Commit Graph

2001 Commits

Author SHA1 Message Date
Mariusz Zaborski
27eff71458 Add link to the setproctitle_fast function.
MFC after:	1 week
2018-10-20 22:25:57 +00:00
Conrad Meyer
243e09430a Embedded chacha: Distinguish via dedicated macro
Set embedding expectations via CHACHA_EMBED macro rather than _KERNEL
definition.

No functional change.

Sponsored by:	Dell EMC Isilon
2018-10-20 22:14:29 +00:00
Conrad Meyer
0a3a36cd94 getentropy(3): Trap non-API errnos from getrandom(2) and abort
Additionally, reconcile our abort behavior with arc4random(3).  Unlike
SIGABRT, SIGKILL cannot be caught by the user program.  These failures
are fatal conditions and should not return to the caller, as they did in
the instance that resulted in D17049.

While here, fix some minor typos in a comment.

Reviewed by:	delphij
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D17050
2018-10-20 21:45:17 +00:00
Edward Tomasz Napierala
8bb6c72e63 Get rid unneccessary useless calls to lseek(2) from getgrent(3).
Looks like this:

 fstatat(AT_FDCWD,"/etc/nsswitch.conf",{ mode=-rw-r--r-- ,inode=2167001,size=390,blksize=32768 },0x0) = 0 (0x0)
 open("/etc/group",O_RDONLY|O_CLOEXEC,0666)      = 3 (0x3)
 fstat(3,{ mode=-rw-r--r-- ,inode=2166927,size=919,blksize=32768 }) = 0 (0x0)
-lseek(3,0x0,SEEK_CUR)                           = 0 (0x0)
-lseek(3,0x0,SEEK_SET)                           = 0 (0x0)
 read(3,"# $FreeBSD: release/10.0.0/etc/g"...,32768) = 919 (0x397)
 close(3)                                        = 0 (0x0)

Reviewed by:	kib
Approved by:	re (gjb)
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D17571
2018-10-16 18:17:07 +00:00
Xin LI
59488f25ad In r331279 the code used ENOSYS to check the existence of getrandom(2).
This will only work if the caller already handles SIGSYS, which is not
always the case.

Address this by checking osreldate instead. Note that because there
was not __FreeBSD_version bump when the system call was added, use
1200061 (r332100) which is the first bump after the introduction of
the system call.

PR:		230762
Reported by:	Jenkins via Mark Millard
Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D16807
2018-08-20 02:17:55 +00:00
Xin LI
c1e80940f3 Update userland arc4random() with OpenBSD's Chacha20 based arc4random().
ObsoleteFiles.inc:

    Remove manual pages for arc4random_addrandom(3) and
    arc4random_stir(3).

  contrib/ntp/lib/isc/random.c:
  contrib/ntp/sntp/libevent/evutil_rand.c:

    Eliminate in-tree usage of arc4random_addrandom().

  crypto/heimdal/lib/roken/rand.c:
  crypto/openssh/config.h:

    Eliminate in-tree usage of arc4random_stir().

  include/stdlib.h:

    Remove arc4random_stir() and arc4random_addrandom() prototypes,
    provide temporary shims for transistion period.

  lib/libc/gen/Makefile.inc:

    Hook arc4random-compat.c to build, add hint for Chacha20 source for
    kernel, and remove arc4random_addrandom(3) and arc4random_stir(3)
    links.

  lib/libc/gen/arc4random.c:

    Adopt OpenBSD arc4random.c,v 1.54 with bare minimum changes, use the
    sys/crypto/chacha20 implementation of keystream.

  lib/libc/gen/Symbol.map:

    Remove arc4random_stir and arc4random_addrandom interfaces.

  lib/libc/gen/arc4random.h:

    Adopt OpenBSD arc4random.h,v 1.4 but provide _ARC4_LOCK of our own.

  lib/libc/gen/arc4random.3:

    Adopt OpenBSD arc4random.3,v 1.35 but keep FreeBSD r114444 and
    r118247.

  lib/libc/gen/arc4random-compat.c:

    Compatibility shims for arc4random_stir and arc4random_addrandom
    functions to preserve ABI.  Log once when called but do nothing
    otherwise.

  lib/libc/gen/getentropy.c:
  lib/libc/include/libc_private.h:

    Fold __arc4_sysctl into getentropy.c (renamed to arnd_sysctl).
    Remove from libc_private.h as a result.

  sys/crypto/chacha20/chacha.c:
  sys/crypto/chacha20/chacha.h:

    Make it possible to use the kernel implementation in libc.

PR:		182610
Reviewed by:	cem, markm
Obtained from:	OpenBSD
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D16760
2018-08-19 17:40:50 +00:00
Xin LI
52809cc35b Workaround ECAPMODE for kernels between revision [331280, 337999)
where getrandom(2) is not available in capability mode.
2018-08-18 08:32:21 +00:00
Xin LI
718863d076 Split arc4random_uniform into it's own file and sync with OpenBSD.
PR:		182610
Obtained from:	OpenBSD
MFC after:	2 weeks
2018-08-18 06:20:45 +00:00
Mariusz Zaborski
8b3c9fac3c Fix style nits. 2018-08-17 14:37:13 +00:00
Jamie Gritton
284001a222 Put jail(2) under COMPAT_FREEBSD11. It has been the "old" way of creating
jails since FreeBSD 7.

Along with the system call, put the various security.jail.allow_foo and
security.jail.foo_allowed sysctls partly under COMPAT_FREEBSD11 (or
BURN_BRIDGES).  These sysctls had two disparate uses: on the system side,
they were global permissions for jails created via jail(2) which lacked
fine-grained permission controls; inside a jail, they're read-only
descriptions of what the current jail is allowed to do.  The first use
is obsolete along with jail(2), but keep them for the second-read-only use.

Differential Revision:	D14791
2018-08-16 18:40:16 +00:00
Warner Losh
3d19db5dfb Update man page to include FreeBSD-specific details.
While this implements a standards-conforming C11 function, there's
implementation details the programmer needs to know. Include those
here. Make changes inspired by comments on the initial review as well,
though mostly this involves stealing the epoch verbage from
gettimeofday(2). Add myself to authors since I've now changed a
substantial amount of this man page.
2018-08-10 15:16:41 +00:00
Warner Losh
de1118b1dd Remove assert.h and commented out _DIAGASSERT.
Remove assert.h and _DIAGASSERT to create a paper-trail of changes
from NetBSD. Specifically didn't fix other style issues since I
don't want this to diverge from the NetBSD original too much and
that's too niggling a change to be worth future merge hassles.

Differential Review: https://reviews.freebsd.org/D16649
2018-08-10 15:16:36 +00:00
Warner Losh
7e299411ac Bring in timespce_get form NetBSD.
Bring in the functionality for timespec_get from NetBSD. I've lightly
edited the .c file to remove _DIAGASSERT because FreeBSD doesn't have
that functionality and the typical #define'ing it to assert isn't
right here. The man page is verbatim from NetBSD, but will be revised
as part of a larger cleanup of the time man pages (they are
inconsistent and vague in all the wrong places).

Differential Review: https://reviews.freebsd.org/D16649
2018-08-10 15:16:30 +00:00
Pedro F. Giffuni
fee1489eb1 libc: fix cases of undefined behavior.
These were found by the Undefined Behavious  GsoC project at NetBSD:

Avoid undefined behavior in ftok(3)

Do not change the signedness bit with a left shift operation.
Cast to unsigned integer to prevent this.

ftok.c:56:10, left shift of 123456789 by 24 places cannot be represented
in type 'int'
ftok.c:56:10, left shift of 4160 by 24 places cannot be represented in
type 'int'

Avoid undefined behavior in an inet_addr.c

Do not change the signedness bit with a left shift operation.
Cast to unsigned integer to prevent this.

inet_addr.c:218:20, left shift of 131 by 24 places cannot be represented
in type 'int'

Detected with micro-UBSan in the user mode.

Obtained from:	NetBSD
MFC after:	2 weeks
2018-08-07 15:24:19 +00:00
Conrad Meyer
337bd62722 exec.3: Add BUGS section and document non-FreeBSD portability
Requested by:	kib (in part)
2018-07-28 23:55:18 +00:00
Brad Davis
a0a1ffcb16 Move etc/shells to lib/libc/gen with getusershell(3).
Approved by:	will (mentor)
Differential Revision:	https://reviews.freebsd.org/D16467
2018-07-28 20:21:23 +00:00
Conrad Meyer
bbc5c8ee32 Clean up execl*(3) manual page prototype formatting
Rendering of execle was missing a comma between the NULL argument and envp.

For unclear reasons, POSIX' definition of these routines comments out the
mandatory trailing NULL argument.  That seems unnecessary and probably
(reasonably) confuses mdoc.

For unclear reasons, POSIX' definition of these routines spells NULL as
"(char *)0."  This is needlessly unclear.  One guess might be that POSIX
targets more exotic computer architectures than FreeBSD does.  Fortunately,
there is no such problem on any reasonable platform for FreeBSD to support.
Spell NULL as NULL.

The comma was probably removed in r117204 while the comment and creative
spelling of NULL were added in r116537 (both 15 years ago).
2018-07-28 19:08:00 +00:00
Ian Lepore
757e8bdbea Stop exporting __pw_scan and __pw_initpwd as freebsd-private libc functions
for use in libutil, and instead compile the small amount of common code
directly into libutil with a .PATH reachover.

Discussed with: kib@
2018-07-27 19:47:42 +00:00
Ian Lepore
34e9190d82 Make pw_scan(3) more compatible with getpwent(3) et. al. when processing
data from /etc/passwd rather than /etc/master.passwd.

The libc getpwent(3) and related functions automatically read master.passwd
when run by root, or passwd when run by a non-root user.  When run by non-
root, getpwent() copes with the missing data by setting the corresponding
fields in the passwd struct to known values (zeroes for numbers, or a
pointer to an empty string for literals).  When libutil's pw_scan(3) was
used to parse a line without the root-accessible data, it was leaving
garbage in the corresponding fields.

These changes rename the static pw_init() function used by getpwent() and
friends to __pw_initpwd(), and move it into pw_scan.c so that common init
code can be shared between libc and libutil.  pw_scan(3) now calls
__pw_initpwd() before __pw_scan(), just like the getpwent() family does, so
that reading an arbitrary passwd file in either format and parsing it with
pw_scan(3) returns the same results as getpwent(3) would.

This also adds a new pw_initpwd(3) function to libutil, so that code which
creates passwd structs from scratch in some manner that doesn't involve
pw_scan() can initialize the struct to the values expected by lots of
existing code, which doesn't expect to encounter NULL pointers or garbage
values in some fields.
2018-07-26 18:34:38 +00:00
Ian Lepore
c798532ffa Revert r336619, it appears to cause problems with ssh, and probably other
things which use pw_scan().
2018-07-23 17:26:38 +00:00
Ian Lepore
cbc397fd10 Set the pw_class field to NULL when scanning the non-master passwd file.
This avoids a null pointer deref in pw_dup(), which assumes that all
pointers are either NULL or valid.
2018-07-22 22:34:20 +00:00
Konstantin Belousov
78f89679fc Add setproctitle_fast(3) for frequent callers.
Some applications, notably PostgreSQL, want to call setproctitle()
very often.  It's slow.  Provide an alternative cheap way of updating
process titles without making any syscalls, instead requiring other
processes (top, ps etc) to do a bit more work to retrieve the data.
This uses a pre-existing code path inherited from ancient BSD, which
always did it that way.

Submitted by:	Thomas Munro
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D16111
2018-07-04 13:31:16 +00:00
John Baldwin
c1920558b3 Clean up the vcs ID strings in libc's gen/ directory.
- Move CSRG IDs into __SCCSID().
- When a file has been copied, consistently use 'From: <tag>' for strings
  referencing the version of the source file copied from in the license
  block comment.
- Some of the 'From:' tags were using $FreeBSD$ that was being expanded on
  each checkout.  Fix those to hardcode the FreeBSD tag from the file that
  was copied at the time of the copy.
- When multiple strings are present list them in "chronological" order,
  so CSRG (__SCCSID) before FreeBSD (__FBSDID).  If a file came from
  OtherBSD and contains a CSRG ID from the OtherBSD file, use the order
  CSRG -> OtherBSD -> FreeBSD.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D15831
2018-07-03 17:31:45 +00:00
Edward Tomasz Napierala
8f9c737173 Get rid of references to /usr/share/doc/ from ports(7) and getosreldate(3).
The handbooks are not installed there anymore. While here, improve the
URLs markup a bit.

Reviewed by:	allanjude@
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D15793
2018-06-13 18:34:49 +00:00
Eric van Gyzen
0155aa938e fts_stat: fix buffer overrun on error path
Reported by:	Coverity
CID:		1375582
MFC after:	1 week
Sponsored by:	Dell EMC
2018-05-28 02:31:49 +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
Brooks Davis
87385baff6 Replace MD assembly exect() with a portable version.
Originally, on the VAX exect() enable tracing once the new executable
image was loaded.  This was possible because tracing was controllable
through user space code by setting the PSL_T flag.  The following
instruction is a system call that activated tracing (as all
instructions do) by copying PSL_T to PSL_TP (trace pending).  The
first instruction of the new executable image would trigger a trace
fault.

This is not portable to all platforms and the behavior was replaced with
ptrace(PT_TRACE_ME, ...) since FreeBSD forked off of the CSRG repository.
Platforms either incorrectly call execve(), trigger trace faults inside
the original executable, or do contain an implementation of this
function.

The exect() interfaces is deprecated or removed on NetBSD and OpenBSD.

Submitted by:	Ali Mashtizadeh <ali@mashtizadeh.com>
Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D14989
2018-04-12 18:23:14 +00:00
Oleksandr Tymoshenko
17b382ec14 Bump .Dd value (forgot to do this in r332439)
MFC after:	3 days
X-MFC-With:	332439
2018-04-12 17:47:36 +00:00
Oleksandr Tymoshenko
eb607f9034 Fix quotes in the example code in syslog(3) BUGS section
mdoc treats verbatim quotes in .Dl as a string delimiter and does
not pass them to the rendered output. Use special char \*q to specify
double quote

PR:		216755
MFC after:	3 days
2018-04-12 17:05:27 +00:00
Brooks Davis
047a2ef697 Remove caching from getlogin(2).
This caching has existed since the CSRG import, but serves no obvious
purpose. Sure, setlogin() is called rarely, but calls to getlogin()
should also be infrequent. The required invalidation was not
implemented on aarch64, arm, mips, amd riscv so updates would never
occur if getlogin() was called before setlogin().

Reported by:	Ali Mashtizadeh <ali@mashtizadeh.com>
Reviewed by:	kib
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14965
2018-04-06 17:17:34 +00:00
Ed Schouten
8129693e78 Let syslog(3) use RFC 5424.
With r332099 changing syslogd(8) to parse RFC 5424 formatted syslog
messages, go ahead and also change the syslog(3) libc function to
generate them. Compared to RFC 3164, RFC 5424 has various advantages,
such as sub-second precision for log entry timestamps.

As this change could have adverse effects when not updating syslogd(8)
or using a different system logging daemon, add a notice to UPDATING and
increase __FreeBSD_version.

Differential Revision:	https://reviews.freebsd.org/D14926
2018-04-06 13:00:45 +00:00
Conrad Meyer
08a7e74c7c getentropy(3): Fallback to kern.arandom sysctl on older kernels
On older kernels, when userspace program disables SIGSYS, catch ENOSYS and
emulate getrandom(2) syscall with the kern.arandom sysctl (via existing
arc4_sysctl wrapper).

Special care is taken to faithfully emulate EFAULT on NULL pointers, because
sysctl(3) as used by kern.arandom ignores NULL oldp.  (This was caught by
getentropy(3) ATF tests.)

Reported by:	kib
Reviewed by:	kib
Discussed with:	delphij
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D14785
2018-03-21 23:52:37 +00:00
Conrad Meyer
e9ac27430c Implement getrandom(2) and getentropy(3)
The general idea here is to provide userspace programs with well-defined
sources of entropy, in a fashion that doesn't require opening a new file
descriptor (ulimits) or accessing paths (/dev/urandom may be restricted
by chroot or capsicum).

getrandom(2) is the more general API, and comes from the Linux world.
Since our urandom and random devices are identical, the GRND_RANDOM flag
is ignored.

getentropy(3) is added as a compatibility shim for the OpenBSD API.

truss(1) support is included.

Tests for both system calls are provided.  Coverage is believed to be at
least as comprehensive as LTP getrandom(2) test coverage.  Additionally,
instructions for running the LTP tests directly against FreeBSD are provided
in the "Test Plan" section of the Differential revision linked below.  (They
pass, of course.)

PR:		194204
Reported by:	David CARLIER <david.carlier AT hardenedbsd.org>
Discussed with:	cperciva, delphij, jhb, markj
Relnotes:	maybe
Differential Revision:	https://reviews.freebsd.org/D14500
2018-03-21 01:15:45 +00:00
Brooks Davis
6d0fe480a8 Don't declare union semun in userspace unless _WANT_SEMUN is defined.
POSIX explicitly states that the application must declare union semun.
This makes no sense, but it is what it is.  This brings us into line
with Linux, MacOS/Darwin, and NetBSD.

In a ports exp-run a moderate number of ports fail due to a lack of
approprate autotools-like discovery mechanisms or local patches.  A
commit to address them will follow shortly.

PR:		224300, 224443 (exp-run)
Reviewed by:	emaste, jhb, kib
Exp-run by:	antoine
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14492
2018-03-02 22:32:53 +00:00
Edward Tomasz Napierala
61abc6bf13 Fix typo.
Submitted by:	jilles@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2018-02-27 10:55:33 +00:00
Edward Tomasz Napierala
1cde387c83 Improve missing tty handling in init(8). This removes a check that did
nothing - it was checking for ENXIO, which, with devfs, is no longer
returned - and was badly placed anyway, and replaces it with similar
one that works, and is done just before starting getty, instead of being
done when rereading ttys(5).

From the practical point of view, this makes init(8) handle disappearing
terminals (eg /dev/ttyU*) gracefully, without unneccessary getty restarts
and resulting error messages.

Reviewed by:	imp@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D14307
2018-02-27 10:54:15 +00:00
Bryan Drewery
8d55975f92 Fix some grammar: "signals <...> are set" 2018-02-27 04:41:14 +00:00
Conrad Meyer
aab3e059e4 libc: Remove unused definition
RANDOMDEV isn't used after r306636.  Remove the unneeded definition.

No functional change.

Sponsored by:	Dell EMC Isilon
2018-02-24 19:40:23 +00:00
Pedro F. Giffuni
8d48e738b5 getpeereid(3): Fix behavior on failure to match documentation.
According to the getpeereid(3) documentation, on failure the value -1 is
returned and the global variable errno is set to indicate the error. We
were returning the error instead.

Obtained from:	Apple's Libc-1244.30.3
MFC after:	5 days
2018-02-23 00:28:00 +00:00
John Baldwin
7193311b15 Clarify that the additional arguments to makecontext() are of type int.
MFC after:	1 week
Sponsored by:	DARPA / AFRL
2018-01-31 17:56:36 +00:00
Kirk McKusick
8557409f20 In the C library, the setting up of the group array by various
utilities is done by calling gr_addgid() for each group to be
added (usually found by traversing /etc/group) then calling the
setgroups() system call after the group set has been created.
The gr_addgid() function (helpfully?) deduplicates the addition
of group members. So, if you call it to add a group member that
already exists, it is just dropped. Because group[0] is the
effective group-ID and is over-written when a setgid program
is run, The value in group[0] is usually duplicated so that
group value is not lost when a setgid program is run.

Historically this happened because the group value indicated
in the password file also appears in /etc/group (e.g., if you
are group staff in the password file, you will also appear in
the staff line in /etc/group). But, with the addition of the
deduplication, the attempt to add group staff was lost because
it already appeared in group[0]. So, the fix is to deduplicate
starting from group[1] which allows a duplicate of the entry in
group[0], but not in later entries.

There is some confusion about the setgroups system call because in
BSD it has (always) set the entire group including the egid group
(in group[0]). However, in Linux, it skips over group[0] and starts
setting from group[1]. See this comment from linux_setgroups:

      /*
       * cr_groups[0] holds egid. Setting the whole set from
       * the supplied set will cause egid to be changed too.
       * Keep cr_groups[0] unchanged to prevent that.
       */

To make it clear what the BSD setgroups system call does, I
added the following paragraph to the setgroups(2) manual page:

   The first entry of the group array (gidset[0]) is used as the effective
   group-ID for the process.  This entry is over-written when a setgid
   program is run.  To avoid losing access to the privileges of the
   gidset[0] entry, it should be duplicated later in the group array.
   By convention, this happens because the group value indicated in the
   password file also appears in /etc/group.  The group value in the
   password file is placed in gidset[0] and that value then gets added a
   second time when the /etc/group file is scanned to create the group set.

Reported by: Paul McMath  paulm at tetrardus.net
Reviewed by: kib
MFC after:   2 weeks
2018-01-23 22:18:45 +00:00
Xin LI
73aaa45510 Remove unused includes. 2018-01-01 08:01:26 +00:00
Eitan Adler
518e4554be isgreater(3): correct description of isunordered macro
PR:		211376
Submitted by:	Duane <parakleta@darkreality.org>
MFC After:	1 week
2017-12-31 00:46:41 +00:00
Mariusz Zaborski
16545cf5d5 Introduce the daemonfd function.
The daemonfd function is equivalent to the daemon(3) function expect that
arguments are descriptors. For example dhclient(8) which is sandboxed is
unable to open /dev/null to close stdio instead it's allows to fail
daemon(3) function to close the descriptors and then do it explicit in code.
Instead of such hacks we can use now daemonfd.

This API can be also helpful to migrate system to platforms like CheriBSD.

Reviewed by:	brooks@, bcr@, jilles@ (earlier version)
Differential Revision:	https://reviews.freebsd.org/D13433
2017-12-23 18:07:43 +00:00
Michal Meloun
6e16d0bc43 Rework alignment handling in __libc_allocate_tls() for Variant I of TLS layout.
There are two versions of variant I of TLS
- ARM and aarch64 uses original version of variant I here TP points to
  start of TCB followed by aligned TLS segment. Both TCB and TLS must
  be aligned to alignment of TLS section. The TCB[0] points to DTV vector
  and DTV values are real addresses (without bias).

- MIPS, PowerPC and RISC-V use modified version of variant I,
  where TP points (with bias) to TLS and TCB immediately precedes TLS
  without any alignment gap. Only TLS should be aligned. The TCB[0]
  points to DTV vector and DTV values are biased by constant value (0x8000)
  from real addresses.

Take all this in account when allocating memory for TLS structures.

MFC after:	1 month
Reviewed by:	kib, mizhka
Tested by:	mizhka(on mips)
Differential Revision:	https://reviews.freebsd.org/D13378
2017-12-12 11:25:30 +00:00
Ed Schouten
6c093deeda Remove basename_r(3).
Now that the POSIX working group is going to require that basename(3)
and dirname(3) are thread-safe in future revisions of the standard,
there is even less of a need to provide basename_r(3). Remove this
function to prevent people from writing code that only builds on
FreeBSD and Bionic.

Removing this function seems to break exactly one port: sbruno@'s
qemu-user-static. I will send him a pull request on GitHub in a bit.
__FreeBSD_version will not be bumped, as any value from 2017 can be used
to test for the presence of a thread-safe basename(3)/dirname(3).

PR:		https://bugs.freebsd.org/224016
2017-12-08 22:06:18 +00:00
Alan Somers
82241ed55c Optimize telldir(3)
Currently each call to telldir() requires a malloc and adds an entry to a
linked list which must be traversed on future telldir(), seekdir(),
closedir(), and readdir() calls. Applications that call telldir() for every
directory entry incur O(n^2) behavior in readdir() and O(n) in telldir() and
closedir().

This optimization eliminates the malloc() and linked list in most cases by
packing the relevant information into a single long. On 64-bit architectures
msdosfs, NFS, tmpfs, UFS, and ZFS can all use the packed representation.  On
32-bit architectures msdosfs, NFS, and UFS can use the packed
representation, but ZFS and tmpfs can only use it for about the first 128
files per directory.  Memory savings is about 50 bytes per telldir(3) call.
Speedup for telldir()-heavy directory traversals is about 20-30x for one
million files per directory.

Reviewed by:	kib, mav, mckusick
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D13385
2017-12-06 22:06:48 +00:00
Warner Losh
8e0cd68ff4 Correct history for Unix 2nd Edition through 6th Edition for the
system calls. Man pages are missing for v2 and v5, so any entries for
those versions were inferred by new implementations of these functions
in libc.

Obtained from: http://www.tuhs.org/cgi-bin/utree.pl
2017-12-01 22:48:20 +00:00
Pedro F. Giffuni
d915a14ef0 libc: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified 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.
2017-11-25 17:12:48 +00:00
Pedro F. Giffuni
8a16b7a18f 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.
2017-11-20 19:49:47 +00:00