN runtime to FreeBSD.
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
2019-11-21 11:22:08 +00:00
Andrew Turner
44e446a1b3 Rename the macros to extract a single arm64 ID field.
Because of the previous naming scheme the old ID_AA64PFR0_EL1 macro
collided with a potential macro for the register of the same name. To fix
this collision rename these macros.

Sponsored by:	DARPA, AFRL
2019-10-30 10:06:57 +00:00
Xin LI
21aae72489 Remove zlib 1.0.4 from kernel.
PR:		229763
Reviewed by:	emaste, Yoshihiro Ota <ota j email ne jp>
Differential Revision:	https://reviews.freebsd.org/D21375
2019-08-25 17:13:00 +00:00
Conrad Meyer
2b0ebb77e4 libkern: Implement strchrnul(3) 2019-08-19 22:53:05 +00:00
Xin LI
0ed1d6fb00 Allow Kernel to link in both legacy libkern/zlib and new sys/contrib/zlib,
with an eventual goal to convert all legacl zlib callers to the new zlib
version:

 * Move generic zlib shims that are not specific to zlib 1.0.4 to
   sys/dev/zlib.
 * Connect new zlib (1.2.11) to the zlib kernel module, currently built
   with Z_SOLO.
 * Prefix the legacy zlib (1.0.4) with 'zlib104_' namespace.
 * Convert sys/opencrypto/cryptodeflate.c to use new zlib.
 * Remove bundled zlib 1.2.3 from ZFS and adapt it to new zlib and make
   it depend on the zlib module.
 * Fix Z_SOLO build of new zlib.

PR:		229763
Submitted by:	Yoshihiro Ota <ota j email ne jp>
Reviewed by:	markm (sys/dev/zlib/zlib_kmod.c)
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D19706
2019-08-01 06:35:33 +00:00
Warner Losh
710becdd96 Remove pre-FreeBSD 7.0 compatibility. 2019-07-19 18:38:47 +00:00
Xin LI
f89d207279 Separate kernel crc32() implementation to its own header (gsb_crc32.h) and
rename the source to gsb_crc32.c.

This is a prerequisite of unifying kernel zlib instances.

PR:		229763
Submitted by:	Yoshihiro Ota <ota at j.email.ne.jp>
Differential Revision:	https://reviews.freebsd.org/D20193
2019-06-17 19:49:08 +00:00
Mateusz Guzik
5e57adc874 random(4): depessimize arc4random
- __predict_false reseeding on entry as it is almost never true.
- don't blindly atomic_cmpset as on x86 it ends up dirtying the cacheline.
it almost ever succeeds per above
- fetch the timestamp prior to getting the cpu number

Reviewed by:	cem
Approved by:	secteam (delphij)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D20242
2019-05-12 06:32:46 +00:00
Conrad Meyer
6b97c2e306 Revert r346410 and r346411
libkern in .PATH has too many filename conflicts with libc and my -DNO_CLEAN
tinderbox didn't catch that ahead of time.  Mea culpa.
2019-04-19 22:08:17 +00:00
Conrad Meyer
7deb4b1964 libkern: Bring in arc4random_uniform(9) from libc
It is a useful arc4random wrapper in the kernel for much the same reasons as
in userspace.  Move the source to libkern (because kernel build is
restricted to sys/, but userspace can include any file it likes) and build
kernel and libc versions from the same source file.

Copy the documentation from arc4random_uniform(3) to the section 9 page.

While here, add missing arc4random_buf(9) symlink.

Sponsored by:	Dell EMC Isilon
2019-04-19 20:05:47 +00:00
Conrad Meyer
3782136ff1 random(4): Restore availability tradeoff prior to r346250
As discussed in that commit message, it is a dangerous default.  But the
safe default causes enough pain on a variety of platforms that for now,
restore the prior default.

Some of this is self-induced pain we should/could do better about; for
example, programmatic CI systems and VM managers should introduce entropy
from the host for individual VM instances.  This is considered a future work
item.

On modern x86 and Power9 systems, this may be wholly unnecessary after
D19928 lands (even in the non-ideal case where early /boot/entropy is
unavailable), because they have fast hardware random sources available early
in boot.  But D19928 is not yet landed and we have a host of architectures
which do not provide fast random sources.

This change adds several tunables and diagnostic sysctls, documented
thoroughly in UPDATING and sys/dev/random/random_infra.c.

PR:		230875 (reopens)
Reported by:	adrian, jhb, imp, and probably others
Reviewed by:	delphij, imp (earlier version), markm (earlier version)
Discussed with:	adrian
Approved by:	secteam(delphij)
Relnotes:	yeah
Security:	related
Differential Revision:	https://reviews.freebsd.org/D19944
2019-04-18 20:48:54 +00:00
Conrad Meyer
13774e8228 random(4): Block read_random(9) on initial seeding
read_random() is/was used, mostly without error checking, in a lot of
very sensitive places in the kernel -- including seeding the widely used
arc4random(9).

Most uses, especially arc4random(9), should block until the device is seeded
rather than proceeding with a bogus or empty seed.  I did not spy any
obvious kernel consumers where blocking would be inappropriate (in the
sense that lack of entropy would be ok -- I did not investigate locking
angle thoroughly).  In many instances, arc4random_buf(9) or that family
of APIs would be more appropriate anyway; that work was done in r345865.

A minor cleanup was made to the implementation of the READ_RANDOM function:
instead of using a variable-length array on the stack to temporarily store
all full random blocks sufficient to satisfy the requested 'len', only store
a single block on the stack.  This has some benefit in terms of reducing
stack usage, reducing memcpy overhead and reducing devrandom output leakage
via the stack.  Additionally, the stack block is now safely zeroed if it was
used.

One caveat of this change is that the kern.arandom sysctl no longer returns
zero bytes immediately if the random device is not seeded.  This means that
FreeBSD-specific userspace applications which attempted to handle an
unseeded random device may be broken by this change.  If such behavior is
needed, it can be replaced by the more portable getrandom(2) GRND_NONBLOCK
option.

On any typical FreeBSD system, entropy is persisted on read/write media and
used to seed the random device very early in boot, and blocking is never a
problem.

This change primarily impacts the behavior of /dev/random on embedded
systems with read-only media that do not configure "nodevice random".  We
toggle the default from 'charge on blindly with no entropy' to 'block
indefinitely.'  This default is safer, but may cause frustration.  Embedded
system designers using FreeBSD have several options.  The most obvious is to
plan to have a small writable NVRAM or NAND to persist entropy, like larger
systems.  Early entropy can be fed from any loader, or by writing directly
to /dev/random during boot.  Some embedded SoCs now provide a fast hardware
entropy source; this would also work for quickly seeding Fortuna.  A 3rd
option would be creating an embedded-specific, more simplistic random
module, like that designed by DJB in [1] (this design still requires a small
rewritable media for forward secrecy).  Finally, the least preferred option
might be "nodevice random", although I plan to remove this in a subsequent
revision.

To help developers emulate the behavior of these embedded systems on
ordinary workstations, the tunable kern.random.block_seeded_status was
added.  When set to 1, it blocks the random device.

I attempted to document this change in random.4 and random.9 and ran into a
bunch of out-of-date or irrelevant or inaccurate content and ended up
rototilling those documents more than I intended to.  Sorry.  I think
they're in a better state now.

PR:		230875
Reviewed by:	delphij, markm (earlier version)
Approved by:	secteam(delphij), devrandom(markm)
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D19744
2019-04-15 18:40:36 +00:00
Matt Macy
744799ead2 Add non-sleepable strdup variant strdup_flags
debugfs expects to do non-sleepable allocations

Reviewed by:	hps@
MFC after:	1 week
Sponsored by:	iX Systems
Differential Revision:	https://reviews.freebsd.org/D19259
2019-02-20 20:48:10 +00:00
Ed Maste
05bc9aa78f mcount: tidy up ANSIfication
libc/gmon's mcount was ANSIfied in r124180, with libkern following over
a decade later, in r325988, but some minor discrepancies remained.
Update libc/gmon's mexitcount to an ANSI C function definition, and use
(void) for libkern-only functions that take no arguments.

Reported by:	bde
2018-10-20 22:39:35 +00:00
Conrad Meyer
e38b830780 Sync strlcpy with userland version, again
No functional change.

Please remember to update libkern copies of libc functions when you update
libc.

Sponsored by:	Dell EMC Isilon
2018-06-21 17:35:13 +00:00
Conrad Meyer
3d825c42ca str(r)chr: Replace union abuse with __DECONST
Writing one union member and reading another is technically illegal C,
although we do it in many places in the tree.  Use the __DECONST macro
instead, which is (technically) a valid C construct.

Trivial style(9) cleanups to touched lines while here.

Sponsored by:	Dell EMC Isilon
2018-06-04 18:47:14 +00:00
Mateusz Guzik
ba96f37758 Use __builtin for various mem* and b* (e.g. bzero) routines.
Some of the routines were using artificially limited builtin already,
drop the explicit limit.

The use of builtins allows quite often allows the compiler to elide the call
or most zeroing to begin with. For instance, if the target object is 32 bytes
in size and gets zeroed + has 16 bytes initialized, the compiler can just
add code to zero out the rest.

Note not all the primites have asm variants and some of the existing ones
are not optimized. Maintaines are strongly encourage to take a look
(regardless of this change).
2018-06-02 18:03:35 +00:00
Mateusz Guzik
97e8984893 libkern: tidy up memset
1. Remove special-casing of 0 as it just results in an extra function call.
This is clearly pessimal.
2. Drop the inline stuff. For the most part it is much better served with
__builtin_memset (coming later).
3. Move the declaration to systm.h to match other funcs.

Archs are encouraged to implement the variant for their own platform so that
this implementation can be dropped.
2018-06-02 17:57:09 +00:00
Bruce Evans
dbe3061729 Fix recent breakages of kernel profiling, mostly on i386 (high resolution
kernel profiling remains broken).

memmove() was broken using ALTENTRY().  ALTENTRY() is only different from
ENTRY() in the profiling case, and its use in that case was sort of
backwards.  The backwardness magically turned memmove() into memcpy()
instead of completely breaking it.  Only the high resolution parts of
profiling itself were broken.  Use ordinary ENTRY() for memmove().
Turn bcopy() into a tail call to memmove() to reduce complications.
This gives slightly different pessimizations and profiling lossage.
The pessimizations are minimized by not using a frame pointer() for
bcopy().

Calls to profiling functions from exception trampolines were not
relocated.  This caused crashes on the first exception.  Fix this using
function pointers.

Addresses of exception handlers in trampolines were not relocated.  This
caused unknown offsets in the profiling data.  Relocate by abusing
setidt_disp as for pmc although this is slower than necessary and
requires namespace pollution.  pmc seems to be missing some relocations.
Stack traces and lots of other things in debuggers need similar relocations.

Most user addresses were misclassified as unknown kernel addresses and
then ignored.  Treat all unknown addresses as user. Now only user
addresses in the kernel text range are significantly misclassified (as
known kernel addresses).

The ibrs functions didn't preserve enough registers.  This is the only
recent breakage on amd64.  Although these functions are written in
asm, in the profiling case they call profiling functions which are
mostly for the C ABI, so they only have to save call-used registers.
They also have to save arg and return registers in some cases and
actually save them in all cases to reduce complications.  They end up
saving all registers except %ecx on i386 and %r10 and %r11 on amd64.
Saving these is only needed for 1 caller on each of amd64 and i386.
Save them there.  This is slightly simpler.

Remove saving %ecx in handle_ibrs_exit on i386.  Both handle_ibrs_entry
and handle_ibrs_exit use %ecx, but only the latter needed to or did
save it.  But saving it there doesn't work for the profiling case.

amd64 has more automatic saving of the most common scratch registers
%rax, %rcx and %rdx (its complications for %r10 are from unusual use
of %r10 by SYSCALL).  Thus profiling of handle_ibrs_exit_rs() was not
broken, and I didn't simplify the saving by moving the saving of these
registers from it to the caller.
2018-06-02 04:25:09 +00:00
Warner Losh
c6f7141fc0 Protect bzero call against macro expansion
Shortly, we'll be moving to defining bzero and memset in terms of
__builting_memset. To do that, we can't have macro calls to bzero in
the fallback impelmentation of memset. Normal calls to bzero are fine.
All 4 architectures that use this have their own copies of bzero, so
there's no mutual recursion issue between memset and bcopy.
2018-05-24 23:20:10 +00:00
Warner Losh
509b94387a This is no unreferenced, so retire it.
Differential Revision: https://reviews.freebsd.org/D15374
2018-05-24 21:11:38 +00:00
Xin LI
b6f7731dba Remove "All rights reserved" from my files.
See r333391 for the rationale.

MFC after:	1 week
2018-05-10 06:41:08 +00:00
Warner Losh
baaa3c4d60 Simplify things a little
Rather than include a copy for memmove to call bcopy to call memcpy
(which handles overlapping copies), make memmove a strong reference to
memcpy to save the two calls.

Differential Revision: https://reviews.freebsd.org/D15374
2018-05-10 02:31:48 +00:00
Warner Losh
5aa07b053a Move MI-ish bcopy routine to libkern
riscv and powerpc have nearly identical bcopy.c that's
supposed to be mostly MI. Move it to the MI libkern.

Differential Revision: https://reviews.freebsd.org/D15374
2018-05-10 02:31:38 +00:00
David Bright
2b08b42bae iconv uses strlen directly on user supplied memory
`iconv_sysctl_add` from `sys/libkern/iconv.c` incorrectly limits the
size of user strings, such that several out of bounds reads could have
been possible.

static int
iconv_sysctl_add(SYSCTL_HANDLER_ARGS)
{
	struct iconv_converter_class *dcp;
	struct iconv_cspair *csp;
	struct iconv_add_in din;
	struct iconv_add_out dout;
	int error;

	error = SYSCTL_IN(req, &din, sizeof(din));
	if (error)
		return error;
	if (din.ia_version != ICONV_ADD_VER)
		return EINVAL;
	if (din.ia_datalen > ICONV_CSMAXDATALEN)
		return EINVAL;
	if (strlen(din.ia_from) >= ICONV_CSNMAXLEN)
		return EINVAL;
	if (strlen(din.ia_to) >= ICONV_CSNMAXLEN)
		return EINVAL;
	if (strlen(din.ia_converter) >= ICONV_CNVNMAXLEN)
		return EINVAL;
...

Since the `din` struct is directly copied from userland, there is no
guarantee that the strings supplied will be NULL terminated. The
`strlen` calls could continue reading past the designated buffer
sizes.

Declaration of `struct iconv_add_in` is found in `sys/sys/iconv.h`:

struct iconv_add_in {
	int	ia_version;
	char	ia_converter[ICONV_CNVNMAXLEN];
	char	ia_to[ICONV_CSNMAXLEN];
	char	ia_from[ICONV_CSNMAXLEN];
	int	ia_datalen;
	const void *ia_data;
};

Our strings are followed by the `ia_datalen` member, which is checked
before the `strlen` calls:

if (din.ia_datalen > ICONV_CSMAXDATALEN)

Since `ICONV_CSMAXDATALEN` has value `0x41000` (and is `unsigned`),
this ensures that `din.ia_datalen` contains at least 1 byte of 0, so
it is not possible to trigger a read out of bounds of the `struct`
however, this code is fragile and could introduce subtle bugs in the
future if the `struct` is ever modified.

PR:		207302
Submitted by:	CTurt <cturt@hardenedbsd.org>
Reported by:	CTurt <cturt@hardenedbsd.org>
Reviewed by:	jhb, vangyzen
MFC after:	1 week
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D14521
2018-02-26 18:23:36 +00:00
Ed Maste
85b648927a libkern: use nul for terminating char rather than 0
Akin to the change made in r188080 for lib/libc/string/.

Reported by:	bde
Sponsored by:	The FreeBSD Foundation
2018-02-13 19:17:48 +00:00
Pedro F. Giffuni
2cc7a55540 SPDX: fix wrong license ID tag in libkern. 2017-12-28 01:20:30 +00:00
Pedro F. Giffuni
8a36da99de sys/kern: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:20:12 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Ed Maste
4a8dea8cf9 ANSIfy sys/libkern
PR:		223641
Submitted by:	ota@j.email.ne.jp
MFC after:	1 week
2017-11-19 00:31:13 +00:00
Pedro F. Giffuni
df57947f08 spdx: initial adoption of licensing ID tags.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes:	yes
Differential Revision:	https://reviews.freebsd.org/D13133
2017-11-18 14:26:50 +00:00
Kirk McKusick
75e3597abb Continuing efforts to provide hardening of FFS, this change adds a
check hash to cylinder groups. If a check hash fails when a cylinder
group is read, no further allocations are attempted in that cylinder
group until it has been fixed by fsck. This avoids a class of
filesystem panics related to corrupted cylinder group maps. The
hash is done using crc32c.

Check hases are added only to UFS2 and not to UFS1 as UFS1 is primarily
used in embedded systems with small memories and low-powered processors
which need as light-weight a filesystem as possible.

Specifics of the changes:

sys/sys/buf.h:
    Add BX_FSPRIV to reserve a set of eight b_xflags that may be used
    by individual filesystems for their own purpose. Their specific
    definitions are found in the header files for each filesystem
    that uses them. Also add fields to struct buf as noted below.

sys/kern/vfs_bio.c:
    It is only necessary to compute a check hash for a cylinder
    group when it is actually read from disk. When calling bread,
    you do not know whether the buffer was found in the cache or
    read. So a new flag (GB_CKHASH) and a pointer to a function to
    perform the hash has been added to breadn_flags to say that the
    function should be called to calculate a hash if the data has
    been read. The check hash is placed in b_ckhash and the B_CKHASH
    flag is set to indicate that a read was done and a check hash
    calculated. Though a rather elaborate mechanism, it should
    also work for check hashing other metadata in the future. A
    kernel internal API change was to change breada into a static
    fucntion and add flags and a function pointer to a check-hash
    function.

sys/ufs/ffs/fs.h:
    Add flags for types of check hashes; stored in a new word in the
    superblock. Define corresponding BX_ flags for the different types
    of check hashes. Add a check hash word in the cylinder group.

sys/ufs/ffs/ffs_alloc.c:
    In ffs_getcg do the dance with breadn_flags to get a check hash and
    if one is provided, check it.

sys/ufs/ffs/ffs_vfsops.c:
    Copy across the BX_FFSTYPES flags in background writes.
    Update the check hash when writing out buffers that need them.

sys/ufs/ffs/ffs_snapshot.c:
    Recompute check hash when updating snapshot cylinder groups.

sys/libkern/crc32.c:
lib/libufs/Makefile:
lib/libufs/libufs.h:
lib/libufs/cgroup.c:
    Include libkern/crc32.c in libufs and use it to compute check
    hashes when updating cylinder groups.

Four utilities are affected:

sbin/newfs/mkfs.c:
    Add the check hashes when building the cylinder groups.

sbin/fsck_ffs/fsck.h:
sbin/fsck_ffs/fsutil.c:
    Verify and update check hashes when checking and writing cylinder groups.

sbin/fsck_ffs/pass5.c:
    Offer to add check hashes to existing filesystems.
    Precompute check hashes when rebuilding cylinder group
    (although this will be done when it is written in fsutil.c
    it is necessary to do it early before comparing with the old
    cylinder group)

sbin/dumpfs/dumpfs.c
    Print out the new check hash flag(s)

sbin/fsdb/Makefile:
    Needs to add libufs now used by pass5.c imported from fsck_ffs.

Reviewed by: kib
Tested by: Peter Holm (pho)
2017-09-22 12:45:15 +00:00
Ryan Libby
9de5f67de2 x86/crc32_sse42.c: quiet unused function warning
Reviewed by:	cem
Approved by:	markj (mentor)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D11980
2017-08-11 17:05:31 +00:00
Ed Maste
c2aa86d19c arm64: add ".arch armv8-a+crc" to allow use of crc instructions
With Clang 5.0 the .arch directive is required, otherwise Clang
complains "error: instruction requires: crc".

This was reported in D10499 but not added initially, because clang 3.8
available on a ref machine reported unknown directive.  Clang 4.0 allows
but does not require the directive.

Submitted by:	andrew
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2017-06-08 20:06:09 +00:00
Xin LI
da31cbbca0 Sync qsort.c with userland r318515.
(Note that MIN macro is removed in favor of sys/param.h's version).

PR:		213922
2017-05-19 06:37:16 +00:00
Ed Maste
3e85b721d6 Remove register keyword from sys/ and ANSIfy prototypes
A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by:	cem, jhb
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D10193
2017-05-17 00:34:34 +00:00
Michael Tuexen
d7f27102b5 armv8 has support for optional CRC32C instructions. This patch checks if they are
available and if that is true make use of them.
Thank you very much to Andrew Turner for providing help and review the patch!
Reviewed by:		andrew
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D10499
2017-04-27 17:53:05 +00:00
Mark Murray
150890b0c6 Replace the RC4 algorithm for generating in-kernel secure random
numbers with Chacha20. Keep the API, though, as that is what the
other *BSD's have done.

Use the boot-time entropy stash (if present) to bootstrap the
in-kernel entropy source.

Reviewed by: delphij,rwatson
Approved by: so(delphij)
MFC after: 2 months
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D10048
2017-04-16 09:11:02 +00:00
Bruce Evans
864c28cf81 Use inline asm instead of unportable intrinsics for the SSE4 crc32
optimization.

This fixes building with gcc-4.2.1 (it doesn't support SSE4).
gas-2.17.50 [FreeBSD] supports SSE4 instructions, so this doesn't
need using .byte directives.

This fixes depending on host user headers in the kernel.

Fix user includes (don't depend on namespace pollution in <nmmintrin.h>
that is not included now).

The instrinsics had no advantages except to sometimes avoid compiler
pessimixations.  clang understands them a bit better than inline asm,
and generates better looking code which also runs better for cem, but
for me it just at the same speed or slower by doing excessive
unrollowing in all the wrong places.  gcc-4.2.1 also doesn't understand
what it is doing with unrolling, but with -O3 somehow it does more
unrolling that helps.

Reduce 1 of the the compiler pessimizations (copying a variable which
already satisfies an "rm" constraint in a good way by being in memory
and not used again, to different memory and accessing it there.  Force
copying it to a register instead).

Try to optimize the inner loops significantly, so as to run at full
speed on smaller inputs.  The algorithm is already very MD, and was
tuned for the throughput of 3 crc32 instructions per cycle found on
at least Sandybridge through Haswell.  Now it is even more tuned for
this, so depends more on the compiler not rearranging or unrolling
things too much.  The main inner loop for should have no difficulty
runing at full speed on these CPUs unless the compiler unrolls it too
much.  However, the main inner loop wasn't even used for buffers smaller
than 24K.  Now it is used for buffers larger than 384 bytes.  Now it
is not so long, and the main outer loop is used more.  The new
optimization is to try to arrange that the outer loop runs in parallel
with the next inner loop except for the final iteration; then reduce
the loop sizes significantly to take advantage of this.

Approved by:	cem
Not tested in production by:	bde
2017-03-26 10:31:48 +00:00
Xin LI
91868665a9 Discard first 3072 bytes of RC4 keystream, this is a bandaid
that allows us to work on switching to a more modern PRNG.

Submitted by:	Steven Chamberlain <steven pyro eu org>
Approved by:	so
2017-03-14 06:00:44 +00:00
Warner Losh
59b34b3404 strstr.c was inadvertently blasted with a copy of isa_nmi.c. Revert
and remove clause 3 while I'm here.
2017-03-01 02:07:51 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00