This is an import of the Google Summer of Code 2018 project completed by
Christian Kramer (and, sadly, ignored by us for two years now). The goals
stated for that project were:
FreeBSD already has support for interrupts implemented in the GPIO
controller drivers of several SoCs, but there are no interfaces to take
advantage of them out of user space yet. The goal of this work is to
implement such an interface by providing descriptors which integrate
with the common I/O system calls and multiplexing mechanisms.
The initial imported code supports the following functionality:
- A kernel driver that provides an interface to the user space; the
existing gpioc(4) driver was enhanced with this functionality.
- Implement support for the most common I/O system calls / multiplexing
mechanisms:
- read() Places the pin number on which the interrupt occurred in the
buffer. Blocking and non-blocking behaviour supported.
- poll()/select()
- kqueue()
- signal driven I/O. Posting SIGIO when the O_ASYNC was set.
- Many-to-many relationship between pins and file descriptors.
- A file descriptor can monitor several GPIO pins.
- A GPIO pin can be monitored by multiple file descriptors.
- Integration with gpioctl and libgpio.
I added some fixes (mostly to locking) and feature enhancements on top of
the original gsoc code. The feature ehancements allow the user to choose
between detailed and summary event reporting. Detailed reporting provides
a record describing each pin change event. Summary reporting provides the
time of the first and last change of each pin, and a count of how many times
it changed state since the last read(2) call. Another enhancement allows
the recording of multiple state change events on multiple pins between each
call to read(2) (the original code would track only a single event at a time).
The phabricator review for these changes timed out without approval, but I
cite it below anyway, because the review contains a series of diffs that
show how I evolved the code from its original state in Christian's github
repo for the gsoc project to what is being commited here. (In effect,
the phab review extends the VC history back to the original code.)
Submitted by: Christian Kramer
Obtained from: https://github.com/ckraemer/freebsd/tree/gsoc2018
Differential Revision: https://reviews.freebsd.org/D27398
Repeating the default WARNS here makes it slightly more difficult to
experiment with default WARNS changes, e.g. if we did something absolutely
bananas and introduced a WARNS=7 and wanted to try lifting the default to
that.
Drop most of them; there is one in the blake2 kernel module, but I suspect
it should be dropped -- the default WARNS in the rest of the build doesn't
currently apply to kernel modules, and I haven't put too much thought into
whether it makes sense to make it so.
Save the last callout function pointer (and its argument) executed
on each CPU for inspection by a debugger. Add a ddb `show callout_last`
command to show these pointers. Add a kernel module that I used
for testing that command.
Relocate `ce_migration_cpu` to reduce padding and therefore preserve
the size of `struct callout_cpu` (320 bytes on amd64) despite the
added members.
This should help diagnose reference-after-free bugs where the
callout's mutex has already been freed when `softclock_call_cc`
tries to unlock it.
You might hope that the pointer would still be available, but it
isn't. The argument to that function is on the stack (because
`softclock_call_cc` uses it later), and that might be enough in
some cases, but even then, it's very laborious. A pointer to the
callout is saved right before these newly added fields, but that
callout might have been freed. We still have the pointer to its
associated mutex, and the name within might be enough, but it might
also have been freed.
Reviewed by: markj jhb
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20794
r235274 added a sort regression test (it operates by comparing output
against GNU sort). The commit included a number of 0-byte files, one
of which ends in a trailing . which reportedly breaks svn/git checkouts
on Windows.
It appears these were added accidentally, so just remove them.
PR: 232479
MFC after: 1 month
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.
listen, and connect. The listen program is a simple server that
accepts and closes sockets, until a fixed limit, then sets the listen
queue to 0 and counts how many remaining connections it processes.
The connect program repeatedly opens connections and closes them
serving as the driver for the listen program.
Sponsored by: Limelight Networks
test suite as tests/sys/posixshm
Some other highlights:
- Convert the testcases over to ATF
- Don't use hardcoded paths to /tmp (which violate the ATF/kyua samdbox); use
mkstemp to generate temporary paths for non-SHM_ANON shm objects.
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
Some users build FreeBSD as non-root in Perforce workspaces. By default,
Perforce sets files read-only unless they're explicitly being edited.
As a result, the -f argument must be used to cp in order to override the
read-only flag when copying source files to object directories. Bare use of
'cp' should be avoided in the future.
Update all current users of 'cp' in the src tree.
Reviewed by: emaste
MFC after: 1 week
Sponsored by: Spectra Logic
At least one test doesn't work yet without gcc, however gcc is
not always available in base. Using the environment compiler
is more trustable and will also work with an external compiler.
Reviewed by: markj
MFC after: 3 days
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.
executable ksh scripts. These are currently not copied into the test
directory the way that compiled executables are, so the tests which make use
of them cannot work. This changes the test Makefile to copy the scripts into
the test directory.
expect the installed ksh binary to be named "ksh", which is not the case
when it's installed on FreeBSD via the shells/ksh93 port. Allow for it to be
"ksh93" as well so that the tests can actually pass.
trivial handler for SIGCHLD is installed, and SIGCHLD is blocked, to
not abandon our zombies to init(8). This way, the zombies are around
slightly longer, allowing to actually exercise the logic for p_pwait
use by the test.
MFC after: 1 week
comply with standards.
On modern branches there is an undocumented alias (see r219084) but on
stable/7 this is still an error.
Sponsored by: Cisco Systems, Inc.
MFC after: 3 days
