We want to be able to pass various settings during import/open of a pool,
which are not only related to rewind. Instead of adding a new policy and
duplicate a bunch of code, we should just rename rewind_policy to a more
generic term like load_policy.
For instance, we'd like to set spa->spa_import_flags from the nvlist,
rather from a flags parameter passed to spa_import as in some cases we want
those flags not only for the import case, but also for the open case. One
such flag could be ZFS_IMPORT_MISSING_LOG (as used in zdb) which would
allow zfs to open a pool when logs are missing.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
ztest failed with uncorrectable IO error despite having the fix for #7163.
Both sides of the mirror have CANT_OPEN_BAD_LABEL, which also distinguishes
it from that issue.
Definitely seems like a racing condition between the vdev_validate and spa_sync:
1. Thread A (spa_sync): vdev label is updated to latest txg
2. Thread B (vdev_validate): vdev label's txg is compared to spa_last_synced_txg and is ahead.
3. Thread A (spa_sync): spa_last_synced_txg is updated to latest txg.
Solution: do not check txg in vdev_validate unless config lock is held.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
The idea of Storage Pool Checkpoint (aka zpool checkpoint) deals with
exactly that. It can be thought of as a “pool-wide snapshot” (or a
variation of extreme rewind that doesn’t corrupt your data). It remembers
the entire state of the pool at the point that it was taken and the user
can revert back to it later or discard it. Its generic use case is an
administrator that is about to perform a set of destructive actions to ZFS
as part of a critical procedure. She takes a checkpoint of the pool before
performing the actions, then rewinds back to it if one of them fails or puts
the pool into an unexpected state. Otherwise, she discards it. With the
assumption that no one else is making modifications to ZFS, she basically
wraps all these actions into a “high-level transaction”.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Gordon Ross <gordon.w.ross@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Andrew Stormont <astormont@racktopsystems.com>
We do not have libfakekernel, but need to reduce code divergence.
MFC r331420 (by avg): zfs: fix mismatch between format specifier and type
vdev_dbgmsg_print_tree printed vdev_id of uint64_t type with %u format
specifier. That caused subsequent parameters to be incorrectly read
from the stack and lead to a crash when a wrong value was interpreted as
a string pointer.
Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Approved by: Joshua M. Clulow <josh@sysmgr.org>
Author: Toomas Soome <tsoome@me.com>
MFC r331404: MFV r331400:
8484 Implement aggregate sum and use for arc counters
In pursuit of improving performance on multi-core systems, we should
implements fanned out counters and use them to improve the performance of
some of the arc statistics. These stats are updated extremely frequently,
and can consume a significant amount of CPU time.
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Paul Dagnelie <pcd@delphix.com>
"zfs send -t <token>" for an incremental send should be able to resume
successfully when sending to the same pool: a subtle issue in
zfs_iter_children() doesn't currently allow this.
Because resuming from a token requires "guid" -> "dataset" mapping
(guid_to_name()), we have to walk the whole hierarchy to find the right
snapshots to send.
When resuming an incremental send both source and destination live in the
same pool and have the same guid: this is where zfs_iter_children() gets
confused and picks up the wrong snapshot, so we end up trying to send an
incremental "destination@snap1 -> source@snap2" stream instead of
"source@snap1 -> source@snap2": this fails with an "Invalid cross-device
link" (EXDEV) error.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: loli10K <ezomori.nozomu@gmail.com>
A scenario came up where a callback executed by vdev_indirect_remap() on a vdev, calls
vdev_indirect_remap() on the same vdev and tries to reacquire vdev_indirect_rwlock that
was already acquired from the first call to vdev_indirect_remap(). The specific scenario,
is that we want to remap a block pointer that is snapshoted but its dataset's remap_deadlist
is not cached. So in order to add it we issue a read through a vdev_indirect_remap() on the
same vdev, which brings up the aforementioned issue.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
The timeline of the race condition is the following:
[1] Thread A is about to finish condesing the first vdev in spa_condense_indirect_thread(),
so it calls the spa_condense_indirect_complete_sync() sync task which sets the
spa_condensing_indirect field to NULL. Waiting for the sync task to finish, thread A
sleeps until the txg is done. When this happens, thread A will acquire spa_async_lock
and set spa_condense_thread to NULL.
[2] While thread A waits for the txg to finish, thread B which is running spa_sync() checks
whether it should condense the second vdev in vdev_indirect_should_condense() by checking
the spa_condensing_indirect field which was set to NULL by spa_condense_indirect_thread()
from thread A. So it goes on and tries to spawn a new condensing thread in
spa_condense_indirect_start_sync() and the aforementioned assertions fails because thread A
has not set spa_condense_thread to NULL (which is basically the last thing it does before
returning).
The main issue here is that we rely on both spa_condensing_indirect and spa_condense_thread to
signify whether a condensing thread is running. Ideally we would only use one throughout the
codebase. In addition, for managing spa_condense_thread we currently use spa_async_lock which
basically tights condensing to scrubing when it comes to pausing and resuming those actions
during spa export.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>
Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:
https://www.illumos.org/issues/7638: Refactor spa_load_impl into several functions
https://www.illumos.org/issues/8961: SPA load/import should tell us why it failed
https://www.illumos.org/issues/7277: zdb should be able to print zfs_dbgmsg's
To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.
The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.
The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.
When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.
This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.
With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
Of data, this feature is for now restricted to a read-only import.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
Reported on the ZFSonLinux https://github.com/zfsonlinux/zfs/issues/4843,
fixed by https://github.com/zfsonlinux/zfs/pull/6339:
If we are in the middle of an incremental zfs receive, the child .../%recv
will exist. If you concurrently run zfs promote .../%recv, it will "work",
but then zfs gets confused. For example, there's no obvious way to destroy
the containing filesystem (because it is now a clone of its invisible child).
Attempting to do this promote should be an error. We could fix this by
having zfs_ioc_promote() check if zc_name contains a %, similar to
zfs_ioc_rename().
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>
Illumos 4080 allows "zpool clear" to work on readonly pools: i don't think
this is the intended behaviour, we shouldn't be allowed to clear readonly
pools. Probably.
When iterating over the input nvlist in dsl_props_set_sync_impl() when we
don't preserve the nvpair name before looking up ZPROP_VALUE, so when we
later go to process it nvpair_name() is always "value" instead of the actual
property name.
This results in a couple of bugs in the recv code:
- received properties are not restored correctly when failing to receive
an incremental send stream
- received properties are not completely replaced by the new ones when
successfully receiving an incremental send stream
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Toomas Soome <tsoome@me.com>
Currently `zdb` consistently fails to examine non-idle pools as it fails
during the `spa_load()` process. The main problem seems to be that
`spa_load_verify()` fails as can be seen below:
ZFS_DBGMSG(zdb):
spa_open_common: opening dcenter
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
spa_load(dcenter): using uberblock with txg=40824950
spa_load(dcenter): UNLOADING
spa_load(dcenter): RELOADING
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
spa_load(dcenter): using uberblock with txg=40824952
spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
spa_load(dcenter): UNLOADING
This change makes `spa_load_verify()` a dryrun when ran from `zdb`. This is
done by creating a global flag in zfs and then setting it in `zdb`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
When we fail to open or import a storage pool, we typically don't get any
additional diagnostic information, just "no pool found" or "can not import".
While there may be no additional user-consumable information, we should at
least make this situation easier to debug/diagnose for developers and support.
For example, we could start by using `zfs_dbgmsg()` to log each thing that we
try when importing, and which things failed. E.g. "tried uberblock of txg X
from label Y of device Z". Also, we could log each of the stages that we go
through in `spa_load_impl()`.
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
spa_load_impl has grown out of proportions. It is currently over 700
lines long and makes it very hard to follow or debug the import process
even for experienced ZFS developers. The objective is to split it up
in a series of well commented functions.
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
To prevent kmem_cache reaping from blocking other system resources, turn
kmem_cache_reap_now() (which blocks) into kmem_cache_reap_soon(). Callers
to kmem_cache_reap_soon() should use kmem_cache_reap_active(), which
exploits #9017's new taskq_empty().
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Author: Tim Kordas <tim.kordas@joyent.com>
FreeBSD does not use taskqueue for kmem caches reaping, so this change
is less dramatic then it is on Illumos, just limiting reaping to 1 time
per second. It may possibly be improved later, if needed.
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Gordon Ross <gordon.w.ross@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Andrew Stormont <astormont@racktopsystems.com>
https://www.illumos.org/issues/7614:
This project allows top-level vdevs to be removed from the storage pool with
“zpool remove”, reducing the total amount of storage in the pool. This
operation copies all allocated regions of the device to be removed onto other
devices, recording the mapping from old to new location. After the removal is
complete, read and free operations to the removed (now “indirect”) vdev must
be remapped and performed at the new location on disk. The indirect mapping
table is kept in memory whenever the pool is loaded, so there is minimal
performance overhead when doing operations on the indirect vdev.
The size of the in-memory mapping table will be reduced when its entries
become “obsolete” because they are no longer used by any block pointers in
the pool. An entry becomes obsolete when all the blocks that use it are
freed. An entry can also become obsolete when all the snapshots that
reference it are deleted, and the block pointers that reference it have been
“remapped” in all filesystems/zvols (and clones). Whenever an indirect block
is written, all the block pointers in it will be “remapped” to their new
(concrete) locations if possible. This process can be accelerated by using
the “zfs remap” command to proactively rewrite all indirect blocks that
reference indirect (removed) vdevs.
Note that when a device is removed, we do not verify the checksum of the data
that is copied. This makes the process much faster, but if it were used on
redundant vdevs (i.e. mirror or raidz vdevs), it would be possible to copy
the wrong data, when we have the correct data on e.g. the other side of the
mirror. Therefore, mirror and raidz devices can not be removed.
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Prashanth Sreenivasa <pks@delphix.com>
MFC r307317: MFV r307313:
5120 zfs should allow large block/gzip/raidz boot pool (loader project)
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Toomas Soome <tsoome@me.com>
r308137:
Fix alignment issues on MIPS: align the pointers properly.
All the 5520 GEOM_ELI tests passed successfully on MIPS64EB.
r316312:
sys/geom/eli: Switch bzero() to explicit_bzero() for sensitive data
In GELI, anywhere we are zeroing out possibly sensitive data, like
the metadata struct, the metadata sector (both contain the encrypted
master key), the user key, or the master key, use explicit_bzero.
Didn't touch the bzero() used to initialize structs.
r332361:
Introduce dry run option for attaching the device.
This will allow us to verify if passphrase and key is valid without
decrypting whole device.
r323108:
Add efimedia attribute for all GPT partitions.
r323125:
The hard drive media device path contains the size of the partition,
not its end. This makes the GEOM efimedia attribute match the
FreeBSD:Boot1Device environment variable now.
r326047:
Implement efi media tagging for MBR partitioning types.
r326048:
Remove trailing whitespace (one I just introduced and a bunch of
others in the same directory).
r326049:
While the EFI spec allows numbers to be in many forms, libefivar
produces hex numbers for the dsn. Since that come is from EDK2, change
this for symmetry, by generating the dsn as a hex number.
[Missed as part of the efivar/efibootmgr MFCs]
Reported by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
geom_bsd, geom_mbr and geom_sunlabel have been obsolete since Marcel
Moolenaar's geom_part was in FreeBSD 7. They haven't been in GENERIC
since FreeBSD 8. Add warning when used.
geom_vol_ffs has been obsolete since ufs support to geom_label was
committed in FreeBSD 5. It hasn't been in GENERIC since FreeBSD 5.
Add warning when used.
geom_fox has been obsolete since gmultipath was committed in FreeBSD 7.
(no warning added, since this is a very obscure class).
Forwarded packets passed through PFIL_OUT, which made it difficult for
firewalls to figure out if they were forwarding or producing packets. This in
turn is an issue for pf for IPv6 fragment handling: it needs to call
ip6_output() or ip6_forward() to handle the fragments. Figuring out which was
difficult (and until now, incorrect).
Having pfil distinguish the two removes an ugly piece of code from pf.
Introduce a new variant of the netpfil callbacks with a flags variable, which
has PFIL_FWD set for forwarded packets. This allows pf to reliably work out if
a packet is forwarded.
sus/modules/Makefile part of r329507 just removed ffec
while r331501 also added conditional clause for bcm283x_clkman
and bcm283x_pwm. Since they're part of another revision,
remove mi-merged chunk
MFC r331077 (brooks): Add _IOC_NEWLEN() and _IOC_NEWTYPE() macros.
These macros take an existing ioctl(2) command and replace the length
with the specified length or length of the specified type respectively.
These can be used to define commands for 32-bit compatibility with fewer
opportunities for cut-and-paste errors then a whole new definition.
Ensure that multiplications for memory allocations cannot overflow, and
that we'll not try to allocate M_WAITOK for potentially overly large
allocations.
pf: Improve ioctl validation for DIOCRGETTABLES, DIOCRGETTSTATS, DIOCRCLRTSTATS and DIOCRSETTFLAGS
These ioctls can process a number of items at a time, which puts us at
risk of overflow in mallocarray() and of impossibly large allocations
even if we don't overflow.
Limit the allocation to required size (or the user allocation, if that's
smaller). That does mean we need to do the allocation with the rules
lock held (so the number doesn't change while we're doing this), so it
can't M_WAITOK.
Add 32-bit compat for ioctls that take struct ifgroupreq.
Use an accessor to access ifgr_group and ifgr_groups.
Use an macro CASE_IOC_IFGROUPREQ(cmd) in place of case statements such
as "case SIOCAIFGROUP:". This avoids poluting the switch statements
with large numbers of #ifdefs.
pf: Improve ioctl validation for DIOCIGETIFACES and DIOCXCOMMIT
These ioctls can process a number of items at a time, which puts us at
risk of overflow in mallocarray() and of impossibly large allocations
even if we don't overflow.
There's no obvious limit to the request size for these, so we limit the
requests to something which won't overflow. Change the memory allocation
to M_NOWAIT so excessive requests will fail rather than stall forever.
pf: Improve ioctl validation for DIOCRADDTABLES and DIOCRDELTABLES
The DIOCRADDTABLES and DIOCRDELTABLES ioctls can process a number of
tables at a time, and as such try to allocate <number of tables> *
sizeof(struct pfr_table). This multiplication can overflow. Thanks to
mallocarray() this is not exploitable, but an overflow does panic the
system.
Arbitrarily limit this to 65535 tables. pfctl only ever processes one
table at a time, so it presents no issues there.
MFC r332372-r332374: tail(1)/head(1) compatibility long options
r332372:
tail(1): Add some long options
Add --blocks, --bytes, and --lines long options for -b, -c, and -n
respectively. This improves tail(1)'s compatibility with its GNU counterpart
in a straightforward way.
r332373:
tail(1): Address mandoc concern (space before punctuation after macro)
r332374:
head(1): Provide long options
Provide long options --bytes and --lines to match -c and -n respectively.
This improves head(1)'s compatibility with its GNU counterpart in a sensible
way.
Exit with usage when extra arguments are on command line
preventing mistakes such as "halt 0p" for "halt -p".
Approved by: bde (mentor, implicit), phk (mentor,implicit)
MFC after: 1 week
MFC r331758: makefs: sync fragment and block size with newfs
r222319 in newfs raised the default blocksize for UFS/FFS filesystems
from 16K to 32K and the default fragment size from 2K to 4K, with a
rationale that most disks were now running with 4K sectors.
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
After multiple start/stop of netmap, ixgbe will get into a bad state
requiring a reboot to recover. Adding a delay before stopping the interface
appears to work around the issue.
The -CURRENT driver has diverged too far from -STABLE for an MFC.
MFC 328101,328911: Require SHF_ALLOC for kernel object module sections.
328101:
Require the SHF_ALLOC flag for program sections from kernel object modules.
ELF object files can contain program sections which are not supposed
to be loaded into memory (e.g. .comment). Normally the static linker
uses these flags to decide which sections are allocated to loadable
program segments in ELF binaries and shared objects (including kernels
on all architectures and kernel modules on architectures other than
amd64).
Mapping ELF object files (such as amd64 kernel modules) into memory
directly is a bit of a grey area. ELF object files are intended to be
used as inputs to the static linker. As a result, there is not a
standardized definition for what the memory layout of an ELF object
should be (none of the section headers have valid virtual memory
addresses for example).
The kernel and loader were not checking the SHF_ALLOC flag but loading
any program sections with certain types such as SHT_PROGBITS. As a
result, the kernel and loader would load into RAM some sections that
weren't marked with SHF_ALLOC such as .comment that are not loaded
into RAM for kernel modules on other architectures (which are
implemented as ELF shared objects). Aside from possibly requiring
slightly more RAM to hold a kernel module this does not affect runtime
correctness as the kernel relocates symbols based on the layout it
uses.
Debuggers such as gdb and lldb do not extract symbol tables from a
running process or kernel. Instead, they replicate the memory layout
of ELF executables and shared objects and use that to construct their
own symbol tables. For executables and shared objects this works
fine. For ELF objects the current logic in kgdb (and probably lldb
based on a simple reading) assumes that only sections with SHF_ALLOC
are memory resident when constructing a memory layout. If the
debugger constructs a different memory layout than the kernel, then it
will compute different addresses for symbols causing symbols in the
debugger to appear to have the wrong values (though the kernel itself
is working fine). The current port of mdb does not check SHF_ALLOC as
it replicates the kernel's logic in its existing kernel support.
The bfd linker sorts the sections in ELF object files such that all of
the allocated sections (sections with SHF_ALLOCATED) are placed first
followed by unallocated sections. As a result, when kgdb composed a
memory layout using only the allocated sections, this layout happened
to match the layout used by the kernel and loader. The lld linker
does not sort the sections in ELF object files and mixed allocated and
unallocated sections. This resulted in kgdb composing a different
memory layout than the kernel and loader.
We could either patch kgdb (and possibly in the future lldb) to use
custom handling when generating memory layouts for kernel modules that
are ELF objects, or we could change the kernel and loader to check
SHF_ALLOCATED. I chose the latter as I feel we shouldn't be loading
things into RAM that the module won't use. This should mostly be a
NOP when linking with bfd but will allow the existing kgdb to work
with amd64 kernel modules linked with lld.
Note that we only require SHF_ALLOC for "program" sections for types
like SHT_PROGBITS and SHT_NOBITS. Other section types such as symbol
tables, string tables, and relocations must also be loaded and are not
marked with SHF_ALLOC.
328911:
Ignore relocation tables for non-memory-resident sections.
As a followup to r328101, ignore relocation tables for ELF object
sections that are not memory resident. For modules loaded by the
loader, ignore relocation tables whose associated section was not
loaded by the loader (sh_addr is zero). For modules loaded at runtime
via kldload(2), ignore relocation tables whose associated section is
not marked with SHF_ALLOC.
MFC r328988,r328989:
Rework ipfw dynamic states implementation to be lockless on fast path.
o added struct ipfw_dyn_info that keeps all needed for ipfw_chk and
for dynamic states implementation information;
o added DYN_LOOKUP_NEEDED() macro that can be used to determine the
need of new lookup of dynamic states;
o ipfw_dyn_rule now becomes obsolete. Currently it used to pass
information from kernel to userland only.
o IPv4 and IPv6 states now described by different structures
dyn_ipv4_state and dyn_ipv6_state;
o IPv6 scope zones support is added;
o ipfw(4) now depends from Concurrency Kit;
o states are linked with "entry" field using CK_SLIST. This allows
lockless lookup and protected by mutex modifications.
o the "expired" SLIST field is used for states expiring.
o struct dyn_data is used to keep generic information for both IPv4
and IPv6;
o struct dyn_parent is used to keep O_LIMIT_PARENT information;
o IPv4 and IPv6 states are stored in different hash tables;
o O_LIMIT_PARENT states now are kept separately from O_LIMIT and
O_KEEP_STATE states;
o per-cpu dyn_hp pointers are used to implement hazard pointers and they
prevent freeing states that are locklessly used by lookup threads;
o mutexes to protect modification of lists in hash tables now kept in
separate arrays. 65535 limit to maximum number of hash buckets now
removed.
o Separate lookup and install functions added for IPv4 and IPv6 states
and for parent states.
o By default now is used Jenkinks hash function.
MFC r331668:
Rework ipfw rules parsing and printing code.
Introduce show_state structure to keep information about printed opcodes.
Split show_static_rule() function into several smaller functions. Make
parsing and printing opcodes into several passes. Each printed opcode
is marked in show_state structure and will be skipped in next passes.
Now show_static_rule() function is simple, it just prints each part
of rule separately: action, modifiers, proto, src and dst addresses,
options. The main goal of this change is avoiding occurrence of wrong
result of `ifpw show` command, that can not be parsed by ipfw(8).
Also now it is possible to make some simple static optimizations
by reordering of opcodes in the rule.
MFC r329388, r331441 and r331898, to bring the -CURRENT ck version.
r329388:
Define CK_MD_TSO for the relevant arches (i386, amd64 and sparc64).
Defaulting to CK_MD_RMO has the unfortunate side effect of generating
memory barriers that are useless on those arches, and the even more
unfortunate side effect of generating lfence/sfence/mfence on i386, even
if older CPUs don't support it.
This should fix the panic reported when using IPFW on a Pentium 3.
Note that mfence and sfence might still be used in a few case, but that
shouldn't happen in FreeBSD right now, and should be fixed upstream first.
r331441:
In __sync_bool_compare_and_swap(), return true if the returned value is the
same as the expected one, not the desired one.
r331898:
Import CK as of commit b19ed4c6a56ec93215ab567ba18ba61bf1cfbac8
It should fix ck_pr_[load|store]_ptr on mips and riscv, make sure no
*fence instructions are used on i386, as older cpus don't support it, and
make sure we don't rely on gcc builtins that can lead to calls to
libatomic when linked with -O0.
When /etc/rc runs all /etc/rc.d scripts, it has already loaded /etc/rc.subr
but each /etc/rc.d script sources it again (since /etc/rc.d scripts must
also work when started stand-alone).
Therefore, if rc.subr is already loaded, return so sh need not parse the
rest of the file.
A second effect is that there is no longer a compound command around most of
rc.subr. This reduces memory usage while sh is loading rc.subr for the first
time (but this memory is free()d once rc.subr is loaded).
For purposes of porting this to other systems, I do not recommend porting
this to systems with shells that do not have the change to the return
special builtin like in r255215 (before FreeBSD 10.0-RELEASE). This change
ensures that return in the top level of a dot script returns from the dot
script, even if the dot script was sourced from a function.
A comparison of CPU time on an amd64 bhyve virtual machine from a times
command added near the end of /etc/rc, all four values summed:
x orig1
+ quickreturn
+--------------------------------------------------------------------------+
| + + + x x x|
||______M__A_________| |______M___A__________| |
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 1.704 1.802 1.726 1.744 0.051419841
+ 3 1.467 1.559 1.487 1.5043333 0.048387326
Difference at 95.0% confidence
-0.239667 +/- 0.113163
-13.7424% +/- 6.48873%
(Student's t, pooled s = 0.0499266)
r324625:
rc.subr: Remove test that is always true.
The code above always sets _pidcmd to a non-empty value.
Revert r331880, MFC of r328331 and bump FreeBSD_version
There are logistics issues that weren't considered when this was originally
MFC'd. All rc scripts in ports need audited (this is in progress) for usage
of ${name}_limits that doesn't line up with the new interpretation, and
individual rc.conf(5)'s need to be scrubbed of usage that doesn't line up.
It's since been decided that it should be left for a feature in 12.
1101514 introduced interpretation of ${name}_limits for rc scripts; this
feature no longer exists as of 1101515.
MFC r326641 by bapt: Split body of mails not respecting RFC2822
For mails which has a body not respecting RFC2822 (which often happen with
crontabs) try to split by words finding the last space before 1000's
character
If no spaces are found then consider the mail to be malformed anyway
I missed that this was an assignment (a bad pattern, use another
member) on i386. As wl(4) is i386 only and gone in head, just
expand the ifr_ifru member rather than adding an accessor.
ifconf(): correct handling of sockaddrs smaller than struct sockaddr.
Portable programs that use SIOCGIFCONF (e.g. traceroute) assume
that each pseudo ifreq is of length MAX(sizeof(struct ifreq),
sizeof(ifr_name) + ifr_addr.sa_len). For short sockaddrs we copied
too much from the source sockaddr resulting in a heap leak.
I believe only one such sockaddr exists (struct sockaddr_sco which
is 8 bytes) and it is unclear if such sockaddrs end up on interfaces
in practice. If it did, the result would be an 8 byte heap leak on
current architectures.
If a user attempts to add two tables with the same name the duplicate table
will not be added, but we forgot to free the duplicate table, leaking memory.
Ensure we free the duplicate table in the error path.
MFC r331969, r332035:
pthread.h: drop nullability attributes.
These have been found to be practically useless. We were actually
following the Android bionic library and had some interest in replicating
the same warnings and behaviour but Android has since removed them.
We are still keeping some uses of nullability attributes in other headers,
somewhat in line with Apple's libc.
MFC r330110: Add kernel retpoline option for amd64
Retpoline is a compiler-based mitigation for CVE-2017-5715, also known
as Spectre V2, that protects against speculative execution branch target
injection attacks.
In this commit it is disabled by default, but will be changed in a
followup commit.
MFC r330962: Remove KERNEL_RETPOLINE from BROKEN_OPTIONS on i386
Clang will compile both amd64 and i386 with retpoline.
The previous split of zeroing ifr_name and ifr_addr seperately is safe
on current architectures, but would be unsafe if pointers were larger
than 8 bytes. Combining the zeroing adds no real cost (a few
instructions) and makes the security property easier to verify.
GC never enabled support for SIOCGADDRROM and SIOCGCHIPID.
When de(4) was imported in 1997 the world was not ready for these ioctls.
In over 20 years that hasn't changed so it seems safe to assume their
time will never come.
Make all kernel accesses to ifru_buffer go via access functions
which take the process ABI into account and use an appropriate union
to access members in the correct place in struct ifreq.
r331654:
Don't access userspace directly from the kernel in nxge(4).
Update to what the previous code seemed to be doing via the correct
interfaces. Further issues exist in xge_ioctl_registers(), but this is
debugging code in a driver that has few users and they don't appear to
be crashes or leaks.
r331869:
Fix the build on arches with default unsigned char. Capture the fubyte()
return value in an int as well as the char, and test the full int value
for fubyte() failure.