The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
understand which code paths aren't possible.
This commit eliminates 117 false positive bug reports of the form
"allocate memory; error out if pointer is NULL; use pointer".
Portability Utilities" option.
Often configure scripts generated by the autotools test if $LINENO works and
refuse to use /bin/sh if not.
Package test run by: pav
to type int.
- Change the type used for arithmetic expansion to intmax_t (ie. 64 bit on all
currently supported FreeBSD architectures). SUSv3 requires at least type
long but allows for larger types. Other shells (eg. bash, zsh, NetBSD's sh)
do that too.
PR: 122659
Submitted by: Jaakko Heinonen (minor modifications by me)
are used to modify the arguments. Not doing so caused random memory reads or
null pointer dereferences when 'getopts' was called again later (SUSv3 says
getopts produces unspecified results in this case).
PR: 48318
computes the new path and the second one, updatepwd(), updates the variables
PWD, OLDPWD and the path used for the pwd builtin according to the new
directory. For a logical directory change, chdir() is now called between
those two functions, no longer causing wrong values to be stored in PWD etc. if
it fails.
PR: 64990, 101316, 120571
on platforms with unsigned chars. The comparison in question is there to
determine whether chars are unsigned or not and is based on comparing a
char, initialized to -1, for less than 0. Change the comparison to check
for geater than 0 instead...
setenv(3) by tracking the size of the memory allocated instead of using
strlen() on the current value.
Convert all calls to POSIX from historic BSD API:
- unsetenv returns an int.
- putenv takes a char * instead of const char *.
- putenv no longer makes a copy of the input string.
- errno is set appropriately for POSIX. Exceptions involve bad environ
variable and internal initialization code. These both set errno to
EFAULT.
Several patches to base utilities to handle the POSIX changes from
Andrey Chernov's previous commit. A few I re-wrote to use setenv()
instead of putenv().
New regression module for tools/regression/environ to test these
functions. It also can be used to test the performance.
Bump __FreeBSD_version to 700050 due to API change.
PR: kern/99826
Approved by: wes
Approved by: re (kensmith)
Not because I admit they are technically wrong and not because of bug
reports (I receive nothing). But because I surprisingly meets so
strong opposition and resistance so lost any desire to continue that.
Anyone who interested in POSIX can dig out what changes and how
through cvs diffs.
1) Under POSIX unsetenv("foo=bar") is explicit error and not equal
to unsetenv("foo")
2) Prepare for upcomig POSIXed putenv() rewrite: make putenv() calls
portable and conforming to standard.
either -v or -V) if a file with a slash in the name doesn't exist (if there is
no slash we already did that).
Additionally, suppress the error message for command -v for files with a slash.
PR: 107674
Submitted by: Martin Kammerhofer
issue a syntax error immediately but save the information that it is erroneous
for later when the parameter expansion is actually done. This means eg. "false
&& ${}" will not generate an error which seems to be required by POSIX.
Include the invalid parameter expansion in the error message (sometimes
abbreviated with ... because recovering it would require a lot of code).
PR: 105078
Submitted by: emaste
process leader for each job. Now the last specified option for the output
format (-l, -p or -s) wins, previously -s trumped -l.
PR: 99926
Submitted by: Ed Schouten and novel (patches modified by me)
Utilities option. Its value is printed at the beginning of the line if tracing
(-x) is active. PS4 defaults to the string "+ " which is compatible with the
old behaviour to always print "+ ".
We still need to expand variables in PS1, PS2 and PS4.
PR: 46441 (part of)
Submitted by: schweikh
Obtained from: NetBSD
.//dir as /dir. Rather strip it only for the purpose of checking if the
directory path should be printed.
PR: 88813
Submitted by: Josh Elsasser
Patch from: NetBSD (cd.c rev 1.38)
MFC after: 2 weeks
own buffer. Interactively typing in long lines (>1023 characters)
previously overflowed the buffer. Unlike the NetBSD people I don't see the
need to subtract 8 from BUFSIZ, so I just used BUFSIZ-1.
Obtained from: NetBSD
PR: 91110
I would have chosen the EOF markers, but they are no longer available
AFAICS, so output "<<HERE" and "<<XHERE" instead.
(NOTE: These changes only affect DEBUG output.)
demanded by POSIX.
- A redirection error is only fatal (meaning the execution of a shell script is
terminated) for special built-ins. Previously it was fatal for all shell
builtins, causing problems like the one reported in PR 88845.
- Variable assignments remain in effect for special built-ins.
- Option or operand errors are only fatal for special built-ins.
This change also makes errors from 'fc' non-fatal (I could not find any reasons
for this behaviour).
Somewhat independently from the above down-grade the error handling in the
shift built-in if the operand is bigger than $# from an error() call (which is
now fatal) to a return 1. I'm not sure if this should be considered a POSIX
"operand error", however this change is needed for now as we trigger that error
while building libncurses. Comparing with other shells, zsh does the same as
our sh before this change (write a diagnostic, return 1), bash behaves as our
sh after this commit (no diagnostic, return 1) and ksh93 and NetBSD's sh treat
it as a fatal error.
is just ". file" according to POSIX, however many other shells allow
arguments to be passed after the file. For compatibility (we even use that
feature in buildworld) additional arguments are not considered to be an
error, even though this shell does not do anything with the arguments at all.
new member to struct builtincmd and set it to 1 if -s was specified. This
is done because there are cases where special builtins must be treated
differently from other builtins.
Obtained from: NetBSD (builtins.def part)
automatically it is possible wait4(2) returns -1 and sets
errno = ECHILD if there were forked children. A user can
set such signal handler e.g. via ``trap "" 20'', see a PR
for the test case. Deal with this case and mark a job as
JOBDONE.
PR: bin/90334
Submitted by: bde
MFC after: 4 weeks
This makes a difference for the trap builtin, where after "trap '' 0" we
printed "trap -- quit". This is wrong, because an empty action means to reset
the action to the default. A side effect of this commit is that empty
variables are now printed as "variable=''" instead of just "variable=".
