. ld.so is linked at 0 but it can relocate itself; we
wish to load ld.so higher though to trap NULL dereferences.
if we know we have to execute ld.so, vfs tells libexec to put it
higher.
. map all objects named usermapped_*.o with globally visible
pages; usermapped_glo_*.o with the VM 'global' bit on, i.e.
permanently in tlb (very scarce resource!)
. added kinfo, machine, kmessages and loadinfo for a start
. modified log, tty to make use of the shared messages struct
. some strncpy/strcpy to strlcpy conversions
. new <minix/param.h> to avoid including other minix headers
that have colliding definitions with library and commands code,
causing parse warnings
. removed some dead code / assignments
This commit removes all traces of Minix segments (the text/data/stack
memory map abstraction in the kernel) and significance of Intel segments
(hardware segments like CS, DS that add offsets to all addressing before
page table translation). This ultimately simplifies the memory layout
and addressing and makes the same layout possible on non-Intel
architectures.
There are only two types of addresses in the world now: virtual
and physical; even the kernel and processes have the same virtual
address space. Kernel and user processes can be distinguished at a
glance as processes won't use 0xF0000000 and above.
No static pre-allocated memory sizes exist any more.
Changes to booting:
. The pre_init.c leaves the kernel and modules exactly as
they were left by the bootloader in physical memory
. The kernel starts running using physical addressing,
loaded at a fixed location given in its linker script by the
bootloader. All code and data in this phase are linked to
this fixed low location.
. It makes a bootstrap pagetable to map itself to a
fixed high location (also in linker script) and jumps to
the high address. All code and data then use this high addressing.
. All code/data symbols linked at the low addresses is prefixed by
an objcopy step with __k_unpaged_*, so that that code cannot
reference highly-linked symbols (which aren't valid yet) or vice
versa (symbols that aren't valid any more).
. The two addressing modes are separated in the linker script by
collecting the unpaged_*.o objects and linking them with low
addresses, and linking the rest high. Some objects are linked
twice, once low and once high.
. The bootstrap phase passes a lot of information (e.g. free memory
list, physical location of the modules, etc.) using the kinfo
struct.
. After this bootstrap the low-linked part is freed.
. The kernel maps in VM into the bootstrap page table so that VM can
begin executing. Its first job is to make page tables for all other
boot processes. So VM runs before RS, and RS gets a fully dynamic,
VM-managed address space. VM gets its privilege info from RS as usual
but that happens after RS starts running.
. Both the kernel loading VM and VM organizing boot processes happen
using the libexec logic. This removes the last reason for VM to
still know much about exec() and vm/exec.c is gone.
Further Implementation:
. All segments are based at 0 and have a 4 GB limit.
. The kernel is mapped in at the top of the virtual address
space so as not to constrain the user processes.
. Processes do not use segments from the LDT at all; there are
no segments in the LDT any more, so no LLDT is needed.
. The Minix segments T/D/S are gone and so none of the
user-space or in-kernel copy functions use them. The copy
functions use a process endpoint of NONE to realize it's
a physical address, virtual otherwise.
. The umap call only makes sense to translate a virtual address
to a physical address now.
. Segments-related calls like newmap and alloc_segments are gone.
. All segments-related translation in VM is gone (vir2map etc).
. Initialization in VM is simpler as no moving around is necessary.
. VM and all other boot processes can be linked wherever they wish
and will be mapped in at the right location by the kernel and VM
respectively.
Other changes:
. The multiboot code is less special: it does not use mb_print
for its diagnostics any more but uses printf() as normal, saving
the output into the diagnostics buffer, only printing to the
screen using the direct print functions if a panic() occurs.
. The multiboot code uses the flexible 'free memory map list'
style to receive the list of free memory if available.
. The kernel determines the memory layout of the processes to
a degree: it tells VM where the kernel starts and ends and
where the kernel wants the top of the process to be. VM then
uses this entire range, i.e. the stack is right at the top,
and mmap()ped bits of memory are placed below that downwards,
and the break grows upwards.
Other Consequences:
. Every process gets its own page table as address spaces
can't be separated any more by segments.
. As all segments are 0-based, there is no distinction between
virtual and linear addresses, nor between userspace and
kernel addresses.
. Less work is done when context switching, leading to a net
performance increase. (8% faster on my machine for 'make servers'.)
. The layout and configuration of the GDT makes sysenter and syscall
possible.
When a file system is mounted some heuristics are used to define
a RS label for that system. This commit allows to specify the
label to use in an optional mount argument using either
mount -o rslabel=fs_myfs or as a mount option in fstab.
This can be used to start services that later also need to be
accessed directly.
make weak symbol references and namespace renames references
the renamed versions.
function renaming, weak symbol references and libc namespace.h
protection interact in hairy ways and causes weak symbol references
for renamed functions to be unresolved; e.g. vfork should be an
alias for _vfork but _vfork doesn't exist because __vfork14()
exists.
this is a problem for dynamically linked executables as all symbols
have to be resolved, used or not, at link time. it was masked by
clang-compiled base system libraries but is a problem when gcc does
it.
. sys_vircopy always uses D for both src and dst
. sys_physcopy uses PHYS_SEG if and only if corresponding
endpoint is NONE, so we can derive the mode (PHYS_SEG or D)
from the endpoint arg in the kernel, dropping the seg args
. fields in msg still filled in for backwards compatability,
using same NONE-logic in the library
. all invocations were S or D, so can safely be dropped
to prepare for the segmentless world
. still assign D to the SCP_SEG field in the message
to make previous kernels usable
. new mode for sys_memset: include process so memset can be
done in physical or virtual address space.
. add a mode to mmap() that lets a process allocate uninitialized
memory.
. this allows an exec()er (RS, VFS, etc.) to request uninitialized
memory from VM and selectively clear the ranges that don't come
from a file, leaving no uninitialized memory left for the process
to see.
. use callbacks for clearing the process, clearing memory in the
process, and copying into the process; so that the libexec code
can be used from rs, vfs, and in the future, kernel (to load vm)
and vm (to load boot-time processes)
. make exec() callers (i.e. vfs and rs) determine the
memory layout by explicitly reserving regions using
mmap() calls on behalf of the exec()ing process,
i.e. handling all of the exec logic, thereby eliminating
all special exec() knowledge from VM.
. the new procedure is: clear the exec()ing process
first, then call third-party mmap()s to reserve memory, then
copy the executable file section contents in, all using callbacks
tailored to the caller's way of starting an executable
. i.e. no more explicit EXEC_NEWMEM-style calls in PM or VM
as with rigid 2-section arguments
. this naturally allows generalizing exec() by simply loading
all ELF sections
. drop/merge of lots of duplicate exec() code into libexec
. not copying the code sections to vfs and into the executable
again is a measurable performance improvement (about 3.3% faster
for 'make' in src/servers/)
justification: soon we won't be able to execute sep I&D aouts at
all (because of the vanishing segments), which was the default mode
to generate them so most binaries will be sep I&D.
this makes the vfs/rs exec() unification work simpler.
after unification, common I&D aout could be added back quite simply.
these two functions will be used to support all exec() functionality
going into a single library shared by RS and VFS and exec() knowledge
leaving VM.
. third-party mmap: allow certain processes (VFS, RS) to
do mmap() on behalf of another process
. PROCCTL: used to free and clear a process' address space
WARNING: this will break existing dynamically linked binaries if they
exist. If you have any:
. re-build world statically first if necessary
. remove libraries from /lib and /usr/lib
. then build world
This change:
. avoids possible future dismay when interfacing other
systems' binaries; done until they are abi-compatible
Thanks to Antoine Leca for pointing this out.
This can be turned back on when the library is compiled with
-DMTHREAD_STRICT (which enables more sanity checks). However,
always performing this check shows up in system profiling results.
. vfs: pass execname in aux vectors
. ld.elf_so: use this to expand $ORIGIN
. this requires the executable to reserve more
space at exec() calling time
building defaults to off until clang is updated.
current clang does not handle -shared, necessary to change the ld
invocation to build shared libraries properly. a new clang should be
installed and MKPIC defaults to no unless the newer clang is detected.
changes:
. mainly small imports of a Makefile or two and small fixes
(turning things back on that were turned off in Makefiles)
. e.g.: dynamic librefuse now depends on dynamic
libpuffs, so libpuffs has to be built dynamically too
and a make dependency barrier is needed in lib/Makefile
. all library objects now have a PIC (for .so) and non-PIC
version, so everything is built twice.
. generate PIC versions of the compat (un-RENAMEd) jump files,
include function type annotation in generated assembly
. build progs with -static by default for now
. also build ld.elf_so
. also import NetBSD ldd
. generalize libexec slightly to get some more necessary information
from ELF files, e.g. the interpreter
. execute dynamically linked executables when exec()ed by VFS
. switch to netbsd variant of elf32.h exclusively, solves some
conflicting headers
. file- and functionality-compatible with previous situation
(FreeBSD csu) (with a crt1.o -> crt0.o symlink in /usr/lib)
. harmonizes source with netbsd
. harmonizes linker invocation (e.g. clang) with netbsd
. helpful to get some arm code in there for the arm port project
This Shared Folders File System library (libsffs) now contains all the
file system logic originally in HGFS. The actual HGFS server code is
now a stub that passes on all the work to libsffs. The libhgfs library
is changed accordingly.
. fixes e.g. ssh sessions not getting their own
controlling tty (causing ^C getting broadcast to too
many processes)
. previously (before -lutil) handled like this by bsd-openpty.c in
openssh
. reported by Andy Kosela, debugged by ThomasV
remove some old minix-userland-specific stuff
. /etc/ttytab as a file, and minix-compat function (fftyslot()),
replaced by /etc/ttys and new libc functions
. also remove minix-specific nlist(), cuserid(), fttyslot(), v8 regex
functions and <compat/regex.h>
. and remaining minix-only utilities that use them
. also unused <compat/pwd.h> and <compat/syslog.h> and
redundant <sys/sigcontext.h>
- add files needed for acpi, ahci, fbd, vfs to libminc
- remove "-lc" from their respective makefiles
- remove setenv from libminc (requires initialization)
- libnetsock - internal implementation of a socket on the lwip
server side. it encapsulates the asynchronous protocol
- lwip server - uses libnetsock to work with the asynchronous
protocol
- if an operation (R, W, IOCTL) is non blocking, a flag is set
and sent to the device.
- nothing changes for sync devices
- asyn devices should reply asap if an operation is non-blocking.
We must trust the devices, but we had to trust them anyway to
reply to CANCEL correctly
- we safe sending CANCEL commands to asyn devices. This greatly
simplifies the protocol. Asynchronous devices can always reply
when a reply is ready and do not need to deal with other
situations
- currently, none of our drivers use the flags since they drive
virtual devices which do not block
. harmonize bsd.lib.mk and bsd.man.mk with netbsd files
. throw out minix section 3 (library calls) manpages,
replaced by netbsd ones that are now installed
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.
Changes in this commit:
. drop boot monitor -> allowing dropping ack support
. facility to copy ELF boot files to /boot so that old boot monitor
can still boot fairly easily, see UPDATING
. no more ack-format libraries -> single-case libraries
. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
. drop several ack toolchain commands, but not all support
commands (e.g. aal is gone but acksize is not yet).
. a few libc files moved to netbsd libc dir
. new /bin/date as minix date used code in libc/
. test compile fix
. harmonize includes
. /usr/lib is no longer special: without ack, /usr/lib plays no
kind of special bootstrapping role any more and bootstrapping
is done exclusively through packages, so releases depend even
less on the state of the machine making them now.
. rename nbsd_lib* to lib*
. reduce mtree
Add guard pages to the top of the stack to catch overflow errors.
Moreover, fix a bug where libmthread would keep using a stack that was
just deallocated; a detached thread would deallocate its own stack after
it was finished running).
This driver can be loaded as an overlay on top of a real block
device, and can then be used to generate block-level failures for
certain transfer requests. Specifically, a rule-based system allows
the user to introduce (overt and silent) data corruption and errors.
It exposes itself through /dev/fbd, and a file system can be mounted
on top of it. The new fbdctl(8) tool can be used to control the
driver; see ``man fbdctl'' for details. It also comes with a test
set, located in test/fbdtest.
This removes a race condition when the block driver performs a
complete restart after a crash (the new default). If any user of
the driver finds out its new endpoint and sends a request to the
new driver instance before this instance has had the chance to
initialize, then its initialization would clear all IPC state and
thereby erroneously cancel the incoming request. Clearing IPC
state is only desired upon a stateful restart (where the driver's
endpoint is retained). This information is now passed to and used
by libblockdriver accordingly.
This patch provides basic protection against damage resulting from
differently compiled servers blindly copying tables to one another.
In every getsysinfo() call, the caller is provided with the expected
size of the requested data structure. The callee fails the call if
the expected size does not match the data structure's actual size.
Each block driver now gets to specify whether it is a disk block
driver, which implies it wants the library to handle getting and
setting partitions for it.
The NetBSD libc provides a mechanism to have versions of system calls.
By 'renaming' symbols to a new version, freshly compiled programs will
automatically use the new symbol iff they use the proper header files. The
old, not renamed, version of the symbol will still exist (after being moved
to the compat directory), so old programs can still link.
Since MINIX doesn't support dynamic linking, the whole rename mechanism
doesn't really work for us. However, removing it would create a huge diff
with the current NetBSD libc.
A lot of the compat code relies on things we don't (seem to) have, and
therefore does not get built and linked. This causes trouble for tools like
autoconf, which will fail to find the renamed symbols. For example,
currently select gets renamed to __select50 in libc. Autoconf looks for
'select' and doesn't find it and reports we don't have it. This is where
the compat.S stub comes into play: it generates the old symbols and jumps to
the new symbols. However, as this is done in one object file, all renamed
symbols get linked together, causing binaries to be huge. This patch fixes
that by generating an object file for each renamed symbol.
This patch also makes the MISSING_SYSCALLS more complete and marginally
reduces the diff with NetBSD.
The implementation is in libblockdriver, and works transparently for
all block drivers. The new btrace(8) tool can be used to control block
tracing; see ``man btrace'' for details.
This patch separates the character and block driver communication
protocols. The old character protocol remains the same, but a new
block protocol is introduced. The libdriver library is replaced by
two new libraries: libchardriver and libblockdriver. Their exposed
API, and drivers that use them, have been updated accordingly.
Together, libbdev and libblockdriver now completely abstract away
the message format used by the block protocol. As the memory driver
is both a character and a block device driver, it now implements its
own message loop.
The most important semantic change made to the block protocol is that
it is no longer possible to return both partial results and an error
for a single transfer. This simplifies the interaction between the
caller and the driver, as the I/O vector no longer needs to be copied
back. Also, drivers are now no longer supposed to decide based on the
layout of the I/O vector when a transfer should be cut short. Put
simply, transfers are now supposed to either succeed completely, or
result in an error.
After this patch, the state of the various pieces is as follows:
- block protocol: stable
- libbdev API: stable for synchronous communication
- libblockdriver API: needs slight revision (the drvlib/partition API
in particular; the threading API will also change shortly)
- character protocol: needs cleanup
- libchardriver API: needs cleanup accordingly
- driver restarts: largely unsupported until endpoint changes are
reintroduced
As a side effect, this patch eliminates several bugs, hacks, and gcc
-Wall and -W warnings all over the place. It probably introduces a
few new ones, too.
Update warning: this patch changes the protocol between MFS and disk
drivers, so in order to use old/new images, the MFS from the ramdisk
must be used to mount all file systems.
. clang-linked binaries were not calling global constructors, as the
code to do so wasn't in csu/ and linked
. it does work for gcc as it uses its self-supplied crt{begin,end} code
. this commit copies netbsd's crt{begin,end}.S, which contains
constructor/destructor calling code, called from .init and .fini
sections already accumulated by the linker. the _init function was already
called by the C startup code before calling main.
. based on work by Antoine Leca
Import libpuffs and our port of libpuffs. The port was done as part of
GSoC 2011 FUSE project, done by Evgeniy Ivanov. The librefuse import
did not require any porting efforts. Libpuffs has been modified to
understand our VFS-FS protocol and translate between that and PUFFS. As
an example that it works, fuse-ntfs-3g from pkgsrc can be compiled and
used to mount ntfs partitions:
mount -t ntfs-3g <device> <mountpoint>
FUSE only works with the asynchronous version of VFS. See <docs/UPDATING> on
how to run AVFS.
This patch further includes some changes to mount(1) and mount(2) so it's
possible to use file systems provided by pkgsrc (note: manual modifications
to /etc/system.conf are still needed. There has been made an exception for
fuse-ntfs-3g, so it already as an entry).
This patch fixes most of current reasons to generate compiler warnings.
The changes consist of:
- adding missing casts
- hiding or unhiding function declarations
- including headers where missing
- add __UNCONST when assigning a const char * to a char *
- adding missing return statements
- changing some types from unsigned to signed, as the code seems to want
signed ints
- converting old-style function definitions to current style (i.e.,
void func(param1, param2) short param1, param2; {...} to
void func (short param1, short param2) {...})
- making the compiler silent about signed vs unsigned comparisons. We
have too many of those in the new libc to fix.
A number of bugs in the test set were fixed. These bugs were never
triggered with our old libc. Consequently, these tests are now forced to
link with the new libc or they will generate errors (in particular tests 43
and 55).
Most changes in NetBSD libc are limited to moving aroudn "#ifndef __minix"
or stuff related to Minix-specific things (code in sys-minix or gen/minix).
The "bdev" library provides basic primitives for file systems to talk
to block device drivers, hiding the details of the underlying protocol
and interaction model.
This version of libbdev is rather basic. It is planned to support the
following features in the long run:
- asynchronous requests and replies;
- recovery support for underlying block drivers;
- retrying of failed I/O requests.
The commit also changes our block-based file systems (mfs, ext2, isofs)
to make use of libbdev.
This patch adds support for executing multiple concurrent requests on
different devices on the same AHCI controller. The libdriver library
has been extended to include a generic multithreading interface, and
the AHCI driver has been extended to make use of this interface.
The original version of this code has been written by Arne Welzel.
. add bsd-style MLINKS to minix man set, restoring aliases
(e.g. man add64 -> int64)
. update daily cron script to run makewhatis and restore makewhatis
in man Makefile (makedb), restores functionality of man -k
. netbsd imports of man, mdocml, makewhatis, libutil, apropos
. update man.conf with manpage locations, restoring man [-s] <section>
. throws out some obsolete manpages
. move cache size heuristic from mfs there
so mfs and ext2 can share it
. add vfs credentials retrieving function, with
backwards compatability from previous struct
format, to be used by both ext2 and mfs
. fix for ext2 - STATICINIT was fed no.
of bytes instead of no. of elements, overallocating
memory by a megabyte or two for the superblock
. default jemalloc is not too easy to compile without threads
libraries/types
. non-default malloc has odd virtual address space binge problem
. switch to ack/minix malloc in old libc for now
. ipc wants to know about processes that get
signals, so that it can break blocking ipc operations
. doing it for every single signal is wasteful
and causes the annoying 'no slot for signals' message
. this fix tells vm on a per-process basis it (ipc)
wants to be notified, i.e. only when it does any ipc calls
. move ipc config to separate config file while we're at it
- BSD-licensed Code gratefully taken from the project at
http://en.sourceforge.jp/projects/sfnet_vassertlinuxsdk/
- For more information on vmware VAssert, a powerful debugging
facility usable under vmware, see:
www.vmware.com/pdf/ws65_vassert_programming.pdf
. don't install minix <termcap.h> as libterminfo
has its own (but still install it in /usr/include.ack)
. forget minix termcap functions in -lcompat_minix
. make commands use -lterminfo in netbsd libc compile mode
Improves cache locality by grouping together dependency generation
with building for each program instead of doing a whole-tree dep
generation phase followed by a whole-tree build phase
. it's a good extra interface to have but doesn't
meet standardised functionality
. applications (in pkgsrc) find it and expect
full functionality the minix mmap doesn't offter
. on the whole probably better to hide these functions
(mmap and friends) until they are grown up; the base system
can use the new minix_* names
. strerror() assumes this
. remove generated libminc/errlist.c
. errno's in <sys/errno.h> have to be in sorted order
. filtering out some errno.h in Makefile lets us use near-stock
errlist.awk
* VFS and installed MFSes must be in sync before and after this change *
Use struct stat from NetBSD. It requires adding new STAT, FSTAT and LSTAT
syscalls. Libc modification is both backward and forward compatible.
Also new struct stat uses modern field sizes to avoid ABI
incompatibility, when we update uid_t, gid_t and company.
Exceptions are ino_t and off_t in old libc (though paddings added).
Now users can choose between libsys, libsys + libminc and
libsys + libc. E.g. PUFFS/FUSE servers need libsys + libc while
old servers can use libsys + libminc.
1. ack, a.out, minix headers (moved to /usr/include.ack),
minix libc
2. gcc/clang, elf, netbsd headers (moved to /usr/include),
netbsd libc (moved to /usr/lib)
So this obsoletes the /usr/netbsd hierarchy.
No special invocation for netbsd libc necessary - it's always used
for gcc/clang.
The opendir(3) function was setting errno to ENOTDIR even
when the directory existed and was opened successfully. This
caused git to falsely detect an error.
This change moves the errno assignment into the failure code
block. It also adds a test to test24 to check for errno
changing when opendir(3) returns success.
Add two makefiles to manage compiling packages with NetBSD libc.
* minix.libc.mk contains the proper CFLAGS/LDFLAGS
* pkgsrchooks.mk contains the logic for setting the flags.
* update bmake
Several pkg-config files were added to help pkgsrc learn about
the c, minlib, and compat_minix libraries.
. remove a few asserts in the kernel and 64bi library
that are not compatible with the timing code
. change the TIME_BLOCKS code a little to work in-kernel
3 sets of libraries are built now:
. ack: all libraries that ack can compile (/usr/lib/i386/)
. clang+elf: all libraries with minix headers (/usr/lib/)
. clang+elf: all libraries with netbsd headers (/usr/netbsd/)
Once everything can be compiled with netbsd libraries and headers, the
/usr/netbsd hierarchy will be obsolete and its libraries compiled with
netbsd headers will be installed in /usr/lib, and its headers
in /usr/include. (i.e. minix libc and current minix headers set
will be gone.)
To use the NetBSD libc system (libraries + headers) before
it is the default libc, see:
http://wiki.minix3.org/en/DevelopersGuide/UsingNetBSDCode
This wiki page also documents the maintenance of the patch
files of minix-specific changes to imported NetBSD code.
Changes in this commit:
. libsys: Add NBSD compilation and create a safe NBSD-based libc.
. Port rest of libraries (except libddekit) to new header system.
. Enable compilation of libddekit with new headers.
. Enable kernel compilation with new headers.
. Enable drivers compilation with new headers.
. Port legacy commands to new headers and libc.
. Port servers to new headers.
. Add <sys/sigcontext.h> in compat library.
. Remove dependency file in tree.
. Enable compilation of common/lib/libc/atomic in libsys
. Do not generate RCSID strings in libc.
. Temporarily disable zoneinfo as they are incompatible with NetBSD format
. obj-nbsd for .gitignore
. Procfs: use only integer arithmetic. (Antoine Leca)
. Increase ramdisk size to create NBSD-based images.
. Remove INCSYMLINKS handling hack.
. Add nbsd_include/sys/exec_elf.h
. Enable ELF compilation with NBSD libc.
. Add 'make nbsdsrc' in tools to download reference NetBSD sources.
. Automate minix-port.patch creation.
. Avoid using fstavfs() as it is *extremely* slow and unneeded.
. Set err() as PRIVATE to avoid name clash with libc.
. [NBSD] servers/vm: remove compilation warnings.
. u32 is not a long in NBSD headers.
. UPDATING info on netbsd hierarchy
. commands fixes for netbsd libc
#if inside macro call is undefined behaviour under the C standard
(3.8.3 paragraph 10 for C90, 6.8.10 paragraph 11 for C99).
The same effect can be achieved with a slightly more verbose construct,
putting the whole macro call inside the #ifdef/#else/#endif.
sys_umap now supports only:
- looking up the physical address of a virtual address in the address space
of the caller;
- looking up the physical address of a grant for which the caller is the
grantee.
This is enough for nearly all umap users. The new sys_umap_remote supports
lookups in arbitrary address spaces and grants for arbitrary grantees.
to upstream.
- revert to upstream version of function prototypes for
setting the uid and gid fields of the archive_entry.
- move uid/gid overflow checks into header_common().
- use archive_set_error() instead of fprintf() for getting
error message text back to the main program.
and minor fixes:
. add ack/clean target to lib, 'unify' clean target
. add includes as library dependency
. mk: exclude warning options clang doesn't have in non-gcc
. set -e in lib/*.sh build files
. clang compile error circumvention (disable NOASSERTS for release builds)
The file timestamps in archives created by libarchive all had
dates in the year 2038. It was caused by a bit shift in
archive_write_set_format_ustar which shifted 1 instead of 1ull.
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.
From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:
- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
when setting REP_ENDPT, matching requests in CANCEL calls, getting
DEV_SELECT flags, and retrieving of the real user process's endpoint
in DEV_OPEN.
The changes in this patch are binary backward compatible.
asynchronous message resulted in an error.
The model here is that:
- Iff a sender wishes to be notified, the sender MUST check for errors
BEFORE sending another asynchronous message.
The reason is that in order to remember the error code, we can't clean up
the message table and hence we risk running out of table space. This is
less of a problem when the sender enables notifications only for errors.
This library includes various random and minix-specific functions
included in the Minix libc. Most of them should be part of libsys,
and in general it would be nice to extinguish this library over
time.
- Remove sanity checks for initialized mutexes and condition variables. This
significantly boosts performance. The checks can be turned back on by
compiling libmthread with MTHREAD_STRICT. According to POSIX operations on
uninitialized variables are a MAY fail if, therefore allowing this
optimization.
- Test59 has to be accommodated to the lack of sanity checks on uninitialized
variables in the library. It specifically tests for them and will run into
segfaults when the checks are absent in the library.
- Fix a few bugs related to the scheduler
- Do some general code cleanups
This patch fixes some wrong error code number in nbsd libc's sys/errno.h
and adds new ones.
As in NetBSD the errno.h is used to automatically generate errlist.c array,
EBADCPU set to 1000 to be a bit too large, so we instruct the awk script
to stop at EDEADEPT (ELAST).
This patch changes the NBSD libc stat implemenation and adds
fstat (and headers), taken from current libc.
It also adds weaks alias to functions in the resolver that
were removed from public use in NetBSD but that are still
used by Minix, and fixes a NetBSD non-REENTRANT bug in
in gen/initdir.c.
This patch add a few weak_alias forgotten, so that non-internal
symbols are defined to be used from application.
Modifying only the minix-specific part, this patch needs no update
to minix-port.patch.
This patch mainly copies and modifies files existing in
the current libc implementing minix specific functions.
To keep consisten with the NetBSD libc, we remove
namespace stubs and we use "namespace.h" and weak
links.
This patch contains changes to NetBSD libc code base to make it
compile and work on Minix. Some of them are due to actual NetBSD
libc bugs, as we're compiling it in non-reentrant mode and with
a.out support, something not exactly frequent in NetBSD.
Others are proper fixes to port it to Minix (mostly sa_len
parameter missing in socket and a few mmap from files).
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is
split between lib/nbsd_libc and common/lib/libc.
M include/Makefile
A include/minix/input.h
M include/minix/com.h
M drivers/tty/keyboard.c
M drivers/tty/tty.c
M drivers/tty/tty.h
M include/minix/syslib.h
M lib/libsys/Makefile
A lib/libsys/input.c
this is a fix for e.g. the situation where lots of processes die
instantly, and PM has to send an asyn msg for each one to VFS, and
panics if there are too many. there are likely more situations in
which this table should be dependent on the no. of processes.
reported by pikpik on #minix3.
Before, the 'main thread' of a process was never taken into account anywhere in
the library, causing mutexes not to work properly (and consequently, neither
did the condition variables). For example, if the 'main thread' (that is, the
thread which is started at the beginning of a process; not a spawned thread by
the library) would lock a mutex, it wasn't actually locked.
- profile --nmi | --rtc sets the profiling mode
- --rtc is default, uses BIOS RTC, cannot profile kernel the presetted
frequency values apply
- --nmi is only available in APIC mode as it uses the NMI watchdog, -f
allows any frequency in Hz
- both modes use compatible data structures
- sys_schedule can change only selected values, -1 means that the
current value should be kept unchanged. For instance we mostly want
to change the scheduling quantum and priority but we want to keep
the process at the current cpu
- RS can hand off its processes to scheduler
- service can read the destination cpu from system.conf
- RS can pass the information farther
- Remove unused includes.
- Add include guards to headers.
- Use unsigned variables in case they're never going to hold a negative
value. This causes GCC's complaints to disappear and should make flexelint
a lot happier, too.
- Make functions private when they're used only within a module.
- Remove unused variables.
- Add casts where appropriate.
-Makefile updates
-Update mkdep
-Build fixes/warning cleanups for some programs
-Restore leading underscores on global syms in kernel asm files
-Increase ramdisk size
In this second phase, scheduling is moved from PM to its own
scheduler (see r6557 for phase one). In the next phase we hope to a)
include useful information in the "out of quantum" message and b)
create some simple scheduling policy that makes use of that
information.
When the system starts up, PM will iterate over its process table and
ask SCHED to take over scheduling unprivileged processes. This is
done by sending a SCHEDULING_START message to SCHED. This message
includes the processes endpoint, the parent's endpoint and its nice
level. The scheduler adds this process to its schedproc table, issues
a schedctl, and returns its own endpoint to PM - as the endpoint of
the effective scheduler. When a process terminates, a SCHEDULING_STOP
message is sent to the scheduler.
The reason for this effective endpoint is for future compatibility.
Some day, we may have a scheduler that, instead of scheduling the
process itself, forwards the SCHEDULING_START message on to another
scheduler.
PM has information on who schedules whom. As such, scheduling
messages from user-land are sent through PM. An example is when
processes change their priority, using nice(). In that case, a
getsetpriority message is sent to PM, which then sends a
SCHEDULING_SET_NICE to the process's effective scheduler.
When a process is forked through PM, it inherits its parent's
scheduler, but is spawned with an empty quantum. As before, a request
to fork a process flows through VM before returning to PM, which then
wakes up the child process. This flow has been modified slightly so
that PM notifies the scheduler of the new process, before waking up
the child process. If the scheduler fails to take over scheduling,
the child process is torn down and the fork fails with an erroneous
value.
Process priority is entirely decided upon using nice levels. PM
stores a copy of each process's nice level and when a child is
forked, its parent's nice level is sent in the SCHEDULING_START
message. How this level is mapped to a priority queue is up to the
scheduler. It should be noted that the nice level is used to
determine the max_priority and the parent could have been in a lower
priority when it was spawned. To prevent a CPU intensive process from
hawking the CPU by continuously forking children that get scheduled
in the max_priority, the scheduler should determine in which queue
the parent is currently scheduled, and schedule the child in that
same queue.
Other fixes: The USER_Q in kernel/proc.h was incorrectly defined as
NR_SCHED_QUEUES/2. That results in a "off by one" error when
converting priority->nice->priority for nice=0. This also had the
side effect that if someone were to set the MAX_USER_Q to something
else than 0, then USER_Q would be off.
model to an instance-based model. Each ethernet driver instance is now
responsible for exactly one network interface card. The port field in
/etc/inet.conf now acts as an instance field instead.
This patch also updates the data link protocol. This update:
- eliminates the concept of ports entirely;
- eliminates DL_GETNAME entirely;
- standardizes on using m_source for IPC and DL_ENDPT for safecopies;
- removes error codes from TASK/STAT replies, as they were unused;
- removes a number of other old or unused fields;
- names and renames a few other fields.
All ethernet drivers have been changed to:
- conform to the new protocol, and exactly that;
- take on an instance number based on a given "instance" argument;
- skip that number of PCI devices in probe iterations;
- use config tables and environment variables based on that number;
- no longer be limited to a predefined maximum of cards in any way;
- get rid of any leftover non-safecopy support and other ancient junk;
- have a correct banner protocol figure, or none at all.
Other changes:
* Inet.conf is now taken to be line-based, and supports #-comments.
No existing installations are expected to be affected by this.
* A new, select-based asynchio library replaces the old one.
Kindly contributed by Kees J. Bot.
* Inet now supports use of select() on IP devices.
Combined, the last two changes together speed up dhcpd
considerably in the presence of multiple interfaces.
* A small bug has been fixed in nonamed.
A new call to vm lets processes yield a part of their memory to vm,
together with an id, getting newly allocated memory in return. vm is
allowed to forget about it if it runs out of memory. processes can ask
for it back using the same id. (These two operations are normally
combined in a single call.)
It can be used as a as-big-as-memory-will-allow block cache for
filesystems, which is how mfs now uses it.
RS CHANGES:
- Crash recovery is now implemented like live update. Two instances are kept
side by side and the dead version is live updated into the new one. The endpoint
doesn't change and the failure is not exposed (by default) to other system
services.
- The new instance can be created reactively (when a crash is detected) or
proactively. In the latter case, RS can be instructed to keep a replica of
the system service to perform a hot swap when the service fails. The flag
SF_USE_REPL is set in that case.
- The new flag SF_USE_REPL is supported for services in the boot image and
dynamically started services through the RS interface (i.e. -p option in the
service utility).
- Fixed a free unallocated memory bug for core system services.
this patch changes the way pagefaults are delivered to VM. It adopts
the same model as the out-of-quantum messages sent by kernel to a
scheduler.
- everytime a userspace pagefault occurs, kernel creates a message
which is sent to VM on behalf of the faulting process
- the process is blocked on delivery to VM in the standard IPC code
instead of waiting in a spacial in-kernel queue (stack) and is not
runnable until VM tell kernel that the pagefault is resolved and is
free to clear the RTS_PAGEFAULT flag.
- VM does not need call kernel and poll the pagefault information
which saves many (1/2?) calls and kernel calls that return "no more
data"
- VM notification by kernel does not need to use signals
- each entry in proc table is by 12 bytes smaller (~3k save)
VFS CHANGES:
- dmap table no longer statically initialized in VFS
- Dropped FSSIGNON svrctl call no longer used by INET
INET CHANGES:
- INET announces its presence to VFS just like any other driver
RS CHANGES:
- The boot image dev table contains all the data to initialize VFS' dmap table
- RS interface supports asynchronous up and update operations now
- RS interface extended to support driver style and flags
SYSLIB CHANGES:
- DS calls to publish / retrieve labels consider endpoints instead of u32_t.
VFS CHANGES:
- mapdriver() only adds an entry in the dmap table in VFS.
- dev_up() is only executed upon reception of a driver up event.
INET CHANGES:
- INET no longer searches for existing drivers instances at startup.
- A newtwork driver is (re)initialized upon reception of a driver up event.
- Networking startup is now race-free by design. No need to waste 5 seconds
at startup any more.
DRIVER CHANGES:
- Every driver publishes driver up events when starting for the first time or
in case of restart when recovery actions must be taken in the upper layers.
- Driver up events are published by drivers through DS.
- For regular drivers, VFS is normally the only subscriber, but not necessarily.
For instance, when the filter driver is in use, it must subscribe to driver
up events to initiate recovery.
- For network drivers, inet is the only subscriber for now.
- Every VFS driver is statically linked with libdriver, every network driver
is statically linked with libnetdriver.
DRIVER LIBRARIES CHANGES:
- Libdriver is extended to provide generic receive() and ds_publish() interfaces
for VFS drivers.
- driver_receive() is a wrapper for sef_receive() also used in driver_task()
to discard spurious messages that were meant to be delivered to a previous
version of the driver.
- driver_receive_mq() is the same as driver_receive() but integrates support
for queued messages.
- driver_announce() publishes a driver up event for VFS drivers and marks
the driver as initialized and expecting a DEV_OPEN message.
- Libnetdriver is introduced to provide similar receive() and ds_publish()
interfaces for network drivers (netdriver_announce() and netdriver_receive()).
- Network drivers all support live update with no state transfer now.
KERNEL CHANGES:
- Added kernel call statectl for state management. Used by driver_announce() to
unblock eventual callers sendrecing to the driver.
reverse order to easily support variadic arguments. Thus, instead of
using the proper stdarg.h macros (that nowadays are
compiler-dependent), it may be tempting to directly take the address of
the last argument and considering it as the start of an array. This is
a shortcut that avoid looping to get all the arguments as the CPU
already pushed them on the stack before the call to the function.
Unfortunately, such an assumption is strictly compiler-dependent and
compilers are free to move the last argument on the stack, as a local
variable, and return the address of the location where the argument was
stored, if asked for. This will break things as the rest of the array's
argument are stored elsewhere (typically, a couple of words above the
location where the argument was stored).
This patch fixes the issue by allowing ACK to take the shortcut and
enabling gcc/llvm-gcc to follow the right way.
- cotributed by Bjorn Swift
- In this first phase, scheduling is moved from the kernel to the PM
server. The next steps are to a) moving scheduling to its own server
and b) include useful information in the "out of quantum" message,
so that the scheduler can make use of this information.
- The kernel process table now keeps record of who is responsible for
scheduling each process (p_scheduler). When this pointer is NULL,
the process will be scheduled by the kernel. If such a process runs
out of quantum, the kernel will simply renew its quantum an requeue
it.
- When PM loads, it will take over scheduling of all running
processes, except system processes, using sys_schedctl().
Essentially, this only results in taking over init. As children
inherit a scheduler from their parent, user space programs forked by
init will inherit PM (for now) as their scheduler.
- Once a process has been assigned a scheduler, and runs out of
quantum, its RTS_NO_QUANTUM flag will be set and the process
dequeued. The kernel will send a message to the scheduler, on the
process' behalf, informing the scheduler that it has run out of
quantum. The scheduler can take what ever action it pleases, based
on its policy, and then reschedule the process using the
sys_schedule() system call.
- Balance queues does not work as before. While the old in-kernel
function used to renew the quantum of processes in the highest
priority run queue, the user-space implementation only acts on
processes that have been bumped down to a lower priority queue.
This approach reacts slower to changes than the old one, but saves
us sending a sys_schedule message for each process every time we
balance the queues. Currently, when processes are moved up a
priority queue, their quantum is also renewed, but this can be
fiddled with.
- do_nice has been removed from kernel. PM answers to get- and
setpriority calls, updates it's own nice variable as well as the
max_run_queue. This will be refactored once scheduling is moved to a
separate server. We will probably have PM update it's local nice
value and then send a message to whoever is scheduling the process.
- changes to fix an issue in do_fork() where processes could run out
of quantum but bypassing the code path that handles it correctly.
The future plan is to remove the policy from do_fork() and implement
it in userspace too.
struct return. For example, GCC and LLVM comply with this (tested on IA32).
ACK doesn't seem to follow this convention and expects the caller to clean up
the stack. Compiling hand-written ACK-compliant assembly code (returning a
struct) with GCC or LLVM used to break things (4-bytes misaligned stack).
The patch fixes this problem.
IPC changes:
- receive() is changed to take an additional parameter, which is a pointer to
a status code.
- The status code is filled in by the kernel to provide additional information
to the caller. For now, the kernel only fills in the IPC call used by the
sender.
Syslib changes:
- sef_receive() has been split into sef_receive() (with the original semantics)
and sef_receive_status() which exposes the status code to userland.
- Ideally, every sys process should gradually switch to sef_receive_status()
and use is_ipc_notify() as a dependable way to check for notify.
- SEF has been modified to use is_ipc_notify() and demonstrate how to use the
new status code.
- before enabling paging VM asks kernel to resize its segments. This
may cause kernel to segfault if APIC is used and an interrupt
happens between this and paging enabled. As these are 2 separate
vmctl calls it is not atomic. This patch fixes this problem. VM does
not ask kernel to resize the segments in a separate call anymore.
The new segments limit is part of the "enable paging" call. It
generalizes this call in such a way that more information can be
passed as need be or the information may be completely different if
another architecture requires this.
UPDATING INFO:
20100317:
/usr/src/etc/system.conf updated to ignore default kernel calls: copy
it (or merge it) to /etc/system.conf.
The hello driver (/dev/hello) added to the distribution:
# cd /usr/src/commands/scripts && make clean install
# cd /dev && MAKEDEV hello
KERNEL CHANGES:
- Generic signal handling support. The kernel no longer assumes PM as a signal
manager for every process. The signal manager of a given process can now be
specified in its privilege slot. When a signal has to be delivered, the kernel
performs the lookup and forwards the signal to the appropriate signal manager.
PM is the default signal manager for user processes, RS is the default signal
manager for system processes. To enable ptrace()ing for system processes, it
is sufficient to change the default signal manager to PM. This will temporarily
disable crash recovery, though.
- sys_exit() is now split into sys_exit() (i.e. exit() for system processes,
which generates a self-termination signal), and sys_clear() (i.e. used by PM
to ask the kernel to clear a process slot when a process exits).
- Added a new kernel call (i.e. sys_update()) to swap two process slots and
implement live update.
PM CHANGES:
- Posix signal handling is no longer allowed for system processes. System
signals are split into two fixed categories: termination and non-termination
signals. When a non-termination signaled is processed, PM transforms the signal
into an IPC message and delivers the message to the system process. When a
termination signal is processed, PM terminates the process.
- PM no longer assumes itself as the signal manager for system processes. It now
makes sure that every system signal goes through the kernel before being
actually processes. The kernel will then dispatch the signal to the appropriate
signal manager which may or may not be PM.
SYSLIB CHANGES:
- Simplified SEF init and LU callbacks.
- Added additional predefined SEF callbacks to debug crash recovery and
live update.
- Fixed a temporary ack in the SEF init protocol. SEF init reply is now
completely synchronous.
- Added SEF signal event type to provide a uniform interface for system
processes to deal with signals. A sef_cb_signal_handler() callback is
available for system processes to handle every received signal. A
sef_cb_signal_manager() callback is used by signal managers to process
system signals on behalf of the kernel.
- Fixed a few bugs with memory mapping and DS.
VM CHANGES:
- Page faults and memory requests coming from the kernel are now implemented
using signals.
- Added a new VM call to swap two process slots and implement live update.
- The call is used by RS at update time and in turn invokes the kernel call
sys_update().
RS CHANGES:
- RS has been reworked with a better functional decomposition.
- Better kernel call masks. com.h now defines the set of very basic kernel calls
every system service is allowed to use. This makes system.conf simpler and
easier to maintain. In addition, this guarantees a higher level of isolation
for system libraries that use one or more kernel calls internally (e.g. printf).
- RS is the default signal manager for system processes. By default, RS
intercepts every signal delivered to every system process. This makes crash
recovery possible before bringing PM and friends in the loop.
- RS now supports fast rollback when something goes wrong while initializing
the new version during a live update.
- Live update is now implemented by keeping the two versions side-by-side and
swapping the process slots when the old version is ready to update.
- Crash recovery is now implemented by keeping the two versions side-by-side
and cleaning up the old version only when the recovery process is complete.
DS CHANGES:
- Fixed a bug when the process doing ds_publish() or ds_delete() is not known
by DS.
- Fixed the completely broken support for strings. String publishing is now
implemented in the system library and simply wraps publishing of memory ranges.
Ideally, we should adopt a similar approach for other data types as well.
- Test suite fixed.
DRIVER CHANGES:
- The hello driver has been added to the Minix distribution to demonstrate basic
live update and crash recovery functionalities.
- Other drivers have been adapted to conform the new SEF interface.
swapcontext, and makecontext).
- Fix VM to not erroneously think the stack segment and data segment have
collided when a user-space thread invokes brk().
- Add test51 to test ucontext functionality.
- Add man pages for ucontext system calls.
-Convert the include directory over to using bsdmake
syntax
-Update/add mkfiles
-Modify install(1) so that it can create symlinks
-Update makefiles to use new install(1) options
-Rename /usr/include/ibm to /usr/include/i386
-Create /usr/include/machine symlink to arch header files
-Move vm_i386.h to its new home in the /usr/include/i386
-Update source files to #include the header files at their
new homes.
-Add new gnu-includes target for building GCC headers
this change
- makes panic() variadic, doing full printf() formatting -
no more NO_NUM, and no more separate printf() statements
needed to print extra info (or something in hex) before panicing
- unifies panic() - same panic() name and usage for everyone -
vm, kernel and rest have different names/syntax currently
in order to implement their own luxuries, but no longer
- throws out the 1st argument, to make source less noisy.
the panic() in syslib retrieves the server name from the kernel
so it should be clear enough who is panicing; e.g.
panic("sigaction failed: %d", errno);
looks like:
at_wini(73130): panic: sigaction failed: 0
syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a
- throws out report() - printf() is more convenient and powerful
- harmonizes/fixes the use of panic() - there were a few places
that used printf-style formatting (didn't work) and newlines
(messes up the formatting) in panic()
- throws out a few per-server panic() functions
- cleans up a tie-in of tty with panic()
merging printf() and panic() statements to be done incrementally.
have malloc/free, alloc_contig/free_contig and mmap/munmap nicely
paired up.
memory uses malloc/free instead of mmap/munmap as it doesn't have
to be contiguous for the ramdisks (and it might help if it doesn't!).
* Userspace change to use the new kernel calls
- _taskcall(SYSTASK...) changed to _kernel_call(...)
- int 32 reused for the kernel calls
- _do_kernel_call() to make the trap to kernel
- kernel_call() to make the actuall kernel call from C using
_do_kernel_call()
- unlike ipc call the kernel call always succeeds as kernel is
always available, however, kernel may return an error
* Kernel side implementation of kernel calls
- the SYSTEm task does not run, only the proc table entry is
preserved
- every data_copy(SYSTEM is no data_copy(KERNEL
- "locking" is an empty operation now as everything runs in
kernel
- sys_task() is replaced by kernel_call() which copies the
message into kernel, dispatches the call to its handler and
finishes by either copying the results back to userspace (if
need be) or by suspending the process because of VM
- suspended processes are later made runnable once the memory
issue is resolved, picked up by the scheduler and only at
this time the call is resumed (in fact restarted) which does
not need to copy the message from userspace as the message
is already saved in the process structure.
- no ned for the vmrestart queue, the scheduler will restart
the system calls
- no special case in do_vmctl(), all requests remove the
RTS_VMREQUEST flag
- put asmconv in /usr/bin so it can be invoked without absolute path
- make it ignore .end in gnu output mode so that it can be invoked
without '|| true' in the gnu lib makefiles and it doesn't produce the
messy error message
Some cases were fixed by declaring the function void, others were fixed
by adding a return <value> statement, thereby avoiding potentially
incorrect behavior (usually in error handling).
Some enum correctness in boot.c.
- taskcall.c is 3x in the trunk as part of libc, libsysutil and
libsys. It should be only part of libsys.
- only system process should be linked with libsys, therefore using
raw _taskcall() in service.c is replaced by _syscall()
- the same for minix_rs.c
- lib/other/sys_eniop.c can go without replacement as it is part of
syslib
- the prototype changes to
_cpuid(u32_t *eax, u32_t *ebx, u32_t *ecx, u32_t *edx)
- this makes possible to use all the features of the cpuid instruction as
described in the Intel specs
Main changes:
- COW optimization for safecopy.
- safemap, a grant-based interface for sharing memory regions between processes.
- Integration with safemap and complete rework of DS, supporting new data types
natively (labels, memory ranges, memory mapped ranges).
- For further information:
http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants
Additional changes not included in the original Wu's branch:
- Fixed unhandled case in VM when using COW optimization for safecopy in case
of a block that has already been shared as SMAP.
- Better interface and naming scheme for sys_saferevmap and ds_retrieve_map
calls.
- Better input checking in syslib: check for page alignment when creating
memory mapping grants.
- DS notifies subscribers when an entry is deleted.
- Documented the behavior of indirect grants in case of memory mapping.
- Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked
and extended.
- Minor fixes and general cleanup.
- TO-DO: Grant ids should be generated and managed the way endpoints are to make
sure grant slots are never misreused.
- allow mounting with "none" block device
- allow unmounting by mountpoint
- make VFS aware of file system process labels
- allow m3_ca1 to use the full available message size
- use *printf in u/mount(1), as mount(2) uses it already
- fix reference leaks for some mount error cases in VFS
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.
SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic
registration / deregistration of system services.
VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.
RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
- clean up kernel section of minix/com.h somewhat
- remove ALLOCMEM and VM_ALLOCMEM calls
- remove non-safecopy and minix-vmd support from Inet
- remove SYS_VIRVCOPY and SYS_PHYSVCOPY calls
- remove obsolete segment encoding in SYS_SAFECOPY*
- remove DEVCTL call, svrctl(FSDEVUNMAP), map_driverX
- remove declarations of unimplemented svrctl requests
- remove everything related to swapping to disk
- remove floppysetup.sh
- remove traces of rescue device
- update DESCRIBE.sh with new devices
- some other small changes
SYSLIB CHANGES:
- SEF must be used by every system process and is thereby part of the system
library.
- The framework provides a receive() interface (sef_receive) for system
processes to automatically catch known system even messages and process them.
- SEF provides a default behavior for each type of system event, but allows
system processes to register callbacks to override the default behavior.
- Custom (local to the process) or predefined (provided by SEF) callback
implementations can be registered to SEF.
- SEF currently includes support for 2 types of system events:
1. SEF Ping. The event occurs every time RS sends a ping to figure out
whether a system process is still alive. The default callback implementation
provided by SEF is to notify RS back to let it know the process is alive
and kicking.
2. SEF Live update. The event occurs every time RS sends a prepare to update
message to let a system process know an update is available and to prepare
for it. The live update support is very basic for now. SEF only deals with
verifying if the prepare state can be supported by the process, dumping the
state for debugging purposes, and providing an event-driven programming
model to the process to react to state changes check-in when ready to update.
- SEF should be extended in the future to integrate support for more types of
system events. Ideally, all the cross-cutting concerns should be integrated into
SEF to avoid duplicating code and ease extensibility. Examples include:
* PM notify messages primarily used at shutdown.
* SYSTEM notify messages primarily used for signals.
* CLOCK notify messages used for system alarms.
* Debug messages. IS could still be in charge of fkey handling but would
forward the debug message to the target process (e.g. PM, if the user
requested debug information about PM). SEF would then catch the message and
do nothing unless the process has registered an appropriate callback to
deal with the event. This simplifies the programming model to print debug
information, avoids duplicating code, and reduces the effort to print
debug information.
SYSTEM PROCESSES CHANGES:
- Every system process registers SEF callbacks it needs to override the default
system behavior and calls sef_startup() right after being started.
- sef_startup() does almost nothing now, but will be extended in the future to
support callbacks of its own to let RS control and synchronize with every
system process at initialization time.
- Every system process calls sef_receive() now rather than receive() directly,
to let SEF handle predefined system events.
RS CHANGES:
- RS supports a basic single-component live update protocol now, as follows:
* When an update command is issued (via "service update *"), RS notifies the
target system process to prepare for a specific update state.
* If the process doesn't respond back in time, the update is aborted.
* When the process responds back, RS kills it and marks it for refreshing.
* The process is then automatically restarted as for a buggy process and can
start running again.
* Live update is currently prototyped as a controlled failure.
- Revise VFS-FS protocol and update VFS/MFS/ISOFS accordingly.
- Clean up MFS by removing old, dead code (backwards compatibility is broken by
the new VFS-FS protocol, anyway) and rewrite other parts. Also, make sure all
functions have proper banners and prototypes.
- VFS should always provide a (syntactically) valid path to the FS; no need for
the FS to do sanity checks when leaving/entering mount points.
- Fix several bugs in MFS:
- Several path lookup bugs in MFS.
- A link can be too big for the path buffer.
- A mountpoint can become inaccessible when the creation of a new inode
fails, because the inode already exists and is a mountpoint.
- Introduce support for supplemental groups.
- Add test 46 to test supplemental group functionality (and removed obsolete
suppl. tests from test 2).
- Clean up VFS (not everything is done yet).
- ISOFS now opens device read-only. This makes the -r flag in the mount command
unnecessary (but will still report to be mounted read-write).
- Introduce PipeFS. PipeFS is a new FS that handles all anonymous and
named pipes. However, named pipes still reside on the (M)FS, as they are part
of the file system on disk. To make this work VFS now has a concept of
'mapped' inodes, which causes read, write, truncate and stat requests to be
redirected to the mapped FS, and all other requests to the original FS.
/etc CHANGES:
- /etc/drivers.conf has been renamed to /etc/system.conf. Every entry in
the file is now marked as "service" rather than driver.
- user "service" has been added to password file /etc/passwd.
- docs/UPDATING updated accordingly, as well as every other mention to the old
drivers.conf in the system.
RS CHANGES:
- No more distinction between servers and drivers.
- RS_START has been renamed to RS_UP and the old legacy RS_UP and RS_UP_COPY
dropped.
- RS asks PCI to set / remove ACL entries only for services whose ACL properties
have been set. This change eliminates unnecessary warnings.
- Temporarily minimize the risk of potential races at boot time or when starting
a new service. Upcoming changes will eliminate races completely.
- General cleanup.
KERNEL CHANGES:
- The kernel only knows about privileges of kernel tasks and the root system
process (now RS).
- Kernel tasks and the root system process are the only processes that are made
schedulable by the kernel at startup. All the other processes in the boot image
don't get their privileges set at startup and are inhibited from running by the
RTS_NO_PRIV flag.
- Removed the assumption on the ordering of processes in the boot image table.
System processes can now appear in any order in the boot image table.
- Privilege ids can now be assigned both statically or dynamically. The kernel
assigns static privilege ids to kernel tasks and the root system process. Each
id is directly derived from the process number.
- User processes now all share the static privilege id of the root user
process (now INIT).
- sys_privctl split: we have more calls now to let RS set privileges for system
processes. SYS_PRIV_ALLOW / SYS_PRIV_DISALLOW are only used to flip the
RTS_NO_PRIV flag and allow / disallow a process from running. SYS_PRIV_SET_SYS /
SYS_PRIV_SET_USER are used to set privileges for a system / user process.
- boot image table flags split: PROC_FULLVM is the only flag that has been
moved out of the privilege flags and is still maintained in the boot image
table. All the other privilege flags are out of the kernel now.
RS CHANGES:
- RS is the only user-space process who gets to run right after in-kernel
startup.
- RS uses the boot image table from the kernel and three additional boot image
info table (priv table, sys table, dev table) to complete the initialization
of the system.
- RS checks that the entries in the priv table match the entries in the boot
image table to make sure that every process in the boot image gets schedulable.
- RS only uses static privilege ids to set privileges for system services in
the boot image.
- RS includes basic memory management support to allocate the boot image buffer
dynamically during initialization. The buffer shall contain the executable
image of all the system services we would like to restart after a crash.
- First step towards decoupling between resource provisioning and resource
requirements in RS: RS must know what resources it needs to restart a process
and what resources it has currently available. This is useful to tradeoff
reliability and resource consumption. When required resources are missing, the
process cannot be restarted. In that case, in the future, a system flag will
tell RS what to do. For example, if CORE_PROC is set, RS should trigger a
system-wide panic because the system can no longer function correctly without
a core system process.
PM CHANGES:
- The process tree built at initialization time is changed to have INIT as root
with pid 0, RS child of INIT and all the system services children of RS. This
is required to make RS in control of all the system services.
- PM no longer registers labels for system services in the boot image. This is
now part of RS's initialization process.
