On architectures with a non-executable stack, eg sparc64, this is used by
libgcc to determine at runtime if its necessary to enable execute permissions
on a region of the stack which will be used to execute code, allowing the
call to mprotect to be avoided if the kernel is configured to map the stack
executable.
problem was a locked directory vnode), do not give the process a chance
to sleep in state "stopevent" (depends on the S_EXEC bit being set in
p_stops) until most resources have been released again.
Approved by: re
indirectly through vm_page_protect(). The one remaining page flag that
is updated by vm_page_protect() is already being updated by our various
pmap implementations.
Note: A later commit will similarly change the VM_PROT_READ case and
eliminate vm_page_protect().
(1) Permit userland applications to request a change of label atomic
with an execve() via mac_execve(). This is required for the
SEBSD port of SELinux/FLASK. Attempts to invoke this without
MAC compiled in result in ENOSYS, as with all other MAC system
calls. Complexity, if desired, is present in policy modules,
rather than the framework.
(2) Permit policies to have access to both the label of the vnode
being executed as well as the interpreter if it's a shell
script or related UNIX nonsense. Because we can't hold both
vnode locks at the same time, cache the interpreter label.
SEBSD relies on this because it supports secure transitioning
via shell script executables. Other policies might want to
take both labels into account during an integrity or
confidentiality decision at execve()-time.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
entrypoints, #ifdef MAC. The supporting logic already existed in
kern_mac.c, so no change there. This permits MAC policies to cause
a process label change as the result of executing a binary --
typically, as a result of executing a specially labeled binary.
For example, the SEBSD port of SELinux/FLASK uses this functionality
to implement TE type transitions on processes using transitioning
binaries, in a manner similar to setuid. Policies not implementing
a notion of transition (all the ones in the tree right now) require
no changes, since the old label data is copied to the new label
via mac_create_cred() even if a transition does occur.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
describes an image activation instance. Instead, make use of the
existing fname structure entry, and introduce two new entries,
userspace_argv, and userspace_envv. With the addition of
mac_execve(), this divorces the image structure from the specifics
of the execve() system call, removes a redundant pointer, etc.
No semantic change from current behavior, but it means that the
structure doesn't depend on syscalls.master-generated includes.
There seems to be some redundant initialization of imgact entries,
which I have maintained, but which could probably use some cleaning
up at some point.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
the locking of the proc lock after the goto to done1 to avoid locking
the lock in an error case just so we can turn around and unlock it.
- Move the exec_setregs() stuff out from under the proc lock and after
the p_args stuff. This allows exec_setregs() to be able to sleep or
write things out to userland, etc. which ia64 does.
Tested by: peter
constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types. Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.
recursion when closef() calls pfind() which also wants the proc lock.
This case only occurred when setugidsafety() needed to close unsafe files.
Reviewed by: truckman
s/SNGL/SINGLE/
s/SNGLE/SINGLE/
Fix abbreviation for P_STOPPED_* etc flags, in original code they were
inconsistent and difficult to distinguish between them.
Approved by: julian (mentor)
sysentvec. Initialized all fields of all sysentvecs, which will allow
them to be used instead of constants in more places. Provided stack
fixup routines for emulations that previously used the default.
kernel access control.
Invoke an appropriate MAC entry point to authorize execution of
a file by a process. The check is placed slightly differently
than it appears in the trustedbsd_mac tree so that it prevents
a little more information leakage about the target of the execve()
operation.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
special actions for safety. One of these is to make sure that file descriptors
0..2 are in use, by opening /dev/null for those that are not already open.
Another is to close any file descriptors 0..2 that reference procfs. However,
these checks were made out of order, so that it was still possible for a
set-user-ID or set-group-ID process to be started with some of the file
descriptors 0..2 unused.
Submitted by: Georgi Guninski <guninski@guninski.com>
during execve() to use a 'credential_changing' variable. This makes it
easier to have outstanding patchsets against this code, as well as to
add conditionally defined clauses.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
handler in the kernel at the same time. Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment. This is a big help for execing i386 binaries
on ia64. The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.
Flesh out the i386 emulation support for ia64. At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.
Obtained from: dfr (mostly, many tweaks from me).
- Grab the vnode object early in exec when we still have the vnode lock.
- Cache the object in the image_params.
- Make use of the cached object in imgact_*.c
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)
Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)
NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..
uifind() with a proc lock held.
change_ruid() and change_euid() have been modified to take a uidinfo
structure which will be pre-allocated by callers, they will then
call uihold() on the uidinfo structure so that the caller's logic
is simplified.
This allows one to call uifind() before locking the proc struct and
thereby avoid a potential blocking allocation with the proc lock
held.
This may need revisiting, perhaps keeping a spare uidinfo allocated
per process to handle this situation or re-examining if the proc
lock needs to be held over the entire operation of changing real
or effective user id.
Submitted by: Don Lewis <dl-freebsd@catspoiler.org>
locks the process.
- Defer other blocking operations such as vrele()'s until after we
release locks.
- execsigs() now requires the proc lock to be held when it is called
rather than locking the process internally.
that we can compile gcc. This is a hack because it adds a fixed 2MB to
each process's VSIZE regardless of how much is really being used since
there is no grow-up stack support. At least it isn't physical memory.
Sigh.
Add a sysctl to enable tweaking it for new processes.
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.
Discussed on: smp@
There is still some locations where the PROC lock should be held
in order to prevent inconsistent views from outside (like the
proc->p_fd fix for kern/vfs_syscalls.c:checkdirs()) that can be
fixed later.
Submitted by: Jonathan Mini <mini@haikugeek.com>
