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68 commits

Author SHA1 Message Date
David van Moolenbroek
b423d7b477 Merge of David's ptrace branch. Summary:
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
2009-09-30 09:57:22 +00:00
Tomas Hruby
97fe6a4ba5 Broken pipes fix
- fix for the broken partial pipes r/w operations
2009-09-24 16:03:25 +00:00
Tomas Hruby
f53377ed67 Removed the broken PROC_EVENT and SYN_ALARM from VFS 2009-09-22 22:11:20 +00:00
Tomas Hruby
8590ac260d Removed dependency of vfs on NR_TASKS macro
- all macros in consts.h that depend on NR_TASKS replaced by a FP_BLOCKED_ON_*

- fp_suspended removed and replaced by fp_blocked_on. Testing whether a process
  is supended is qeual to testing whether fp_blocked_on is FP_BLOCKED_ON_NONE or
  not

- fp_task is valid only if fp_blocked_on == FP_BLOCKED_ON_OTHER

- no need of special values that do not colide with valid and special endpoints
  since they are not used as endpoints anymore

- suspend only takes FP_BLOCKED_ON_* values not endpoints anymore

- suspend(task) replaced by wait_for(task) which sets fp_task so we remember who
  are we waiting for and suspend sets fp_blocked_on to FP_BLOCKED_ON_OTHER to
  signal that we are waiting for some other process

- some functions should take endpoint_t instead of int, fixed
2009-09-22 21:48:26 +00:00
Ben Gras
f5459e38db - some exec debugging prints when errors happen
- lookup mounted_on check to avoid NULL dereference
 - some errors in exec() shouldn't be fatal
2009-09-21 14:49:26 +00:00
David van Moolenbroek
1a9e07b0e5 PM: fix ptrace(T_EXIT) 'exit_proc: not idle' race condition. 2009-07-11 13:22:56 +00:00
Ben Gras
dc1238b7b9 make unpause() decrease susp_count, as it shouldn't be decreased
if the process was REVIVING. (susp_count doesn't count those
 processes.) this together with dev_io SELECT suspend side effect
 for asynch. character devices solves the hanging pipe bug. or
 at last vastly improves it.

 added sanity checks, turned off by default.

 made the {NOT_,}{SUSPENDING,REVIVING} constants weirder to
 help sanity checking.
2009-05-08 13:56:41 +00:00
Ben Gras
fd7ef243e4 cleanup of vfs shutdown logic; makes clean unmounts easier (but
needs checking if fp_wd or fp_rd is NULL before use)
2009-04-29 16:59:18 +00:00
Ben Gras
3cc092ff06 . new kernel call sysctl for generic unprivileged system operations;
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.
2009-01-26 17:43:59 +00:00
Ben Gras
7d674f4b8e no more HZ; less debugging statements 2008-12-11 14:47:48 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00
Philip Homburg
097d8fee66 Use nonblocking send for reply. Support for asynchronous message passing
(needs cleaning up).
2008-02-22 14:53:02 +00:00
Philip Homburg
f46319037b New VFS interface 2007-08-07 12:52:47 +00:00
Ben Gras
41e9fedf87 Mostly bugfixes of bugs triggered by the test set.
bugfixes:
 SYSTEM:
 . removed
        rc->p_priv->s_flags = 0;
   for the priv struct shared by all user processes in get_priv(). this
   should only be done once. doing a SYS_PRIV_USER in sys_privctl()
   caused the flags of all user processes to be reset, so they were no
   longer PREEMPTIBLE. this happened when RS executed a policy script.
   (this broke test1 in the test set)

 VFS/MFS:
 . chown can change the mode of a file, and chmod arguments are only
   part of the full file mode so the full filemode is slightly magic.
   changed these calls so that the final modes are returned to VFS, so
   that the vnode can be kept up-to-date.
   (this broke test11 in the test set)

 MFS:
 . lookup() checked for sizeof(string) instead of sizeof(user_path),
   truncating long path names
   (caught by test 23)
 . truncate functions neglected to update ctime
   (this broke test16)

 VFS:
 . corner case of an empty filename lookup caused fields of a request
   not to be filled in in the lookup functions, not making it clear
   that the lookup had failed, causing messages to garbage processes,
   causing strange failures.
   (caught by test 30)
 . trust v_size in vnode when doing reads or writes on non-special
   files, truncating i/o where necessary; this is necessary for pipes,
   as MFS can't tell when a pipe has been truncated without it being
   told explicitly each time.
   when the last reader/writer on a pipe closes, tell FS about
   the new size using truncate_vn().
   (this broke test 25, among others)
 . permission check for chdir() had disappeared; added a
   forbidden() call
   (caught by test 23)

new code, shouldn't change anything:
 . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their
   LOCK variants. These macros set and clear the p_rts_flags field,
   causing a lot of duplicated logic like

       old_flags = rp->p_rts_flags;            /* save value of the flags */
       rp->p_rts_flags &= ~NO_PRIV;
       if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp);

   to change into the simpler

       RTS_LOCK_UNSET(rp, NO_PRIV);

   so the macros take care of calling dequeue() and enqueue() (or lock_*()),
   as the case may be). This makes the code a bit more readable and a
   bit less fragile.
 . removed return code from do_clocktick in CLOCK as it currently
   never replies
 . removed some debug code from VFS
 . fixed grant debug message in device.c
 
preemptive checks, tests, changes:
 . added return code checks of receive() to SYSTEM and CLOCK
 . O_TRUNC should never arrive at MFS (added sanity check and removed
   O_TRUNC code)
 . user_path declared with PATH_MAX+1 to let it be null-terminated
 . checks in MFS to see if strings passed by VFS are null-terminated
 
 IS:
 . static irq name table thrown out
2007-02-01 17:50:02 +00:00
Ben Gras
94b936d7c1 . added super-user check for mount
. corrected device match for unmount (otherwise unmount would
  proceed with bogus mount slot, often sending messages to 0 (PM))
. added some sanity checking to fs process number
. made fs_sendrec PRIVATE to request.c
2007-01-16 13:57:35 +00:00
Philip Homburg
9092146be7 VFS cleanup (mostly open). 2007-01-05 16:36:55 +00:00
Ben Gras
da42185e1c Removed verbose statements from vfs and mfs 2006-12-22 11:54:42 +00:00
Ben Gras
fa0ba56bc9 Merge of VFS by Balasz Gerofi with Minix trunk. 2006-10-25 13:40:36 +00:00
Renamed from servers/fs/main.c (Browse further)