Commit graph

178 commits

Author SHA1 Message Date
Simon J. Gerraty f77b5b295d Allow -DNO_STRICT_REGEX to restore historic regex behavior
Allow restoring the behavior of '{' as described in regex(3).
Ie. only treat it as start of bounds if followed by a digit.

If NO_STRICT_REGEX is not defined, the behavior introduced by
commit a4a801688c is retained,
otherwise the previous behavior is restored.

Differential Revision:	https://reviews.freebsd.org/D45134
2024-05-09 18:29:43 -07:00
Corinna Vinschen 619f455b8f regex: fix freeing g->charjump in low memory condition
computejumps() moves g->charjump to a position relativ to the value of
CHAR_MIN.  As such, g->charjump doesn't necessarily point to the address
actually allocated.  While regfree() takes that into account, the low
memory handling in regcomp_internal() doesn't.  Fix that by free'ing
the actually allocated address, as in regfree().

MFC After: 2 weeks
Reviewed by: imp,jrtc27
Pull Request: https://github.com/freebsd/freebsd-src/pull/692
2024-02-02 11:51:54 -07:00
Bill Sommerfeld 8f7ed58a15 regex: mixed sets are misidentified as singletons
Fix "singleton" function used by regcomp() to turn character set matches
into exact character matches if a character set has exactly one
element.

The underlying cset representation is complex; most critically it
records"small" characters (codepoint less than either 128
or 256 depending on locale) in a bit vector, and "wide" characters in
a secondary array.

Unfortunately the "singleton" function uses to identify singleton sets
treated a cset as a singleton if either the "small" or the "wide" sets
had exactly one element (it would then ignore the other set).

The easiest way to demonstrate this bug:

	$ export LANG=C.UTF-8
	$ echo 'a' | grep '[abà]'

It should match (and print "a") but instead it doesn't match because the
single accented character in the set is misinterpreted as a singleton.

Reviewed by:	kevans, yuripv
Obtained from:	illumos
Differential Revision:	https://reviews.freebsd.org/D43149
2023-12-22 12:19:59 +07:00
Warner Losh dc36d6f9bb lib: Remove ancient SCCS tags.
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by:		Netflix
2023-11-26 22:23:28 -07:00
Brooks Davis 1ca63a8219 libc: Remove empty comments in Symbol.map
These were left over from $FreeBSD$ removal.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D42612
2023-11-15 17:51:03 +00:00
Warner Losh 559a218c9b 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
2023-11-01 16:44:30 -06:00
Christos Zoulas 3fb80f1476 regcomp: use unsigned char when testing for escapes
- cast GETNEXT to unsigned where it is being promoted to int to prevent
  sign-extension (really it would have been better for PEEK*() and
  GETNEXT() to return unsigned char; this would have removed a ton of
  (uch) casts, but it is too intrusive for now).
- fix an isalpha that should have been iswalpha

PR:		264275, 274032
Reviewed by:	kevans, eugen (previous version)
Obtained from:	NetBSD
Differential Revision:	https://reviews.freebsd.org/D41947
2023-09-26 00:49:14 +02:00
Warner Losh b2c76c41be Remove $FreeBSD$: one-line nroff pattern
Remove /^\.\\"\s*\$FreeBSD\$$\n/
2023-08-16 11:55:15 -06:00
Warner Losh d0b2dbfa0e Remove $FreeBSD$: one-line sh pattern
Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/
2023-08-16 11:55:03 -06:00
Warner Losh 1d386b48a5 Remove $FreeBSD$: one-line .c pattern
Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/
2023-08-16 11:54:42 -06:00
Warner Losh 42b388439b Remove $FreeBSD$: one-line .h pattern
Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/
2023-08-16 11:54:23 -06:00
Ed Maste 5b5fa75acf libc: drop "All rights reserved" from Foundation copyrights
This has already been done for most files that have the Foundation as
the only listed copyright holder.  Do it now for files that list
multiple copyright holders, but have the Foundation copyright in its own
section.

Sponsored by:	The FreeBSD Foundation
2022-08-04 16:57:50 -04:00
Jessica Clarke 0aa8b18bc9 libc: Fix regexec when sizeof(char *) > sizeof(long)
The states macro is the type for engine.c to use, with states1 being a
local macro for regexec to use to determine whether it can use the small
matcher or not (by comparing nstates and 8*sizeof(states1)). However,
macro bodies are expanded in the context of their use, and so when
regexec uses states1 it uses the current value of states, which is left
over as char * from the large version (or, really, the multi-byte one,
but that reuses large's states). For all supported architectures in
FreeBSD, the two have the same size, and so this confusion is harmless.
However, for architectures like CHERI where that is not the case (or
Windows's LLP64 as discovered by LLVM and fixed in 2010 in 2e071faed8e2)
and sizeof(char *) is bigger than sizeof(long) regexec will erroneously
try to use the small matcher when nstates is between sizeof(long) and
sizeof(char *) (i.e. between 64 and 128 on CHERI, or 32 and 64 on LLP64)
and end up overflowing the number of bits in the underlying long if it
ever uses those high states. On weirder architectures where sizeof(long)
is greater than sizeof(char *) this also fixes it to not fall back on
the large matcher prematurely, but such architectures are likely limited
to the embedded space, if they exist at all.

Fix this by swapping round states and states1, so that states1 is
defined directly as being long and states is an alias for it for the
small matcher case.

Found by:	CHERI
2021-12-23 16:38:10 +00:00
Miod Vallat d36b5dbe28 libc: regex: rework unsafe pointer arithmetic
regcomp.c uses the "start + count < end" idiom to check that there are
"count" bytes available in an array of char "start" and "end" both point to.

This is fine, unless "start + count" goes beyond the last element of the
array. In this case, pedantic interpretation of the C standard makes the
comparison of such a pointer against "end" undefined, and optimizers from
hell will happily remove as much code as possible because of this.

An example of this occurs in regcomp.c's bothcases(), which defines
bracket[3], sets "next" to "bracket" and "end" to "bracket + 2". Then it
invokes p_bracket(), which starts with "if (p->next + 5 < p->end)"...

Because bothcases() and p_bracket() are static functions in regcomp.c, there
is a real risk of miscompilation if aggressive inlining happens.

The following diff rewrites the "start + count < end" constructs into "end -
start > count". Assuming "end" and "start" are always pointing in the array
(such as "bracket[3]" above), "end - start" is well-defined and can be
compared without trouble.

As a bonus, MORE2() implies MORE() therefore SEETWO() can be simplified a
bit.

PR:		252403
2021-01-08 13:58:35 -06:00
Kyle Evans 4afa7dd61a libc: regex: retire internal EMPTBR ("Empty branch present")
It was realized just a little too late that this was a hack that belonged in
individual regex(3)-using applications. It was surrounded in NOTYET and not
implemented in the engine, so remove it.
2020-12-05 03:18:48 +00:00
Kyle Evans 6b986646d4 libregex: implement \b and \B (word boundary, not word boundary)
This is the last of the needed GNU expressions before we can unleash bsdgrep
by default. \b is effectively an agnostic equivalent of \< and \>, while
\B will match every space that isn't making a transition from
nonchar -> char or char -> nonchar.
2020-12-05 03:16:05 +00:00
Kyle Evans ca53e5aedf libregex: implement \` and \' (begin-of-subj, end-of-subj)
These are GNU extensions, generally equivalent to ^ and $ except that the
new syntax will not match beginning of line after the first in a multi-line
expression or the end of line before absolute last in a multi-line
expression.
2020-12-05 03:13:47 +00:00
Kyle Evans 7518fb346f libc: regex: factor out ISBOW/ISEOW macros
These will be reused for \b (word boundary, which matches both sides).

No functional change.
2020-12-05 02:23:11 +00:00
Kyle Evans 18a1e2e9b9 libregex: Implement a subset of the GNU extensions
The entire patch-set is not yet mature enough for commit, but this usable
subset is generally enough for googletest to be happy with and mostly map to
some existing concepts, so they're not as invasive.

The specific changes included here are:

- Branching in BREs with \|
- \w and \W for [[:alnum:]] and [^[:alnum:]] respectively
- \s and \S for [[:space:]] and [^[:space:]] respectively
- Additional quantifiers in BREs, \? and \+ (self-explanatory)

There's some #ifdef'd out work for allowing empty branches as a match-all.
This is a feature that's under assessment... future work will determine
how standard this behavior is and act accordingly.
2020-08-04 02:14:51 +00:00
Kyle Evans ba8b64de05 regex(3): belatedly document REG_POSIX from r363734
My original patch included this documented, but it appears that I failed to
include the manpage update. Do so now.
2020-08-04 02:06:49 +00:00
Kyle Evans adeebf4cd4 regex(3): Interpret many escaped ordinary characters as EESCAPE
In IEEE 1003.1-2008 [1] and earlier revisions, BRE/ERE grammar allows for
any character to be escaped, but "ORD_CHAR preceded by an unescaped
<backslash> character [gives undefined results]".

Historically, we've interpreted an escaped ordinary character as the
ordinary character itself. This becomes problematic when some extensions
give special meanings to an otherwise ordinary character
(e.g. GNU's \b, \s, \w), meaning we may have two different valid
interpretations of the same sequence.

To make this easier to deal with and given that the standard calls this
undefined, we should throw an error (EESCAPE) if we run into this scenario
to ease transition into a state where some escaped ordinaries are blessed
with a special meaning -- it will either error out or have extended
behavior, rather than have two entirely different versions of undefined
behavior that leave the consumer of regex(3) guessing as to what behavior
will be used or leaving them with false impressions.

This change bumps the symbol version of regcomp to FBSD_1.6 and provides the
old escape semantics for legacy applications, just in case one has an older
application that would immediately turn into a pumpkin because of an
extraneous escape that's embedded or otherwise critical to its operation.

This is the final piece needed before enhancing libregex with GNU extensions
and flipping the switch on bsdgrep.

[1] http://pubs.opengroup.org/onlinepubs/9699919799.2016edition/

PR:		229925 (exp-run, courtesy of antoine)
Differential Revision:	https://reviews.freebsd.org/D10510
2020-07-29 23:21:56 +00:00
Yuri Pankov 3c78771400 lib/libc/regex: fix build with REDEBUG defined
Reviewed by:	kevans
Differential Revision:	https://reviews.freebsd.org/D21760
2019-09-24 12:21:01 +00:00
Yuri Pankov e2a87ae3af regcomp: revert part of r341838 which turned out to be unrelated
and caused issues with search in less.

PR:		234066
Reviewed by:	pfg
Differential revision:	https://reviews.freebsd.org/D18611
2018-12-19 23:28:56 +00:00
Yuri Pankov 547bc083d6 regcomp: reduce size of bitmap for multibyte locales
This fixes the obscure endless loop seen with case-insensitive
patterns containing characters in 128-255 range;  originally
found running GNU grep test suite.

Our regex implementation being kludgy translates the characters
in case-insensitive pattern to bracket expression containing both
cases for the character and doesn't correctly handle the case when
original character is in bitmap and the other case is not, falling
into the endless loop going through in p_bracket(), ordinary(),
and bothcases().

Reducing the bitmap to 0-127 range for multibyte locales solves this
as none of these characters have other case mapping outside of bitmap.
We are also safe in the case when the original character outside of
bitmap has other case mapping in the bitmap (there are several of those
in our current ctype maps having unidirectional mapping into bitmap).

Reviewed by:	bapt, kevans, pfg
Differential revision:	https://reviews.freebsd.org/D18302
2018-12-12 04:23:00 +00:00
Yuri Pankov 63cbe8d1d9 regexec: fix processing multibyte strings.
Matcher function incorrectly assumed that moffset that we get from
findmust is in bytes. Fix this by introducing a stepback function,
taking short path if MB_CUR_MAX is 1, and going back byte-by-byte,
checking if we have a legal character sequence otherwise.

PR:		153502
Reviewed by:	pfg, kevans
Approved by:	kib (mentor, implicit)
Differential revision:	https://reviews.freebsd.org/D18297
2018-11-23 15:49:18 +00:00
Toomas Soome 307546ec52 regex/engine.c: error: variable 'dp' set but not used
The issue found with gcc6 build (originally on illumos, confirmed on FreeBSD).
Mark it __unused.

Differential Revision:	https://reviews.freebsd.org/D13109
2018-07-14 09:29:45 +00:00
Kyle Evans fe5bf674e6 Add missing patch from r328240
regcomp uses some libc internal collation bits that are not available in the
libregex context. It's easy enough to bring in the needed parts that can
work in a libregex world, so do so.

Pointy hat to:	me
2018-01-22 02:58:33 +00:00
Kyle Evans b37f6c9805 Add libregex, connect it to the build
libregex is a regex(3) implementation intended to feature GNU extensions and
any other non-POSIX compliant extensions that are deemed worthy.

These extensions are separated out into a separate library for the sake of
not cluttering up libc further with them as well as not deteriorating the
speed (or lack thereof) of the libc implementation.

libregex is implemented as a build of the libc implementation with LIBREGEX
defined to distinguish this from a libc build. The reasons for
implementation like this are two-fold:

1.) Maintenance- This reduces the overhead induced by adding yet another
regex implementation to base.

2.) Ease of use- Flipping on GNU extensions will be as simple as linking
against libregex, and POSIX-compliant compilations can be guaranteed with a
REG_POSIX cflag that should be ignored by libc/regex and disables extensions
in libregex. It is also easier to keep REG_POSIX sane and POSIX pure when
implemented in this fashion.

Tests are added for future functionality, but left disconnected for the time
being while other testing is done.

Reviewed by:	cem (previous version)
Differential Revision:	https://reviews.freebsd.org/D12934
2018-01-22 02:44:41 +00:00
Kyle Evans 4f8f1c798e regex(3): Resolve issues with higher WARNS levels
libc is set for WARNS=2, but the incoming libregex will use WARNS=6.
Sprinkle some casts and (void)bc's to alleviate the warnings that come along
with the higher WARNS level.

These 'bc' parameters could be outright removed, but as of right now they
will be used in some parts of libregex land. Silence the warnings instead
rather than flip-flopping.
2018-01-21 04:57:29 +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
Pedro F. Giffuni 0f23ab8aac Fix out-of-bounds read in libc/regex.
The bug is an out-of-bounds read detected with address sanitizer that
happens when 'sp' in p_b_coll_elems() includes NUL byte[s], e.g. if it's
equal to "GS\x00". In that case len will be equal to 4, and the
strncmp(cp->name, sp, len) call will succeed when cp->name is "GS" but the
cp->name[len] == '\0' comparison will cause the read to go out-of-bounds.

Checking the length using strlen() instead eliminates the issue.

The bug was found in LLVM with oss-fuzz:
	https://reviews.llvm.org/D39380

MFC after:	1 week
Obtained from:	Vlad Tsyrklevich through posting on openbsd-tech
2017-10-28 20:09:34 +00:00
Kyle Evans a0bf5d8a68 regex(3): Refactor fast/slow stepping bits in the matching engine
Adding features for matching is fairly straightforward, but this requires
some duplication because of this fast/slow setup. They can be fairly
trivially combined into a single walk(), so do it to make future additions
less error prone.

Reviewed by:	cem (earlier version), emaste, pfg
Approved by:	emaste (mentor)
Differential Revision:	https://reviews.freebsd.org/D11233
2017-08-09 01:04:36 +00:00
Kyle Evans a4a801688c regex(3): Handle invalid {} constructs consistently and adjust tests
Currently, regex(3) exhibits the following wrong behavior as demonstrated
with sed:

 - echo "a{1,2,3}b" | sed -r "s/{/_/"     (1)
 - echo "a{1,2,3}b" | sed "s/\}/_/"       (2)
 - echo "a{1,2,3}b" | sed -r "s/{}/_/"    (3)

Cases (1) and (3) should throw errors but they actually succeed, and (2)
throws an error when it should match the literal '}'. The correct behavior
was decided by comparing to the behavior with the equivalent BRE (1)(3) or
ERE (2) and consulting POSIX, along with some reasonable evaluation.

Tests were also adjusted/added accordingly.

PR:		166861
Reviewed by:	emaste, ngie, pfg
Approved by:	emaste (mentor)
MFC after:	never
Differential Revision:	https://reviews.freebsd.org/D10315
2017-08-08 04:10:46 +00:00
Kyle Evans 79c9a695c3 Correctly ignore branch operators in the top-level parser when applicable.
An oversight in r320742 caused BREs to become sensitive to the branching operator prematurely, which caused
breakage in some limited situations -- namely, those that tried to use branching in a BRE. Most of these scenarios
had already been corrected beforehand to properly use gsed or grep for GNU extensions, so the damage is
slightly mitigated.

Reported by: antoine

Reported by:	antoine
Approved by:	emaste (mentor)
Differential Revision:	https://reviews.freebsd.org/D11522
2017-07-07 22:00:39 +00:00
Kyle Evans 3ea376f690 Fix sparc64 libc build after r320742.
p_branch_empty was declared but never used due to an oversight. Use it as
designed, further comment on its return value.

Reported by:	Jenkins (head-sparc64)
Reviewed by:	emaste
Approved by:	emaste (mentor)
MFC with:	r320742
Differential Revision:	https://reviews.freebsd.org/D11506
2017-07-06 18:21:30 +00:00
Kyle Evans 15ae9efabe The impending libregex will implement GNU extensions to bring BREs and
EREs closer together. Prepare for this and reduce the diff of libregex changes by
refactoring and combining the top-level parsers for EREs/BREs ahead of time.

Branching functionality has been split out to make it easier to follow the combined
version of the top-level parser. It may also be enabled in the parsing context to make
it easier when libregex enables branching for BREs.

A branching context was also added for the various branching functions and so that
BREs, for instance, can determine if they're the first expression in a chain of expressions
within the current branch and treat '*' as ordinary if so.

This should have no functional impact and negligible performance impact.

Reviewed by:	cem, emaste, pfg
Approved by:	emaste (mentor)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D10920
2017-07-06 17:01:51 +00:00
Brooks Davis 9806ef7852 Correct an out-of-bounds read in regcomp when the RE is bad.
When passed the invalid regular expression "a**", the error is
eventually detected and seterr() is called. It sets p->error
appropriatly and p->next and p->end to nuls which is a never used char
nuls[10] which is zeros due to .bss initialization. Unfortunatly,
p_ere_exp() and p_simp_re() both have fall through cases where they set
the error, decrement p->next and access it which means a read from what
ever .bss variable comes before nuls.

Found with regex_test:repet_multi and CHERI bounds checking.

Reviewed by:	ngie, pfg, emaste
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D10541
2017-05-02 21:20:27 +00:00
Pedro F. Giffuni 8d0f9a9364 regex: unsign and constify some variables.
Taking some hints from the regex variant in nvi(1) and higher-level
compiler warnings, update some types in our regex(3) implementation.

Joint work with:	Kyle Evans
MFC after:		2 weeks
2017-04-23 21:51:29 +00:00
Pedro F. Giffuni 9f36610f9e libc: provide some bounds-checking through reallocarray(3).
reallocarray(3) is a non portable extension that originated in OpenBSD.
Given that it is already in FreeBSD's libc it is useful for the cases
where reallocation involves a multiplication.

MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D9955
2017-03-12 16:03:34 +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
Gleb Smirnoff efe3b0de14 Remove SVR4 (System V Release 4) binary compatibility support.
UNIX System V Release 4 is operating system released in 1988. It ceased
to exist in early 2000-s.
2017-02-28 05:14:42 +00:00
Enji Cooper d0fd0203fb Replace dot-dot relative pathing with SRCTOP-relative paths where possible
This reduces build output, need for recalculating paths, and makes it clearer
which paths are relative to what areas in the source tree. The change in
performance over a locally mounted UFS filesystem was negligible in my testing,
but this may more positively impact other filesystems like NFS.

LIBC_SRCTOP was left alone so Juniper (and other users) can continue to
manipulate lib/libc/Makefile (and other Makefile.inc's under lib/libc) as
include Makefiles with custom options.

Discussed with:	marcel, sjg
MFC after:	1 week
Reviewed by:	emaste
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D9207
2017-01-20 03:23:24 +00:00
Enji Cooper a0888761e8 Use SRCTOP where possible and use :H to manipulate .CURDIR to get rid of
unnecessarily long relative path .PATH values with make

MFC after:	1 days
Sponsored by:	Dell EMC Isilon
2017-01-17 03:58:37 +00:00
Andrey A. Chernov 12eae8c8f3 1) Eliminate possibility to call __*collate_range_cmp() with inclomplete
locale (which cause core dump) by removing whole 'table' argument
by which it passed.

2) Restore __collate_range_cmp() in __sccl().

3) Collating [a-z] range in regcomp() only for single bytes locales
(we can't do it now for other ones). In previous state only first 256
wchars are considered and all others are just silently dropped from the
range.
2016-07-14 09:07:25 +00:00
Andrey A. Chernov 1daad8f5ad Back out non-collating [a-z] ranges.
Instead of changing whole course to another POSIX-permitted way
for consistency and uniformity I decide to completely ignore missing
regex fucntionality and concentrace on fixing bugs in what we have now,
too many small obstacles instead, counting ports.
2016-07-14 08:18:12 +00:00
Andrey A. Chernov 5a5807dd4c Remove broken support for collation in [a-z] type ranges.
Only first 256 wide chars are considered currently, all other are just
dropped from the range. Proper implementation require reverse tables
database lookup, since objects are really big as max UTF-8 (1114112
code points), so just the same scanning as it was for 256 chars will
slow things down.

POSIX does not require collation for [a-z] type ranges and does not
prohibit it for non-POSIX locales. POSIX require collation for ranges
only for POSIX (or C) locale which is equal to ASCII and binary for
other chars, so we already have it.

No other *BSD implements collation for [a-z] type ranges.

Restore ABI compatibility with unused now __collate_range_cmp() which
is visible from outside (will be removed later).
2016-07-10 03:49:38 +00:00
Pedro F. Giffuni 3c2c0c0443 libc/locale: Fix type breakage in __collate_range_cmp().
When collation support was brought in, the second and third
arguments in __collate_range_cmp() were changed from int to
wchar_t, breaking the ABI. Change them to a "char" type which
makes more sense and keeps the ABI compatible.

Also introduce __wcollate_range_cmp() which does work with wide
characters. This function is used only internally in libc so
we don't export it. Use the new function in glob(3), fnmatch(3),
and regexec(3).

PR:		179721
Suggested by:	ache. jilles
MFC after:	3 weeks (perhaps partial only)
2016-06-05 19:12:52 +00:00
Pedro F. Giffuni 93ea9f9fa1 libc: regexec(3) adjustment.
Change the behavior of when REG_STARTEND is combined with REG_NOTBOL.

From the original posting[1]:

"Enable the assumption that pmatch[0].rm_so is a continuation offset
to  a string and allows us to do a proper assessment of the character
in  regards to it's word position ('^' or '\<'), without risking going
into unallocated memory."

This change makes us similar to how glibc handles REG_STARTEND |
REG_NOTBOL, and is closely related to a soon-to-land fix to sed.

Special thanks to Martijn van Duren and Ingo Schwarze for working
out some consistent behaviour.

Differential Revision:	https://reviews.freebsd.org/D6257
Taken from:	openbsd-tech 2016-05-24 [1]  (Martijn van Duren)
Relnotes:	yes
MFC after:	1 month
2016-05-25 15:35:23 +00:00
Pedro F. Giffuni e9fe9edde7 libc/regex: fix two buffer underruns.
Fix some rather complex regex issues found on OpenBSD as part of some
ongoing work to fix a sed(1) bug.

Curiously the OpenBSD tests don't trigger segfaults on FreeBSD but the
bugs were confirmed by running a port of FreeBSD's regex under OpenBSD's
malloc. Huge thanks to Ingo for confirming the behavior.

Taken from:	Ingo Schwarze (through openbsd-tech 2016-05-15)
MFC after:	1 week
2016-05-21 19:54:10 +00:00
Pedro F. Giffuni 32223c1b7d libc: spelling fixes.
Mostly on comments.
2016-04-30 01:24:24 +00:00