MFC r359968:
Cast all ioctl command arguments through uint32_t internally.

Hide debug print showing use of sign extended ioctl command argument
under INVARIANTS. The print is available to all and can easily fill
up the logs.

No functional change intended.

Sponsored by: Mellanox Technologies

MFC r314996:
Fix NULL pointer dereference and panic with shm file pread/pwrite.

PR: 217429
Approved by: dchagin

MFC r264388 (by davide):
Define SBT_MAX.

MFC r267896 (by davide):
Improve r264388.

MFC note. The SBT_MAX definition already existed on stable/10, but without
the refinement from r267896. Also, consumers of SBT_MAX were not converted,
since r264388 was not merged properly.

Reviewed by: mav

Merge r263233 from HEAD to stable/10:

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.

Sponsored by: Google, Inc.

MFC r274462: Add the ppoll() system call.

MFC r274017, r274088 and r275205:

Provide an on-stack temporary buffer for small IOCTL requests.
Avoiding a memory allocation per IOCTL request can give a significant
speedup for applications which heavily rely on IOCTLs.

MFC r267710:

fd: replace fd_nfiles with fd_lastfile where appropriate

fd_lastfile is guaranteed to be the biggest open fd, so when the intent
is to iterate over active fds or lookup one, there is no point in looking
beyond that limit.

Few places are left unpatched for now.

MFC r258148,r258149,r258150,r258152,r258153,r258154,r258181,r258182:

r258148:

Add a note that this file is compiled as part of the kernel and libc.

Requested by: kib

r258149:

Change cap_rights_merge(3) and cap_rights_remove(3) to return pointer
to the destination cap_rights_t structure.

This already matches manual page.

r258150:

Sync return value with actual implementation.

r258151:

Style.

r258152:

Precisely document capability rights here too (they are already documented
in rights(4)).

r258153:

The CAP_LINKAT, CAP_MKDIRAT, CAP_MKFIFOAT, CAP_MKNODAT, CAP_RENAMEAT,
CAP_SYMLINKAT and CAP_UNLINKAT capability rights make no sense without
the CAP_LOOKUP right, so include this rights.

r258154:

- Move CAP_EXTATTR_* and CAP_ACL_* rights to index 1 to have more room
in index 0 for the future.
- Move CAP_BINDAT and CAP_CONNECTAT rights to index 0 so we can include
CAP_LOOKUP right in them.
- Shuffle the bits around so there are no gaps. This is last chance to do
that as all moved rights are not used yet.

r258181:

Replace CAP_POLL_EVENT and CAP_POST_EVENT capability rights (which I had
a very hard time to fully understand) with much more intuitive rights:

CAP_EVENT - when set on descriptor, the descriptor can be monitored
with syscalls like select(2), poll(2), kevent(2).

CAP_KQUEUE_EVENT - When set on a kqueue descriptor, the kevent(2)
syscall can be called on this kqueue to with the eventlist
argument set to non-NULL value; in other words the given
kqueue descriptor can be used to monitor other descriptors.
CAP_KQUEUE_CHANGE - When set on a kqueue descriptor, the kevent(2)
syscall can be called on this kqueue to with the changelist
argument set to non-NULL value; in other words it allows to
modify events monitored with the given kqueue descriptor.

Add alias CAP_KQUEUE, which allows for both CAP_KQUEUE_EVENT and
CAP_KQUEUE_CHANGE.

Add backward compatibility define CAP_POLL_EVENT which is equal to CAP_EVENT.

r258182:

Correct right names.

Sponsored by: The FreeBSD Foundation
Approved by: re (kib)

MFC r256502:
Similar to debug.iosize_max_clamp sysctl, introduce
devfs_iosize_max_clamp sysctl, which allows/disables SSIZE_MAX-sized
i/o requests on the devfs files.

Approved by: re (glebius)

Merge r263233 from HEAD to stable/10:

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.

Sponsored by: Google, Inc.

MFC r274462: Add the ppoll() system call.

MFC r274017, r274088 and r275205:

Provide an on-stack temporary buffer for small IOCTL requests.
Avoiding a memory allocation per IOCTL request can give a significant
speedup for applications which heavily rely on IOCTLs.

MFC r267710:

fd: replace fd_nfiles with fd_lastfile where appropriate

fd_lastfile is guaranteed to be the biggest open fd, so when the intent
is to iterate over active fds or lookup one, there is no point in looking
beyond that limit.

Few places are left unpatched for now.

MFC r258148,r258149,r258150,r258152,r258153,r258154,r258181,r258182:

r258148:

Add a note that this file is compiled as part of the kernel and libc.

Requested by: kib

r258149:

Change cap_rights_merge(3) and cap_rights_remove(3) to return pointer
to the destination cap_rights_t structure.

This already matches manual page.

r258150:

Sync return value with actual implementation.

r258151:

Style.

r258152:

Precisely document capability rights here too (they are already documented
in rights(4)).

r258153:

The CAP_LINKAT, CAP_MKDIRAT, CAP_MKFIFOAT, CAP_MKNODAT, CAP_RENAMEAT,
CAP_SYMLINKAT and CAP_UNLINKAT capability rights make no sense without
the CAP_LOOKUP right, so include this rights.

r258154:

- Move CAP_EXTATTR_* and CAP_ACL_* rights to index 1 to have more room
in index 0 for the future.
- Move CAP_BINDAT and CAP_CONNECTAT rights to index 0 so we can include
CAP_LOOKUP right in them.
- Shuffle the bits around so there are no gaps. This is last chance to do
that as all moved rights are not used yet.

r258181:

Replace CAP_POLL_EVENT and CAP_POST_EVENT capability rights (which I had
a very hard time to fully understand) with much more intuitive rights:

CAP_EVENT - when set on descriptor, the descriptor can be monitored
with syscalls like select(2), poll(2), kevent(2).

CAP_KQUEUE_EVENT - When set on a kqueue descriptor, the kevent(2)
syscall can be called on this kqueue to with the eventlist
argument set to non-NULL value; in other words the given
kqueue descriptor can be used to monitor other descriptors.
CAP_KQUEUE_CHANGE - When set on a kqueue descriptor, the kevent(2)
syscall can be called on this kqueue to with the changelist
argument set to non-NULL value; in other words it allows to
modify events monitored with the given kqueue descriptor.

Add alias CAP_KQUEUE, which allows for both CAP_KQUEUE_EVENT and
CAP_KQUEUE_CHANGE.

Add backward compatibility define CAP_POLL_EVENT which is equal to CAP_EVENT.

r258182:

Correct right names.

Sponsored by: The FreeBSD Foundation
Approved by: re (kib)

MFC r256502:
Similar to debug.iosize_max_clamp sysctl, introduce
devfs_iosize_max_clamp sysctl, which allows/disables SSIZE_MAX-sized
i/o requests on the devfs files.

Approved by: re (glebius)