The closing comment is required only for long conditionally defined
code sections, with the exception of lint cases. Attempt to document
also the logic for using '!' before the SOMETIMESSOMETHGINGHERE.
The goal of these comments is to make complex cases more
comprehensible, not to require them in all cases. The rules here are
derived from behavior used in 90+% of the kernel source code.
Reviewed by and discussed with: jhb, bde, mike
linking.
* Fix disorder in the SEE ALSO sections of aio_*(2).
* Remove unnecessary cross-references from the SEE ALSO sections of
aio_*(2); config(8), kldload(8) and kldunload(8) are cross-referenced
from aio(4).
* Remove the KERNEL OPTIONS sections from aio_*(2), now that these
pages cross-reference aio(4), which contains suitable kernel linking
reference material.
associated with the TrustedBSD MAC Framework, as well as some credits
to developers and contributors.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
a server process bound to a wildcard UDP socket to select the IP
address from which outgoing packets are sent on a per-datagram
basis. When combined with IP_RECVDSTADDR, such a server process can
guarantee to reply to an incoming request using the same source IP
address as the destination IP address of the request, without having
to open one socket per server IP address.
Discussed on: -net
Approved by: re
which may surprise developers coming from Solaris, or other platforms
which have a similar interface, but slightly different rules.
Reviewed by: jhb, ru
o describe additional argument in driver callbacks
o describe flow-control mechanism for processing crypto requests
o remove old cruft
o remove openbsd-specific cruft
o fixup some references
o yada yada ...
One bug fixed: Use getmicrouptime() to trigger reseeds so that we
cannot be tricked by a clock being stepped backwards.
Express parameters in natural units and with natural names.
Don't use struct timeval more than we need to.
Various stylistic and readability polishing.
Introduce arc4rand(void *ptr, u_int len, int reseed) function which
returns a stream of pseudo-random bytes, observing the automatic
reseed criteria as well as allowing forced reseeds.
Rewrite arc4random() in terms of arc4rand().
Sponsored by: DARPA & NAI Labs.
Capitalize the first letter of the descriptions for the entries in the ERRORS
section if they are complete sentences and end the sentences with periods.
and adjacent tokens in declarations.
The added text was originally a single sentence I wrote and which
was heavily modified and extended by Bruce Evans.
This clarification attempt originates from differing usage of the
'restrict' type-qualifier.
Although various documents documents dicussing the C Programming
Language put a space between an asterisk and the 'restrict' keyword,
including the C99 standard (at least the n869.txt draft) and other
ISO/IEC JTC1/SC22/WG14 documents, the IEEE Std 1003.1-2001 document
does not separate them.
Discussed with: bde
Requested by: tjr
Separation using a single space also liked by: mike
which became wrong after using do { } while (0) became recommended.
Move the definition of what braces are to their new first occurrence.
Reviewed by: bde
Fix device hints entry for disabling acpi(4).
This also should fix the arbitration with apm(4) when both drivers
are enabled.
Note that your /boot/device.hints needs to be updated if you want to
stop auto-loading acpi.ko or disable acpi(4).
since apparently people were missing that you aren't supposed to access
the name buffer following namei() unless you specify one of these flags.
Pointed out by: green
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
including documenting that ucreds must not be pulled out of thin air,
when to use td_cred vs. p_ucred, how to avoid race conditions in
credential updates, and why to use p_ucred when targetting a thread
or process in an access control operation involving two processes.
Reviewed by: julian, jhb (earlier revision)
now needs to set COPY=-C as -C is no longer compatible with the -d
option. It is also likely to be renamed to INSTALL_COPY soon.
Update documentation to reflect this change.
PR: bin/40724
mi_switch(9) is still wildly innacurate. I suggest that every kernel
developer takes 20 minutes a day for the next few days and updates one or
two of his favourite chapter 9 man pages as they are now WAY out of date
in general. I will add a couple of KSE related pages soon.
try to avoid ambiguous cases in the future.
Wording approved by: julian (early draft), grog, rwatson, wes and maybe other
members of core I'm forgetting.
MAKEDEV: Add MAKEDEV glue for the ti(4) device nodes.
ti.4: Update the ti(4) man page to include information on the
TI_JUMBO_HDRSPLIT and TI_PRIVATE_JUMBOS kernel options,
and also include information about the new character
device interface and the associated ioctls.
man9/Makefile: Add jumbo.9 and zero_copy.9 man pages and associated
links.
jumbo.9: New man page describing the jumbo buffer allocator
interface and operation.
zero_copy.9: New man page describing the general characteristics of
the zero copy send and receive code, and what an
application author should do to take advantage of the
zero copy functionality.
NOTES: Add entries for ZERO_COPY_SOCKETS, TI_PRIVATE_JUMBOS,
TI_JUMBO_HDRSPLIT, MSIZE, and MCLSHIFT.
conf/files: Add uipc_jumbo.c and uipc_cow.c.
conf/options: Add the 5 options mentioned above.
kern_subr.c: Receive side zero copy implementation. This takes
"disposable" pages attached to an mbuf, gives them to
a user process, and then recycles the user's page.
This is only active when ZERO_COPY_SOCKETS is turned on
and the kern.ipc.zero_copy.receive sysctl variable is
set to 1.
uipc_cow.c: Send side zero copy functions. Takes a page written
by the user and maps it copy on write and assigns it
kernel virtual address space. Removes copy on write
mapping once the buffer has been freed by the network
stack.
uipc_jumbo.c: Jumbo disposable page allocator code. This allocates
(optionally) disposable pages for network drivers that
want to give the user the option of doing zero copy
receive.
uipc_socket.c: Add kern.ipc.zero_copy.{send,receive} sysctls that are
enabled if ZERO_COPY_SOCKETS is turned on.
Add zero copy send support to sosend() -- pages get
mapped into the kernel instead of getting copied if
they meet size and alignment restrictions.
uipc_syscalls.c:Un-staticize some of the sf* functions so that they
can be used elsewhere. (uipc_cow.c)
if_media.c: In the SIOCGIFMEDIA ioctl in ifmedia_ioctl(), avoid
calling malloc() with M_WAITOK. Return an error if
the M_NOWAIT malloc fails.
The ti(4) driver and the wi(4) driver, at least, call
this with a mutex held. This causes witness warnings
for 'ifconfig -a' with a wi(4) or ti(4) board in the
system. (I've only verified for ti(4)).
ip_output.c: Fragment large datagrams so that each segment contains
a multiple of PAGE_SIZE amount of data plus headers.
This allows the receiver to potentially do page
flipping on receives.
if_ti.c: Add zero copy receive support to the ti(4) driver. If
TI_PRIVATE_JUMBOS is not defined, it now uses the
jumbo(9) buffer allocator for jumbo receive buffers.
Add a new character device interface for the ti(4)
driver for the new debugging interface. This allows
(a patched version of) gdb to talk to the Tigon board
and debug the firmware. There are also a few additional
debugging ioctls available through this interface.
Add header splitting support to the ti(4) driver.
Tweak some of the default interrupt coalescing
parameters to more useful defaults.
Add hooks for supporting transmit flow control, but
leave it turned off with a comment describing why it
is turned off.
if_tireg.h: Change the firmware rev to 12.4.11, since we're really
at 12.4.11 plus fixes from 12.4.13.
Add defines needed for debugging.
Remove the ti_stats structure, it is now defined in
sys/tiio.h.
ti_fw.h: 12.4.11 firmware.
ti_fw2.h: 12.4.11 firmware, plus selected fixes from 12.4.13,
and my header splitting patches. Revision 12.4.13
doesn't handle 10/100 negotiation properly. (This
firmware is the same as what was in the tree previously,
with the addition of header splitting support.)
sys/jumbo.h: Jumbo buffer allocator interface.
sys/mbuf.h: Add a new external mbuf type, EXT_DISPOSABLE, to
indicate that the payload buffer can be thrown away /
flipped to a userland process.
socketvar.h: Add prototype for socow_setup.
tiio.h: ioctl interface to the character portion of the ti(4)
driver, plus associated structure/type definitions.
uio.h: Change prototype for uiomoveco() so that we'll know
whether the source page is disposable.
ufs_readwrite.c:Update for new prototype of uiomoveco().
vm_fault.c: In vm_fault(), check to see whether we need to do a page
based copy on write fault.
vm_object.c: Add a new function, vm_object_allocate_wait(). This
does the same thing that vm_object allocate does, except
that it gives the caller the opportunity to specify whether
it should wait on the uma_zalloc() of the object structre.
This allows vm objects to be allocated while holding a
mutex. (Without generating WITNESS warnings.)
vm_object_allocate() is implemented as a call to
vm_object_allocate_wait() with the malloc flag set to
M_WAITOK.
vm_object.h: Add prototype for vm_object_allocate_wait().
vm_page.c: Add page-based copy on write setup, clear and fault
routines.
vm_page.h: Add page based COW function prototypes and variable in
the vm_page structure.
Many thanks to Drew Gallatin, who wrote the zero copy send and receive
code, and to all the other folks who have tested and reviewed this code
over the years.
