libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Kee

libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

(cherry picked from commit 559a218c9b257775fb249b67945fe4a05b7a6b9f)

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Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

rand(3): Replace implementation with one backed by random(3) algorithm

rand(3)'s standard C API is extremely limiting, but we can do better
than the historical 32-bit state Park-Miller LCG we've shi

rand(3): Replace implementation with one backed by random(3) algorithm

rand(3)'s standard C API is extremely limiting, but we can do better
than the historical 32-bit state Park-Miller LCG we've shipped since
2001: r73156.

The justification provided at the time for not using random(3) was that
rand_r(3) could not be made to use the same algorithm. That is still
true. However, the irrelevance of rand_r(3) is increasingly obvious.
Since that time, POSIX has marked the interface obsolescent. rand_r(3)
never became part of the standard C library. If not for API
compatibility reasons, I would just remove rand_r(3) entirely.

So, I do not believe it is a problem for rand_r(3) and rand(3) to
diverge.

The 12 ABI is maintained with compatibility definitions, but this
revision does subtly change the API of rand(3). The sequences of
pseudorandom numbers produced in programs built against new versions of
libc will differ from programs built against prior versions of libc.

Reviewed by: kevans, markm
MFC after: no
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D23290

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random(3): Abstract routines into _r versions on explicit state

The existing APIs simply pass the implicit global state to the _r variants.

No functional change.

Note that these routines are not e

random(3): Abstract routines into _r versions on explicit state

The existing APIs simply pass the implicit global state to the _r variants.

No functional change.

Note that these routines are not exported from libc and are not intended to be
exported. If someone wished to export them from libc (which I would
discourage), they should first be modified to match the inconsistent parameter
type / order of the glibc public interfaces of the same names.

I know Ravi will ask, so: the eventual goal of this series is to replace
rand(3) with the implementation from random(3) (D23290). However, I'd like to
wait a bit longer on that one to see if more feedback emerges.

Reviewed by: kevans, markm
Differential Revision: https://reviews.freebsd.org/D23289

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random(3): Abstract state into a single context object

No functional change.

Reviewed by: kevans, markm
Differential Revision: https://reviews.freebsd.org/D23288

General 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 f

General 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.

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Add comment on use of abort() in libc

Suggested by: jonathan (in review D8133)

abort in srandomdev if kern.arandom sysctl fails

The sysctl cannot fail. If it does fail on some FreeBSD derivative or
after some future change, just abort() so that the problem will be found
and fi

abort in srandomdev if kern.arandom sysctl fails

The sysctl cannot fail. If it does fail on some FreeBSD derivative or
after some future change, just abort() so that the problem will be found
and fixed.

While abort() is not normally suitable for a library, it makes sense
here.

This is akin to r306636 for arc4random.

Reviewed by: ed
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8077

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Fix typing of srandom() and initstate().

POSIX requires that these functions have an unsigned int for their first
argument; not an unsigned long.

My reasoning is that we can safely change these fun

Fix typing of srandom() and initstate().

POSIX requires that these functions have an unsigned int for their first
argument; not an unsigned long.

My reasoning is that we can safely change these functions without
breaking the ABI. As far as I know, our supported architectures either
use registers for passing function arguments that are at least as big as
long (e.g., amd64), or int and long are of the same size (e.g., i386).

Reviewed by: ache
Differential Revision: https://reviews.freebsd.org/D6644

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Micro optimize: C standard guarantees that right shift for unsigned value
fills left bits with zero, and we have exact 32bit unsigned value
(uint32_t), so there is no reason to add "& 0x7fffffff" her

Micro optimize: C standard guarantees that right shift for unsigned value
fills left bits with zero, and we have exact 32bit unsigned value
(uint32_t), so there is no reason to add "& 0x7fffffff" here.

MFC after: 1 week

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1) Unifdef USE_WEAK_SEEDING it is too obsolete to support and makes reading
harder.

2) ACM paper require seed to be in [1, 2^31-2] range, so use the same range
shifting as already done for rand(3).

1) Unifdef USE_WEAK_SEEDING it is too obsolete to support and makes reading
harder.

2) ACM paper require seed to be in [1, 2^31-2] range, so use the same range
shifting as already done for rand(3). Also protect srandomdev() + TYPE_0 case
(non default) from negative seeds.

3) Don't check for valid "type" range in setstate(), it is always valid as
calculated. Instead add a check that rear pointer not exceeed end pointer.

MFC after: 1 week

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1) POSIX prohibits printing errors to stderr here and require
returning NULL:

"Upon successful completion, initstate() and setstate() shall return a
pointer to the previous state array; otherwise, a

1) POSIX prohibits printing errors to stderr here and require
returning NULL:

"Upon successful completion, initstate() and setstate() shall return a
pointer to the previous state array; otherwise, a null pointer shall
be returned.

Although some implementations of random() have written messages to
standard error, such implementations do not conform to POSIX.1-2008."

2) Move error detections earlier to prevent state modifying.

MFC after: 1 week

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Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic number the clauses 1 through 3,
so follow suit to make comparison easier.

Replace access to /dev/random with the kernel pseudo-random number
source sysctl(KERN_ARND) and remove the fallback code.

Obtained from: OpenBSD
Reviewed by: secteam
MFC after: 1 month

Remove undefined behavior from sranddev() and
srandomdev(). This doesn't actually work
with any modern C compiler:

In particular, both clang and modern gcc
verisons silently elide any xor operation

Remove undefined behavior from sranddev() and
srandomdev(). This doesn't actually work
with any modern C compiler:

In particular, both clang and modern gcc
verisons silently elide any xor operation
with 'junk'.

Approved by: secteam
MFC after: 3 days

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libc: Use O_CLOEXEC for various internal file descriptors.

This fixes a race condition where another thread may fork() before CLOEXEC
is set, unintentionally passing the descriptor to the child proc

libc: Use O_CLOEXEC for various internal file descriptors.

This fixes a race condition where another thread may fork() before CLOEXEC
is set, unintentionally passing the descriptor to the child process.

This commit only adds O_CLOEXEC flags to open() or openat() calls where no
fcntl(fd, F_SETFD, FD_CLOEXEC) follows. The separate fcntl() call still
leaves a race window so it should be fixed later.

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Slight stylification.

Make 'junk' volatile so that compilers won't be tempted to optimize

Reviewed by: ache
MFC after: 3 days

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Use 'uint32_t' instead of 'long' when a 32-bit integer is intended.
This results in no functional change, aside from fixing a data
corruption bug on LP64 platforms. The code here could still use a
s

Use 'uint32_t' instead of 'long' when a 32-bit integer is intended.
This results in no functional change, aside from fixing a data
corruption bug on LP64 platforms. The code here could still use a
significant amount of cleanup.

PR: 56502
Submitted by: hrs (earlier version)

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For type 0 rng lower initial drop to 50, it is enough to hide linearity
Reorganize historic #ifdef section

For rand(3) and random(3) TYPE_0 drop NSHUFF values right after srand{om}()
to remove part of seed -> 1st value correlation. Correlation still remains
because of algorithm limits. Note that old algor

For rand(3) and random(3) TYPE_0 drop NSHUFF values right after srand{om}()
to remove part of seed -> 1st value correlation. Correlation still remains
because of algorithm limits. Note that old algorithm have even stronger
correlation, especially in the lower bits area, but not eye-visible, as
current one.

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Park & Miller PRNG can be safely initialized with any value but 0 and stuck
at 0 as designed. Its BSD adaptation tries to fight it by mapping 0 to
2147483647 after calculation, but this method not wo

Park & Miller PRNG can be safely initialized with any value but 0 and stuck
at 0 as designed. Its BSD adaptation tries to fight it by mapping 0 to
2147483647 after calculation, but this method not works since 2147483647
seed returns to 0 again on the next interation. Instead of after calculation
mapping, map 0 to another value _before_ calculation, so it never stucks.

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Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove __P() usage.