Commit Graph

15 Commits

Author SHA1 Message Date
Konstantin Belousov
b4490c6e93 The si_status field of the siginfo_t, provided by the waitid(2) and
SIGCHLD signal, should keep full 32 bits of the status passed to the
_exit(2).

Split the combined p_xstat of the struct proc into the separate exit
status p_xexit for normal process exit, and signalled termination
information p_xsig.  Kernel-visible macro KW_EXITCODE() reconstructs
old p_xstat from p_xexit and p_xsig.  p_xexit contains complete status
and copied out into si_status.

Requested by:	Joerg Schilling
Reviewed by:	jilles (previous version), pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2015-07-18 09:02:50 +00:00
John Baldwin
9696feebe2 Add a new fo_fill_kinfo fileops method to add type-specific information to
struct kinfo_file.
- Move the various fill_*_info() methods out of kern_descrip.c and into the
  various file type implementations.
- Rework the support for kinfo_ofile to generate a suitable kinfo_file object
  for each file and then convert that to a kinfo_ofile structure rather than
  keeping a second, different set of code that directly manipulates
  type-specific file information.
- Remove the shm_path() and ksem_info() layering violations.

Differential Revision:	https://reviews.freebsd.org/D775
Reviewed by:	kib, glebius (earlier version)
2014-09-22 16:20:47 +00:00
John Baldwin
2d69d0dcc2 Fix various issues with invalid file operations:
- Add invfo_rdwr() (for read and write), invfo_ioctl(), invfo_poll(),
  and invfo_kqfilter() for use by file types that do not support the
  respective operations.  Home-grown versions of invfo_poll() were
  universally broken (they returned an errno value, invfo_poll()
  uses poll_no_poll() to return an appropriate event mask).  Home-grown
  ioctl routines also tended to return an incorrect errno (invfo_ioctl
  returns ENOTTY).
- Use the invfo_*() functions instead of local versions for
  unsupported file operations.
- Reorder fileops members to match the order in the structure definition
  to make it easier to spot missing members.
- Add several missing methods to linuxfileops used by the OFED shim
  layer: fo_write(), fo_truncate(), fo_kqfilter(), and fo_stat().  Most
  of these used invfo_*(), but a dummy fo_stat() implementation was
  added.
2014-09-12 21:29:10 +00:00
Ed Schouten
38219d6acd Implement kqueue(2) for procdesc(4).
kqueue(2) already supports EVFILT_PROC. Add an EVFILT_PROCDESC that
behaves the same, but operates on a procdesc(4) instead. Only implement
NOTE_EXIT for now. The nice thing about NOTE_EXIT is that it also
returns the exit status of the process, meaning that we can now obtain
this value, even if pdwait4(2) is still unimplemented.

Notes:

- Simply reuse EVFILT_NETDEV for EVFILT_PROCDESC. As both of these will
  be used on totally different descriptor types, this should not clash.

- Let procdesc_kqops_event() reuse the same structure as filt_proc().
  The only difference is that procdesc_kqops_event() should also be able
  to deal with the case where the process was already terminated after
  registration. Simply test this when hint == 0.

- Fix some style(9) issues in filt_proc() to keep it consistent with the
  newly added procdesc_kqops_event().

- Save the exit status of the process in pd->pd_xstat, as we cannot pick
  up the proctree_lock from within procdesc_kqops_event().

Discussed on:	arch@
Reviewed by:	kib@
2014-04-07 18:10:49 +00:00
Ed Schouten
d7a39436e5 Fix a typo. The function name is pdfork; not pfork. 2014-04-06 20:20:07 +00:00
Ed Schouten
a90feb39a2 Nit: fix locking of p->p_state in procdesc_close().
According to <sys/proc.h>, this field needs to be locked with either the
p_mtx or the p_slock. In this case the damage was quite small. Instead
of being reaped, the process would just be reparented to init, so it
could be reaped from there.
2014-04-06 20:00:42 +00:00
Robert Watson
4a14441044 Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

MFC after:	3 weeks
2014-03-16 10:55:57 +00:00
Pawel Jakub Dawidek
f2b525e6b9 Make process descriptors standard part of the kernel. rwhod(8) already
requires process descriptors to work and having PROCDESC in GENERIC
seems not enough, especially that we hope to have more and more consumers
in the base.

MFC after:	3 days
2013-11-30 15:08:35 +00:00
Pawel Jakub Dawidek
7008be5bd7 Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

	struct cap_rights {
		uint64_t	cr_rights[CAP_RIGHTS_VERSION + 2];
	};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

	#define	CAP_PDKILL	CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

	#define	CAP_LOOKUP	CAPRIGHT(0, 0x0000000000000400ULL)
	#define	CAP_FCHMOD	CAPRIGHT(0, 0x0000000000002000ULL)

	#define	CAP_FCHMODAT	(CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

	cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
	void cap_rights_set(cap_rights_t *rights, ...);
	void cap_rights_clear(cap_rights_t *rights, ...);
	bool cap_rights_is_set(const cap_rights_t *rights, ...);

	bool cap_rights_is_valid(const cap_rights_t *rights);
	void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
	void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
	bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

	cap_rights_t rights;

	cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

	#define	cap_rights_set(rights, ...)				\
		__cap_rights_set((rights), __VA_ARGS__, 0ULL)
	void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

	cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by:	The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
Konstantin Belousov
b1dd38f408 Restore the previous sendfile(2) behaviour on the block devices.
Provide valid .fo_sendfile method for several missed struct fileops.

Reviewed by:	glebius
Sponsored by:	The FreeBSD Foundation
2013-08-16 14:22:20 +00:00
Konstantin Belousov
f13b5a0f01 Add the wait6(2) system call. It takes POSIX waitid()-like process
designator to select a process which is waited for. The system call
optionally returns siginfo_t which would be otherwise provided to
SIGCHLD handler, as well as extended structure accounting for child
and cumulative grandchild resource usage.

Allow to get the current rusage information for non-exited processes
as well, similar to Solaris.

The explicit WEXITED flag is required to wait for exited processes,
allowing for more fine-grained control of the events the waiter is
interested in.

Fix the handling of siginfo for WNOWAIT option for all wait*(2)
family, by not removing the queued signal state.

PR:	standards/170346
Submitted by:	"Jukka A. Ukkonen" <jau@iki.fi>
MFC after:	1 month
2012-11-13 12:52:31 +00:00
Pawel Jakub Dawidek
707641ec28 Fix panic in procdesc that can be triggered in the following scenario:
1. Process A pdfork(2)s process B.
2. Process A passes process descriptor of B to unrelated process C.
3. Hit CTRL+C to terminate process A. Process B is also terminated
   with SIGINT.
4. init(8) collects status of process B.
5. Process C closes process descriptor associated with process B.

When we have such order of events, init(8), by collecting status of
process B, will call procdesc_reap(). This function sets pd_proc to NULL.

Now when process C calls close on this process descriptor,
procdesc_close() is called. Unfortunately procdesc_close() assumes that
pd_proc points at a valid proc structure, but it was set to NULL earlier,
so the kernel panics.

The patch also adds setting 'p->p_procdesc' to NULL in procdesc_reap(),
which I think should be done.

MFC after:	1 week
2012-09-01 11:21:56 +00:00
Pawel Jakub Dawidek
53e1646325 Check proper flag (PDF_DAEMON, not PD_DAEMON) when deciding if the process
should be killed or not.

This fixes killing pdfork(2)ed process on last close of the corresponding
process descriptor.

Reviewed by:	rwatson
MFC after:	1 month
2012-06-19 22:23:59 +00:00
Kip Macy
8451d0dd78 In order to maximize the re-usability of kernel code in user space this
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)
2011-09-16 13:58:51 +00:00
Jonathan Anderson
cfb5f76865 Add experimental support for process descriptors
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
2011-08-18 22:51:30 +00:00