This has three advantages over write(2)/read(2):
* Fewer context switches and data copies
* Mostly preserves a file's sparseness
* On some file systems (currently NFS 4.2) the file system will perform the
copy in an especially efficient way.
Reviewed by: rmacklem
MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D26377
POSIX is pretty clear that command -v, command -V and type shall write
absolute pathnames. Therefore, we need to prepend the current directory's
name to relative pathnames.
This can happen either when PATH contains a relative pathname or when the
operand contains a slash but is not an absolute pathname.
If job control is not enabled, a background job (... &) ignores SIGINT and
SIGQUIT, but this can be reverted using the trap builtin in the same shell
environment.
Using the set builtin to change options would also revert SIGINT and SIGQUIT
to their previous dispositions.
This broke due to r317298. Calling setsignal() reverts the effect of
ignoresig().
Reported by: bdrewery
MFC after: 1 week
When -H is specified, for kernel threads the command is formatted as
"<proc name>/<td name>" and truncated to MAXCOMLEN. But each of the
proc name and td name may be up to MAXCOMLEN bytes in length.
Also handle the ki_moretdname field to ensure that the full thread name
gets printed. This is already handled correctly when formatting for
"-o tdname".
Reported by: freqlabs
Reviewed by: freqlabs
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25840
I've always found this a little bit confusing:
> sh
$ ^D> sh
$ ^D>
Reviewed by: 0mp, jilles
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25813
realtime priorities
The current `ps -axO rtprio' show threads running at interrupt
priority such as the [intr] thread as '1:48' and threads running
at kernel priority such as [pagedaemon] as normal:4294967260.
This change shows [intr] as intr:48 and [pagedaemon] as kernel:4.
Reviewed by: kib
MFC after: 1 week (together with -r362369)
Differential Revision: https://reviews.freebsd.org/D25660
INTOFF postpones SIGINT processing and INTON enables it again. This is
important so an interactive shell can return to the top level prompt when
Ctrl+C is pressed.
Given that INTON is automatically done when a builtin completes, the part
where onsig() ignores suppressint when in_dotrap is true is both unnecessary
and unsafe. If the trap is for some other signal than SIGINT, arbitrary code
could have been interrupted.
Historically, INTOFF remained in effect for longer.
Reviewed by: bdrewery
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25270
The manual page documents "\$" to expand to either "$" or "#" followed by
a single space. In reality, the single space character is not appended.
PR: 247791
Submitted by: kd-dev@pm.me
MFC after: 7 days
When job control is not enabled, the shell ignores SIGINT while waiting for
a foreground process unless that process exits on SIGINT. In this case, the
foreground process is sleep and it does not exit on SIGINT because the
signal is only sent to the shell. Depending on order of events, this could
cause the SIGINT to be unexpectedly ignored.
On lightly loaded bare metal, the chance of this happening tends to be less
than 0.01% but with higher loads and/or virtualization it becomes more
likely.
Starting the sleep in background and using the wait builtin ensures SIGINT
will not be ignored.
PR: 247559
Reported by: lwhsu
MFC after: 1 week
This flag will now show the processor number on which a process is running.
This change was inspired by PR129965. Initially I didn't think that the
patch attached to it was correct -- it sacrificed ki_estcpu use in "cpu"
for ki_lastcpu and I thought that the old functionality should be kept and
the new (cpu#) one added to it. But I've since discovered that ki_estcpu is
sched_4bsd-specific. What's worse, it represents the same thing as
ki_pctcpu, except ki_pctcpu is universal -- so "%cpu" has been using it
successfully. Therefore, I've decided to replace information based on
ki_estcpu with information based on ki_oncpu/ki_lastcpu.
Key parts of the code and manual changes were borrowed from top(1).
PR: 129965
Reported by: Nikola Knežević
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25377
Fix the rtprio option that for some reason was progessively becoming an
option showing the priority class of threads. In particular:
- use the constants defined in sys/sys/rtprio.h instead of those defined in
sys/sys/priority.h: this helps making clearer that the code actually is
about realtime priorities and not standard scheduler priorities;
- remove the PRI_ITHD case that has nothing to do with realtime priorities;
- convert the priority levels to realtime priority levels using the same
formulas used for pri_to_rtp function in sys/kern/kern_resource.c.
- remove outdated note "101 = not a realtime process" in the man page and
replace it with a more useful reference to man 1 rtprio.
Approved by: src (mckusick), manpages (bcr), gerald (mentor)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25266
If job control is not enabled, background commands shall ignore SIGINT and
SIGQUIT, and it shall be possible to override that ignore in the same shell.
MFC after: 1 week
Use %hs (locale-based encoding) instead of %s (UTF-8) format for
strings that are expected to be in current locale encoding (date/time,
process names/argument list).
PR: 241491
Reviewed by: phil
Differential Revision: https://reviews.freebsd.org/D22160
FreeBSD DD utility has not had support for the O_DIRECT flag, which
is useful to bypass local caching, e.g. for unconditionally issuing
NFS IO requests during testing.
Reviewed by: rgrimes (mentor)
Approved by: rgrimes (mentor, blanket)
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D25066
Historically, we've allowed read() of a directory and some filesystems will
accommodate (e.g. ufs/ffs, msdosfs). From the history department staffed by
Warner: <<EOF
pdp-7 unix seemed to allow reading directories, but they were weird, special
things there so I'm unsure (my pdp-7 assembler sucks).
1st Edition's sources are lost, mostly. The kernel allows it. The
reconstructed sources from 2nd or 3rd edition read it though.
V6 to V7 changed the filesystem format, and should have been a warning, but
reading directories weren't materially changed.
4.1b BSD introduced readdir because of UFS. UFS broke all directory reading
programs in 1983. ls, du, find, etc all had to be rewritten. readdir() and
friends were introduced here.
SysVr3 picked up readdir() in 1987 for the AT&T fork of Unix. SysVr4 updated
all the directory reading programs in 1988 because different filesystem
types were introduced.
In the 90s, these interfaces became completely ubiquitous as PDP-11s running
V7 faded from view and all the folks that initially started on V7 upgraded
to SysV. Linux never supported this (though I've not done the software
archeology to check) because it has always had a pathological diversity of
filesystems.
EOF
Disallowing read(2) on a directory has the side-effect of masking
application bugs from relying on other implementation's behavior
(e.g. Linux) of rejecting these with EISDIR across the board, but allowing
it has been a vector for at least one stack disclosure bug in the past[0].
By POSIX, this is implementation-defined whether read() handles directories
or not. Popular implementations have chosen to reject them, and this seems
sensible: the data you're reading from a directory is not structured in some
unified way across filesystem implementations like with readdir(2), so it is
impossible for applications to portably rely on this.
With this patch, we will reject most read(2) of a dirfd with EISDIR. Users
that know what they're doing can conscientiously set
bsd.security.allow_read_dir=1 to allow read(2) of directories, as it has
proven useful for debugging or recovery. A future commit will further limit
the sysctl to allow only the system root to read(2) directories, to make it
at least relatively safe to leave on for longer periods of time.
While we're adding logic pertaining to directory vnodes to vn_io_fault, an
additional assertion has also been added to ensure that we're not reaching
vn_io_fault with any write request on a directory vnode. Such request would
be a logical error in the kernel, and must be debugged rather than allowing
it to potentially silently error out.
Commented out shell aliases have been placed in root's chsrc/shrc to promote
awareness that grep may become noisy after this change, depending on your
usage.
A tentative MFC plan has been put together to try and make it as trivial as
possible to identify issues and collect reports; note that this will be
strongly re-evaluated. Tentatively, I will MFC this knob with the default as
it is in HEAD to improve our odds of actually getting reports. The future
priv(9) to further restrict the sysctl WILL NOT BE MERGED BACK, so the knob
will be a faithful reversion on stable/12. We will go into the merge
acknowledging that the sysctl default may be flipped back to restore
historical behavior at *any* point if it's warranted.
[0] https://www.freebsd.org/security/advisories/FreeBSD-SA-19:10.ufs.asc
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
MFC after: 1 month (note the MFC plan mentioned above)
Relnotes: absolutely, but will amend previous RELNOTES entry
Differential Revision: https://reviews.freebsd.org/D24596
Austin Group bugs #1226 and #1250 changed the requirements for shell scripts
without #! (POSIX does not specify #!; this is about the shell execution
when execve(2) returns an [ENOEXEC] error).
POSIX says we shall allow execution if the initial part intended to be
parsed by the shell consists of characters and does not contain the NUL
character. This allows concatenating a shell script (ending with exec or
exit) and a binary payload.
In order to reject common binary files such as PNG images, check that there
is a lowercase letter or expansion before the last newline before the NUL
character, in addition to the check for the newline character suggested by
POSIX.
Highlights:
- CLICOLOR in the environment should imply --color=auto to maintain
compatibility with historical behavior
- -G should set CLICOLOR and imply --color=auto
The manpage has been updated to draw the connection between -G and --color;
the former is in-fact a sort of compromise between --color=always and
--color=auto, where we'll output color regardless of the environment lacking
CLICOLOR/COLORTERM assuming stdout is a tty.
X-MFC-With: r361318
The regression is in-fact that I flipped the default from never to auto. The
incorrect impression was based on an alias that I failed to notice,
installed by the Linux distribution that I used for testing compatibility
here. Users that want the old default should be doing so with a shell alias
as is done elsewhere, rather than making this decision in ls(1).
Many thanks to rgrimes for pointing out the alias that I clearly overlooked
that resulted in this; if you despised colors in your terminal from this,
consider buying him a beer at the next venue that you see him at.
MFC after: 1 week
Relnotes: yes
The shell maintains a count of the number of times SIGINT processing has
been disabled via INTOFF, so SIGINT processing resumes when all disables
have enabled again (INTON).
If an error occurs in a vfork() child, the processing of the error enables
SIGINT processing again, and the INTON in vforkexecshell() causes the count
to become negative.
As a result, a later INTOFF may not actually disable SIGINT processing. This
might cause memory corruption if a SIGINT arrives at an inopportune time. As
of r360452, it causes the shell to abort when it would unsafely allocate or
free memory in certain ways.
Note that various places such as errors in non-special builtins
unconditionally reset the count to 0, so the problem might still not always
be visible.
PR: 246497
Reported by: jbeich
MFC after: 2 weeks
Initially it seemed that there were multiple possible ways to do it.
Processing option -p could conditionally add selected processes and
their descendants to the list for further work, but it is not guaranteed
to know whether the -d option has been used or not, and it also doesn't
have access to the process list just yet.
There is also descendant_sort() which has access to all possibly needed
information, but serves the purely post-processing purpose of sorting
output.
Then there is the loop that uses invocation information and full process
list to create a list of processes for final display. It seems the most
natural place to implement this, but indeterminate state of the process
list and volatility of the final list that is being created obstruct
adding an elegant search for all elements of process descendancy trees.
So I opted for adding another loop, just before the one I mentioned
above. For all selected processes it conditionally adds direct
descendants to the end of this list of selected processes.
Possible usage:
* ps -auxd -p $$
* ps -auxd -p 1
* while x=$(pgrep svnlite); do clear; ps auxd -p $x; sleep 2; done
* ps -auxd -p `pgrep make`
Reviewed by: kevans, kaktus (earlier version)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D24380
As I noted in https://reviews.freebsd.org/D22756, INTOFF should be in effect
when calling ckmalloc/ckrealloc/ckfree to avoid memory leaks and double
frees. Therefore, change the functions to check if INTOFF is in effect
instead of applying it.
Reviewed by: bdrewery
Differential Revision: https://reviews.freebsd.org/D24599
r360139 made compiling with NO_HISTORY work. This #define does not remove
the fc and bind builtins completely but makes them always write an error
message.
However, there was also some code in builtins.def and mkbuiltins to remove
the fc builtin entirely (but not the bind builtin). The additional build
system complication to make this work seems not worth it, so remove that
code.
mips-gcc for mips32 was complaining that c was potentially used before
being set. Setting it to 0 before calling fdgetsc() looks like the right
thing to do in this instance; there's an explicit check for c == 0 later
on.
Tested: mips-gcc mips32 build, running /bin/sh on mips32
el is declared extern in myhistedit.h and defined in histedit.c. Remove the
duplicate definition in input.c to appease the -fno-common build.
-fno-common will become the default in GCC10/LLVM11.
MFC after: 3 days
Specifically, any system with a 32-bit size_t; -residue is calculated as a
32-bit *then* promoted to the 64-bit off_t and the result is ultimately
wrong. This resulted in what would appear to be truncated output, as only
the first line would be read.
Correct it by just making residue an off_t to begin with, since this is what
lseek will take anyways.
Reported by: antoine, dim
Triaged by: cem
Tested by: kevans
X-MFC-With: r358152
fd.
The read built-in command calls read(2) with a 1-byte buffer because
newline characters need to be detected even on a byte stream which
comes from a non-seekable file descriptor. Because of this, the
following script calls >6,000 read(2) to show a 6KiB file:
while read IN; do echo "$IN"; done < /COPYRIGHT
When the input byte stream is seekable, it is possible to read a data
block and then reposition the file pointer to where a newline
character found. This change adds a small buffer to do this and
reduces the number of read(2) calls.
Theoretically, multiple built-in commands reading the same seekable
byte stream in a single pipe chain can share the buffer. However,
this change just makes a single invocation of the read built-in
allocate a buffer and deallocate it every time for simplicity.
Although this causes read(2) to read the same regions multiple times,
the performance penalty should be small compared to the reduction of
read(2) calls.
Reviewed by: jilles
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23747
`cat -l` is needed during the installworld phase and other system's cat
don't support that flag. To avoid portability issues when compiling on
Linux/macOS (such as the the direct access to &fp->_mbstate), we
disable the entire multibyte support when building as a boostrap tool.
Reviewed By: brooks, emaste
Differential Revision: https://reviews.freebsd.org/D13939
