Change the kernel to add features to vircopy and safecopies so that
transparent copy fixing won't happen to avoid deadlocks, and such copies
fail with EFAULT.
Transparently making copying work from filesystems (as normally done by
the kernel & VM when copying fails because of missing/readonly memory)
is problematic as it can happen that, for file-mapped ranges, that that
same filesystem that is blocked on the copy request is needed to satisfy
the memory range, leading to deadlock. Dito for VFS itself, if done with
a blocking call.
This change makes the copying done from a filesystem fail in such cases
with EFAULT by VFS adding the CPF_TRY flag to the grants. If a FS call
fails with EFAULT, VFS will then request the range to be made available
to VM after the FS is unblocked, allowing it to be used to satisfy the
range if need be in another VFS thread.
Similarly, for datacopies that VFS itself does, it uses the failable
vircopy variant and callers use a wrapper that talk to VM if necessary
to get the copy to work.
. kernel: add CPF_TRY flag to safecopies
. kernel: only request writable ranges to VM for the
target buffer when copying fails
. do copying in VFS TRY-first
. some fixes in VM to build SANITYCHECK mode
. add regression test for the cases where
- a FS system call needs memory mapped in a process that the
FS itself must map.
- such a range covers more than one file-mapped region.
. add 'try' mode to vircopy, physcopy
. add flags field to copy kernel call messages
. if CP_FLAG_TRY is set, do not transparently try
to fix memory ranges
. for use by VFS when accessing user buffers to avoid
deadlock
. remove some obsolete backwards compatability assignments
. VFS: let thread scheduling work for VM requests too
Allows VFS to make calls to VM while suspending and resuming
the currently running thread. Does currently not work for the
main thread.
. VM: add fix memory range call for use by VFS
Change-Id: I295794269cea51a3163519a9cfe5901301d90b32
The constants ANY, NONE, and SELF are now a function of the way the
endpoint number is split between a generation number and a process
slot number, rather than the other way around. This allows for the
use of bit masking and shifting instead of the previous (and more
expensive) multiplication and division.
Change-Id: Id890eea74435444128c75eb0c89816b948f43c0b
This allows us to write things like this:
message m;
m.m_notify.interrupts = new_value;
or
message *mp;
mp->m_notify.interrupts = new_value;
The shorthands macro have been adapted for the new scheme, and will be
kept as long as we have generic messages being used.
Change-Id: Icfd02b5f126892b1d5d2cebe8c8fb02b180000f7
. create signals-related struct message type to store sigset_t
directly
. create notify-specific message types, so the generic NOTIFY_ARG
doesn't exist anymore
. various related test expansions, improvements, fixes
. add a few error-checks to sigismember() calls
. rename kernel call specific signals fields to SYS_*
Change-Id: I53c18999b5eaf0cfa0cb25f5330bee9e7ad2b478
- introduce new call numbers, names, and field aliases;
- initialize request messages to zero for all ABI calls;
- format callnr.h in the same way as com.h;
- redo call tables in both servers;
- remove param.h namespace pollution in the servers;
- make brk(2) go to VM directly, rather than through PM;
- remove obsolete BRK, UTIME, and WAIT calls;
- clean up path copying routine in VFS;
- move remaining system calls from libminlib to libc;
- correct some errno-related mistakes in libc routines.
Change-Id: I2d8ec5d061cd7e0b30c51ffd77aa72ebf84e2565
These calls are sent to VFS, and thus should be prefixed with VFS_.
Clean up the protocol and PM's main function a bit.
Since the protocol is substantially big and different from normal VFS
requests, this protocol retains its own numbering range for now.
Change-Id: Ia62104b5c5c929ed787144816d2e4cc70bed3b0b
The getsysinfo(2), getrusage(2), and svrctl(2) calls used the same
call number to different services. Since we want to give each service
its own call number ranges, this is no longer tenable. This patch
introduces per-service call numbers for these calls.
Note that the remainder of the COMMON_ range is left intact, as these
the remaining requests in it are processed by SEF and thus server-
agnostic. The range should really be prefixed with SEF_ now.
Change-Id: I80d728bbeb98227359c525494c433965b40fefc3
- move system calls for use by services from libminlib into libsys;
- move srv_fork(2) and srv_kill(2) from RS and into libsys;
- replace getprocnr(2) with sef_self(3);
- rename previous getnprocnr(2) to getprocnr(2);
- clean up getepinfo(2);
- change all libsys calls that used _syscall to use _taskcall, so as
to avoid going through errno to pass errors; this is already how
most calls work anyway, and many of the calls previously using
_syscall were already assumed to return the actual error;
- initialize request messages to zero, for future compatibility
(note that this does not include PCI calls, which are in need of a
much bigger overhaul, nor kernel calls);
- clean up more of dead DS code as a side effect.
Change-Id: I8788f54c68598fcf58e23486e270c2d749780ebb
This single function allows copying file descriptors from and to
processes, and closing a previously copied remote file descriptor.
This function replaces the five FD-related UDS backcalls. While it
limits the total number of in-flight file descriptors to OPEN_MAX,
this change greatly improves crash recovery support of UDS, since all
in-flight file descriptors will be closed instead of keeping them
open indefinitely (causing VFS to crash on system shutdown). With the
new copyfd call, UDS becomes simpler, and the concept of filps is no
longer exposed outside of VFS.
This patch also moves the checkperms(2) stub into libminlib, thus
fully abstracting away message details of VFS communication from UDS.
Change-Id: Idd32ad390a566143c8ef66955e5ae2c221cff966
