o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL
o PM signal handling logic should now work properly, even with debuggers
being present
o Asynchronous PM/VFS protocol, full IPC support for senda(), and
AMF_NOREPLY senda() flag
DETAILS
Process stop and delay call handling of PM:
o Added sys_runctl() kernel call with sys_stop() and sys_resume()
aliases, for PM to stop and resume a process
o Added exception for sending/syscall-traced processes to sys_runctl(),
and matching SIGKREADY pseudo-signal to PM
o Fixed PM signal logic to deal with requests from a process after
stopping it (so-called "delay calls"), using the SIGKREADY facility
o Fixed various PM panics due to race conditions with delay calls versus
VFS calls
o Removed special PRIO_STOP priority value
o Added SYS_LOCK RTS kernel flag, to stop an individual process from
running while modifying its process structure
Signal and debugger handling in PM:
o Fixed debugger signals being dropped if a second signal arrives when
the debugger has not retrieved the first one
o Fixed debugger signals being sent to the debugger more than once
o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR
protocol message
o Detached debugger signals from general signal logic and from being
blocked on VFS calls, meaning that even VFS can now be traced
o Fixed debugger being unable to receive more than one pending signal in
one process stop
o Fixed signal delivery being delayed needlessly when multiple signals
are pending
o Fixed wait test for tracer, which was returning for children that were
not waited for
o Removed second parallel pending call from PM to VFS for any process
o Fixed process becoming runnable between exec() and debugger trap
o Added support for notifying the debugger before the parent when a
debugged child exits
o Fixed debugger death causing child to remain stopped forever
o Fixed consistently incorrect use of _NSIG
Extensions to ptrace():
o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a
debugger to and from a process
o Added T_SYSCALL ptrace request, to trace system calls
o Added T_SETOPT ptrace request, to set trace options
o Added TO_TRACEFORK trace option, to attach automatically to children
of a traced process
o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon
a successful exec() of the tracee
o Extended T_GETUSER ptrace support to allow retrieving a process's priv
structure
o Removed T_STOP ptrace request again, as it does not help implementing
debuggers properly
o Added MINIX3-specific ptrace test (test42)
o Added proper manual page for ptrace(2)
Asynchronous PM/VFS interface:
o Fixed asynchronous messages not being checked when receive() is called
with an endpoint other than ANY
o Added AMF_NOREPLY senda() flag, preventing such messages from
satisfying the receive part of a sendrec()
o Added asynsend3() that takes optional flags; asynsend() is now a
#define passing in 0 as third parameter
o Made PM/VFS protocol asynchronous; reintroduced tell_fs()
o Made PM_BASE request/reply number range unique
o Hacked in a horrible temporary workaround into RS to deal with newly
revealed RS-PM-VFS race condition triangle until VFS is asynchronous
System signal handling:
o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal
o Removed is-superuser check from PM's do_procstat() (aka getsigset())
o Added sigset macros to allow system processes to deal with the full
signal set, rather than just the POSIX subset
Miscellaneous PM fixes:
o Split do_getset into do_get and do_set, merging common code and making
structure clearer
o Fixed setpriority() being able to put to sleep processes using an
invalid parameter, or revive zombie processes
o Made find_proc() global; removed obsolete proc_from_pid()
o Cleanup here and there
Also included:
o Fixed false-positive boot order kernel warning
o Removed last traces of old NOTIFY_FROM code
THINGS OF POSSIBLE INTEREST
o It should now be possible to run PM at any priority, even lower than
user processes
o No assumptions are made about communication speed between PM and VFS,
although communication must be FIFO
o A debugger will now receive incoming debuggee signals at kill time
only; the process may not yet be fully stopped
o A first step has been made towards making the SYSTEM task preemptible
addr and taddr don't have to be defined any more, so that <sys/mman.h>
can be included for proper prototypes of munmap() and friends.
- rename our GETPID to MINIX_GETPID to avoid a name conflict with
other sources
- PM needs its own munmap() and munmap_text() to avoid sending messages
to VM at the startup phase. It *does* want to do that, but only
after initialising. So they're called again with unmap_ok set to 1
later.
- getnuid(), getngid() implementation
o Don't call vm_willexit() more than once upon normal process exit
o Correct two cases of indenting of the no-discussion-possible kind
o Perform slightly stricter ptrace(2) checks:
- process calling ptrace must be target process's parent
- process must call wait/waitpid before using ptrace on stopped child
- no ptrace on zombies
o Allow user processes to use ptrace(T_STOP) to stop an active child
- ipc checking code in kernel didn't properly catch the
sendrec() to self case; added special case check
- triggered by PM using stock panic() - needs its own _exit()
reported by Joren l'Ami.
now used for printing diagnostic messages through the kernel message
buffer. this lets processes print diagnostics without sending messages
to tty and log directly, simplifying the message protocol a lot and
reducing difficulties with deadlocks and other situations in which
diagnostics are blackholed (e.g. grants don't work). this makes
DIAGNOSTICS(_S), ASYN_DIAGNOSTICS and DIAG_REPL obsolete, although tty
and log still accept the codes for 'old' binaries. This also simplifies
diagnostics in several servers and drivers - only tty needs its own
kputc() now.
. simplifications in vfs, and some effort to get the vnode references
right (consistent) even during shutdown. m_mounted_on is now NULL
for root filesystems (!) (the original and new root), a less awkward
special case than 'm_mounted_on == m_root_node'. root now has exactly
one reference, to root, if no files are open, just like all other
filesystems. m_driver_e is unused.
mainly in the kernel and headers. This split based on work by
Ingmar Alting <iaalting@cs.vu.nl> done for his Minix PowerPC architecture
port.
. kernel does not program the interrupt controller directly, do any
other architecture-dependent operations, or contain assembly any more,
but uses architecture-dependent functions in arch/$(ARCH)/.
. architecture-dependent constants and types defined in arch/$(ARCH)/include.
. <ibm/portio.h> moved to <minix/portio.h>, as they have become, for now,
architecture-independent functions.
. int86, sdevio, readbios, and iopenable are now i386-specific kernel calls
and live in arch/i386/do_* now.
. i386 arch now supports even less 86 code; e.g. mpx86.s and klib86.s have
gone, and 'machine.protected' is gone (and always taken to be 1 in i386).
If 86 support is to return, it should be a new architecture.
. prototypes for the architecture-dependent functions defined in
kernel/arch/$(ARCH)/*.c but used in kernel/ are in kernel/proto.h
. /etc/make.conf included in makefiles and shell scripts that need to
know the building architecture; it defines ARCH=<arch>, currently only
i386.
. some basic per-architecture build support outside of the kernel (lib)
. in clock.c, only dequeue a process if it was ready
. fixes for new include files
files deleted:
. mpx/klib.s - only for choosing between mpx/klib86 and -386
. klib86.s - only for 86
i386-specific files files moved (or arch-dependent stuff moved) to arch/i386/:
. mpx386.s (entry point)
. klib386.s
. sconst.h
. exception.c
. protect.c
. protect.h
. i8269.c
as living processes before they are cleaned up (fixes
wait()/waitpid() hanging forever on previously-ZOMBIE processes)
. stop processes from running using sys_nice() with PRIO_STOP
when a handled signal is delivered, before computing
stack locations for sys_sigsend(). (fixes race condition
when runnable processes get signals, and e.g. get scheduled
before FS sends a reply to unpause(), which can make the
signal stack location wrong.)
library to the memory driver. Always put output from within TTY directly on
the console. Removed second include of driver.h from tty.c. Made tty_inrepcode
bigger. First step to move PM and FS calls that are not regular (API)
system calls out of callnr.h (renumbered them, and removed them from the
table.c files). Imported the Minix-vmd uname implementation. This provides
a more stable ABI than the current implementation. Added a bit of security
checking. Unfortunately not nearly enough to get a secure system. Fixed a
bug related to the sizes of the programs in the image (in PM patch_mem_chunks).
instead of keeping a running total of enqueued processes
(because somehow the load average was broken)
. added SI_KPROC_TAB to get a copy of kernel process table from PM, for
a top implementation
. fixed arg to sys_nice() to make it an endpoint, not a slot number
pm: fixed rebooting by making a copy of the monitor code from the user
process. this is necessary because that process is dead by the time
sys_abort() is called.
also added more info to the "can't reply" panic.
'who', indicating caller number in pm and fs and some other servers, has
been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.).
In both PM and FS, isokendpt() convert endpoints to process slot
numbers, returning OK if it was a valid and consistent endpoint number.
okendpt() does the same but panic()s if it doesn't succeed. (In PM,
this is pm_isok..)
pm and fs keep their own records of process endpoints in their proc tables,
which are needed to make kernel calls about those processes.
message field names have changed.
fs drivers are endpoints.
fs now doesn't try to get out of driver deadlock, as the protocol isn't
supposed to let that happen any more. (A warning is printed if ELOCKED
is detected though.)
fproc[].fp_task (indicating which driver the process is suspended on)
became an int.
PM and FS now get endpoint numbers of initial boot processes from the
kernel. These happen to be the same as the old proc numbers, to let
user processes reach them with the old numbers, but FS and PM don't know
that. All new processes after INIT, even after the generation number
wraps around, get endpoint numbers with generation 1 and higher, so
the first instances of the boot processes are the only processes ever
to have endpoint numbers in the old proc number range.
More return code checks of sys_* functions have been added.
IS has become endpoint-aware. Ditched the 'text' and 'data' fields
in the kernel dump (which show locations, not sizes, so aren't terribly
useful) in favour of the endpoint number. Proc number is still visible.
Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got
the formatting changed.
PM reading segments using rw_seg() has changed - it uses other fields
in the message now instead of encoding the segment and process number and
fd in the fd field. For that it uses _read_pm() and _write_pm() which to
_taskcall()s directly in pm/misc.c.
PM now sys_exit()s itself on panic(), instead of sys_abort().
RS also talks in endpoints instead of process numbers.
Implemented by changing write_map to accept a WMAP_FREE flag. In that
case, it doesn't update the datablock (creating indirect zones as
necessary) pointer, but it frees the datablock if present. Also it
frees the single and double indirect blocks if unused.
This makes the implementation of truncate_inode() simpler.
truncate_inode() now accepts a truncation length which makes
implementing truncate() and ftruncate() simple.
This also allowed implementing the F_FREESP fcntl().
. new_node() now returns inode of parent dir as argument that
has to be put_node()d again by the caller of new_node().
it can also return the name of the last component as last_dir()
did.
. advance() takes a pointer to a pointer of an inode as the
parent now. This parent can change, in which case the old
one is put_node()d and a new one is put there.
. eat_path() replaced by more flexible parse_path()
. last_dir() replaced by call to parse_path().
. do_slink(), do_readlink(), do_lstat() and slink_traverse() added.
Also added some truncate()/ftruncate()-introduction related changes.
(e.g. renamed truncate() to truncate_inode().)
New Shift-F6 dump for RS server at IS.
New getnpid, getnproc, getpproc library calls at PM.
New reincarnation server (basic functionality is there now).
enforced. If a call is denied, this will be kprinted. Please report any such
errors, so that I can adjust the mask before returning errors instead of
warnings.
Wrote CMOS driver. All CMOS code from FS has been removed. Currently the
driver only supports get time calls. Set time is left out as an exercise
for the book readers ... startup scripts were updated because the CMOS driver
is needed early on. (IS got same treatment.) Don't forget to run MAKEDEV cmos
in /dev/, otherwise the driver cannot be loaded.
