Commit Graph

48 Commits

Author SHA1 Message Date
Conrad Meyer
6b6e2954dd List-ify kernel dump device configuration
Allow users to specify multiple dump configurations in a prioritized list.
This enables fallback to secondary device(s) if primary dump fails.  E.g.,
one might configure a preference for netdump, but fallback to disk dump as a
second choice if netdump is unavailable.

This change does not list-ify netdump configuration, which is tracked
separately from ordinary disk dumps internally; only one netdump
configuration can be made at a time, for now.  It also does not implement
IPv6 netdump.

savecore(8) is already capable of scanning and iterating multiple devices
from /etc/fstab or passed on the command line.

This change doesn't update the rc or loader variables 'dumpdev' in any way;
it can still be set to configure a single dump device, and rc.d/savecore
still uses it as a single device.  Only dumpon(8) is updated to be able to
configure the more complicated configurations for now.

As part of revving the ABI, unify netdump and disk dump configuration ioctl
/ structure, and leave room for ipv6 netdump as a future possibility.
Backwards-compatibility ioctls are added to smooth ABI transition,
especially for developers who may not keep kernel and userspace perfectly
synced.

Reviewed by:	markj, scottl (earlier version)
Relnotes:	maybe
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D19996
2019-05-06 18:24:07 +00:00
Mark Johnston
bd92e6b6f5 Refactor some of the MI kernel dump code in preparation for netdump.
- Add clear_dumper() to complement set_dumper().
- Drain netdump's preallocated mbuf pool when clearing the dumper.
- Don't do bounds checking for dumpers with mediasize 0.
- Add dumper callbacks for initialization for writing out headers.

Reviewed by:	sbruno
MFC after:	1 month
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D15252
2018-05-06 00:22:38 +00:00
Brooks Davis
6469bdcdb6 Move most of the contents of opt_compat.h to opt_global.h.
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.

Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c.  A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.

Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.

Reviewed by:	kib, cem, jhb, jtl
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14941
2018-04-06 17:35:35 +00:00
Pedro F. Giffuni
718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00
Mark Johnston
64a16434d8 Add support for compressed kernel dumps.
When using a kernel built with the GZIO config option, dumpon -z can be
used to configure gzip compression using the in-kernel copy of zlib.
This is useful on systems with large amounts of RAM, which require a
correspondingly large dump device. Recovery of compressed dumps is also
faster since fewer bytes need to be copied from the dump device.

Because we have no way of knowing the final size of a compressed dump
until it is written, the kernel will always attempt to dump when
compression is configured, regardless of the dump device size. If the
dump is aborted because we run out of space, an error is reported on
the console.

savecore(8) is modified to handle compressed dumps and save them to
vmcore.<index>.gz, as it does when given the -z option.

A new rc.conf variable, dumpon_flags, is added. Its value is added to
the boot-time dumpon(8) invocation that occurs when a dump device is
configured in rc.conf.

Reviewed by:	cem (earlier version)
Discussed with:	def, rgrimes
Relnotes:	yes
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D11723
2017-10-25 00:51:00 +00:00
Konrad Witaszczyk
480f31c214 Add support for encrypted kernel crash dumps.
Changes include modifications in kernel crash dump routines, dumpon(8) and
savecore(8). A new tool called decryptcore(8) was added.

A new DIOCSKERNELDUMP I/O control was added to send a kernel crash dump
configuration in the diocskerneldump_arg structure to the kernel.
The old DIOCSKERNELDUMP I/O control was renamed to DIOCSKERNELDUMP_FREEBSD11 for
backward ABI compatibility.

dumpon(8) generates an one-time random symmetric key and encrypts it using
an RSA public key in capability mode. Currently only AES-256-CBC is supported
but EKCD was designed to implement support for other algorithms in the future.
The public key is chosen using the -k flag. The dumpon rc(8) script can do this
automatically during startup using the dumppubkey rc.conf(5) variable.  Once the
keys are calculated dumpon sends them to the kernel via DIOCSKERNELDUMP I/O
control.

When the kernel receives the DIOCSKERNELDUMP I/O control it generates a random
IV and sets up the key schedule for the specified algorithm. Each time the
kernel tries to write a crash dump to the dump device, the IV is replaced by
a SHA-256 hash of the previous value. This is intended to make a possible
differential cryptanalysis harder since it is possible to write multiple crash
dumps without reboot by repeating the following commands:
# sysctl debug.kdb.enter=1
db> call doadump(0)
db> continue
# savecore

A kernel dump key consists of an algorithm identifier, an IV and an encrypted
symmetric key. The kernel dump key size is included in a kernel dump header.
The size is an unsigned 32-bit integer and it is aligned to a block size.
The header structure has 512 bytes to match the block size so it was required to
make a panic string 4 bytes shorter to add a new field to the header structure.
If the kernel dump key size in the header is nonzero it is assumed that the
kernel dump key is placed after the first header on the dump device and the core
dump is encrypted.

Separate functions were implemented to write the kernel dump header and the
kernel dump key as they need to be unencrypted. The dump_write function encrypts
data if the kernel was compiled with the EKCD option. Encrypted kernel textdumps
are not supported due to the way they are constructed which makes it impossible
to use the CBC mode for encryption. It should be also noted that textdumps don't
contain sensitive data by design as a user decides what information should be
dumped.

savecore(8) writes the kernel dump key to a key.# file if its size in the header
is nonzero. # is the number of the current core dump.

decryptcore(8) decrypts the core dump using a private RSA key and the kernel
dump key. This is performed by a child process in capability mode.
If the decryption was not successful the parent process removes a partially
decrypted core dump.

Description on how to encrypt crash dumps was added to the decryptcore(8),
dumpon(8), rc.conf(5) and savecore(8) manual pages.

EKCD was tested on amd64 using bhyve and i386, mipsel and sparc64 using QEMU.
The feature still has to be tested on arm and arm64 as it wasn't possible to run
FreeBSD due to the problems with QEMU emulation and lack of hardware.

Designed by:	def, pjd
Reviewed by:	cem, oshogbo, pjd
Partial review:	delphij, emaste, jhb, kib
Approved by:	pjd (mentor)
Differential Revision:	https://reviews.freebsd.org/D4712
2016-12-10 16:20:39 +00:00
Pawel Jakub Dawidek
5ebb15b942 Add missing privilege check when setting the dump device. Before that change it
was possible for a regular user to setup the dump device if he had write access
to the given device. In theory it is a security issue as user might get access
to kernel's memory after provoking kernel crash, but in practise it is not
recommended to give regular users direct access to storage devices.

Rework the code so that we do privileges check within the set_dumper() function
to avoid similar problems in the future.

Discussed with:	secteam
2014-11-11 04:48:09 +00:00
Eitan Adler
9ca1db6598 null.c: uio is unused
Mark another parameter as unused

Reported by:	rpaulo
2014-04-30 06:40:30 +00:00
Eitan Adler
7a07ae0a8e null.c: fix ordering
Use a consistent ordering of full -> null -> zero (alphabetical) in null.c

Reported by:	mjg
2014-04-30 06:30:37 +00:00
Eitan Adler
a345aa5953 Add a /dev/full device.
/dev/full is similar to /dev/zero except it always returns
ENOSPC when you attempt to write to it.

Reviewed by:	jhibbits
Discussed with:	rpaulo
2014-04-30 06:20:48 +00:00
Alfred Perlstein
bad7e7f3dd Provide a device name in the sysctl tree for programs to query the
state of crashdump target devices.

This will be used to add a "-l" (ell) flag to dumpon(8) to list the
currently configured dumpdev.

Reviewed by:	phk
2012-11-01 17:01:05 +00:00
George V. Neville-Neil
844d43d94b Fix for PR 138526.
Add the ability for /dev/null and /dev/zero to accept
being set into non blocking mode via fcntl().  This
brings the code into compliance with IEEE Std 1003.1-2001
as referenced in another PR, 94729.

Reviewed by:	jhb
MFC after:	1 week
2012-01-11 15:00:16 +00:00
Matthew D Fleming
cfb00e5aa7 Move the ZERO_REGION_SIZE to a machine-dependent file, as on many
architectures (i386, for example) the virtual memory space may be
constrained enough that 2MB is a large chunk.  Use 64K for arches
other than amd64 and ia64, with special handling for sparc64 due to
differing hardware.

Also commit the comment changes to kmem_init_zero_region() that I
missed due to not saving the file.  (Darn the unfamiliar development
environment).

Arch maintainers, please feel free to adjust ZERO_REGION_SIZE as you
see fit.

Requested by:	alc
MFC after:	1 week
MFC with:	r221853
2011-05-13 19:35:01 +00:00
Matthew D Fleming
89cb2a19ec Usa a globally visible region of zeros for both /dev/zero and the md
device.  There are likely other kernel uses of "blob of zeros" than can
be converted.

Reviewed by:	alc
MFC after:	1 week
2011-05-13 18:48:00 +00:00
Konstantin Belousov
f53444bc4d Mark /dev/zero and /dev/null as eternal.
In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:47:48 +00:00
Ed Schouten
61c177bf11 Remove unneeded minor numbers from /dev/null and /dev/zero. 2009-09-06 09:59:02 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
Poul-Henning Kamp
3f8bb25bd0 Use dynamic major number allocation. 2005-02-27 22:01:09 +00:00
Mark Murray
4ec450cefd Go back to the historical minor numbers. Add a module version while
I'm here.

Asked for minor numbers by:	jhb
2004-08-02 19:59:41 +00:00
Mark Murray
228a86bf7d YA oops. Remove code that was being tested locally. 2004-08-01 18:22:44 +00:00
Mark Murray
8ab2f5ecc5 Break out the MI part of the /dev/[k]mem and /dev/io drivers into
their own directory and module, leaving the MD parts in the MD
area (the MD parts _are_ part of the modules). /dev/mem and /dev/io
are now loadable modules, thus taking us one step further towards
a kernel created entirely out of modules. Of course, there is nothing
preventing the kernel from having these statically compiled.
2004-08-01 11:40:54 +00:00
Poul-Henning Kamp
3e019deaed Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
2004-07-15 08:26:07 +00:00
Mark Murray
4456263490 Micro-tweaking. 2004-06-20 13:50:50 +00:00
Poul-Henning Kamp
89c9c53da0 Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.
2004-06-16 09:47:26 +00:00
Poul-Henning Kamp
dc08ffec87 Device megapatch 4/6:
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.

Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
2004-02-21 21:10:55 +00:00
Mark Murray
4e0a104f91 Shorten the code by removing one "do-nothing" function, replacing it
with nullop(), which is in kern_conf.c.
2003-11-01 09:31:54 +00:00
Mark Murray
8f559ca08e Mark as __unused some arguments that are, erm, unused. 2003-10-18 09:16:01 +00:00
Poul-Henning Kamp
36449dc48e Return ENOIOCTL for unknown ioctls, don't use noioctl to return ENODEV. 2003-09-27 12:27:23 +00:00
Poul-Henning Kamp
70cd771337 The present defaults for the open and close for device drivers which
provide no methods does not make any sense, and is not used by any
driver.

It is a pretty hard to come up with even a theoretical concept of
a device driver which would always fail open and close with ENODEV.

Change the defaults to be nullopen() and nullclose() which simply
does nothing.

Remove explicit initializations to these from the drivers which
already used them.
2003-09-27 12:01:01 +00:00
David E. O'Brien
aad970f1fe Use __FBSDID().
Also some minor style cleanups.
2003-08-24 17:55:58 +00:00
Poul-Henning Kamp
85cefd1dc0 /dev/null and /dev/zero does not need Giant 2003-06-24 19:50:48 +00:00
Poul-Henning Kamp
7ac40f5f59 Gigacommit to improve device-driver source compatibility between
branches:

Initialize struct cdevsw using C99 sparse initializtion and remove
all initializations to default values.

This patch is automatically generated and has been tested by compiling
LINT with all the fields in struct cdevsw in reverse order on alpha,
sparc64 and i386.

Approved by:    re(scottl)
2003-03-03 12:15:54 +00:00
Poul-Henning Kamp
a36ef7f365 Don't use evil casts in cdevsw initialization. 2003-03-02 19:17:51 +00:00
Mark Murray
ef8b020c73 Warns and lint fix. Nearly all trivial stuff. 2003-02-27 18:07:11 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Mark Murray
963b82c64c Everywhere else, an argument passed to a device containing flags
is called "flags". Make it so here.
2002-09-21 17:28:17 +00:00
Mark Murray
052c7c89c2 Modernise the cdevsw WRT to (unused) kqueue. 2002-08-02 11:24:43 +00:00
Poul-Henning Kamp
7f086a0852 Rename DIOCGKERNELDUMP to DIOCSKERNELDUMP as it strictly speaking
is a "set" not a "get" operation.

Sponsored by:	DARPA & NAI Labs.
2002-04-09 10:04:09 +00:00
Poul-Henning Kamp
2dd527b3ac Move generic disk ioctls from <sys/disklabel.h> to <sys/disk.h>.
Sponsored by:	DARPA & NAI Labs
2002-04-08 09:20:07 +00:00
John Baldwin
44731cab3b Change the suser() API to take advantage of td_ucred as well as do a
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@
2002-04-01 21:31:13 +00:00
Poul-Henning Kamp
81661c94b6 Here follows the new kernel dumping infrastructure.
Caveats:

The new savecore program is not complete in the sense that it emulates
enough of the old savecores features to do the job, but implements none
of the options yet.

I would appreciate if a userland hacker could help me out getting savecore
to do what we want it to do from a users point of view, compression,
email-notification, space reservation etc etc.  (send me email if
you are interested).

Currently, savecore will scan all devices marked as "swap" or "dump" in
/etc/fstab _or_ any devices specified on the command-line.

All architectures but i386 lack an implementation of dumpsys(), but
looking at the i386 version it should be trivial for anybody familiar
with the platform(s) to provide this function.

Documentation is quite sparse at this time, more to come.

Details:

ATA and SCSI drivers should work as the dump formatting code has been
removed.  The IDA, TWE and AAC have not yet been converted.

Dumpon now opens the device and uses ioctl(DIOCGKERNELDUMP) to set
the device as dumpdev.  To implement the "off" argument, /dev/null
is used as the device.

Savecore will fail if handed any options since they are not (yet)
implemented.  All devices marked "dump" or "swap" in /etc/fstab
will be scanned and dumps found will be saved to diskfiles
named from the MD5 hash of the header record.  The header record
is dumped in readable format in the .info file.  The kernel
is not saved.  Only complete dumps will be saved.

All maintainer rights for this code are disclaimed: feel free to
improve and extend.

Sponsored by:   DARPA, NAI Labs
2002-03-31 22:37:00 +00:00
Poul-Henning Kamp
f83880518b Send the remains (such as I have located) of "block major numbers" to
the bit-bucket.
2001-03-26 12:41:29 +00:00
David Malone
7cc0979fd6 Convert more malloc+bzero to malloc+M_ZERO.
Submitted by:	josh@zipperup.org
Submitted by:	Robert Drehmel <robd@gmx.net>
2000-12-08 21:51:06 +00:00
John Baldwin
511652767f During a verbose boot, call the null device 'null' rather than 'null0' to
be more consistent with the rest of the kernel.
2000-10-06 00:46:29 +00:00
John Baldwin
005b841fd6 Move sys/dev/nulldev to sys/dev/null to be more consistent with naming
under sys/dev.
2000-10-02 20:16:37 +00:00
Mark Murray
11197ed12c Small style change; make function names less likely to clash with
existing names. "null" is too common a string; use "null_".
2000-07-09 12:29:24 +00:00
Mark Murray
f6011da8dc New machine independant /dev/null and /dev/zero driver. This device is
severely stripped down compared with its predecessor, and is measurably
a _lot_ faster.

Many thanks to Jeroen van Gelderen for lots of good ideas.

There is still a problem with this; it is written as a mudule, and as
such is theoretically unloadable. However, there is no refcounting done
as I would prefer to do that a'la device_busy(9), rather than some
"home-rolled" scheme. The point is pretty moot, as /dev/null is
effectively compulsory.

Reviewed by:	dfr
2000-06-25 08:32:39 +00:00