Commit graph

32 commits

Author SHA1 Message Date
Tomas Hruby
62203ec287 NOREC_ENTER and NOREC_RETURN checks removed
- the reasons for these checks no longer exist

- these check are problematic on SMP
2010-03-29 11:43:10 +00:00
Ben Gras
0937d6c367 re-establish kernel assert()s.
use the regular <assert.h> assert() instead of vmassert() in
kernel. throw out some #if 0 code. fix a few assert() conditions.
enable by default.
2010-03-10 13:00:05 +00:00
Ben Gras
35a108b911 panic() cleanup.
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.
2010-03-05 15:05:11 +00:00
Ben Gras
e6cb76a2e2 no more kprintf - kernel uses libsys printf now, only kputc is special
to the kernel.
2010-03-03 15:45:01 +00:00
Erik van der Kouwe
ff835e0e35 use the verbose=2 boot monitor setting to get extensive output for debugging 2010-02-13 22:11:16 +00:00
Tomas Hruby
c9da61022b intr_disabled() tests removed
- we don't need to test this in kernel as we always have interrupts
  disabled

- if interrupts are enabled in kernel, it is only at very carefully
  chosen places. There are no such places now.
2010-02-09 15:29:58 +00:00
Tomas Hruby
c6fec6866f No locking in kernel code
- No locking in RTS_(UN)SET macros

- No lock_notify()

- Removed unused lock_send()

- No lock/unlock macros anymore
2010-02-09 15:26:58 +00:00
Tomas Hruby
98563a4afa Killing Minix by typing Q on serial console
- if debugging on serial console is enabled typing Q kills the system. It is
  handy if the system gets locked up and the timer interrupts still work. Good
  for remote debugging.

- NOT_REACHABLE reintroduced and fixed. It should be used for marking code which
  is not reachable because the previous code _should_ not return. Such places
  are not always obvious
2010-01-14 09:46:16 +00:00
Tomas Hruby
8a44a44cb9 Local APIC
- local APIC timer used as the source of time

- PIC is still used as the hw interrupt controller as we don't have
  enough info without ACPI or MPS to set up IO APICs

- remapping of APIC when switching paging on, uses the new mechanism
  to tell VM what phys areas to map in kernel's virtual space

- one more step to SMP

based on code by Arun C.
2009-11-16 21:41:44 +00:00
Tomas Hruby
616d936638 vmassert reports also the source file in which it was triggered 2009-11-04 15:30:08 +00:00
Ben Gras
53567bf741 no DEBUG_VMASSERT committed 2009-10-18 20:08:55 +00:00
Ben Gras
24e1e83028 really revert endpoint_t -> int
debugging info on panic: decode segment selectors and descriptors, now moved
to arch-specific part, prototypes added; sanity checking in debug.h made
optional with vmassert().
2009-10-05 15:47:23 +00:00
Ben Gras
6bd3002f06 - exact magic values for entered/nonentered states in recursive enter check
- read_*() functions to read segment selector values
 - decode loaded segments on panic
2009-10-03 12:17:46 +00:00
Ben Gras
fe35879325 - panic if there's no runnable process
- more basic sanity check before recursive enter check (data segment)
 - try to jump to boot monitor instantly on recursive panic
2009-10-03 11:30:35 +00:00
Tomas Hruby
48602fcfae NOT_REACHABLE macro
- marks code path that should be unreachable (never executed)

- if hit, panics and reports the problem

- the end of main() marked as such. The SMP changes need some magic with stack
  switching before the AP can be started as they need to run on the boot stack
  before figuring out what is their own stack. As main() uses the boot stack to,
  we need to switch to to the stack of BSP before executing the last part of
  main() which needs to be in a separate function so we can jump to it.
  Therefore restart() won't be the last call in main() which may be confusing.
  The macro can/should be used in other such places too.
2009-09-22 21:46:47 +00:00
Ben Gras
cd8b915ed9 Primary goal for these changes is:
- no longer have kernel have its own page table that is loaded
    on every kernel entry (trap, interrupt, exception). the primary
    purpose is to reduce the number of required reloads.
Result:
  - kernel can only access memory of process that was running when
    kernel was entered
  - kernel must be mapped into every process page table, so traps to
    kernel keep working
Problem:
  - kernel must often access memory of arbitrary processes (e.g. send
    arbitrary processes messages); this can't happen directly any more;
    usually because that process' page table isn't loaded at all, sometimes
    because that memory isn't mapped in at all, sometimes because it isn't
    mapped in read-write.
So:
  - kernel must be able to map in memory of any process, in its own
    address space.
Implementation:
  - VM and kernel share a range of memory in which addresses of
    all page tables of all processes are available. This has two purposes:
      . Kernel has to know what data to copy in order to map in a range
      . Kernel has to know where to write the data in order to map it in
    That last point is because kernel has to write in the currently loaded
    page table.
  - Processes and kernel are separated through segments; kernel segments
    haven't changed.
  - The kernel keeps the process whose page table is currently loaded
    in 'ptproc.'
  - If it wants to map in a range of memory, it writes the value of the
    page directory entry for that range into the page directory entry
    in the currently loaded map. There is a slot reserved for such
    purposes. The kernel can then access this memory directly.
  - In order to do this, its segment has been increased (and the
    segments of processes start where it ends).
  - In the pagefault handler, detect if the kernel is doing
    'trappable' memory access (i.e. a pagefault isn't a fatal
     error) and if so,
       - set the saved instruction pointer to phys_copy_fault,
	 breaking out of phys_copy
       - set the saved eax register to the address of the page
	 fault, both for sanity checking and for checking in
	 which of the two ranges that phys_copy was called
	 with the fault occured
  - Some boot-time processes do not have their own page table,
    and are mapped in with the kernel, and separated with
    segments. The kernel detects this using HASPT. If such a
    process has to be scheduled, any page table will work and
    no page table switch is done.

Major changes in kernel are
  - When accessing user processes memory, kernel no longer
    explicitly checks before it does so if that memory is OK.
    It simply makes the mapping (if necessary), tries to do the
    operation, and traps the pagefault if that memory isn't present;
    if that happens, the copy function returns EFAULT.
    So all of the CHECKRANGE_OR_SUSPEND macros are gone.
  - Kernel no longer has to copy/read and parse page tables.
  - A message copying optimisation: when messages are copied, and
    the recipient isn't mapped in, they are copied into a buffer
    in the kernel. This is done in QueueMess. The next time
    the recipient is scheduled, this message is copied into
    its memory. This happens in schedcheck().
    This eliminates the mapping/copying step for messages, and makes
    it easier to deliver messages. This eliminates soft_notify.
  - Kernel no longer creates a page table at all, so the vm_setbuf
    and pagetable writing in memory.c is gone.

Minor changes in kernel are
  - ipc_stats thrown out, wasn't used
  - misc flags all renamed to MF_*
  - NOREC_* macros to enter and leave functions that should not
    be called recursively; just sanity checks really
  - code to fully decode segment selectors and descriptors
    to print on exceptions
  - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 14:31:52 +00:00
Ben Gras
bdab3c4cfb Library call for cpu features; make kernel and vm use this to query cpu
features (specifically: 4MB pages and TLB global bit).  Only enable
these features in CR4 if available. 4MB pages to be used in the near
future.
2009-05-15 17:07:36 +00:00
Ben Gras
e3ca89c0be more sanity checking. sanity checking disabled by default.
give every process a full pagetable by default now.

first step to disabling kernel page table code (processes
might not have page tables -> no address translation).
2009-05-12 11:35:01 +00:00
Ben Gras
e0f3a5acf1 - enable ipc warnings by default
- 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.
2009-04-17 13:46:37 +00:00
Ben Gras
128a0508c0 timing measurement code out of kernel and into library
(so other components can use it too)
2009-01-09 16:15:15 +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
Ben Gras
6f77685609 Split of architecture-dependent and -independent functions for i386,
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
2006-12-22 15:22:27 +00:00
Ben Gras
f1222a09a6 Make stack traces on exceptions possible. 2006-06-29 13:35:27 +00:00
Philip Homburg
15b8fe54a8 Better initialization of the memory map of processes that are part of the
image. Removed NO_MAP flag.
2006-05-11 14:49:46 +00:00
Ben Gras
88ba4b5268 added reenter check to lock_dequeue() to avoid unlocking of interrupts
via cause_sig() during an exception.

moved lock check configuration to <minix/sys_config.h> instead of
kernel/config.h, because the 'relocking' field in kinfo depends on it.

other prettification: common locking macro, whether lock timing is on or
not.
2006-02-10 16:53:51 +00:00
Ben Gras
0a02bfb056 Moved ipc debug out of conditional.
Gave pci server sys_getinfo privilege.
2006-02-06 15:16:14 +00:00
Ben Gras
2bf8bfe126 Turn IPC warning messages off by default
(because inet deadlocks are normal and will confuse our users).
2005-10-18 16:13:12 +00:00
Ben Gras
911ff6a873 Formatting fixes for the book 2005-08-29 16:47:18 +00:00
Ben Gras
d11b2e4b8c Al's double-blank-line removal request 2005-08-22 15:23:47 +00:00
Jorrit Herder
42ab148155 Reorganized system call library; uses separate file per call now.
New configuration header file to include/ exclude functionality.
Extracted privileged features from struct proc and create new struct priv.
Renamed various system calls for readability.
2005-07-14 15:12:12 +00:00
Jorrit Herder
0e2a7a9730 Kernel cleanup.
Reduced kernel size by 512KB by moving private buffer into cstart() function.
Replaced assertions with erroneous return values. Removed assertions relating
to isuserp(rp), since all processes should become user processes; system
processes are now treated similar to other processes.
2005-06-07 12:34:25 +00:00
Ben Gras
c977bd8709 Added args to lock() and unlock() to tell them apart, for use
when lock timing is enabled in minix/config.h.

Added phys_zero() routine to klib386.s that zeroes a range of memory, and
added corresponding system call.
2005-06-01 09:37:52 +00:00