Commit graph

327 commits

Author SHA1 Message Date
Erik van der Kouwe
57c748b968 Remove ability to pass commands to bootloader 2012-11-22 19:16:17 +01:00
Erik van der Kouwe
22fa466268 Restore poweroff to some of it's former glory (on QEMU, at least) 2012-11-21 20:28:37 +01:00
Ben Gras
b1da7fafd0 vm: fix a null dereference on out-of-memory
. also make other out-of-memory conditions less fatal
	. add a test case for a user program using all the memory
	  it can
	. remove some diagnostic prints for situations that are normal
	  when running out of memory so running the test isn't noisy
2012-11-09 18:36:51 +01:00
David van Moolenbroek
ff84d11216 PM: do not panic if sys_sigsend returns ENOMEM 2012-11-09 16:11:02 +00:00
Thomas Veerman
edefb7b35f PM: don't deliver signals to VM 2012-09-17 11:01:46 +00:00
Ben Gras
053fa581b5 vm: remove stack handling for signals
. moved to the kernel as the handling was only
	  reading it; the kernel may as well write it too
2012-08-29 17:31:38 +02:00
Ben Gras
e4ac80eb60 various warning/errorwarning fixes for gcc47
. warnings (sometimes promoted to errors) in servers/ and kernel/
 . -Os for ext2 boot module to make it small enough
2012-08-27 16:19:18 +02:00
Arun Thomas
263ec1e885 pm: update for ARM 2012-08-12 23:30:54 +02:00
David van Moolenbroek
be87fdda3d PM: resolve Coverity warnings 2012-08-09 00:16:35 +02:00
Arun Thomas
6723dcfab7 Replace MACHINE/CHIP macros with compiler macros 2012-08-06 17:49:22 +02:00
Thomas Veerman
238a9a057b PM: a few Coverity inspired fixes
.initialize variable to prevent negative array indexing
.remove dead code
2012-07-30 09:44:58 +00:00
Ben Gras
cbcdb838f1 various coverity-inspired fixes
. 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
2012-07-16 14:00:56 +02:00
Ben Gras
50e2064049 No more intel/minix segments.
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.
2012-07-15 22:30:15 +02:00
Ben Gras
cfe1ed4df4 profiling related cleanup
. do not declare any data in <minix/profile.h>
	. addr check no longer necessary
2012-07-15 21:56:55 +02:00
Thomas Veerman
f93afa00e9 Remove MINIXSRCDIR and use NETBSDSRCDIR
NETBSDSRCDIR is used all over the place anyway, and this reduces
our diff with NetBSD a little.
2012-06-18 10:53:35 +00:00
Ben Gras
0fb2f83da9 drop from segments physcopy/vircopy invocations
. 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
2012-06-18 12:28:40 +00:00
Ben Gras
5e38c802d8 pm: ignore notify() from unknown sender
. avoids annoying error message if e.g. buggy drivers
	  send pm notify()s that pm tries to reply() ENOSYS to
2012-06-14 15:36:38 +02:00
Ben Gras
040362e379 exec() cleanup, generalization, improvement
. 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/)
2012-06-07 15:15:01 +02:00
Ben Gras
53002f6f6c recognize and execute dynamically linked executables
. 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
2012-04-16 00:41:42 +00:00
Ben Gras
204ae72525 retire _ANSI and <minix/ansi.h> 2012-03-25 21:58:27 +02:00
Ben Gras
7336a67dfe retire PUBLIC, PRIVATE and FORWARD 2012-03-25 21:58:14 +02:00
Ben Gras
6a73e85ad1 retire _PROTOTYPE
. only good for obsolete K&R support
	. also remove a stray ansi.h and the proto cmd
2012-03-25 16:17:10 +02:00
Ben Gras
6af9856d4a libcompat_minix-centric cleanup
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>
2012-03-16 17:06:24 +01:00
Arun Thomas
ff56906879 Remove obsolete INSTALLFLAGS from makefiles 2012-02-16 23:26:38 +01:00
Antoine Leca
3fb8cb760c More cleaning up 2012-02-15 19:04:58 +00:00
Thomas Veerman
becf700bc2 APFS: drop privileges upon startup
Move SERVICE_LOGIN to rs.h global header so it's accessible for all.
2012-01-30 15:16:20 +00:00
Thomas Veerman
0bd011affd PM: extend srv_fork to set a specific UID
Currently, all servers and drivers run as root as they are forks of
RS. srv_fork now tells PM with which credentials to run the resulting
fork. Subsequently, PM lets VFS now as well.

This patch also fixes the following bugs:
 - RS doesn't initialize the setugid variable during exec, causing the
   servers and drivers to run setuid rendering the srv_fork extension
   useless.
 - PM erroneously tells VFS to run processes setuid. This doesn't
   actually lead to setuid processes as VFS sets {r,e}uid and {r,e}gid
   properly before checking PM's approval.
2012-01-30 15:16:19 +00:00
Thomas Veerman
a6d0ee24c3 Use correct value for _NSIG
User processes can send signals with number up to _NSIG. There are a few
signal numbers above that used by the kernel, but should explicitly not
be included in the range or range checks in PM will fail.

The system processes use a different version of sigaddset, sigdelset,
sigemptyset, sigfillset, and sigismember which does not include a range
check on signal numbers (as opposed to the normal functions used by normal
processes).

This patch unbreaks test37 when the boot image is compiled with GCC/Clang.
2012-01-16 11:42:29 +00:00
David van Moolenbroek
c89aaf7a87 vfs/avfs: renumber stat calls so as to be unique
The old stat call numbers are still supported for a while.
2012-01-14 00:27:07 +01:00
David van Moolenbroek
2c685f34e0 Cut PM out of the adddma/deldma/getdma call path 2012-01-14 00:27:06 +01:00
David van Moolenbroek
8cb7ba7951 Remove obsolete PROCSTAT/getsigset call. 2012-01-14 00:27:06 +01:00
David van Moolenbroek
6f374faca5 Add "expected size" parameter to getsysinfo()
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.
2011-12-11 22:34:14 +01:00
David van Moolenbroek
9701e9dfd2 Servers: cleanup of some gcc -W warnings 2011-12-11 22:33:37 +01:00
Thomas Veerman
b4fb061802 Implement issetugid syscall
Implement issetugid syscall and provide a test. This gets rid of the
scary "Unsecure. Implement me" warning during compilation.
2011-11-28 10:03:43 +00:00
Adriana Szekeres
c30f014a89 gcore command to coredump a process 2011-11-22 22:07:41 +01:00
Adriana Szekeres
eaa29370f4 ELF core files 2011-11-22 22:07:40 +01:00
Ben Gras
c24d15b2db pm: add mproc table sanity check feature
. make procfs check it
	. detects pm/procfs mismatches
	. was triggered by ack/clang pm/procfs:
	  add padding to mproc struct to align ack/clang layout
	  to fix this
2011-11-18 17:18:10 +01:00
David van Moolenbroek
0bb27bb0b1 Servers: remove ABI comment 2011-11-07 22:24:59 +01:00
David van Moolenbroek
b02c260ecb Miscellaneous legacy cleanup 2011-11-07 22:20:55 +01:00
Arun Thomas
62841e2935 pm: remove dead minix_munmap functions 2011-11-02 18:43:59 +01:00
Antoine LECA
b1c2329954 clean up PM_SCHEDULED 2011-10-25 16:37:21 +00:00
Arun Thomas
8a0901c4cb Add MKTRACE 2011-09-07 17:52:48 +02:00
Thomas Veerman
8a266a478e Increase gid_t and uid_t to 32 bits
Increase gid_t and uid_t to 32 bits and provide backwards compatibility
where needed.
2011-09-05 13:56:14 +00:00
Arun Thomas
9602f63a72 pm: remove dead function 2011-08-11 17:51:27 +02:00
Ben Gras
c4ea2a195c getsid() implementation 2011-08-02 22:16:59 +02:00
Arun Thomas
aaefc6f838 Add MKMCONTEXT option 2011-08-02 13:57:31 +02:00
Ben Gras
02081e4b62 rename mmap() and munmap()
. 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
2011-07-16 13:01:19 +02:00
Evgeniy Ivanov
ef0a265086 New stat structure.
* 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).
2011-07-12 16:39:55 +02:00
Ben Gras
a9d15dd3e4 pm, vfs: don't print something for bogus calls 2011-07-05 13:21:48 +02:00
Arun Thomas
93ae43f577 boot: Add multiboot support
Not yet fully spec-compliant; work in progress
2011-06-24 17:21:51 +02:00
Gianluca Guida
cc17b27a2b Build NetBSD libc library in world in ELF mode.
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
2011-06-24 11:46:30 +02:00
Erik van der Kouwe
6e0f3b3bda Split off sys_umap_remote from sys_umap
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.
2011-06-10 14:28:20 +00:00
Ben Gras
a77c2973b3 fix clang warnings -R in kernel/ and servers/ 2011-06-09 16:09:13 +02:00
Arun Thomas
350b60661a ELF multiboot support 2011-05-04 18:51:43 +02:00
Arun Thomas
25a790a631 VM and kernel support for ELF 2011-02-26 23:00:55 +00:00
Ben Gras
32f3d9842d pm - sys_sigsend can fail legitimately
. specifically, if a signal handler can't be invoked due
    to process memory, EFAULT is returned from the kernel.
    don't panic() then.
2011-02-18 15:44:54 +00:00
Ben Gras
dc1cc91df1 <ansi.h> -> <minix/ansi.h> 2011-01-28 11:35:02 +00:00
Tomas Hruby
74c5cd7668 The profile utility can set the sprofiling mode
- 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
2010-09-23 10:49:42 +00:00
Tomas Hruby
1f89845bb2 SMP - can boot even if some cpus fail to boot
- EBADCPU is returned is scheduler tries to run a process on a CPU
  that either does not exist or isn't booted

- this change was originally meant to deal with stupid cpuid
  instruction which provides totally useless information about
  hyper-threading and MPS which does not deal with ht at all. ACPI
  provides correct information. If ht is turned off it looks like some
  CPUs failed to boot.  Nevertheless this patch may be handy for
  testing/benchmarking in the future.
2010-09-15 14:11:21 +00:00
Tomas Hruby
e87d29171f SMP - Compiles for both single and multi processor again
- this patch adds various fixes as some of the previous patches break
  compilations without CONFIG_SMP being set
2010-09-15 14:11:03 +00:00
Tomas Hruby
06b6e5624a SMP - Changed prototype of sys_schedule()
- 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
2010-09-15 14:10:42 +00:00
Tomas Hruby
1e273f640e SMP - Scheduler can assign process to a cpu
- machine information contains the number of cpus and the bsp id

- a dummy SMP scheduler which keeps all system processes on BSP and
  all other process on APs. The scheduler remembers how many processes
  are assigned to each CPU and always picks the one with the least
  processes for a new process.
2010-09-15 14:10:33 +00:00
David van Moolenbroek
354da24f5b make getsysinfo() a system-land call 2010-09-14 21:50:05 +00:00
David van Moolenbroek
7763fd67c7 PM: save process frame length 2010-09-14 21:21:54 +00:00
Ben Gras
5d6c2aae0a gcov support, based on work contributed by Anton Kuijsten. 2010-08-25 13:06:43 +00:00
Arun Thomas
de231a713e Move MIN() and MAX() macros to sys/params.h 2010-08-21 13:10:41 +00:00
Erik van der Kouwe
98725c443e Fix RS warning at start-up by inheriting scdeduling properties from init for unprivileged children of system processes 2010-07-16 14:56:05 +00:00
Cristiano Giuffrida
8cedace2f5 Scheduling parameters out of the kernel. 2010-07-13 15:30:17 +00:00
David van Moolenbroek
895850b8cf move timers code to libsys 2010-07-09 12:58:18 +00:00
Thomas Veerman
34a2864e27 Fix a few compile time warnings 2010-07-02 12:41:19 +00:00
Erik van der Kouwe
23284ee7bd User-space scheduling for system processes 2010-07-01 08:32:33 +00:00
Arun Thomas
c0c8d25799 Rename mkfiles from minix.*.mk to bsd.*.mk
Makes things easier for pkgsrc
2010-06-25 18:29:09 +00:00
Erik van der Kouwe
498d7d8a4c Don't use kernel responses in servers 2010-06-24 07:37:26 +00:00
Erik van der Kouwe
11193f5fa4 Don't allow PM to sys_kill itself, this causes a race with RS calling waitpid during shutdown 2010-06-18 13:49:07 +00:00
Cristiano Giuffrida
ad5771aa28 Don't forget about pending signals coming from the kernel. 2010-06-18 12:04:20 +00:00
Arun Thomas
1bf6d23f34 Make exec() use entry point in a.out header 2010-06-10 14:59:10 +00:00
Arun Thomas
f0a158d8c1 More cleanup to remove MM and FS references 2010-06-10 14:04:46 +00:00
Arun Thomas
eec65ac664 Rename tell_fs to tell_vfs 2010-06-09 14:31:30 +00:00
Arun Thomas
4c10a31440 Remove legacy MM, FS, and FS_PROC_NR macros 2010-06-08 13:58:01 +00:00
Arun Thomas
b641afc78a VM: Remove legacy non-paging code paths 2010-06-05 14:39:40 +00:00
Cristiano Giuffrida
354d88f883 Put initialization code where it belongs. 2010-06-04 18:08:15 +00:00
Cristiano Giuffrida
332842295a Always skip signals for PM itself when broadcasting. 2010-06-03 11:18:43 +00:00
Kees van Reeuwijk
ed0b81c25c Removed some unused variables and functions. 2010-06-02 19:41:38 +00:00
Kees van Reeuwijk
ac14a989b3 Fixed some inconsistent strict typing declarations.
Better strict typing.
2010-05-25 07:23:24 +00:00
Erik van der Kouwe
1f11a57141 Oops, last commit included more than was intended 2010-05-20 08:07:47 +00:00
Erik van der Kouwe
5f15ec05b2 More system processes, this was not enough for the release script to run on some configurations 2010-05-20 08:05:07 +00:00
Ben Gras
bcdaf033b5 pm - fix sched interaction
For coredumping processes, PM forgets to inform SCHED that the
process has vanished, causing future fork()s to fail.
2010-05-19 13:22:29 +00:00
Tomas Hruby
b09bcf6779 Scheduling server (by Bjorn Swift)
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.
2010-05-18 13:39:04 +00:00
Tomas Hruby
d3e991a7b6 PM signal handling check too strict
- this panic may be unnecessarily triggered if PM gets the delayed
  stop signal from kernel before it gets reply from VFS to the UNPAUSE
  call.

- after this change PM does not proceed to delivering the signal until
  the reply from VFS is received. Perhaps PM could deliver the signal
  straight away as it knows that the process does not run. Possibly
 i dangerous.

- the signal is deliverd immediately after the UNPAUSE reply as the
  pending signals are always checked at the moment.
2010-05-10 14:27:22 +00:00
Tomas Hruby
6e25ad8b0a Use of all NIL_* defines converted to NULL 2010-05-10 13:26:00 +00:00
Erik van der Kouwe
93f3bf5bda Fix wrong word 2010-04-28 20:37:08 +00:00
Tomas Hruby
86378ff645 PM remembers what it should schedule
- while PM implements fork also for RS it needs to remember what to
  schedule and what not. PM_SCHEDULED flag serves this purpose.

- PM only schedules processes that are descendaints of init, i.e. normal
  user processes

- after a process is forked PM schedules for the first time only
  processes that have PM_SCHEDULED set. The others are handled iether
  by kernel or some other scheduler
2010-04-13 10:45:08 +00:00
Tomas Hruby
9b599bac1d Quantum in fork
- This patch removes the time slice split between parent and child in
  fork.

- The time slice of the parent remains unchanged and the child does
  not have any.

- If the process has a scheduler, the scheduler must assign the
  quantum and priority of the new process and let it run.

- If the child does not inherit a scheduler, it is scheduled by the
  dummy default kernel policy. (servers, drivers, etc.)

- In theory, the scheduler can change the quantum even of the parent
  process and implement any policy for splitting the quantum as
  neither the parent nor the child are runnable.  Sending the
  out-of_quantum message on behalf of the processes may look like the
  right solution, however, the scheduler would probably handle the
  message before the whole fork protocol is finished. This way the
  scheduler has absolute control when the process should become
  runnable.
2010-04-10 15:27:38 +00:00
Tomas Hruby
1a31d158ad Restructure and simplyfycation of the scheduling code in PM a little bit.
- It introduces schedule_process() which makes a kernel call to set
  the scheduling parameters of a process. It is used in the next patch.
2010-04-10 15:24:49 +00:00
Cristiano Giuffrida
48c6bb79f4 Driver refactory for live update and crash recovery.
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.
2010-04-08 13:41:35 +00:00
Arun Thomas
4ed3a0cf3a Convert kernel over to bsdmake 2010-04-01 22:22:33 +00:00
Kees van Reeuwijk
fc7dced1fa Fix printfs with too few or too many parms, remove unused vars, fix incorrect flag tests, other code cleanup. 2010-04-01 13:25:05 +00:00
Cristiano Giuffrida
d8b42a755d Move kernel signal SIGKNDELAY to system signal SIGSNDELAY and fix broken ptrace. 2010-03-31 08:55:12 +00:00
Tomas Hruby
5b52c5aa02 A reliable way for userspace to check if a msg is from kernel
- IPC_FLG_MSG_FROM_KERNEL status flag is returned to userspace if the
  receive was satisfied by s message which was sent by the kernel on
  behalf of a process. This perfectly reliale information.

- MF_SENDING_FROM_KERNEL flag added to processes to be able to set
  IPC_FLG_MSG_FROM_KERNEL when finishing receive if the receiver
  wasn't ready to receive immediately.

- PM is changed to use this information to confirm that the scheduling
  messages are indeed from the kernel and not faked by a process.

  PM uses sef_receive_status()

- get_work() is removed from PM to make the changes simpler
2010-03-29 11:25:01 +00:00
Tomas Hruby
b4cf88a04f Userspace scheduling
- 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.
2010-03-29 11:07:20 +00:00