kern.poweroff_on_panic which, when enabled, instructs a system to
power off on a panic instead of a reboot.
kern.powercyle_on_panic which, when enabled, instructs a system to
power cycle, if possible, on a panic instead of a reboot.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13042
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
All of the kernel dump implementations keep track of the current offset
("dumplo") within the dump device. However, except for textdumps, they
all write the dump sequentially, so we can reduce code duplication by
having the MI code keep track of the current offset. The new
dump_append() API can be used to write at the current offset.
This is needed to implement support for kernel dump compression in the
MI kernel dump code.
Also simplify dump_encrypted_write() somewhat: use dump_write() instead
of duplicating its bounds checks, and get rid of the redundant offset
tracking.
Reviewed by: cem
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D11722
Right now we only need to pad when writing kernel dump headers, so
flatten three related subroutines into one. The encrypted kernel dump
code already writes out its key in a dumper.blocksize-sized block.
No functional change intended.
Reviewed by: cem, def
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D11647
This helps simplify the code in kern_shutdown.c and reduces the number
of globally visible functions.
No functional change intended.
Reviewed by: cem, def
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D11603
dump_start() and dump_finish() are responsible for writing kernel dump
headers, optionally writing the key when encryption is enabled, and
initializing the initial offset into the dump device.
Also remove the unused dump_pad(), and make some functions static now that
they're only called from kern_shutdown.c.
No functional change intended.
Reviewed by: cem, def
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D11584
header. This will help to correlate console server logs with dump files,
no matter how precise is clock on a console server appliance, and how
buggy the appliance is.
This is needed for kernel dumps to work, as the panicking thread will call
into code that makes use of kernel locks.
Reported and tested by: Eugene Grosbein
MFC after: 1 week
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
option, not INVARIANTS. The function is required if we want
to load in a module that is compiled with INVARIANTS.
Reviewed by: jhb
Approved by: re (gjb)
panic string again if set, in case it scrolled out of the active
window. This avoids having to remember the symbol name.
Also add a show callout <addr> command to DDB in order to inspect
some struct callout fields in case of panics in the callout code.
This may help to see if there was memory corruption or to further
ease debugging problems.
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Reviewed by: jhb (comment only on the show panic initally)
Differential Revision: https://reviews.freebsd.org/D4527
(And 4Kn minidump support, but only for amd64.)
Make sure all I/O to the dump device is of the native sector size. To
that end, we keep a native sector sized buffer associated with dump
devices (di->blockbuf) and use it to pad smaller objects as needed (e.g.
kerneldumpheader).
Add dump_write_pad() as a convenience API to dump smaller objects with
zero padding. (Rather than pull in NPM leftpad, we wrote our own.)
Savecore(1) has been updated to deal with these dumps. The format for
512-byte sector dumps should remain backwards compatible.
Minidumps for other architectures are left as an exercise for the
reader.
PR: 194279
Submitted by: ambrisko@
Reviewed by: cem (earlier version), rpokala
Tested by: rpokala (4Kn/512 except 512 fulldump), cem (512 fulldump)
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D5848
to shut down; close laptop lid" scenario which otherwise tended to end
with a laptop overheating or the battery dying.
The implementation uses a new sysctl, kern.suspend_blocked; init(8) sets
this while rc.suspend runs, and the ACPI sleep code ignores requests while
the sysctl is set.
Discussed on: freebsd-acpi (35 emails)
MFC after: 1 week
Note that the mountlist manipulations are somewhat fragile, and not very
pretty. The reason for this is to avoid changing vfs_mountroot(), which
is (obviously) rather mission-critical, but not very well documented,
and thus hard to test properly. It might be possible to rework it to use
its own simple root mount mechanism instead of vfs_mountroot().
Reviewed by: kib@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D2698
'buf' is inconvenient and has lead me to some irritating to discover
bugs over the years. It also makes it more challenging to refactor
the buf allocation system.
- Move swbuf and declare it as an extern in vfs_bio.c. This is still
not perfect but better than it was before.
- Eliminate the unused ffs function that relied on knowledge of the buf
array.
- Move the shutdown code that iterates over the buf array into vfs_bio.c.
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
longer than 192 bytes will cause the version field of a dump header to
overflow. strncpy doesn't null terminate it, so savecore will print a
corrupted info file. Using strlcpy fixes the bug.
Differential Revision: https://reviews.freebsd.org/D2560
Reviewed by: markj
MFC after: 3 weeks
Sponsored by: Spectra Logic
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.
PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division
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
This commit does not add error returns to minidumpsys() or
textdump_dumpsys(); those can also be added later.
Submitted by: Conrad Meyer (EMC / Isilon storage division)
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
Right now, init(8) cannot distinguish between an ACPI power button press
or a Ctrl+Alt+Del sequence on the keyboard. This is because
shutdown_nice() sends SIGINT to init(8) unconditionally, but later
modifies the arguments to reboot(2) to force a certain behaviour.
Instead of doing this, patch up the code to just forward the appropriate
signal to userspace. SIGUSR1 and SIGUSR2 can already be used to halt the
system.
While there, move waittime to the function where it's used; kern_reboot().
defaults to PANIC_REBOOT_WAIT_TIME (a long-existing kernel config
setting). Use this now-variable value in place of the defined constant
to control how long the system waits after a panic before rebooting.
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.
The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.
The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).
Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho
This is an ongoing effort to provide runtime debug information
useful in the field that does not panic existing installations.
This gives us the flexibility needed when shipping images to a
potentially large audience with WITNESS enabled without worrying
about formerly non-fatal LORs hurting a release.
Sponsored by: iXsystems
This is to allow debug images to be used without taking down the
system when non-fatal asserts are hit.
The following sysctls are added:
debug.kassert.warn_only: 1 = log, 0 = panic
debug.kassert.do_ktr: set to a ktr mask for logging via KTR
debug.kassert.do_log: 1 = log, 0 = quiet
debug.kassert.warnings: stats, number of kasserts hit
debug.kassert.log_panic_at:
number of kasserts before we actually panic, 0 = never
debug.kassert.log_pps_limit: pps limit for log messages
debug.kassert.log_mute_at: stop warning after N kasserts, 0 = never stop
debug.kassert.kassert: set this sysctl to trigger a kassert
Discussed with: scottl, gnn, marcel
Sponsored by: iXsystems
There has not been any complaints about the default behavior, so there
is no need to keep a knob that enables the worse alternative.
Now that the hard-stopping of other CPUs is the only behavior, the panic_cpu
spinlock-like logic can be dropped, because only a single CPU is
supposed to win stop_cpus_hard(other_cpus) race and proceed past that
call.
MFC after: 1 month
this is a VNET-kernel or not. gcc used to put the static symbol into
the symbol table, clang does not. This fixes the 'netstat: no namelist'
error seen on clang+VNET systems.
primitives by breaking stop_scheduler into a per-thread variable.
Also, store the new td_stopsched very close to td_*locks members as
they will be accessed mostly in the same codepaths as td_stopsched and
this results in avoiding a further cache-line pollution, possibly.
STOP_SCHEDULER() was pondered to use a new 'thread' argument, in order to
take advantage of already cached curthread, but in the end there should
not really be a performance benefit, while introducing a KPI breakage.
In collabouration with: flo
Reviewed by: avg
MFC after: 3 months (or never)
X-MFC: r228424
