r355473 vastly improved the readability and cleanliness of these Makefiles.
Every single one of them follows the same pattern and duplicates the exact
same logic.
Now that we have GENERATED/SRCS, split SRCS up into the two parameters we'll
use for ${MAKESYSCALLS} rather than assuming a specific ordering of SRCS and
include a common sysent.mk to handle the rest. This makes it less tedious to
make sweeping changes.
Some default values are provided for GENERATED/SYSENT_*; almost all of these
just use a 'syscalls.master' and 'syscalls.conf' in cwd, and they all use
effectively the same filenames with an arbitrary prefix. Most ABIs will be
able to get away with just setting GENERATED_PREFIX and including
^/sys/conf/sysent.mk, while others only need light additions. kern/Makefile
is the notable exception, as it doesn't take a SYSENT_CONF and the generated
files are spread out between ^/sys/kern and ^/sys/sys, but it otherwise fits
the pattern enough to use the common version.
Reviewed by: brooks, imp
Nice!: emaste
Differential Revision: https://reviews.freebsd.org/D23197
When either makesyscalls.lua or syscalls.master changes, all of the
${GENERATED} targets are now out-of-date. With make jobs > 1, this means we
will run the makesyscalls script in parallel for the same ABI, generating
the same set of output files.
Prior to r356603 , there is a large window for interlacing output for some
of the generated files that we were generating in-place rather than staging
in a temp dir. After that, we still should't need to run the script more
than once per-ABI as the first invocation should update all of them. Add
.ORDER to do so cleanly.
Reviewed by: brooks
Discussed with: sjg
Differential Revision: https://reviews.freebsd.org/D23099
Use the power of variable to avoid spelling out source and generated
files too many times. The previous Makefiles were hard to read, hard to
edit, and badly formatted.
Reviewed by: kevans, emaste
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22714
- Use ustringp for the location of the argv and environment strings
and allow destp to travel further down the stack for the stackgap
and auxv regions.
- Update the Linux copyout_strings variants to move destp down the
stack as was done for the native ABIs in r263349.
- Stop allocating a space for a stack gap in the Linux ABIs. This
used to hold translated system call arguments, but hasn't been used
since r159992.
Reviewed by: kib
Tested on: md64 (amd64, i386, linux64), i386 (i386, linux)
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22501
flua is bootstrapped as part of the build for those on older
versions/revisions that don't yet have flua installed. Once upgraded past
r354833, "make sysent" will again naturally work as expected.
Reviewed by: brooks
Differential Revision: https://reviews.freebsd.org/D21894
syscalls.conf is included using "." which per the Open Group:
If file does not contain a <slash>, the shell shall use the search
path specified by PATH to find the directory containing file.
POSIX shells don't fall back to the current working directory.
Submitted by: Nathaniel Wesley Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: bdrewery
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D20476
Given a zeroed struct image_args with an allocated buf member,
exec_args_add_fname() must be called to install a file name (or NULL).
Then zero or more calls to exec_args_add_env() followed by zero or
more calls to exec_args_add_env(). exec_args_adjust_args() may be
called after args and/or env to allow an interpreter to be prepended to
the argument list.
To allow code reuse when adding arg and env variables, begin_envv
should be accessed with the accessor exec_args_get_begin_envv()
which handles the case when no environment entries have been added.
Use these functions to simplify exec_copyin_args() and
freebsd32_exec_copyin_args().
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15468
Even though pthreads doesn't support this, there are various alternative
APIs that use this. For example, uv_cond_timedwait() accepts a relative
timeout. So does Rust's std::sync::Condvar::wait_timeout().
Though I personally think that relative timeouts are bad (due to
imprecision for repeated operations), it does seem that people want
this. Extend the existing futex functions to keep track of whether an
absolute timeout is used in a boolean flag.
MFC after: 1 month
Compared to the previous version, v0.16, there are a couple of minor
changes:
- CLOUDABI_AT_PID: Process identifiers for CloudABI processes.
Initially, BSD process identifiers weren't exposed inside the runtime,
due to them being pretty much useless inside of a cluster computing
environment. When jobs are scheduled across systems, the BSD process
number doesn't act as an identifier. Even on individual systems they
may recycle relatively quickly.
With this change, the kernel will now generate a UUIDv4 when executing
a process. These UUIDs can be obtained within the process using
program_getpid(). Right now, FreeBSD will not attempt to store this
value. This should of course happen at some point in time, so that it
may be printed by administration tools.
- Removal of some unused structure members for polling.
With the polling framework being simplified/redesigned, it turns out
some of the structure fields were not used by the C library. We can
remove these to keep things nice and tidy.
Obtained from: https://github.com/NuxiNL/cloudabi
The most important change in this release is the removal of the
poll_fd() system call; CloudABI's equivalent of kevent(). Though I think
that kqueue is a lot saner than many of its alternatives, our
experience is that emulating this system call on other systems
accurately isn't easy. It has become a complex API, even though I'm not
convinced this complexity is needed. This is why we've decided to take a
different approach, by looking one layer up.
We're currently adding an event loop to CloudABI's C library that is API
compatible with libuv (except when incompatible with Capsicum).
Initially, this event loop will be built on top of plain inefficient
poll() calls. Only after this is finished, we'll work our way backwards
and design a new set of system calls to optimize it.
Interesting challenges will include integrating asynchronous I/O into
such a system call API. libuv currently doesn't aio(4) on Linux/BSD, due
to it being unreliable and having undesired semantics.
Obtained from: https://github.com/NuxiNL/cloudabi
Now that all of the packaged software has been adjusted to either use
Flower (https://github.com/NuxiNL/flower) for making incoming/outgoing
network connections or can have connections injected, there is no longer
need to keep accept() around. It is now a lot easier to write networked
services that are address family independent, dual-stack, testable, etc.
Remove all of the bits related to accept(), but also to
getsockopt(SO_ACCEPTCONN).
With Flower (CloudABI's network connection daemon) becoming more
complete, there is no longer any need for creating any unconnected
sockets. Socket pairs in combination with file descriptor passing is all
that is necessary, as that is what is used by Flower to pass network
connections from the public internet to listening processes.
Remove all of the kernel bits that were used to implement socket(),
listen(), bindat() and connectat(). In principle, accept() and
SO_ACCEPTCONN may also be removed, but there are still some consumers
left.
Obtained from: https://github.com/NuxiNL/cloudabi
MFC after: 1 month
The CloudABI specification has had some minor changes over the last half
year. No substantial features have been added, but some features that
are deemed unnecessary in retrospect have been removed:
- mlock()/munlock():
These calls tend to be used for two different purposes: real-time
support and handling of sensitive (cryptographic) material that
shouldn't end up in swap. The former use case is out of scope for
CloudABI. The latter may also be handled by encrypting swap.
Removing this has the advantage that we no longer need to worry about
having resource limits put in place.
- SOCK_SEQPACKET:
Support for SOCK_SEQPACKET is rather inconsistent across various
operating systems. Some operating systems supported by CloudABI (e.g.,
macOS) don't support it at all. Considering that they are rarely used,
remove support for the time being.
- getsockname(), getpeername(), etc.:
A shortcoming of the sockets API is that it doesn't allow you to
create socket(pair)s, having fake socket addresses associated with
them. This makes it harder to test applications or transparently
forward (proxy) connections to them.
With CloudABI, we're slowly moving networking connectivity into a
separate daemon called Flower. In addition to passing around socket
file descriptors, this daemon provides address information in the form
of arbitrary string labels. There is thus no longer any need for
requesting socket address information from the kernel itself.
This change also updates consumers of the generated code accordingly.
Even though system calls end up getting renumbered, this won't cause any
problems in practice. CloudABI programs always call into the kernel
through a kernel-supplied vDSO that has the numbers updated as well.
Obtained from: https://github.com/NuxiNL/cloudabi
Similar to the change for sendmsg(), create a pointer size independent
implementation of recvmsg() and let cloudabi32 and cloudabi64 call into
it. In case userspace requests one or more file descriptors, call
kern_recvit() in such a way that we get the control message headers in
an mbuf. Iterate over all of the headers and copy the file descriptors
to userspace.
Reduce the potential amount of code duplication between cloudabi32 and
cloudabi64 by creating a cloudabi_sock_recv() utility function. The
cloudabi32 and cloudabi64 modules will then only contain code to convert
the iovecs to the native pointer size.
In cloudabi_sock_recv(), we can now construct an SCM_RIGHTS cmsghdr in
an mbuf and pass that on to kern_sendit().
Right now we're casting uint64_t's to native pointers. This isn't
causing any problems right now, but if we want to provide a 32-bit
compatibility layer that works on 64-bit systems as well, this will
cause problems. Casting a uint32_t to a 64-bit pointer throws a compiler
error.
Introduce a TO_PTR() macro that casts the value to uintptr_t before
casting it to a pointer.
Though uio_resid is of type ssize_t, we need to take into account that
this source file contains an implementation specific to a certain
userspace pointer size. If this file provided 32-bit implementations,
this should have used INT32_MAX, even when running a 64-bit kernel.
This change has no effect, but is simply in preparation for adding
support for running 32-bit CloudABI executables.
Now that we've switched over to using the vDSO on CloudABI, it becomes a
lot easier for us to phase out old features. System call numbering is no
longer something that's part of the ABI. It's fully based on names. As
long as the numbering used by the kernel and the vDSO is consistent
(which it always is), it's all right.
Let's put this to the test by removing a system call (thread_tcb_set())
that's already unused for quite some time now, but was only left intact
to serve as a placeholder. Sync in the new system call table that uses
alphabetic sorting of system calls.
Obtained from: https://github.com/NuxiNL/cloudabi
CloudABI executables already provide support for passing in vDSOs. This
functionality is used by the emulator for OS X to inject system call
handlers. On FreeBSD, we could use it to optimize calls to
gettimeofday(), etc.
Though I don't have any plans to optimize any system calls right now,
let's go ahead and already pass in a vDSO. This will allow us to
simplify the executables, as the traditional "syscall" shims can be
removed entirely. It also means that we gain more flexibility with
regards to adding and removing system calls.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D7438
We're currently seeing how hard it would be to run CloudABI binaries on
operating systems cannot be modified easily (Windows, Mac OS X). The
idea is that we want to just run them without any sandboxing. Now
that CloudABI executables are PIE, this is already a bit easier, but TLS
is still problematic:
- CloudABI executables want to write to the %fs, which typically
requires extra system calls by the emulator every time it needs to
switch between CloudABI's and its own TLS.
- If CloudABI executables overwrite the %fs base unconditionally, it
also becomes harder for the emulator to store a backup of the old
value of %fs. To solve this, let's no longer overwrite %fs, but just
%fs:0.
As CloudABI's C library does not use a TCB, this space can now be used
by an emulator to keep track of its internal state. The executable can
now safely overwrite %fs:0, as long as it makes sure that the TCB is
copied over to the new TLS area.
Ensure that there is an initial TLS area set up when the process starts,
only containing a bogus TCB. We don't really care about its contents on
FreeBSD.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D5836
- Set BI_CAN_EXEC_DYN, so we can execute ET_DYN ELF files in addition to
regular ET_EXECs.
- Provide an AT_BASE entry in the auxiliary vector, so the executable
knows at which address it got loaded and can apply relocations.
Some time ago I made a change to merge together the memory scope
definitions used by mmap (MAP_{PRIVATE,SHARED}) and lock objects
(PTHREAD_PROCESS_{PRIVATE,SHARED}). Though that sounded pretty smart
back then, it's backfiring. In the case of mmap it's used with other
flags in a bitmask, but for locking it's an enumeration. As our plan is
to automatically generate bindings for other languages, that looks a bit
sloppy.
Change all of the locking functions to use separate flags instead.
Obtained from: https://github.com/NuxiNL/cloudabi
The type definitions and constants that were used by COMPAT_CLOUDABI64
are a literal copy of some headers stored inside of CloudABI's C
library, cloudlibc. What is annoying is that we can't make use of
cloudlibc's system call list, as the format is completely different and
doesn't provide enough information. It had to be synced in manually.
We recently decided to solve this (and some other problems) by moving
the ABI definitions into a separate file:
https://github.com/NuxiNL/cloudabi/blob/master/cloudabi.txt
This file is processed by a pile of Python scripts to generate the
header files like before, documentation (markdown), but in our case more
importantly: a FreeBSD system call table.
This change discards the old files in sys/contrib/cloudabi and replaces
them by the latest copies, which requires some minor changes here and
there. Because cloudabi.txt also enforces consistent names of the system
call arguments, we have to patch up a small number of system call
implementations to use the new argument names.
The new header files can also be included directly in FreeBSD kernel
space without needing any includes/defines, so we can now remove
cloudabi_syscalldefs.h and cloudabi64_syscalldefs.h. Patch up the
sources to include the definitions directly from sys/contrib/cloudabi
instead.
In order to make it easier to support CloudABI on ARM64, move out all of
the bits from the AMD64 cloudabi_sysvec.c into a new file
cloudabi_module.c that would otherwise remain identical. This reduces
the AMD64 specific code to just ~160 lines.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3974
There is still one TODO item for these calls: add file descriptor
passing. The data structures are already prepared for this. It's just
the translation that's missing.
Obtained from: http://github.com/NuxiNL/freebsd
Blocking on locks and condition variables can be accomplished by polling
and using the special filters CONDVAR, LOCK_RDLOCK and LOCK_WRLOCK.
For now it wouldn't make sense to implement this functionality into
kqueue() itself, for the reason that they are CloudABI specific and
would require us to resize 'struct kevent' to hold all of the parameters
of interest.
Add a bandaid to the CloudABI poll system call to call into the futex
code directly if it detects specific combinations of events that are
used by the C library.
Obtained from: https://github.com/NuxiNL/freebsd
This change implements two functions, cloudabi64_kevent_copyin() and
cloudabi64_kevent_copyout(), that convert CloudABI structures to
FreeBSD's struct kevent. CloudABI uses two structures: subscription_t
and event_t. The former is used for input, whereas the latter is used
for output. Unlike struct kevent, fields aren't overloaded for multiple
purposes or for separate event types.
For poll() we call into the newly introduced kern_kevent_anonymous()
function that allows us to poll without a file descriptor. This function
is not only used by poll(), but also by functions such as
sleep() and clock_nanosleep().
Reviewed by: jmg
Obtained from: https://github.com/NuxiNL/freebsd
Differential Revision: https://reviews.freebsd.org/D3308
Futex object scopes have been renamed from using their own constants to
simply reusing the existing CLOUDABI_MAP_{PRIVATE,SHARED} flags, as they
are more accurate in this context.
