Commit graph

281 commits

Author SHA1 Message Date
Arne Welzel
d8a89dcbe6 kernel: add safememset() kernel call 2012-09-26 02:18:00 +02:00
Arne Welzel
0617743bd1 kernel: handle pagefaults in vm_memset() 2012-09-26 02:17:59 +02:00
Ben Gras
2d72cbec41 SYSENTER/SYSCALL support
. add cpufeature detection of both
	. use it for both ipc and kernelcall traps, using a register
	  for call number
	. SYSENTER/SYSCALL does not save any context, therefore userland
	  has to save it
	. to accomodate multiple kernel entry/exit types, the entry
	  type is recorded in the process struct. hitherto all types
	  were interrupt (soft int, exception, hard int); now SYSENTER/SYSCALL
	  is new, with the difference that context is not fully restored
	  from proc struct when running the process again. this can't be
	  done as some information is missing.
	. complication: cases in which the kernel has to fully change
	  process context (i.e. sigreturn). in that case the exit type
	  is changed from SYSENTER/SYSEXIT to soft-int (i.e. iret) and
	  context is fully restored from the proc struct. this does mean
	  the PC and SP must change, as the sysenter/sysexit userland code
	  will otherwise try to restore its own context. this is true in the
	  sigreturn case.
	. override all usage by setting libc_ipc=1
2012-09-24 15:53:43 +02:00
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
d69cc76e03 rename struct mem_range to minix_mem_range
. avoid a name clash with gdb
2012-08-15 15:17:25 +02:00
David van Moolenbroek
8e116b71a1 Kernel: resolve Coverity warnings 2012-08-15 11:12:11 +00:00
David van Moolenbroek
0b5c2a058c Kernel: use okendpt() to resolve stored endpoints
This adds an integrity check at very little cost, and should stop
Coverity from flagging array overruns on the result.
2012-08-15 08:50:30 +00:00
Arun Thomas
19ffad7692 Remove ACK EM_WSIZE/EM_PSIZE macro usage 2012-08-06 17:49:22 +02:00
Arun Thomas
6723dcfab7 Replace MACHINE/CHIP macros with compiler macros 2012-08-06 17:49:22 +02:00
Ben Gras
b6ea15115c kernel: facility for user-visible memory
. 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
2012-07-28 20:57:38 +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
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
0e35eb0c6b drop segments from safemap/safeunmap invocations 2012-06-18 12:28:40 +00:00
Ben Gras
2bfeeed885 drop segment from safecopy invocations
. 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
2012-06-16 16:22:51 +00:00
Ben Gras
769af57274 further libexec generalization
. 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)
2012-06-07 15:15:02 +02:00
Ben Gras
cfb2d7bca5 retire BIOS_SEG and umap_bios
. readbios call is now a physical copy with range check in
	  the kernel call instead of BIOS_SEG+umap_bios
	. requires all access to physical memory in bios range to go
	  through sys_readbios
	. drivers/dpeth: wasn't using it
	. adjusted printer
2012-05-09 19:03:59 +02:00
Ben Gras
a149be43fc use linker to align fpu state save area 2012-04-19 15:06:47 +02:00
Ben Gras
1e399dd8bd various kernel printing fixes
. remove some call cycles by low-level functions invoking printf(); e.g.
	  send_sig() gets a return value that the caller should check
	. reason: very-early-phase printf() would trigger a printf() causing
	  infinite recursion -> GPF
	. move serial initialization a little earlier so DEBUG_EXTRA works for
	  serial earlier (e.g. its first instance, for "cstart")
	. closes tracker item 583:
	  System Fails to Complete Startup with Verbose 2 and 3 Boot Parameters,
	  reported by Stephen Hatton / pikpik.
2012-03-28 18:23:12 +02:00
David van Moolenbroek
9cca9d7566 Kernel: arch-related cleanup
- move umap_bios() into arch-specific code
- move proc.p_fpu_state access into arch-specific blocks
2012-03-26 14:19:33 +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
David van Moolenbroek
70abb127cc Add sys_vumap() kernel call
This new call is a vectored version of sys_umap(). It supports batch
lookups, non-contiguous memory, faulting in memory, and basic access
checks.
2012-03-24 19:51:13 +01:00
David van Moolenbroek
08af3f672b Kernel: replace vm_contiguous with vm_lookup_range 2012-03-24 19:51:12 +01:00
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
David van Moolenbroek
4b6a98de5f Kernel: adjust FPU state upon process slot swap
This fixes seemingly random FPU exceptions and kernel panics occurring
after a system server restart.
2012-03-05 22:32:14 +01:00
Antoine Leca
3fb8cb760c More cleaning up 2012-02-15 19:04:58 +00:00
Tomas Hruby
758d788bbe SMP - asyn send SMP safe
- we must not deliver messages from/to unstable address spaces.
  In such a case, we must postpone the delivery. To make sute
  that a process which is expecting an asynchronous message does
  not starve, we must remember that we skipped delivery of some
  messages and we must try to deliver again once the source
  address space is stable again.
2012-01-13 11:30:01 +00:00
Tomas Hruby
8fa95abae4 SMP - fixed usage of stale TLB entries
- when kernel copies from userspace, it must be sure that the TLB
  entries are not stale and thus the referenced memory is correct

- everytime we change a process' address space we set p_stale_tlb
  bits for all CPUs.

- Whenever a cpu finds its bit set when it wants to access the
  process' memory, it refreshes the TLB

- it is more conservative than it needs to be but it has low
  overhead than checking precisely
2012-01-13 11:30:00 +00:00
Tomas Hruby
0468fca72b SMP - do_update fix
- adjust_proc_slot() must preserve scheduling info, for example
  on which cpu the process should run

- do_update() - consitency check
2012-01-13 11:30:00 +00:00
Tomas Hruby
8d0a1f71bf KERNEL - do_privctl() fix
- after a driver is restarted, do not register permissions
  which are already set again.
2012-01-13 11:29:59 +00:00
David van Moolenbroek
84662ec4b3 libsys: unbreak getidle() 2011-12-16 16:06:09 +00:00
David van Moolenbroek
1e1db53986 Introduce sys_getregs call, and let vfs use it 2011-11-22 02:07:33 +01:00
David van Moolenbroek
8b00ebde78 Kernel: remove unused MF_ASYNMSG 2011-11-01 19:21:19 +00:00
Arun Thomas
d69519f86a kernel: don't build cprofile code by default 2011-08-02 15:25:54 +02:00
Arun Thomas
aaefc6f838 Add MKMCONTEXT option 2011-08-02 13:57:31 +02:00
Ben Gras
b984fa41df Revert "print kernel stacktrace for exceptions in kernel"
This reverts commit eff1369cab.

This was in a working branch and I only intended to commit
exception.c. But I committed the exact inverse. Sorry.
2011-07-22 15:01:44 +02:00
Ben Gras
eff1369cab print kernel stacktrace for exceptions in kernel
fpu alignment check feature, checksum feature
2011-07-22 11:03:45 +00:00
Arun Thomas
c356e9997e kernel: fix GCC warnings 2011-07-18 19:44:59 +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
Erik van der Kouwe
1e5f9dfa14 Make sys_umap on grants check grantee 2011-06-09 05:05:20 +00:00
Erik van der Kouwe
e969b5e11b Remote unused segctl kernel call 2011-04-26 23:28:23 +02:00
Arun Thomas
25a790a631 VM and kernel support for ELF 2011-02-26 23:00:55 +00:00
Ben Gras
c6e6aa8850 mark forked process as such in the kernel p_name
. helps debugging output; you can see the difference
    between parent and child easily (it's sometimes 
    confusing to see an expected endpoint number with
    an unexpected name, i.e. before exec())
  . when processes crash after fork and before exec, it's
    an instant hint that that's what's going on, instead of
    it being the parent (endpoint numbers don't usually convey
    this)
  . name returns to 'normal' after exec(), so *F isn't visible
    normally at all. (Except for for RS which forks apparently.)
2011-02-21 15:05:32 +00:00
Ben Gras
07bfb4f4e4 kernel - account for kernel cpu time (ipc, kcalls) in caller 2011-02-08 13:58:32 +00:00
Ben Gras
95702f970b kernel - doesn't do lock timings any more 2011-02-04 13:42:17 +00:00
David van Moolenbroek
5d8d5e0c3a change bitchunk_t from 16-bit to 32-bit 2010-12-21 10:44:45 +00:00
Arun Thomas
361f377493 Fix multiboot for ACK-built images
Move the profiling buffer to the end of the data segment
2010-12-17 13:47:11 +00:00