| 27852ebe | 21-Feb-2016 |
David van Moolenbroek <david@minix3.org> |
UDS: full rewrite
This new implementation of the UDS service is built on top of the
libsockevent library. It thereby inherits all the advantages that
libsockevent brings. However, the fundamental
UDS: full rewrite
This new implementation of the UDS service is built on top of the
libsockevent library. It thereby inherits all the advantages that
libsockevent brings. However, the fundamental restructuring
required for that change also paved the way for resolution of a
number of other important open issues with the old UDS code. Most
importantly, the rewrite brings the behavior of the service much
closer to POSIX compliance and NetBSD compatibility. These are the
most important changes:
- due to the use of libsockevent, UDS now supports multiple suspending
calls per socket and a large number of standard socket flags and
options;
- socket address matching is now based on <device,inode> lookups
instead of canonized path names, and socket addresses are no longer
altered either due to canonization or at connect time;
- the socket state machine is now well defined, most importantly
resolving the erroneous reset-on-EOF semantics of the old UDS, but
also allowing socket reuse;
- sockets are now connected before being accepted instead of being
held in connecting state, unless the LOCAL_CONNWAIT option is set
on either the connecting or the listening socket;
- connect(2) on datagram sockets is now supported (needed by syslog),
and proper datagram socket disconnect notification is provided;
- the receive queue now supports segmentation, associating ancillary
data (in-flight file descriptors and credentials) with each segment
instead of being kept fully separately; this is a POSIX requirement
(and needed by tmux);
- as part of the segmentation support, the receive queue can now hold
as many packets as can fit, instead of one;
- in addition to the flags supported by libsockevent, the MSG_PEEK,
MSG_WAITALL, MSG_CMSG_CLOEXEC, MSG_TRUNC, and MSG_CTRUNC send and
receive flags are now supported;
- the SO_PASSCRED and SO_PEERCRED socket options are replaced by
LOCAL_CREDS and LOCAL_PEEREID respectively, now following NetBSD
semantics and allowing use of NetBSD libc's getpeereid(3);
- memory usage is reduced by about 250 KB due to centralized in-flight
file descriptor tracking, with a limit of OPEN_MAX total rather than
of OPEN_MAX per socket;
- memory usage is reduced by another ~50 KB due to removal of state
redundancy, despite the fact that socket path names may now be up to
253 bytes rather than the previous 104 bytes;
- compared to the old UDS, there is now very little direct indexing on
the static array of sockets, thus allowing dynamic allocation of
sockets more easily in the future;
- the UDS service now has RMIB support for the net.local sysctl tree,
implementing preliminary support for NetBSD netstat(1).
Change-Id: I4a9b6fe4aaeef0edf2547eee894e6c14403fcb32
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| 491d647a | 25-Jul-2016 |
David van Moolenbroek <david@minix3.org> |
VFS: support for suspending close(2) for sockets
This change effectively adds the VFS side of support for the SO_LINGER
socket option, by allowing file descriptor close operations to be
suspended (a
VFS: support for suspending close(2) for sockets
This change effectively adds the VFS side of support for the SO_LINGER
socket option, by allowing file descriptor close operations to be
suspended (and later resumed) by socket drivers. Currently, support
is limited to the close(2) system call--in all other cases where file
descriptors are closed (dup2, close-on-exec, process exit..), the
close operation still completes instantly. As a general policy, the
close(2) return value will always indicate that the file descriptor
has been closed: either 0, or -1 with errno set to EINPROGRESS. The
latter error may be thrown only when a suspended close is interrupted
by a signal.
As necessary for UDS, this change also introduces a closenb(2) system
call extension, allowing the caller to bypass blocking SO_LINGER close
behavior. This extension allows UDS to avoid blocking on closing the
last reference to an in-flight file descriptor, in an atomic fashion.
The extension is currently part of libsys, but there is no reason why
userland would not be allowed to make this call, so it is deliberately
not protected from use by userland.
Change-Id: Iec77d6665232110346180017fc1300b1614910b7
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| 6956dd2b | 05-Oct-2016 |
David van Moolenbroek <david@minix3.org> |
libc: bugfixes for minix's poll(3) wrapper
- clear "revents" fields even when the call times out;
- do not call FD_ISSET with a negative file descriptor number.
Change-Id: I7aeaae79e73e39aed127a754
libc: bugfixes for minix's poll(3) wrapper
- clear "revents" fields even when the call times out;
- do not call FD_ISSET with a negative file descriptor number.
Change-Id: I7aeaae79e73e39aed127a75495ea08256b18c182
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| 3ac58492 | 24-Sep-2016 |
David van Moolenbroek <david@minix3.org> |
Add LLVM GCOV coverage support
With this patch, it is now possible to generate coverage information
for MINIX3 system services with LLVM. In particular, the system can
be built with MKCOVERAGE=yes,
Add LLVM GCOV coverage support
With this patch, it is now possible to generate coverage information
for MINIX3 system services with LLVM. In particular, the system can
be built with MKCOVERAGE=yes, either with a native "make build" or
with crosscompilation. Either way, MKCOVERAGE=yes will build the
MINIX3 system services with coverage profiling support, generating a
.gcno file for each source module. After a reboot it is possible to
obtain runtime coverage data (.gcda files) for individual system
services using gcov-pull(8). The combination of the .gcno and .gcda
files can then be inspected with llvm-cov(1).
For reasons documented in minix.gcov.mk, only system service program
modules are supported for now; system service libraries (libsys etc.)
are not included. Userland programs are not affected by MKCOVERAGE.
The heart of this patch is the libsys code that writes data generated
by the LLVM coverage hooks into a serialized format using the routines
we already had for GCC GCOV. Unfortunately, the new llvm_gcov.c code
is LLVM ABI dependent, and may therefore have to be updated later when
we upgrade LLVM. The current implementation should support all LLVM
versions 3.x with x >= 4.
The rest of this patch is mostly a light cleanup of our existing GCOV
infrastructure, with as most visible change that gcov-pull(8) now
takes a service label string rather than a PID number.
Change-Id: I6de055359d3d2b3f53e426f3fffb17af7877261f
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| 232819dd | 04-Jan-2016 |
David van Moolenbroek <david@minix3.org> |
VFS: store process suspension state as union
Previously, VFS would use various subsets of a number of fproc
structure fields to store state when the process is blocked
(suspended) for various reason
VFS: store process suspension state as union
Previously, VFS would use various subsets of a number of fproc
structure fields to store state when the process is blocked
(suspended) for various reasons. As a result, there was a fair
amount of abuse of fields, hidden state, and confusion as to
which fields were used with which suspension states.
Instead, the suspension state is now split into per-state
structures, which are then stored in a union. Each of the union's
structures should be accessed only right before, during, and right
after the fp_blocked_on field is set to the corresponding blocking
type. As a result, it is now very clear which fields are in use
at which times, and we even save a bit of memory as a side effect.
Change-Id: I5c24e353b6cb0c32eb41c70f89c5cfb23f6c93df
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| 84ed480e | 27-Feb-2016 |
David van Moolenbroek <david@minix3.org> |
libc: fix local from-source upgrades
Commit git-c38dbb9 inadvertently broke local MINIX3-on-MINIX3 builds,
since its libc changes relied on VFS being upgraded already as well.
As a result, after ins
libc: fix local from-source upgrades
Commit git-c38dbb9 inadvertently broke local MINIX3-on-MINIX3 builds,
since its libc changes relied on VFS being upgraded already as well.
As a result, after installing the new libc, networking ceased to work,
leading to curl(1) failing later on in the build process. This patch
introduces transitional code that is necessary for the build process
to complete, after which it is obsolete again.
Change-Id: I93bf29c01d228e3d7efc7b01befeff682954f54d
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| c38dbb97 | 21-Feb-2016 |
David van Moolenbroek <david@minix3.org> |
Prepare for switch to native BSD socket API
Currently, the BSD socket API is implemented in libc, translating the
API calls to character driver operations underneath. This approach
has several issu
Prepare for switch to native BSD socket API
Currently, the BSD socket API is implemented in libc, translating the
API calls to character driver operations underneath. This approach
has several issues:
- it is inefficient, as most character driver operations are specific
to the socket type, thus requiring that each operation start by
bruteforcing the socket protocol family and type of the given file
descriptor using several system calls;
- it requires that libc itself be changed every time system support
for a new protocol is added;
- various parts of the libc implementations violate the asynchronous
signal safety POSIX requirements.
In order to resolve all these issues at once, the plan is to turn the
BSD socket calls into system calls, thus making the BSD socket API the
"native" ABI, removing the complexity from libc and instead letting
VFS deal with the socket calls.
The overall change is going to break all networking functionality. In
order to smoothen the transition, this patch introduces the fifteen
new BSD socket system calls, and makes libc try these first before
falling back on the old behavior. For now, the VFS implementations of
the new calls fail such that libc will always use the fallback cases.
Later on, when we introduce the actual implementation of the native
BSD socket calls, all statically linked programs will automatically
use the new ABI, thus limiting actual application breakage.
In other words: by itself, this patch does nothing, except add a bit
of transitional overhead that will disappear in the future. The
largest part of the patch is concerned with adding full support for
the new BSD socket system calls to trace(1) - this early addition has
the advantage of making system call tracing output of several socket
calls much more readable already.
Both the system call interfaces and the trace(1) support have already
been tested using code that will be committed later on.
Change-Id: I3460812be50c78be662d857f9d3d6840f3ca917f
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| 0df28c9f | 16-Jan-2016 |
David van Moolenbroek <david@minix3.org> |
libc: reorganize vector I/O wrappers
The reorganization allows other libc system call wrappers (namely,
sendmsg and recvmsg) to perform I/O vector coalescing as well.
Change-Id: I116b48a6db39439053
libc: reorganize vector I/O wrappers
The reorganization allows other libc system call wrappers (namely,
sendmsg and recvmsg) to perform I/O vector coalescing as well.
Change-Id: I116b48a6db39439053280ee805e0dcbdaec667a3
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| c33d6ef3 | 14-Jan-2016 |
David van Moolenbroek <david@minix3.org> |
VFS: start off cleanup of pipe2 IPC message
There is no reason to use a single message for nonoverlapping requests
and replies combined, and in fact splitting them out allows reuse of
messages and a
VFS: start off cleanup of pipe2 IPC message
There is no reason to use a single message for nonoverlapping requests
and replies combined, and in fact splitting them out allows reuse of
messages and avoids various problems with field layouts. Since the
upcoming socketpair(2) system call will be using the same reply as
pipe2(2), split up the single message used for the latter. In order
to keep the used parts of messages at the front, start a transitional
phase to move the pipe(2) flags field to the front of its request.
Change-Id: If3f1c3d348ec7e27b7f5b7147ce1b9ef490dfab9
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| d991a2be | 09-Oct-2015 |
David van Moolenbroek <david@minix3.org> |
Retire sysuname(2), synchronize sys/utsname.h
Now that uname(3) uses sysctl(2), we no longer need sysuname(2).
Backward compatibility is retained for old statically linked
binaries for a short while
Retire sysuname(2), synchronize sys/utsname.h
Now that uname(3) uses sysctl(2), we no longer need sysuname(2).
Backward compatibility is retained for old statically linked
binaries for a short while.
Also remove the now-obsolete MINIX3-specific "arch" field from the
utsname structure. While this is an ABI break at the libc level,
it should pose no problems in practice, because:
- statically linked programs (i.e., all of the base system) are not
affected, as they will use headers synchronized with libc;
- the structure is getting smaller, thus, older dynamically linked
programs (typically in pkgsrc) using the new libc will end up with
garbage in the "arch" field, but it is unlikely they will use this
field anyway, since it was specific to MINIX3;
- new dynamically linked programs using an old libc could end up with
memory corruption, but this is not a scenario that is expected to
occur in the first place - certainly not with programs from pkgsrc.
Change-Id: I29c76576f509feacc8f996f0bd353ca8961d4917
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