If fdalloc() decides to grow fdtable it does it once and at most doubles
the size. This still may be not enough for sufficiently large fd. Use fd
in calculations of new size in order to fix this.
When growing the table, fd is already equal to first free descriptor >= minfd,
also fdgrowtable() no longer drops the filedesc lock. As a result of this there
is no need to retry allocation nor lookup.
Fix description of fd_first_free to note all return values.
In co-operation with: pjd
Approved by: trasz (mentor)
MFC after: 1 month
code duplication in kern_close() and do_dup().
This is committed separately from the actual removal of the duplicated
code, as the combined diff was very hard to read.
Discussed with: kib
Tested by: pho
MFC after: 1 month
outside the range of valid file descriptors
PR: kern/164970
Submitted by: Peter Jeremy <peterjeremy@acm.org>
Reviewed by: jilles
Approved by: cperciva
MFC after: 1 week
via procstat(1) and fstat(1):
- Change shm file descriptors to track the pathname they are associated
with and add a shm_path() method to copy the path out to a caller-supplied
buffer.
- Use the fo_stat() method of shared memory objects and shm_path() to
export the path, mode, and size of a shared memory object via
struct kinfo_file.
- Add a struct shmstat to the libprocstat(3) interface along with a
procstat_get_shm_info() to export the mode and size of a shared memory
object.
- Change procstat to always print out the path for a given object if it
is valid.
- Teach fstat about shared memory objects and to display their path,
mode, and size.
MFC after: 2 weeks
file descriptor drops to zero out of _fdrop() and into devfs_close_f()
as it is only relevant for devfs file descriptors.
Reviewed by: kib
MFC after: 1 week
supporting procstat -f: properly provide capability rights information to
userspace. The bug resulted from a merge-o during upstreaming (or rather,
a failure to properly merge FreeBSD-side changed downstream).
Spotted by: des, kibab
MFC after: 3 days
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
A "process descriptor" file descriptor is used to manage processes
without using the PID namespace. This is required for Capsicum's
Capability Mode, where the PID namespace is unavailable.
New system calls pdfork(2) and pdkill(2) offer the functional equivalents
of fork(2) and kill(2). pdgetpid(2) allows querying the PID of the remote
process for debugging purposes. The currently-unimplemented pdwait(2) will,
in the future, allow querying rusage/exit status. In the interim, poll(2)
may be used to check (and wait for) process termination.
When a process is referenced by a process descriptor, it does not issue
SIGCHLD to the parent, making it suitable for use in libraries---a common
scenario when using library compartmentalisation from within large
applications (such as web browsers). Some observers may note a similarity
to Mach task ports; process descriptors provide a subset of this behaviour,
but in a UNIX style.
This feature is enabled by "options PROCDESC", but as with several other
Capsicum kernel features, is not enabled by default in GENERIC 9.0.
Reviewed by: jhb, kib
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
to implement fchown(2) and fchmod(2) support for several file types
that previously lacked it. Add MAC entries for chown/chmod done on
posix shared memory and (old) in-kernel posix semaphores.
Based on the submission by: glebius
Reviewed by: rwatson
Approved by: re (bz)
access to file system subtrees to sandboxed processes.
- Use of absolute paths and '..' are limited in capability mode.
- Use of absolute paths and '..' are limited when looking up relative
to a capability.
- When a name lookup is performed, identify what operation is to be
performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP.
With these constraints, openat() and friends are now safe in capability
mode, and can then be used by code such as the capability-mode runtime
linker.
Approved by: re (bz), mentor (rwatson)
Sponsored by: Google Inc
kernel for FreeBSD 9.0:
Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.
Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.
In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.
Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.
Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc
When reporting on a capability, flag the fact that it is a capability,
but also unwrap to report all of the usual information about the
underlying file.
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
Code to actually implement Capsicum capabilities, including fileops and
kern_capwrap(), which creates a capability to wrap an existing file
descriptor.
We also modify kern_close() and closef() to handle capabilities.
Finally, remove cap_filelist from struct capability, since we don't
actually need it.
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
Rather than checking to see if a descriptor is a kqueue, check to see if
its fileops flags include DFLAG_PASSABLE.
At the moment, these two tests are equivalent, but this will change with
the addition of capabilities that wrap kqueues but are themselves of type
DTYPE_CAPABILITY. We already have the DFLAG_PASSABLE abstraction, so let's
use it.
This change has been tested with [the newly improved] tools/regression/kqueue.
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
won't happen before 9.0. This commit adds "#ifdef RACCT" around all the
"PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order
to avoid useless locking/unlocking in kernels built without "options RACCT".
This new version of _fget() requires new parameters:
- cap_rights_t needrights
the rights that we expect the capability's rights mask to include
(e.g. CAP_READ if we are going to read from the file)
- cap_rights_t *haverights
used to return the capability's rights mask (ignored if NULL)
- u_char *maxprotp
the maximum mmap() rights (e.g. VM_PROT_READ) that can be permitted
(only used if we are going to mmap the file; ignored if NULL)
- int fget_flags
FGET_GETCAP if we want to return the capability itself, rather than
the underlying object which it wraps
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
descriptors, we will want to allocate a new descriptor without installing
it in the FD array.
Split falloc() into falloc_noinstall() and finstall(), and rewrite
falloc() to call them with appropriate atomicity.
Approved by: mentor (rwatson), re (bz)
file and processes information retrieval from the running kernel via sysctl
in the form of new library, libprocstat. The library also supports KVM backend
for analyzing memory crash dumps. Both procstat(1) and fstat(1) utilities have
been modified to take advantage of the library (as the bonus point the fstat(1)
utility no longer need superuser privileges to operate), and the procstat(1)
utility is now able to display information from memory dumps as well.
The newly introduced fuser(1) utility also uses this library and able to operate
via sysctl and kvm backends.
The library is by no means complete (e.g. KVM backend is missing vnode name
resolution routines, and there're no manpages for the library itself) so I
plan to improve it further. I'm commiting it so it will get wider exposure
and review.
We won't be able to MFC this work as it relies on changes in HEAD, which
was introduced some time ago, that break kernel ABI. OTOH we may be able
to merge the library with KVM backend if we really need it there.
Discussed with: rwatson
The new function fallocf(9), that is renamed falloc(9) with added
flag argument, is provided to facilitate the merge to stable branch.
Reviewed by: jhb
MFC after: 1 week
- Hold the proc lock while changing the state from PRS_NEW to PRS_NORMAL
in fork to honor the locking requirements. While here, expand the scope
of the PROC_LOCK() on the new process (p2) to avoid some LORs. Previously
the code was locking the new child process (p2) after it had locked the
parent process (p1). However, when locking two processes, the safe order
is to lock the child first, then the parent.
- Fix various places that were checking p_state against PRS_NEW without
having the process locked to use PROC_LOCK(). Every place was already
locking the process, just after the PRS_NEW check.
- Remove or reduce the use of PROC_SLOCK() for places that were checking
p_state against PRS_NEW. The PROC_LOCK() alone is sufficient for reading
the current state.
- Reorder fill_kinfo_proc() slightly so it only acquires PROC_SLOCK() once.
MFC after: 1 week
VNET socket push back:
try to minimize the number of places where we have to switch vnets
and narrow down the time we stay switched. Add assertions to the
socket code to catch possibly unset vnets as seen in r204147.
While this reduces the number of vnet recursion in some places like
NFS, POSIX local sockets and some netgraph, .. recursions are
impossible to fix.
The current expectations are documented at the beginning of
uipc_socket.c along with the other information there.
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH
Reviewed by: jhb
Tested by: zec
Tested by: Mikolaj Golub (to.my.trociny gmail.com)
MFC after: 2 weeks
The fdcheckstd() function makes sure fds 0, 1 and 2 are open by opening
/dev/null. If this fails (e.g. missing devfs or wrong permissions),
fdcheckstd() will return failure and the process will exit as if it received
SIGABRT. The KASSERT is only to check that kern_open() returns the expected
fd, given that it succeeded.
Tripping the KASSERT is most likely if fd 0 is open but fd 1 or 2 are not.
MFC after: 2 weeks
unlock Giant twice.
While there, bring conditions in the do/while loops closer to style,
that also makes the lines fit into 80 columns.
Reported and tested by: dougb
- F_READAHEAD: specify the amount for sequential access. The amount is
specified in bytes and is rounded up to nearest block size.
- F_RDAHEAD: Darwin compatible version that use 128KB as the sequential
access size.
A third argument of zero disables the read-ahead behavior.
Please note that the read-ahead amount is also constrainted by sysctl
variable, vfs.read_max, which may need to be raised in order to better
utilize this feature.
Thanks Igor Sysoev for proposing the feature and submitting the original
version, and kib@ for his valuable comments.
Submitted by: Igor Sysoev <is rambler-co ru>
Reviewed by: kib@
MFC after: 1 month
specific macros for each audit argument type. This makes it easier to
follow call-graphs, especially for automated analysis tools (such as
fxr).
In MFC, we should leave the existing AUDIT_ARG() macros as they may be
used by third-party kernel modules.
Suggested by: brooks
Approved by: re (kib)
Obtained from: TrustedBSD Project
MFC after: 1 week
