MFC r313774: localtime: return NULL if time_t out of range of struct tm

Previously we would truncate tm.tm_year for any time_t corresponding to
a year that does not fit in int. This issue was discovered because it
caused the bash-static build to fail when linking with LLD.

As reported by Rafael Espíndola:

Configure has

AC_FUNC_MKTIME

which expands to a test of mktime that fails with the freebsd
implementation. Given that, bash compiles a mktime.o file that
defines just mktime and uses localtime. That goes in a .a file
that is before libc.

The freebsd libc defines mktime in localtime.o, which also defines
localtime among other functions.

When lld sees an undefined reference to mktime from libc, it uses
the bash provided one and then tries to find a definition of
localtime. It is found on libc's localtime.o, but now we have a
duplicated error.

The reason it works with bfd is that bash doesn't use mktime
directly and the undefined reference from libc is resolved to the
libc implementation. It would also fail to link if bash itself
directly used mktime.

The bash-static configure test verifies that, for many values of t, either
localtime(t) returns NULL or mktime(localtime(t)) == t. This test failed
when localtime returned a truncated tm_year.

This was fixed in tzcode in 2004 but has persisted in our tree since
rS2708.

Sponsored by: The FreeBSD Foundation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Merge:
commit 400ecf36bb0b73f6390f9641e6cb8bbfb91a5cfd
Author: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri Oct 12 07:53:12 2012 -0700

Assume C89.

https://github.com/eggert/tz/commit/400ecf36bb0b73f6390f9641e6cb8bbfb91a5cfd

Revert WiP to contrib/tzcode accidentally committed with r274364

Add baud rate support to telnet(1)

This implements part of RFC-2217

It's based off a patch originally written by Sujal Patel at Isilon, and
contributions from other Isilon employees.

PR: 173728
Phabric: D995
Reviewed by: markj, markm
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division

Fix a memory leak in tzload().

Reported by: valgrind
Reviewed by: kib
MFC after: 3 days

Do not overallocate on the stack. Threaded code might use custom stack
size.

Reported by: many
Tested by: Jeremie Le Hen <jeremie@le-hen.org> (previous version)
Reviewed by: jilles
Approved by: re (bz)
MFC after: 2 weeks

Sync code with tzcode2010m

asctime.c:
* Set errno to EINVAL and return "??? ??? ?? ??:??:?? ????\n" if
asctime_r is called with a NULL struct tm pointer. (Note that
asctime_r is called by ctime_r and asctime; asctime is called by
ctime.)

localtime.c:
* Set errno to EINVAL and return WRONG if time1 is called with a
NULL struct tm pointer; avoid dereference if a NULL struct tm
pointer is passed to timelocal, timegm, or timeoff. (Note that
time1 is called by mktime, timegm, and timeoff; mktime is called
by timelocal.)
* more core-avoidance work
* Change to set timezone and altzone based on time types with
greatest transition times (for the benefit of Asia/Seoul).

zic.8:
* Warning about case-sensitivity of names, but not of abbrevations

zic.c:
* Conditionally output extra types with most-recently-use offsets
last (for use by systems with pre-2011 versions of localtime.c,
helping to ensure that globals "altzone and "timezone" get set
correctly).

The code has been running for nearly four weeks on my laptop running
FreeBSD 8.1 without a problem.

MFC after: 1 month

Copy lib/libc/stdtime to contrib/tzcode/stdtime for the proper split
of contributed code and FreeBSD specific code.

Use _pthread_once() rather than _once() for localtime() and gmtime(). These
methods are only invoked when __isthreaded is true at which point it is safe
to use _pthread_once() directly.

MFC after: 1 week

Use _once() to initialize the pthread key for thread-local storage to hold
the results of gmtime() instead of using a pthread mutex directly.

MFC after: 1 week

Use _once() to initialize the pthread key for thread-local storage to hold
the results of localtime() instead of using a pthread mutex directly.

MFC after: 1 week

Replace gmt_is_set and the gmt_mutex lock with a pthread_once_t variable and
an init routine run on the first invocation via _once().

MFC after: 1 week

Improve the way failure of pthread_key_create() gets detected.

PR: threads/138603
Submitted by: Mikulas Patocka
MFC after: 1 week

Remove duplicate if-statement on gmt_is_set in gmtsub().

MFC after: 1 week

MFV of tzcode2009e:

Upgrade of the tzcode from 2004a to 2009e.

Changes are numerous, but include...

- New format of the output of zic, which supports both 32 and 64
bit time_t formats.

- zdump on 64 bit platforms will actually produce some output instead
of doing nothing for a looooooooong time.

- linux_base-fX, with X >= at least 8, will work without problems related
to the local time again.

The original patch, based on the 2008e, has been running for a long
time on both my laptop and desktop machine and have been tested by
other people.

After the installation of this code and the running of zic(8), you
need to run tzsetup(8) again to install the new datafile.

Approved by: wollman@ for usr.sbin/zic
MFC after: 1 month

Normally, we are often reading local time rather than setting time zone,
replace mutex with rwlock, this should eliminate lock contention in
most cases.

Reduce lock contention for simple cases.

# this really should be done with pthread_once, but I've debugged this code.

Reviewed by: arch@

On FreeBSD/arm, any value > 50 bits will result in a rediculously huge
number being returned for mktime and timegm calls. Choose 48 because
that works well. This does reduce the dynamic range of tm_year from
about 2 billion years down to "only" about 9 million years. Please
contact me if this restriction poses a problem.

Due to the complexity of the code, I admit that I didn't trace down
what, exactly, was overflowing with longer bits. This fixes software
that we run on the embedded systems we have.

struct tm.tm_year is listed as 'years since 1900', and is signed. On
64 bit systems, years roughly -2^31 through 2^31 can be represented in
time_t without any trouble. 32 bit time_t systems only range from
roughly 1902 through 2038. As a consequence, none of the date munging
code for all the various calendar tweaks before then is present. There
are other problems including the fact that there was no 'year zero' and
so on. So rather than get excited about trying to figure out when the
calendar jumped by two weeks etc, simply disallow negative (ie: prior to
1900) years.

This happens to have an important side effect. If you bzero a 'struct
tm', it corresponds to 'Jan 0, 1900, 00:00 GMT'. This happens to be
representable (after canonification) in 64 bit time_t space. Zero tm
structs are generally an error and mktime normally returns -1 for them.
Interestingly, it tries to canonify the 'jan 0' to 'dec 31, 1899', ie:
year -1. This conveniently trips the negative year test above, which
means we can trivially detect the null 'tm' struct.

This actually tripped up code at work. :-/ (Don't ask)

Merge changes from the tzcode2004a import. Wherever possible I tried to bring
us closer to the vendor branch.

Requested by: wollman

Change defualt time zone from GMT to UTC. This will not be MFC-ed, and
was done before 5-STABLE on purpose...

Remove a couple of casts added for an ancient Sun compiler.

Approved by: das (mentor)

Eliminate 61 warnings emitted at WARNS=2 (leaving 53 to go).
Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.

Reviewed by: /sbin/md5

Do not guarantee an overflow of tm_year when doing the binary search in
localtime/mktime/tmcomp and friends on ia64.

Approved by: re

Replace rev 1.33 with a real fix. The problem was integer overflows
when trying to store the year in a signed int. The maximum time_t on ia64
is around 292 billion years in the future, but 'int' and struct tm.tm_year
can only represent then ext 2.1 billion years or so.

This solves the problem of mktime/localtime looping on ia64. Unfortunately,
the standards say that tm_year is an 'int', so we are still stuck with a
y2147483647 bug. bash2's configure script looks for bugs in mktime() and
fails on ia64 because of this. However, mktime() on FreeBSD fails the test
normally anyway so this is no big loss.

This change does not affect any other platforms besides ia64.

Approved by: re

Fix a nasty bug exposed by mktime() when time_t is significantly bigger
than 32 bits. It was trying to figure out things like the day of week
of when time_t is roughly 2^62 etc. Make a better guess for the starting
point for the binary search that works on both 32 and 64 bit types. I have
been using this for a while now.

Remove use of __P() (actually P()) from code now that it's no longer
available.

Fix fd leak. Threads people: does the call above to `access' need to be
underscored as well?

PR: 37717
Submitted by: fred@clift.org (slightly modified by me)

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

Remove 'register' keyword.

Don't mung the user's tm_sec field if we don't need to. (Belt-and-suspenders
version.)

PR: bin/27630
Submitted by: Arthur David Olson <ado@nci.nih.gov>
Obtained from: Timezone mailing-list <tz@elsie.nci.nih.gov>
MFC after: 1 month

Don't depend on lcl_mutex being a recursive mutex.

Reviewed by: deischen

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

Temporary cosmetic change to prevent gcc-2.95.2 from doing an
optimization that generates code our current as doesn't understand.

The result is bad code that damages dynamic symbol locations at
runtime. Ouch. See PR bin/16862 and discussion in -current.

This change will be backed out when gcc and gas are back in sync.

PR: Fixes bin/16862, but not the underlying problem.
Submitted by: bde
Approved by: jdk

Simplify sytem call renaming. Instead of _foo() <-- _libc_foo <-- foo(),
just use _foo() <-- foo(). In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate. In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().

Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().

Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().

Make thread cancellation fully POSIX-compliant.

Suggested by: deischen

Add three-tier symbol naming in support of POSIX thread cancellation
points. For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep(). The arrows represent weak aliases. For
system calls, the pattern is _read() <-- _libc_read() <-- read().

Merge from vendor branch: timezone file structure changes and doco.
Fix localtime.c to deal with new magic number field.

Obtained from: ftp://elsie.nci.nih.gov/pub/tzcode1999a.tar.gz

Make ctime_r, asctime_r, gmtime_r, and localtime_r available in libc.

Replace memory leaking instances of realloc with non-leaking reallocf.
In some cases replace if (a == null) a = malloc(x); else a =
realloc(a, x); with simple reallocf(a, x). Per ANSI-C, this is
guaranteed to be the same thing.

I've been running these on my system here w/o ill effects for some
time. However, the CTM-express is at part 6 of 34 for the CAM
changes, so I've not been able to do a build world with the CAM in the
tree with these changes. Shouldn't impact anything, but...

Add a #ifdef _THREAD_SAFE around ctime_r

ctime_r and asctime_r are not implemented.
prototypes in time.h do not match POSIX.

PR: 6345
Reviewed by: phk
Submitted by: Dmitry Khrustalev <dima@xyzzy.machaon.ru>

Change in name of the static initializer define.

Submitted by: Jeremy Allison (jallison@whistle.com)
fix a slight confusion about which draft of threads we are supporting.
this allows something as big and ugly as samba to be compiled with libc_r
and still work! our user-level pthreads seems amazingly robust!

Back out 1.14 until I reproduce trouble reports

Don't open the tz file if we're running setuid or setgid to prevent infomration
leakage.

Submitted by: Julian Assange

Submitted by: John Birrell
uthreads update from the author.

When attempting to load a `lastditch' timezone (e.g., because the load
of the user's timezone failed), don't bail if the specified timezone
doesn't have an offset; in this case it isn't going to. (Perhaps it would
be better to change the caller to always supply one, but this is quick
and clean and fixes the bug in the easiest possible way.)

Should be in 2.2. Fixes (properly) PR#1740.

Parameters for localtime_r() and gmtime_r() definitions changed.
Parameters for pthread_getspecific() call changed.
pthread_keycreate() renamed to pthread_key_create().

Require that a timezone specified via the TZ envariable be a regular
file (and not a directory or a device which might also be readable).
Closes PR#1740.

Submitted by: John Birrell <cimaxp1!jb@werple.net.au>

Here are the diffs for libc_r to get it one step closer to P1003.1c
These make most of the thread/mutex/condvar structures opaque to the
user. There are three functions which have been renamed with _np
suffixes because they are extensions to P1003.1c (I did them for JAVA,
which needs to suspend/resume threads and also start threads suspended).

I've created a new header (pthread_np.h) for the non-POSIX stuff.

The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented
doesn't work. I think its best to delete it. I don't think libc_r needs
tags anyway, 'cause most of the source is in libc which does have tags.

also:

Here's the first batch of man pages for the thread functions.
The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was
inherited from /usr/src/lib/libc/Makefile that should only be done with
libc.

also:

I should have sent this diff with the pthread(3) man page.
It allows people to type

make -DWANT_LIBC_R world

to get libc_r built with the rest of the world. I put this in the
pthread(3) man page. The default is still not to build libc_r.


also:
The diff attached adds a pthread(3) man page to /usr/src/share/man/man3.
The idea is that without libc_r installed, this man page will give people
enough info to know that they have to build libc_r.

Merge the recently-imported tzcode96h distribution (libc portion). The
part that does zic(8)/zdump(8) is still yet to be imported (but the old
zic and zdump will work just fine with these header files and the
data format has not changed).

Removed false copyrights...

Added in appropriate Berkeley copyright and RCS Id: string

Closes PR#doc/536

Reviewed by: julian and (hsu?)
Submitted by: John Birrel(L?)

changes for threadsafe operations

The European Commission went out and invented a new sort of summer-time
changeover, so we have to extend the format of timezone files (in a backward-
compatible way, of course). This probably means that libc needs a minor
version number bump before 2.2 is released (or maybe not).

Remove trailing whitespace.

Port to FreeBSD. Not ready for inclusion in libc just yet, but here
so we can compile zic.

This commit was generated by cvs2svn to compensate for changes in r2710,
which included commits to RCS files with non-trunk default branches.

One more try, and if it doesn't work this time I'm giving up.
(Check in original localtime.c.)

The rest of tzcode94g from Arthur David Olson.

Obtained From: Arthur David Olson, ftp://elsie.nci.nih.gov/pub/tzcode94g.tar.gz