. libc: add vfs_mmap, a way for vfs to initiate mmap()s.
This is a good special case to have as vfs is a slightly
different client from regular user processes. It doesn't do it
for itself, and has the dev & inode info already so the callback
to VFS for the lookup isn't necessary. So it has different info
to have to give to VM.
. libc: also add minix_mmap64() that accepts a 64-bit offset, even
though our off_t is still 32 bit now.
. to support mmap, we need to create new references to FD's (such
as an FD) so that the mmapped object can never be removed even if
all FD's are closed. To do that we conceptually dup the
filedescriptor into a new range that is only visible to the system.
So there are FDS_PER_PROCESS fd's, which is more than OPEN_MAX,
per process, and user processes can still use up to OPEN_MAX
FD's. mmap()ped objects then get extra reference in the invisible
range so user processes can't close them. The in-vfs fd_set is
of size FDS_PER_PROCESS.
. On exec() time, try to mmap() in the executable if available.
(It is not yet available in this commit.)
. To support mmap(), add do_vm_call that allows VM to lookup
(to ino+dev), do i/o from and close FD's on behalf of other
processes.
. To make this possible, a few functions have 2 more arguments
to make the target process explicit (instead of the implicit
global fp) and to specify whether the request is from a user
process or the system (which implies whether FD's starting at
OPEN_MAX are valid). These are close_fd, common_open, actual_llseek,
actual_read_write_peek, get_fd and get_filp2.
Change-Id: I831551e45a6781c74313c450eb9c967a68505932
Primary purpose of change: to support the mmap implementation, VM must
know both (a) about some block metadata for FS cache blocks, i.e.
inode numbers and inode offsets where applicable; and (b) know about
*all* cache blocks, i.e. also of the FS primary caches and not just
the blocks that spill into the secondary one. This changes the
interface and VM data structures.
This change is only for the interface (libminixfs) and VM data
structures; the filesystem code is unmodified, so although the
secondary cache will be used as normal, blocks will not be annotated
with inode information until the FS is modified to provide this
information. Until it is modified, mmap of files will fail gracefully
on such filesystems.
This is indicated to VFS/VM by returning ENOSYS for REQ_PEEK.
Change-Id: I1d2df6c485e6c5e89eb28d9055076cc02629594e
. 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)
these two functions will be used to support all exec() functionality
going into a single library shared by RS and VFS and exec() knowledge
leaving VM.
. third-party mmap: allow certain processes (VFS, RS) to
do mmap() on behalf of another process
. PROCCTL: used to free and clear a process' address space
. rc script and service know to look in /usr/pkg/.. for
extra binaries and conf files
. service split into parsing config and doing RS request
so that a new utility (printconfig) can just print the
config in machine-parseable format for netconf integration
. converted all base system eth drivers/netconf
