for directories. bsdtar used to add this, but that recently got
lost somehow. So now I'm adding it back in libarchive.
The only odd part of doing this in libarchive: Adding a directory to
a tar archive and then reading it back again can yield a different name.
Add a test case to exercise some boundary conditions with
tar filenames and ensure that trailing slashes are added to
dir names only as necessary.
Thanks to: Oliver Lehmann for bringing this regression to my attention.
conditionally use utime() when utimes() is not available;
allow the most common wide-char functions to be replaced
when local alternatives are lacking.
Update the description of the "p6-div" and "p6-mul" events according
to the "Intel(r) 64 and IA-32 Architectures Software Developers
Manual Volume 3B: System Programming Guide, Part 2, November 2006".
Reported by: Harald Servat <redcrash at gmail dot com> [1]
message in the reader to the error message from the writer if the
error which occurred was in the writer. This avoids error messages
of "Empty error message" when extracting truncated archives.
redeclared as static in res_debug.c.
Make __p_rcode_syms global and add it to Symbol map. The rest of
__p_??_syms are already global.
Choice of FBSD_1.0 version for these debug symbols seems strange and
should be revisited before symbol versioning is enabled for libc.so.7.
unmount jail-friendly file systems from within a jail.
Precisely it grants PRIV_VFS_MOUNT, PRIV_VFS_UNMOUNT and
PRIV_VFS_MOUNT_NONUSER privileges for a jailed super-user.
It is turned off by default.
A jail-friendly file system is a file system which driver registers
itself with VFCF_JAIL flag via VFS_SET(9) API.
The lsvfs(1) command can be used to see which file systems are
jail-friendly ones.
There currently no jail-friendly file systems, ZFS will be the first one.
In the future we may consider marking file systems like nullfs as
jail-friendly.
Reviewed by: rwatson
implementation, and mark it as deprecated. It will be removed entirely
in libarchive 3.0 (in FreeBSD 8.0?) but there's no reason for anyone to
use it instead of archive_read_data.
Approved by: kientzle
two values, the latter does not tend to have sign extension
and/or overflow bugs, and makes the code more obvious.
While I'm there, make use of a macro which is derived from
bin/ps/ps.c: ps_compat() to improve the readability of the
code.
Suggested by: bde
MFC after: 1 week
skip over the end-of-entry padding instead of reading and discarding
it.
Considering that tar files normally have a block size of 10kB, this
isn't likely to avoid reading any data, but at least it makes the code
simpler and clearer.
discards it, for use when the compression layer code doesn't know how to
skip data (e.g., everything other than the "none" compressor). This makes
format level code simpler because that code can now assume that the
compression layer always knows how to skip and will always skip exactly
the requested number of bytes.
Discussed with: kientzle (3 months ago)
avoid downcasting issues. In particular, this change fixes
posix_memalign(3) for alignments greater than 2^31 on LP64 systems.
Make sure that NDEBUG is always set to be compatible with MALLOC_DEBUG. [1]
Reported by: [1] Lee Hyo geol <hyogeollee@gmail.com>
trees that track all non-full runs for each bin. Use the red-black
trees to be able to guarantee that each new allocation is placed in the
lowest address available in any non-full run. This change completes the
transition to allocating from low addresses in order to reduce the
retention of sparsely used chunks.
If the run in current use by a bin becomes empty, deallocate the run
rather than retaining it for later use. The previous behavior had the
tendency to spread empty runs across multiple chunks, thus preventing
the release of chunks that were completely unused.
Generalize base_chunk_alloc() (and rename it to base_pages_alloc()) to
handle allocation sizes larger than the chunk size, so that it is
possible to support chunk sizes that are smaller than an arena object.
Reduce the minimum chunk size from 64kB to 8kB.
Optimize tracking of addresses for deleted chunks.
Fix a statistics bug for huge allocations.
with `pw lock', so that it's impossible to log into a locked account
using an alternative authentication mechanism, such as an ssh key.
This change affects only accounts locked with pw(8), i.e., having a
`*LOCKED*' prefix in their password hash field, so people still can
use a different pattern to disable password authentication only.
Mention all account management criteria in the manpage.
Approved by: maintainer (timeout)
PR: bin/71147
MFC after: 1 month
- Correctly retrieve the initial (special) members of an archive after
an archive descriptor is rewound using elf_rand(SARMAG).
- Do not strip trailing white space from the 'raw' names retrieved
using elf_getarhdr().
Reported by: "Hyo geol, Lee" <hyogeollee at gmail dot com>
rounding and overflow. Carefully document what the various overflow
tests actually detect.
The bugs mostly canceled out, such that the worst possible failure
cases resulted in non-fatal over-allocations.
Don't change permissions on an existing dir unless _EXTRACT_PERM
is requested.
In particular, bsdtar -x should not edit mode of existing dirs
now; bsdtar -xp will.
than binary buddies, the alignment guarantees are weaker, which requires
a more complex aligned allocation algorithm, similar to that used for
alignment greater than the chunk size.
Reported by: matteo
chunks. This allows runs to be any multiple of the page size. The
primary advantage is that large objects are no longer constrained to be
2^n pages, which can dramatically decrease internal fragmentation for
large objects. This also allows the sizes for runs that back small
objects to be more finely tuned.
Free runs are searched for linearly using the chunk page map (with the
help of some heuristic optimizations). This changes the allocation
policy from "first best fit" to "first fit". A prototype red-black tree
implementation for tracking free runs that implemented "first best fit"
did not cause a measurable speed or memory usage difference for
realistic chunk sizes (though of course it is possible to construct
benchmarks that favor one allocation policy over another).
Refine the handling of fullness constraints for small runs to be more
tunable.
Restructure the per chunk page map to contain only two fields per entry,
rather than four. Also, increase each entry from 4 to 8 bytes, since it
allows for 32-bit integers, without increasing the number of chunk
header pages.
Relax the maximum chunk size constraint. This is of no practical
interest; it is merely fallout from the chunk page map restructuring.
Revamp statistics gathering and reporting to be faster, clearer and more
informative. Statistics gathering is fast enough now to have little
to no impact on application speed, but it still requires approximately
two extra pages of memory per arena (per process). This memory overhead
may be acceptable for most systems, but we still need to leave
statistics gathering disabled by default in RELENG branches.
Rename NO_MALLOC_EXTRAS to MALLOC_PRODUCTION in order to make its intent
clearer (i.e. it should be defined in RELENG branches).
avoid substantial potential bloat for static binaries that do not
otherwise use any printf(3)-family functions. [1]
Rearrange arena_run_t so that the region bitmask can be minimally sized
according to constraints related to each bin's size class. Previously,
the region bitmask was the same size for all run headers, which wasted
a measurable amount of memory.
Rather than making runs for small objects as large as possible, make
runs as small as possible such that header overhead stays below a
certain bound. There are two exceptions that override the header
overhead bound:
1) If the bound is impossible to honor, it is relaxed on a
per-size-class basis. Since there is one bit of header
overhead per object (plus a constant), it is impossible to
achieve a header overhead less than or equal to 1/(# of bits
per object). For the current setting of maximum 0.5% header
overhead, this relaxation comes into play for {2, 4, 8,
16}-byte objects, for which header overhead is (on 64-bit
systems) {7.1, 4.3, 2.2, 1.2}%, respectively.
2) There is still a cap on small run size, still set to 64kB.
This comes into play for {1024, 2048}-byte objects, for which
header overhead is {1.6, 3.1}%, respectively.
In practice, this reduces the run sizes, which makes worst case
low-water memory usage due to fragmentation less bad. It also reduces
worst case high-water run fragmentation due to non-full runs, but this
is only a constant improvement (most important to small short-lived
processes).
Reduce the default chunk size from 2MB to 1MB. Benchmarks indicate that
the external fragmentation reduction makes 1MB the new sweet spot (as
small as possible without adversely affecting performance).
Reported by: [1] kientzle
prefix) as an argument and mount point path. At the end it has to find
device name file system is stored on, which means when mount point path is
given, it tries to look into /etc/fstab and find special device
corresponding to the given mount point. This is not perfect, because it
doesn't handle the case when file system is mounted by hand and mount point
is given as an argument.
I found this problem while trying to use snapinfo(8), which passes mount
points to the ufs_disk_fillout(3) function, but I had file system mounted
manually, so snapinfo(8) was exiting with the error below:
ufs_disk_fillout: No such file or directory
I modified libufs(3) to handle those arguments (the order is important):
1. special device with /dev/ prefix
2. special device without /dev/ prefix
3. mount point listed in /etc/fstab, directory exists
4. mount point listed in /etc/fstab, directory doesn't exist
5. mount point of a file system mounted by hand
- moved away from ifn/ifa access to sctp_ifa/sctp_ifn
built and managed by the add-ip code.
- cleaned up add-ip code to use the iterator
- made iterator be a thread, which enables auto-asconf now.
- rewrote and cleaned up source address selection (also
made it use new structures).
- Fixed a couple of memory leaks.
- DACK now settable as to how many packets to delay as
well as time.
- connectx() to latest socket API, new associd arg.
- Fixed issue with revoking and loosing potential to
send when we inflate the flight size. We now inflate
the cwnd too and deflate it later when the revoked
chunk is sent or acked.
- Got rid of some temp debug code
- src addr selection moved to a common file (sctp_output.c)
- Support for simple VRF's (we have support for multi-vfr
via compile switch that is scrubbed from BSD but we won't
need multi-vrf until we first get VRF :-D)
- Rest of mib work for address information now done
- Limit number of addresses in INIT/INIT-ACK to
a #def (30).
Reviewed by: gnn
* Only try to remove the existing item if we're not restoring a directory.
* If unlink fails, try rmdir next.
This should fix the broken --unlink option in bsdtar.
Thanks again to: Kris Kennaway, for beating up bsdtar on pointyhat.
* The ACL formatter was mis-formatting entries which had a
user/group ID but no name. Make the parser tolerant of
these, so that old archives can be correctly restored;
fix the formatter to generate correct entries.
* Fix overwrite detection by introducing a new "FAILED" return
code that indicates the current entry cannot be continued
but the archive as a whole is still sound.
* Header cleanup: Remove some unused headers, add some that
are required with new Linux systems.
- first line is $FreeBSD$
- Reorder special variables: DPADD, LPADD, CFLAGS
- Use = instead of += for variables that are initially empty
- Use space instead of tab after :
- Use one tab after =
- Use .SUFFIXES for section 3 manual page which simplifies Makefile a lot
- Use SHAREDIR instead of /usr/share
- Remove SRCDIR in INCS since we set .PATH properly
- Use plural in variable name when it stands for more that one source file
Reviewed by: ru
Approved by: delphij (mentor)
These tests verify that archive_entry objects can store and return
ACL data and that pax format archives can read and write ACL
information. These do not (yet) test that ACL data is read or
written to disk correctly. (And hence would not have caught the
recent snafu about ACL read-from-disk being turned off.)
ACL data from the archive entry. This doesn't impact
archive_read_extract or archive_write_disk since they only
check for != ARCHIVE_OK when calling this function. (Though
they should be more careful.)
poll(2) or kqueue(2). Previously we rejected fd's higher than FD_SETSIZE
for kevent(2), and larger than sysconf(_SC_OPEN_MAX) for poll(2). However,
the check for poll(2) wasn't really needed. open(2) and socket(2) won't
return an fd you can't pass to either poll(2) or kevent(2). This fixes
a but where gethostbyname() would fail if you had more than 1023 files
open in a process.
MFC after: 1 week
Reviewed by: ume
Found by: ps
child thread goes back to system scope rather than process
scope. This allows an ensuing exec() to actually work.
This change was made a year ago here, but I "forgot" to
commit it :(
Approved by: deischen
MFC after: 3 weeks
Add IMPLEMENTATION NOTES section explaining in detail the effect this
system call has in common use cases involving PF_INET and PF_INET6 sockets.
PR: kern/84761
MFC after: 2 days
behind _FREEFALL_CONFIG). This is done mainly to make NIS even more
resistant to packet loss.
This is not enabled by default for "normal" FreeBSD since it might cause
the server providing the RPC service to be hit heavily with RPC traffic
in case of problems. freefall.FreeBSD.org and hub.FreeBSD.org have been
running with a patch similar to this for a couple of weeks.
MFC after: 1 week
Discussed with: peter
packet loss when talking to a NIS server.
- Set 1 second retry timeout to further realistically handle UDP
packet loss for yp_next packet bursts. If the packet hasn't come
back within 1 second its rather unlikely to come back at all. There
is still back-off mechanism in RPC so if there is another reason
than packet loss for the lack of response within 1 second, the NIS
server will not be totally bombarded with requests.
This reduces the risk of NIS failing with:
yp_next: clnt_call: RPC: Timed out
considerably. This is mainly a problem if you have larger NIS maps
(like at FreeBSD.org) since enumerations of the lists will cause a UDP
packet bursts where a few packets being lost once in a while do
happen.
MFC after: 1 week
Discussed with: peter
Problem mainly diagnosed by: peter
* libarchive_test program exercises many of the core features
* Refactored old "read_extract" into new "archive_write_disk", which
uses archive_write methods to put entries onto disk. In particular,
you can now use archive_write_disk to create objects on disk
without having an archive available.
* Pushed some security checks from bsdtar down into libarchive, where
they can be better optimized.
* Rearchitected the logic for creating objects on disk to reduce
the number of system calls. Several common cases now use a
minimum number of system calls.
* Virtualized some internal interfaces to provide a clearer separation
of read and write handling and make it simpler to override key
methods.
* New "empty" format reader.
* Corrected return types (this ABI breakage required the "2.0" version bump)
* Many bug fixes.
copy the symlink target name, not just copy the reference.
This problem sometimes caused crashes when extracting
symlinks from ISO9660 images.
Thanks to: Diego "Flameeyes" Pettenò
in FreeBSD, and originated from INRIA IPv6.
Stub out netstat reference to addr2ascii() I mistakenly introduced.
Update misleading man page sections.
Merge NetBSD's getnameinfo() AF_LINK extensions for a portable way to
print link-layer addresses given a sockaddr_dl(), minus the IEEE 1394
bits which don't map directly to our code.
Obtained from: NetBSD (getnameinfo.c)
Discussed on: current (March 2006)
acl_from_text.c. Since acl_from_text.c is the only place it
is used, we can now make this internal utility function "static."
As a bonus, acl_set_fd() no longer pulls in getpwuid() for no reason.
MFC after: 7 days
This has no impact unless USE_BRK is defined (32-bit platforms), in
which case user allocations are allocated via mmap() if at all possible,
in order to avoid the possibility of unreclaimable chunks in the data
segment.
Fix an obscure bug in base_alloc() that could have allowed undefined
behavior if an application were to use sbrk() in conjunction with a
USE_BRK-enabled malloc.
called with only one address, we then can call the
generic system call. Also fixes some socket api
type issues and cleans up the "magic" numbers that
were being used in the code.
Reviewed by: gnn
- Restore support for fetching swap information from crash dumps via
kvm_get_swapinfo(3) to fix pstat -T/-s on crash dumps.
Reviewed by: arch@, phk
MFC after: 1 week
Fallout from changing the skip API to use off_t instead of size_t: Print
the skip length using %jd and cast to (intmax_t) instead of %d / (int),
and if ARCHIVE_API_VERSION >= 2, allow the client skipper to be called
for requests longer than SSIZE_MAX. [2]
Approved by: kientzle
Pointy hats to: kientzle [1], cperciva [2]
MFC after: 3 days
Point out that FreeBSD libc has compat stubs for GNU glibc NSS
modules which access NSDB_PASSWD/NSDB_GROUP, but not NSDB_HOSTS;
based on painful experience porting nss_mdns.
Reviewed by: ru
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.
effective group ID (and any of our group) doesn't match the group ID of the
file, we get EPERM. This doesn't conform POSIX. POSIX requires that we should
return 0, but silently clear the set-gid bit.
a vanilla 2-clause BSD license, but somehow some confusing
extra verbage get copied from somewhere.
Also, update the copyright dates to 2007 for all of the files.
Prompted by: several questions about what those extra words really mean
bogusly used the kvm_powerpc.c file as a template for the license, but
then either wrote the code himself, or cribbed it from the kvm_i386
file. The only thing from the kvm_powerpc.c file was the license.
Correct this mistake with his blessing.
- O_NONBLOCK flag has to be set, if it is not set, open(2) will wait for
another process opening the fifo for reading,
- Use O_WRONLY which implies that the file has to be opened _only_ for write.
This is quite tricky situation, because we allow to open a file with
O_RDONLY|O_TRUNC. O_TRUNC modifies a file, but we actually don't open
it for writing. EISDIR is also returned when we try to open a directory
O_RDONLY|O_TRUNC, which is correct.
POSIX says that "The result of using O_TRUNC with O_RDONLY is undefined.",
we choose to accept it (Solaris did the same), that's why "to be modified"
seems more accurate to me.
Details: As a side-effect of restoring a saved FP environment,
fesetenv() overwrites the tag word, which indicates which i387
registers are in use. Normally this isn't a problem because
the calling convention requires the register stack to be empty
on function entry and exit. However, fesetenv() is inlined, so we
need to tell gcc explicitly that the i387 registers get clobbered.
PR: 85101
wrap this within #if/#else/#endif so that it will only take effect once
ARCHIVE_API_VERSION is increased (which should happen on HEAD some time
between now and when RELENG_7 is branched).
returning the length skipped in a ssize_t to using off_t for both. This
does not break any A[BP]Is, since compression_skip is entirely internal
to libarchive.
If a skip request is > SSIZE_MAX, don't pass it down to the client layer
skip function, since those still uses size_t / ssize_t. Instead, just
read the data and throw it away.
With this commit, libarchive/bsdtar should now successfully skip archive
entries of >2GB on 32-bit systems, but does so slower than necessary.
The performance will improve with a future A[BP]I breaking commit which
makes client layer skip functions use off_t.
Discussed with: kientzle
MFC after: 1 week
functions are required to skip the requested distance, so we can avoid
lots of bookkeeping which would otherwise be necessary.
Reviewed by: kientzle
MFC after: 1 week
members of the ELF Executable Header inside the library-private
`struct _Elf' descriptor and only update the underlying Elf{32,64}_Ehdr
structure on an elf_update(3) call. These fields of the Ehdr
structure are technically `out of bounds' for an application program
per the ELF(3) API, but we've seen applications that initialize
a new Ehdr structure using memcpy(), messing up the library's
invariants. [1]
Implement elf_getphnum() and handle ELF objects with more than
64K program header table entries.
Reported by: jb [1]
conversion of negative numbers to always result in -1.
While at it, rearrange the nearby comment so it fits in 80 chars per line,
like the rest of this file does.
PR: 107130
MFC after: 1 day
chunk per arena, rather than immediately deallocating all unused chunks.
This fixes a potential performance issue when allocating/deallocating
an object of size (4kB..1MB] in a loop.
Reported by: davidxu
they become candidates for reuse. Without this fix, some of the
state from a thread structure's previous incarnation could interfere
with its new one. Specifically, a non-bound thread started as
"suspended" (see pthread_attr_setcreatesuspend_np()) might not get
scheduled at all when resumed, as the "active" flag would be set
spuriously.
Reviewed by: deischen@, davidxu@
MFC after: 1 week
to determine which Elf Types are to be handled. Change the M4
templates to wrap an `#if __FreeBSD_version >= NNN'/`#endif' pair
around the generated code for each ELF data type, where `NNN' is
the OS version where the ELF type was added to the source tree.
This change allows cross-builds of old sources on newer FreeBSD
systems to work correctly.
Problem reported by: ru
_thr_ucond_broadcast, clear condition variable pointer in cancellation
info after returing from _thr_ucond_wait, since kernel has already
dropped the internal lock, so we don't need to unlock it in cancellation
handler again.
flag set, rmdir(2) returns EPERM.
- If the parent directory of the directory to be removed has its immutable or
append-only flag set, rmdir(2) returns EPERM.
immutable or append-only flag set, rename(2) returns EPERM.
- If the parent directory of the file pointed at by the to argument has its
immutable flag set, rename(2) returns EPERM.
config_freebsd.h. archive_platform.h decides which config file
to bring in and uses some of those selectors to define wrapper
macros and other compatibility glue.
is also returned by pthread_detach() if a thread was already
detached, the error code was already documented:
> [EINVAL] The implementation has detected that the value speci-
> fied by thread does not refer to a joinable thread.
* Correct a signed/unsigned problem that broke handling of files >2G.
* Implement "skip" support for much faster "tar -t".
Thanks to: Robert Sciuk for sending me a DVD that illustrated the first problem
* If write block size is zero, don't block at all.
This supports the unusual requirement of applications
that need "no-delay" writes.
* Expose _write_finish_entry() to give such applications more
control over write boundaries. (Normal applications do not
need this, as entries are completed automatically.)
* Correct the type of write callbacks; this is a minor API
change that does not affect the ABI.
* Correct the error handling in _write_next_header() around
completing the previous entry.
* Correct the documentation for block-size markers: Remove
docs for the long-defunct _read_set_block_size(); document
all of the write block size manipulators.
MFC after: 14 days
traditional shortcut of defining on-disk layouts using structures of
character arrays. Unfortunately, as recently discussed on cvs-all@,
this usage is not actually sanctioned by the standards and
specifically fails on GCC/arm (unless your data structures happen to
be "naturally aligned").
The new code defines offsets/sizes for data fields and accesses
them using explicit pointer arithmetic, instead of casting to
a structure and accessing structure fields. In particular,
the new code is now clean with WARNS=6 on arm.
MFC after: 14 days
and correct the use of unary minus with an unsigned value. (The unary
minus here is actually being used as a bitwise operation, which is
unusual enough to deserve a clarifying cast.)
archive_{read,write}_open_filename():
* Update Makefile to build the files using the new name.
* Update docs to document the new names, mentioning the
old ones as "deprecated synonyms."
* The old filenames will be reconnected to the build soon;
I'll soon recyce those files for a slightly different purpose.
internal format-specific functions return the same as the public
function, so that the public API layer doesn't have to guess the
correct return value. This addresses an obscure problem that occurs
when someone tries to write more data than the size of the entry (as
indicated in the entry header). In this case, the return value from
archive_write_data() was incorrect, reflecting the requested write
rather than the amount actually written.
MFC after: 15 days
- make document title match filename;
- remove hard sentence breaks, whitespace at EOL, and double whitespace;
- sort SEE ALSO xrefs, adding missing section numbers;
- fix a misspelled macro name.
* Use public API, don't access struct archive directly. (People should be able to copy these into their applications as a template for custom I/O callbacks.)
* Set "skip" only for regular files. ("skip" allows the low-level library to catch attempts to add an archive to itself or extract over itself.)
* Simplify the write_open functions by just calling stat() at the beginning. Somehow, these functions had acquired some complex logic that tried to avoid the stat() call but never succeeded.
MFC after: 10 days
file. This doesn't happen in normal use, because the file I/O and
decompression layers only pass through smaller blocks. It can happen
with custom read functions that block I/O in larger blocks.
* Actually use the HAVE_<header>_H macros to conditionally include
system headers. They've been defined for a long time, but only
used in a few places. Now they're used pretty consistently
throughout.
* Fill in a lot of missing casts for conversions from void*.
Although Standard C doesn't require this, some people have been
trying to use C++ compilers with this code, and they do require it.
Bit-for-bit, the compiled object files are identical, except for
one assert() whose line number changed, so I'm pretty confident I
didn't break anything. ;-)
h_errno is not an extern int, just a macro providing an integer lvalue.
PR: doc/50573
Submitted by: Ronald F.Guilmette <rfg@monkeys.com>
Reviewed by: trhodes
MFC after: 3 days
following fix:
Retransmission timeouts should be based on which attempt
it is to the nameserver and not the nameserver itself.
Obtained from: ISC
MFC after: 3 days
Remove the const qualifier from ap argument for __v2printf, that induced
that breakage, and seems to be the real reason for bad code. ap is modified
inside the __v2printf body by va_arg macro.
Pointy hat to: kib
Approved by: pjd (mentor)
i386 with default optimization level (-O2), va_list pointer ap in the
__v2printf function is advanced before the use. That cause argument
shift and garbage instead last argument in printf-family when xprintf is
activated.
The nsswitch is easy victim of the bug.
Reviewed by: kan
Approved by: kan (mentor)
MFC after: 1 week
Issue __sflush() before possible setting O_APPEND mode or ftruncate(),
write to wrong place may occurse oserwise.
Use simplified _sseek() to the start, if no O_APPEND is set, instead
of _fseeko() (_sseek() to the end, if O_APPEND, occurse later, as for
file != NULL).
Don't check seek error return, as original fopen() and freopen() never
does.
file != NULL:
Add missing _sseek() to the end.
thread signal mask has been updated to avoid stack overflow during signal
bursts.
Don't block signal forever if no threads can currently handle signal.
Check for pending signal after direct invocation of signal handler.
UNIX signalling semantics require that processes in the same
session always be able to deliver SIGCONT to one another,
overriding the remaining protections.
Fix SIGCONT special case description similar to rev. 1.22 kill.2.
PR: docs/58710
Submitted by: Ryan Younce
MFC after: 2 weeks
