Commit Graph

7 Commits

Author SHA1 Message Date
Mateusz Guzik
3ff65f71cb Remove duplicated empty lines from kern/*.c
No functional changes.
2020-01-30 20:05:05 +00:00
John Baldwin
fbb9879c0c Fix use of an uninitialized variable.
ctx (and thus ctx.flags) is stack garbage at the start of this
function, so initialize ctx.flags to an explicit value instead of
using binary operations on the garbage.

Reported by:	gcc9
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D23368
2020-01-30 18:28:02 +00:00
John Baldwin
425e5f9dcf Revert accidental change from r357146. 2020-01-26 14:23:27 +00:00
John Baldwin
c73222d0e6 Fix some misleading indentation warnings reported by recent clang.
These should not be any functional change.  While the change in
emul10kx-pcm.c looks like a real bug fix (as opposed to inconsistent
whitespace), the extra statements were not harmful.

Reviewed by:	kib
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D23363
2020-01-26 14:20:57 +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
Brooks Davis
89f34d4611 libstats: Improve ABI assertion.
On platforms where pointers are larger than 64-bits, struct statsblob
may be harmlessly padded out such that opaque[] always has some included
space.  Make the assertion more general by comparing to the offset of
opaque rather than the size of struct statsblob.

Discussed with:	jhb, James Clarke
Reviewed by:	trasz, lstewart
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D22188
2019-11-06 19:44:44 +00:00
Edward Tomasz Napierala
1a13f2e6b4 Introduce stats(3), a flexible statistics gathering API.
This provides a framework to define a template describing
a set of "variables of interest" and the intended way for
the framework to maintain them (for example the maximum, sum,
t-digest, or a combination thereof).  Afterwards the user
code feeds in the raw data, and the framework maintains
these variables inside a user-provided, opaque stats blobs.
The framework also provides a way to selectively extract the
stats from the blobs.  The stats(3) framework can be used in
both userspace and the kernel.

See the stats(3) manual page for details.

This will be used by the upcoming TCP statistics gathering code,
https://reviews.freebsd.org/D20655.

The stats(3) framework is disabled by default for now, except
in the NOTES kernel (for QA); it is expected to be enabled
in amd64 GENERIC after a cool down period.

Reviewed by:	sef (earlier version)
Obtained from:	Netflix
Relnotes:	yes
Sponsored by:	Klara Inc, Netflix
Differential Revision:	https://reviews.freebsd.org/D20477
2019-10-07 19:05:05 +00:00