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46 commits

Author SHA1 Message Date
Ben Gras
298b41b523 libexec: detect short files
if an exec() fails partway through reading in the sections, the target
process is already gone and a defunct process remains. sanity checking
the binary beforehand helps that.

test10 mutilates binaries and exec()s them on purpose; making an exec()
fail cleanly in such cases seems like acceptable behaviour.

fixes test10 on ARM.

Change-Id: I1ed9bb200ce469d4d349073cadccad5503b2fcb0
2013-02-04 12:04:35 +01:00
Ben Gras
31d8526346 libexec: add load_offset feature, used for ld.so
. ld.so is linked at 0 but it can relocate itself; we
	  wish to load ld.so higher though to trap NULL dereferences.
	  if we know we have to execute ld.so, vfs tells libexec to put it
	  higher.
2012-08-12 23:22:54 +02:00
Thomas Veerman
77dbd766c1 VFS: Use safe string copy functions 2012-07-16 10:57:43 +00:00
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
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
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
41b869d4d6 drop aout support
justification: soon we won't be able to execute sep I&D aouts at
all (because of the vanishing segments), which was the default mode
to generate them so most binaries will be sep I&D.

this makes the vfs/rs exec() unification work simpler.

after unification, common I&D aout could be added back quite simply.
2012-06-07 12:43:16 +02:00
Thomas Veerman
7b81254069 VFS: simplify stat for pipes
According to POSIX the st_size field of struct stat is undefined for
fifos and anonymous pipes. Thus we can do anything we want. We save a
copy by not being accurate on pipe sizes.
2012-04-27 08:50:49 +00:00
Thomas Veerman
db8198d99d VFS: use S_IS* macros 2012-04-27 08:49:38 +00:00
Ben Gras
755102d67f AT_SUN_EXECNAME support
. vfs: pass execname in aux vectors
	. ld.elf_so: use this to expand $ORIGIN
	. this requires the executable to reserve more
	  space at exec() calling time
2012-04-26 13:32:39 +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
Thomas Veerman
b956493367 VFS: fix new signed/unsigned comparisons 2012-04-13 13:00:11 +00:00
Thomas Veerman
8f55767619 VFS: make m_in job local
By making m_in job local (i.e., each job has its own copy of m_in instead
of refering to the global m_in) we don't have to store and restore m_in
on every thread yield. This reduces overhead. Moreover, remove the
assumption that m_in is preserved. Do_XXX functions have to copy the
system call parameters as soon as possible and only pass those copies to
other functions.

Furthermore, this patch cleans up some code and uses better types in a lot
of places.
2012-04-13 12:50:38 +00:00
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
Thomas Veerman
80c4685324 VFS: replace VFS with AVFS 2012-02-13 16:53:21 +00:00
Thomas Veerman
1fc399a5c1 Add permission test for bind and socket
Also, apply forbidden patch to VFS from AVFS (fixes hanging test56 if
it has the permission test).
2012-01-30 15:16:20 +00:00
Ben Gras
34a8901eb8 vfs,avfs: verify an interpreter was found on #! line
. if not, NULL *interp is dereferenced
2011-12-21 23:44:13 +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
Arun Thomas
530bd5d486 vfs/rs: for ELF, sep_id should be 0 2011-07-26 15:21:07 +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
674cd6fd48 larger i/o buffer for exec()
. makes exec() for large executables (e.g. clang, gcc)
    significantly faster

Thanks to Antoine Leca.
2011-05-12 19:12:28 +02:00
Thomas Veerman
f0740680cd Do not print an error message when a binary is corrupt 2011-04-12 13:09:19 +00:00
Arun Thomas
cd9b4b46f4 libexec: return physaddr info from ELF headers 2011-04-07 12:22:36 +00:00
Ben Gras
f0f34dd8d9 vfs - use a static buffer instead of malloc()+free(), solving
recently appeared ENOMEM problems during exec().
2010-12-15 14:43:59 +00:00
Arun Thomas
372b873413 VFS/RS support for ELF 2010-12-10 09:27:56 +00:00
Dirk Vogt
9ed280d1ec decouple file system server start/termination from mount/umount 2010-11-23 19:34:56 +00:00
Thomas Veerman
13ef7f1f38 Prepare VFS to support back calls from PFS. For security reasons and to support
file descriptor passing, PFS does some back calls to VFS. For example, to
verify the validity of a path provided by a process and to tell VFS it must
copy file descriptors from one process to another.
2010-08-30 13:44:07 +00:00
Thomas Veerman
34a2864e27 Fix a few compile time warnings 2010-07-02 12:41:19 +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
4c10a31440 Remove legacy MM, FS, and FS_PROC_NR macros 2010-06-08 13:58:01 +00:00
Tomas Hruby
6e25ad8b0a Use of all NIL_* defines converted to NULL 2010-05-10 13:26:00 +00:00
Kees van Reeuwijk
86a23c1fbd Remove U16_t and most other similar types. Rewrite functions to ansi-style
declaration if necessary.
2010-04-21 11:05:22 +00:00
Kees van Reeuwijk
bc314bda91 Remove the types Dev_t, _mnx_Gui, _mnx_Uid, and similar.
Use ANSI-style function declarations where necessary.
2010-04-13 10:58:41 +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
Thomas Veerman
958b25be50 - Introduce support for sticky bit.
- Revise VFS-FS protocol and update VFS/MFS/ISOFS accordingly.
- Clean up MFS by removing old, dead code (backwards compatibility is broken by
  the new VFS-FS protocol, anyway) and rewrite other parts. Also, make sure all
  functions have proper banners and prototypes.
- VFS should always provide a (syntactically) valid path to the FS; no need for
  the FS to do sanity checks when leaving/entering mount points.
- Fix several bugs in MFS:
  - Several path lookup bugs in MFS.
  - A link can be too big for the path buffer.
  - A mountpoint can become inaccessible when the creation of a new inode
    fails, because the inode already exists and is a mountpoint.
- Introduce support for supplemental groups.
- Add test 46 to test supplemental group functionality (and removed obsolete
  suppl. tests from test 2).
- Clean up VFS (not everything is done yet).
- ISOFS now opens device read-only. This makes the -r flag in the mount command
  unnecessary (but will still report to be mounted read-write).
- Introduce PipeFS. PipeFS is a new FS that handles all anonymous and
  named pipes. However, named pipes still reside on the (M)FS, as they are part
  of the file system on disk. To make this work VFS now has a concept of
  'mapped' inodes, which causes read, write, truncate and stat requests to be
  redirected to the mapped FS, and all other requests to the original FS.
2009-12-20 20:27:14 +00:00
Ben Gras
8d9aa1fe4f throw out exec debugging message. 2009-09-30 08:36:13 +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
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
f46319037b New VFS interface 2007-08-07 12:52:47 +00:00
Ben Gras
dc67b37a10 more removing of warning and debug messages. 2007-04-13 14:00:31 +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
Philip Homburg
bafc45a309 First cut at 64-bit file offsets in block devices for mkfs/fsck. 2006-11-27 14:21:43 +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/exec.c (Browse further)