Pull x86 cleanups from Ingo Molnar:
"Misc cleanups, including a large series from Thomas Gleixner to cure
sparse warnings"
* tag 'x86-cleanups-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Drop unused declaration of proc_nmi_enabled()
x86/callthunks: Use EXPORT_PER_CPU_SYMBOL_GPL() for per CPU variables
x86/cpu: Provide a declaration for itlb_multihit_kvm_mitigation
x86/cpu: Use EXPORT_PER_CPU_SYMBOL_GPL() for x86_spec_ctrl_current
x86/uaccess: Add missing __force to casts in __access_ok() and valid_user_address()
x86/percpu: Cure per CPU madness on UP
smp: Consolidate smp_prepare_boot_cpu()
x86/msr: Add missing __percpu annotations
x86/msr: Prepare for including <linux/percpu.h> into <asm/msr.h>
perf/x86/amd/uncore: Fix __percpu annotation
x86/nmi: Remove an unnecessary IS_ENABLED(CONFIG_SMP)
x86/apm_32: Remove dead function apm_get_battery_status()
x86/insn-eval: Fix function param name in get_eff_addr_sib()
Pull x86 APIC updates from Thomas Gleixner:
"Rework of APIC enumeration and topology evaluation.
The current implementation has a couple of shortcomings:
- It fails to handle hybrid systems correctly.
- The APIC registration code which handles CPU number assignents is
in the middle of the APIC code and detached from the topology
evaluation.
- The various mechanisms which enumerate APICs, ACPI, MPPARSE and
guest specific ones, tweak global variables as they see fit or in
case of XENPV just hack around the generic mechanisms completely.
- The CPUID topology evaluation code is sprinkled all over the vendor
code and reevaluates global variables on every hotplug operation.
- There is no way to analyze topology on the boot CPU before bringing
up the APs. This causes problems for infrastructure like PERF which
needs to size certain aspects upfront or could be simplified if
that would be possible.
- The APIC admission and CPU number association logic is
incomprehensible and overly complex and needs to be kept around
after boot instead of completing this right after the APIC
enumeration.
This update addresses these shortcomings with the following changes:
- Rework the CPUID evaluation code so it is common for all vendors
and provides information about the APIC ID segments in a uniform
way independent of the number of segments (Thread, Core, Module,
..., Die, Package) so that this information can be computed instead
of rewriting global variables of dubious value over and over.
- A few cleanups and simplifcations of the APIC, IO/APIC and related
interfaces to prepare for the topology evaluation changes.
- Seperation of the parser stages so the early evaluation which tries
to find the APIC address can be seperately overridden from the late
evaluation which enumerates and registers the local APIC as further
preparation for sanitizing the topology evaluation.
- A new registration and admission logic which
- encapsulates the inner workings so that parsers and guest logic
cannot longer fiddle in it
- uses the APIC ID segments to build topology bitmaps at
registration time
- provides a sane admission logic
- allows to detect the crash kernel case, where CPU0 does not run
on the real BSP, automatically. This is required to prevent
sending INIT/SIPI sequences to the real BSP which would reset
the whole machine. This was so far handled by a tedious command
line parameter, which does not even work in nested crash
scenarios.
- Associates CPU number after the enumeration completed and
prevents the late registration of APICs, which was somehow
tolerated before.
- Converting all parsers and guest enumeration mechanisms over to the
new interfaces.
This allows to get rid of all global variable tweaking from the
parsers and enumeration mechanisms and sanitizes the XEN[PV]
handling so it can use CPUID evaluation for the first time.
- Mopping up existing sins by taking the information from the APIC ID
segment bitmaps.
This evaluates hybrid systems correctly on the boot CPU and allows
for cleanups and fixes in the related drivers, e.g. PERF.
The series has been extensively tested and the minimal late fallout
due to a broken ACPI/MADT table has been addressed by tightening the
admission logic further"
* tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
x86/topology: Ignore non-present APIC IDs in a present package
x86/apic: Build the x86 topology enumeration functions on UP APIC builds too
smp: Provide 'setup_max_cpus' definition on UP too
smp: Avoid 'setup_max_cpus' namespace collision/shadowing
x86/bugs: Use fixed addressing for VERW operand
x86/cpu/topology: Get rid of cpuinfo::x86_max_cores
x86/cpu/topology: Provide __num_[cores|threads]_per_package
x86/cpu/topology: Rename topology_max_die_per_package()
x86/cpu/topology: Rename smp_num_siblings
x86/cpu/topology: Retrieve cores per package from topology bitmaps
x86/cpu/topology: Use topology logical mapping mechanism
x86/cpu/topology: Provide logical pkg/die mapping
x86/cpu/topology: Simplify cpu_mark_primary_thread()
x86/cpu/topology: Mop up primary thread mask handling
x86/cpu/topology: Use topology bitmaps for sizing
x86/cpu/topology: Let XEN/PV use topology from CPUID/MADT
x86/xen/smp_pv: Count number of vCPUs early
x86/cpu/topology: Assign hotpluggable CPUIDs during init
x86/cpu/topology: Reject unknown APIC IDs on ACPI hotplug
x86/topology: Add a mechanism to track topology via APIC IDs
...
Pull workqueue updates from Tejun Heo:
"This cycle, a lot of workqueue changes including some that are
significant and invasive.
- During v6.6 cycle, unbound workqueues were updated so that they are
more topology aware and flexible, which among other things improved
workqueue behavior on modern multi-L3 CPUs. In the process, commit
636b927eba ("workqueue: Make unbound workqueues to use per-cpu
pool_workqueues") switched unbound workqueues to use per-CPU
frontend pool_workqueues as a part of increasing front-back mapping
flexibility.
An unwelcome side effect of this change was that this made max
concurrency enforcement per-CPU blowing up the maximum number of
allowed concurrent executions. I incorrectly assumed that this
wouldn't cause practical problems as most unbound workqueue users
are self-regulate max concurrency; however, there definitely are
which don't (e.g. on IO paths) and the drastic increase in the
allowed max concurrency led to noticeable perf regressions in some
use cases.
This is now addressed by separating out max concurrency enforcement
to a separate struct - wq_node_nr_active - which makes @max_active
consistently mean system-wide max concurrency regardless of the
number of CPUs or (finally) NUMA nodes. This is a rather invasive
and, in places, a bit clunky; however, the clunkiness rises from
the the inherent requirement to handle the disagreement between the
execution locality domain and max concurrency enforcement domain on
some modern machines.
See commit 5797b1c189 ("workqueue: Implement system-wide
nr_active enforcement for unbound workqueues") for more details.
- BH workqueue support is added.
They are similar to per-CPU workqueues but execute work items in
the softirq context. This is expected to replace tasklet. However,
currently, it's missing the ability to disable and enable work
items which is needed to convert many tasklet users. To avoid
crowding this merge window too much, this will be included in the
next merge window. A separate pull request will be sent for the
couple conversion patches that are currently pending.
- Waiman plugged a long-standing hole in workqueue CPU isolation
where ordered workqueues didn't follow wq_unbound_cpumask updates.
Ordered workqueues now follow the same rules as other unbound
workqueues.
- More CPU isolation improvements: Juri fixed another deficit in
workqueue isolation where unbound rescuers don't respect
wq_unbound_cpumask. Leonardo fixed delayed_work timers firing on
isolated CPUs.
- Other misc changes"
* tag 'wq-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (54 commits)
workqueue: Drain BH work items on hot-unplugged CPUs
workqueue: Introduce from_work() helper for cleaner callback declarations
workqueue: Control intensive warning threshold through cmdline
workqueue: Make @flags handling consistent across set_work_data() and friends
workqueue: Remove clear_work_data()
workqueue: Factor out work_grab_pending() from __cancel_work_sync()
workqueue: Clean up enum work_bits and related constants
workqueue: Introduce work_cancel_flags
workqueue: Use variable name irq_flags for saving local irq flags
workqueue: Reorganize flush and cancel[_sync] functions
workqueue: Rename __cancel_work_timer() to __cancel_timer_sync()
workqueue: Use rcu_read_lock_any_held() instead of rcu_read_lock_held()
workqueue: Cosmetic changes
workqueue, irq_work: Build fix for !CONFIG_IRQ_WORK
workqueue: Fix queue_work_on() with BH workqueues
async: Use a dedicated unbound workqueue with raised min_active
workqueue: Implement workqueue_set_min_active()
workqueue: Fix kernel-doc comment of unplug_oldest_pwq()
workqueue: Bind unbound workqueue rescuer to wq_unbound_cpumask
kernel/workqueue: Let rescuers follow unbound wq cpumask changes
...
Pull RCU updates from Boqun Feng:
- Eliminate deadlocks involving do_exit() and RCU tasks, by Paul:
Instead of SRCU read side critical sections, now a percpu list is
used in do_exit() for scaning yet-to-exit tasks
- Fix a deadlock due to the dependency between workqueue and RCU
expedited grace period, reported by Anna-Maria Behnsen and Thomas
Gleixner and fixed by Frederic: Now RCU expedited always uses its own
kthread worker instead of a workqueue
- RCU NOCB updates, code cleanups, unnecessary barrier removals and
minor bug fixes
- Maintain real-time response in rcu_tasks_postscan() and a minor fix
for tasks trace quiescence check
- Misc updates, comments and readibility improvement, boot time
parameter for lazy RCU and rcutorture improvement
- Documentation updates
* tag 'rcu.next.v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux: (34 commits)
rcu-tasks: Maintain real-time response in rcu_tasks_postscan()
rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks
rcu-tasks: Maintain lists to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Initialize callback lists at rcu_init() time
rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Repair RCU Tasks Trace quiescence check
rcu/sync: remove un-used rcu_sync_enter_start function
rcutorture: Suppress rtort_pipe_count warnings until after stalls
srcu: Improve comments about acceleration leak
rcu: Provide a boot time parameter to control lazy RCU
rcu: Rename jiffies_till_flush to jiffies_lazy_flush
doc: Update checklist.rst discussion of callback execution
doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU
context_tracking: Fix kerneldoc headers for __ct_user_{enter,exit}()
doc: Add EARLY flag to early-parsed kernel boot parameters
doc: Add CONFIG_RCU_STRICT_GRACE_PERIOD to checklist.rst
doc: Make checklist.rst note that spinlocks are implied RCU readers
doc: Make whatisRCU.rst note that spinlocks are RCU readers
doc: Spinlocks are implied RCU readers
...
Pull block handle updates from Christian Brauner:
"Last cycle we changed opening of block devices, and opening a block
device would return a bdev_handle. This allowed us to implement
support for restricting and forbidding writes to mounted block
devices. It was accompanied by converting and adding helpers to
operate on bdev_handles instead of plain block devices.
That was already a good step forward but ultimately it isn't necessary
to have special purpose helpers for opening block devices internally
that return a bdev_handle.
Fundamentally, opening a block device internally should just be
equivalent to opening files. So now all internal opens of block
devices return files just as a userspace open would. Instead of
introducing a separate indirection into bdev_open_by_*() via struct
bdev_handle bdev_file_open_by_*() is made to just return a struct
file. Opening and closing a block device just becomes equivalent to
opening and closing a file.
This all works well because internally we already have a pseudo fs for
block devices and so opening block devices is simple. There's a few
places where we needed to be careful such as during boot when the
kernel is supposed to mount the rootfs directly without init doing it.
Here we need to take care to ensure that we flush out any asynchronous
file close. That's what we already do for opening, unpacking, and
closing the initramfs. So nothing new here.
The equivalence of opening and closing block devices to regular files
is a win in and of itself. But it also has various other advantages.
We can remove struct bdev_handle completely. Various low-level helpers
are now private to the block layer. Other helpers were simply
removable completely.
A follow-up series that is already reviewed build on this and makes it
possible to remove bdev->bd_inode and allows various clean ups of the
buffer head code as well. All places where we stashed a bdev_handle
now just stash a file and use simple accessors to get to the actual
block device which was already the case for bdev_handle"
* tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
block: remove bdev_handle completely
block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access
bdev: remove bdev pointer from struct bdev_handle
bdev: make struct bdev_handle private to the block layer
bdev: make bdev_{release, open_by_dev}() private to block layer
bdev: remove bdev_open_by_path()
reiserfs: port block device access to file
ocfs2: port block device access to file
nfs: port block device access to files
jfs: port block device access to file
f2fs: port block device access to files
ext4: port block device access to file
erofs: port device access to file
btrfs: port device access to file
bcachefs: port block device access to file
target: port block device access to file
s390: port block device access to file
nvme: port block device access to file
block2mtd: port device access to files
bcache: port block device access to files
...
Pull pdfd updates from Christian Brauner:
- Until now pidfds could only be created for thread-group leaders but
not for threads. There was no technical reason for this. We simply
had no users that needed support for this. Now we do have users that
need support for this.
This introduces a new PIDFD_THREAD flag for pidfd_open(). If that
flag is set pidfd_open() creates a pidfd that refers to a specific
thread.
In addition, we now allow clone() and clone3() to be called with
CLONE_PIDFD | CLONE_THREAD which wasn't possible before.
A pidfd that refers to an individual thread differs from a pidfd that
refers to a thread-group leader:
(1) Pidfds are pollable. A task may poll a pidfd and get notified
when the task has exited.
For thread-group leader pidfds the polling task is woken if the
thread-group is empty. In other words, if the thread-group
leader task exits when there are still threads alive in its
thread-group the polling task will not be woken when the
thread-group leader exits but rather when the last thread in the
thread-group exits.
For thread-specific pidfds the polling task is woken if the
thread exits.
(2) Passing a thread-group leader pidfd to pidfd_send_signal() will
generate thread-group directed signals like kill(2) does.
Passing a thread-specific pidfd to pidfd_send_signal() will
generate thread-specific signals like tgkill(2) does.
The default scope of the signal is thus determined by the type
of the pidfd.
Since use-cases exist where the default scope of the provided
pidfd needs to be overriden the following flags are added to
pidfd_send_signal():
- PIDFD_SIGNAL_THREAD
Send a thread-specific signal.
- PIDFD_SIGNAL_THREAD_GROUP
Send a thread-group directed signal.
- PIDFD_SIGNAL_PROCESS_GROUP
Send a process-group directed signal.
The scope change will only work if the struct pid is actually
used for this scope.
For example, in order to send a thread-group directed signal the
provided pidfd must be used as a thread-group leader and
similarly for PIDFD_SIGNAL_PROCESS_GROUP the struct pid must be
used as a process group leader.
- Move pidfds from the anonymous inode infrastructure to a tiny pseudo
filesystem. This will unblock further work that we weren't able to do
simply because of the very justified limitations of anonymous inodes.
Moving pidfds to a tiny pseudo filesystem allows for statx on pidfds
to become useful for the first time. They can now be compared by
inode number which are unique for the system lifetime.
Instead of stashing struct pid in file->private_data we can now stash
it in inode->i_private. This makes it possible to introduce concepts
that operate on a process once all file descriptors have been closed.
A concrete example is kill-on-last-close. Another side-effect is that
file->private_data is now freed up for per-file options for pidfds.
Now, each struct pid will refer to a different inode but the same
struct pid will refer to the same inode if it's opened multiple
times. In contrast to now where each struct pid refers to the same
inode.
The tiny pseudo filesystem is not visible anywhere in userspace
exactly like e.g., pipefs and sockfs. There's no lookup, there's no
complex inode operations, nothing. Dentries and inodes are always
deleted when the last pidfd is closed.
We allocate a new inode and dentry for each struct pid and we reuse
that inode and dentry for all pidfds that refer to the same struct
pid. The code is entirely optional and fairly small. If it's not
selected we fallback to anonymous inodes. Heavily inspired by nsfs.
The dentry and inode allocation mechanism is moved into generic
infrastructure that is now shared between nsfs and pidfs. The
path_from_stashed() helper must be provided with a stashing location,
an inode number, a mount, and the private data that is supposed to be
used and it will provide a path that can be passed to dentry_open().
The helper will try retrieve an existing dentry from the provided
stashing location. If a valid dentry is found it is reused. If not a
new one is allocated and we try to stash it in the provided location.
If this fails we retry until we either find an existing dentry or the
newly allocated dentry could be stashed. Subsequent openers of the
same namespace or task are then able to reuse it.
- Currently it is only possible to get notified when a task has exited,
i.e., become a zombie and userspace gets notified with EPOLLIN. We
now also support waiting until the task has been reaped, notifying
userspace with EPOLLHUP.
- Ensure that ESRCH is reported for getfd if a task is exiting instead
of the confusing EBADF.
- Various smaller cleanups to pidfd functions.
* tag 'vfs-6.9.pidfd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
libfs: improve path_from_stashed()
libfs: add stashed_dentry_prune()
libfs: improve path_from_stashed() helper
pidfs: convert to path_from_stashed() helper
nsfs: convert to path_from_stashed() helper
libfs: add path_from_stashed()
pidfd: add pidfs
pidfd: move struct pidfd_fops
pidfd: allow to override signal scope in pidfd_send_signal()
pidfd: change pidfd_send_signal() to respect PIDFD_THREAD
signal: fill in si_code in prepare_kill_siginfo()
selftests: add ESRCH tests for pidfd_getfd()
pidfd: getfd should always report ESRCH if a task is exiting
pidfd: clone: allow CLONE_THREAD | CLONE_PIDFD together
pidfd: exit: kill the no longer used thread_group_exited()
pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN))
pid: kill the obsolete PIDTYPE_PID code in transfer_pid()
pidfd: kill the no longer needed do_notify_pidfd() in de_thread()
pidfd_poll: report POLLHUP when pid_task() == NULL
pidfd: implement PIDFD_THREAD flag for pidfd_open()
...
Pull misc vfs updates from Christian Brauner:
"Misc features, cleanups, and fixes for vfs and individual filesystems.
Features:
- Support idmapped mounts for hugetlbfs.
- Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
where the passed offset is ignored if the file is O_APPEND. The new
flag allows a caller to enforce that the offset is honored to
conform to posix even if the file was opened in append mode.
- Move i_mmap_rwsem in struct address_space to avoid false sharing
between i_mmap and i_mmap_rwsem.
- Convert efs, qnx4, and coda to use the new mount api.
- Add a generic is_dot_dotdot() helper that's used by various
filesystems and the VFS code instead of open-coding it multiple
times.
- Recently we've added stable offsets which allows stable ordering
when iterating directories exported through NFS on e.g., tmpfs
filesystems. Originally an xarray was used for the offset map but
that caused slab fragmentation issues over time. This switches the
offset map to the maple tree which has a dense mode that handles
this scenario a lot better. Includes tests.
- Finally merge the case-insensitive improvement series Gabriel has
been working on for a long time. This cleanly propagates case
insensitive operations through ->s_d_op which in turn allows us to
remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
It also improves performance by trying a case-sensitive comparison
first and then fallback to case-insensitive lookup if that fails.
This also fixes a bug where overlayfs would be able to be mounted
over a case insensitive directory which would lead to all sort of
odd behaviors.
Cleanups:
- Make file_dentry() a simple accessor now that ->d_real() is
simplified because of the backing file work we did the last two
cycles.
- Use the dedicated file_mnt_idmap helper in ntfs3.
- Use smp_load_acquire/store_release() in the i_size_read/write
helpers and thus remove the hack to handle i_size reads in the
filemap code.
- The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
fs/
- It's no longer necessary to perform a second built-in initramfs
unpack call because we retain the contents of the previous
extraction. Remove it.
- Now that we have removed various allocators kfree_rcu() always
works with kmem caches and kmalloc(). So simplify various places
that only use an rcu callback in order to handle the kmem cache
case.
- Convert the pipe code to use a lockdep comparison function instead
of open-coding the nesting making lockdep validation easier.
- Move code into fs-writeback.c that was located in a header but can
be made static as it's only used in that one file.
- Rewrite the alignment checking iterators for iovec and bvec to be
easier to read, and also significantly more compact in terms of
generated code. This saves 270 bytes of text on x86-64 (with
clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
saves a bit of time for the same workload.
- Switch various places to use KMEM_CACHE instead of
kmem_cache_create().
- Use inode_set_ctime_to_ts() in inode_set_ctime_current()
- Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.
- Various smaller cleanups for eventfds.
Fixes:
- Fix various comments and typos, and unneeded initializations.
- Fix stack allocation hack for clang in the select code.
- Improve dump_mapping() debug code on a best-effort basis.
- Fix build errors in various selftests.
- Avoid wrap-around instrumentation in various places.
- Don't allow user namespaces without an idmapping to be used for
idmapped mounts.
- Fix sysv sb_read() call.
- Fix fallback implementation of the get_name() export operation"
* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
hugetlbfs: support idmapped mounts
qnx4: convert qnx4 to use the new mount api
fs: use inode_set_ctime_to_ts to set inode ctime to current time
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
efs: remove SLAB_MEM_SPREAD flag usage
jfs: remove SLAB_MEM_SPREAD flag usage
minix: remove SLAB_MEM_SPREAD flag usage
openpromfs: remove SLAB_MEM_SPREAD flag usage
proc: remove SLAB_MEM_SPREAD flag usage
qnx6: remove SLAB_MEM_SPREAD flag usage
...
The synchronization here is to ensure the ordering of freeing of a module
init so that it happens before W+X checking. It is worth noting it is not
that the freeing was not happening, it is just that our sanity checkers
raced against the permission checkers which assume init memory is already
gone.
Commit 1a7b7d9220 ("modules: Use vmalloc special flag") moved calling
do_free_init() into a global workqueue instead of relying on it being
called through call_rcu(..., do_free_init), which used to allowed us call
do_free_init() asynchronously after the end of a subsequent grace period.
The move to a global workqueue broke the gaurantees for code which needed
to be sure the do_free_init() would complete with rcu_barrier(). To fix
this callers which used to rely on rcu_barrier() must now instead use
flush_work(&init_free_wq).
Without this fix, we still could encounter false positive reports in W+X
checking since the rcu_barrier() here can not ensure the ordering now.
Even worse, the rcu_barrier() can introduce significant delay. Eric
Chanudet reported that the rcu_barrier introduces ~0.1s delay on a
PREEMPT_RT kernel.
[ 0.291444] Freeing unused kernel memory: 5568K
[ 0.402442] Run /sbin/init as init process
With this fix, the above delay can be eliminated.
Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com
Fixes: 1a7b7d9220 ("modules: Use vmalloc special flag")
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Tested-by: Eric Chanudet <echanude@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Xiaoyi Su <suxiaoyi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is no point in having seven architectures implementing the same empty
stub.
Provide a weak function in the init code and remove the stubs.
This also allows to utilize the function on UP which is required to
sanitize the per CPU handling on X86 UP.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-02-29
We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).
The main changes are:
1) Extend the BPF verifier to enable static subprog calls in spin lock
critical sections, from Kumar Kartikeya Dwivedi.
2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
in BPF global subprogs, from Andrii Nakryiko.
3) Larger batch of riscv BPF JIT improvements and enabling inlining
of the bpf_kptr_xchg() for RV64, from Pu Lehui.
4) Allow skeleton users to change the values of the fields in struct_ops
maps at runtime, from Kui-Feng Lee.
5) Extend the verifier's capabilities of tracking scalars when they
are spilled to stack, especially when the spill or fill is narrowing,
from Maxim Mikityanskiy & Eduard Zingerman.
6) Various BPF selftest improvements to fix errors under gcc BPF backend,
from Jose E. Marchesi.
7) Avoid module loading failure when the module trying to register
a struct_ops has its BTF section stripped, from Geliang Tang.
8) Annotate all kfuncs in .BTF_ids section which eventually allows
for automatic kfunc prototype generation from bpftool, from Daniel Xu.
9) Several updates to the instruction-set.rst IETF standardization
document, from Dave Thaler.
10) Shrink the size of struct bpf_map resp. bpf_array,
from Alexei Starovoitov.
11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
from Benjamin Tissoires.
12) Fix bpftool to be more portable to musl libc by using POSIX's
basename(), from Arnaldo Carvalho de Melo.
13) Add libbpf support to gcc in CORE macro definitions,
from Cupertino Miranda.
14) Remove a duplicate type check in perf_event_bpf_event,
from Florian Lehner.
15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
with notrace correctly, from Yonghong Song.
16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
array to fix build warnings, from Kees Cook.
17) Fix resolve_btfids cross-compilation to non host-native endianness,
from Viktor Malik.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
selftests/bpf: Test if shadow types work correctly.
bpftool: Add an example for struct_ops map and shadow type.
bpftool: Generated shadow variables for struct_ops maps.
libbpf: Convert st_ops->data to shadow type.
libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
bpf, arm64: use bpf_prog_pack for memory management
arm64: patching: implement text_poke API
bpf, arm64: support exceptions
arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
bpf: add is_async_callback_calling_insn() helper
bpf: introduce in_sleepable() helper
bpf: allow more maps in sleepable bpf programs
selftests/bpf: Test case for lacking CFI stub functions.
bpf: Check cfi_stubs before registering a struct_ops type.
bpf: Clarify batch lookup/lookup_and_delete semantics
bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
bpf, docs: Fix typos in instruction-set.rst
selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
bpf: Shrink size of struct bpf_map/bpf_array.
...
====================
Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This moves pidfds from the anonymous inode infrastructure to a tiny
pseudo filesystem. This has been on my todo for quite a while as it will
unblock further work that we weren't able to do simply because of the
very justified limitations of anonymous inodes. Moving pidfds to a tiny
pseudo filesystem allows:
* statx() on pidfds becomes useful for the first time.
* pidfds can be compared simply via statx() and then comparing inode
numbers.
* pidfds have unique inode numbers for the system lifetime.
* struct pid is now stashed in inode->i_private instead of
file->private_data. This means it is now possible to introduce
concepts that operate on a process once all file descriptors have been
closed. A concrete example is kill-on-last-close.
* file->private_data is freed up for per-file options for pidfds.
* Each struct pid will refer to a different inode but the same struct
pid will refer to the same inode if it's opened multiple times. In
contrast to now where each struct pid refers to the same inode. Even
if we were to move to anon_inode_create_getfile() which creates new
inodes we'd still be associating the same struct pid with multiple
different inodes.
The tiny pseudo filesystem is not visible anywhere in userspace exactly
like e.g., pipefs and sockfs. There's no lookup, there's no complex
inode operations, nothing. Dentries and inodes are always deleted when
the last pidfd is closed.
We allocate a new inode for each struct pid and we reuse that inode for
all pidfds. We use iget_locked() to find that inode again based on the
inode number which isn't recycled. We allocate a new dentry for each
pidfd that uses the same inode. That is similar to anonymous inodes
which reuse the same inode for thousands of dentries. For pidfds we're
talking way less than that. There usually won't be a lot of concurrent
openers of the same struct pid. They can probably often be counted on
two hands. I know that systemd does use separate pidfd for the same
struct pid for various complex process tracking issues. So I think with
that things actually become way simpler. Especially because we don't
have to care about lookup. Dentries and inodes continue to be always
deleted.
The code is entirely optional and fairly small. If it's not selected we
fallback to anonymous inodes. Heavily inspired by nsfs which uses a
similar stashing mechanism just for namespaces.
Link: https://lore.kernel.org/r/20240213-vfs-pidfd_fs-v1-2-f863f58cfce1@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
This was already defined locally by init/main.c, but let's make
it generic, as arch/x86/kernel/cpu/topology.c is going to make
use of it to have more uniform code.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Holding a mutex across synchronize_rcu_tasks() and acquiring
that same mutex in code called from do_exit() after its call to
exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop()
results in deadlock. This is by design, because tasks that are far
enough into do_exit() are no longer present on the tasks list, making
it a bit difficult for RCU Tasks to find them, let alone wait on them
to do a voluntary context switch. However, such deadlocks are becoming
more frequent. In addition, lockdep currently does not detect such
deadlocks and they can be difficult to reproduce.
In addition, if a task voluntarily context switches during that time
(for example, if it blocks acquiring a mutex), then this task is in an
RCU Tasks quiescent state. And with some adjustments, RCU Tasks could
just as well take advantage of that fact.
This commit therefore initializes the data structures that will be needed
to rely on these quiescent states and to eliminate these deadlocks.
Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/
Reported-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reported-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Yang Jihong <yangjihong1@huawei.com>
Tested-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes
need be built in to avoid compiling error when building kexec code even
though the crash dumping functionality is not enabled. E.g
--------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC=y
CONFIG_KEXEC_FILE=y
---------------------
After splitting out crashkernel reservation code and vmcoreinfo exporting
code, there's only crash related code left in kernel/crash_core.c. Now
move crash related codes from kexec_core.c to crash_core.c and only build it
in when CONFIG_CRASH_DUMP=y.
And also wrap up crash codes inside CONFIG_CRASH_DUMP ifdeffery scope,
or replace inappropriate CONFIG_KEXEC_CORE ifdef with CONFIG_CRASH_DUMP
ifdef in generic kernel files.
With these changes, crash_core codes are abstracted from kexec codes and
can be disabled at all if only kexec reboot feature is wanted.
Link: https://lkml.kernel.org/r/20240124051254.67105-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
'def_bool X' is a shorthand for 'bool' plus 'default X'.
'def_bool' is redundant where 'bool' is already present, so 'def_bool X'
can be replaced with 'default X', or removed if X is 'n'.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2f34d7337d ("workqueue: Fix queue_work_on() with BH workqueues") added
irq_work usage to workqueue; however, it turns out irq_work is actually
optional and the change breaks build on configuration which doesn't have
CONFIG_IRQ_WORK enabled.
Fix build by making workqueue use irq_work only when CONFIG_SMP and enabling
CONFIG_IRQ_WORK when CONFIG_SMP is set. It's reasonable to argue that it may
be better to just always enable it. However, this still saves a small bit of
memory for tiny UP configs and also the least amount of change, so, for now,
let's keep it conditional.
Verified to do the right thing for x86_64 allnoconfig and defconfig, and
aarch64 allnoconfig, allnoconfig + prink disable (SMP but nothing selects
IRQ_WORK) and a modified aarch64 Kconfig where !SMP and nothing selects
IRQ_WORK.
v2: `depends on SMP` leads to Kconfig warnings when CONFIG_IRQ_WORK is
selected by something else when !CONFIG_SMP. Use `def_bool y if SMP`
instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Fixes: 2f34d7337d ("workqueue: Fix queue_work_on() with BH workqueues")
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
In commit 4356e9f841 ("work around gcc bugs with 'asm goto' with
outputs") I did the gcc workaround unconditionally, because the cause of
the bad code generation wasn't entirely clear.
In the meantime, Jakub Jelinek debugged the issue, and has come up with
a fix in gcc [2], which also got backported to the still maintained
branches of gcc-11, gcc-12 and gcc-13.
Note that while the fix technically wasn't in the original gcc-14
branch, Jakub says:
"while it is true that no GCC 14 snapshots until today (or whenever the
fix will be committed) have the fix, for GCC trunk it is up to the
distros to use the latest snapshot if they use it at all and would
allow better testing of the kernel code without the workaround, so
that if there are other issues they won't be discovered years later.
Most userland code doesn't actually use asm goto with outputs..."
so we will consider gcc-14 to be fixed - if somebody is using gcc
snapshots of the gcc-14 before the fix, they should upgrade.
Note that while the bug goes back to gcc-11, in practice other gcc
changes seem to have effectively hidden it since gcc-12.1 as per a
bisect by Jakub. So even a gcc-14 snapshot without the fix likely
doesn't show actual problems.
Also, make the default 'asm_goto_output()' macro mark the asm as
volatile by hand, because of an unrelated gcc issue [1] where it doesn't
match the documented behavior ("asm goto is always volatile").
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2]
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Requested-by: Jakub Jelinek <jakub@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Async can schedule a number of interdependent work items. However, since
5797b1c189 ("workqueue: Implement system-wide nr_active enforcement for
unbound workqueues"), unbound workqueues have separate min_active which sets
the number of interdependent work items that can be handled. This default
value is 8 which isn't sufficient for async and can lead to stalls during
resume from suspend in some cases.
Let's use a dedicated unbound workqueue with raised min_active.
Link: http://lkml.kernel.org/r/708a65cc-79ec-44a6-8454-a93d0f3114c3@samsung.com
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When unpacking the initramfs or when mounting block devices we need to
ensure that any delayed fput() finished to prevent spurious errors.
The init process can be a proper kernel thread or a user mode helper.
In the latter case PF_KTHREAD isn't set. So we need to do both
flush_delayed_work() and task_work_run().
Since we'll port block device opening and closing to regular file open
and closing we need to ensure the same as for the initramfs. So just
make that a little helper.
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/CA+G9fYttTwsbFuVq10igbSvP5xC6bf_XijM=mpUqrJV=uvUirQ@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Declaring rodata_enabled and mark_rodata_ro() at all time
helps removing related #ifdefery in C files.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
It turns out it was never just gcc-11 that was broken. Apparently it
just happens to work on x86-64 with other gcc versions.
On arm64, I see warnings with gcc version 13.2.1, and the kernel test
robot reports the same problem on s390 with gcc 13.2.0.
Admittedly it seems to be just the new Xe drm driver, but this is
keeping me from doing my normal arm64 build testing. So it gets
reverted until somebody figures out what causes the problem (and why it
doesn't show on x86-64, which is what makes me suspect it was never just
about gcc-11, and more about just random happenstance).
This also changes the Kconfig naming a bit - just make the "disable this
for GCC" conditional be one simple Kconfig entry, and we can put the gcc
version dependencies in that entry once we figure out what the correct
rules are.
The version dependency _may_ still end up being "gcc version larger than
11" if the issue is purely in the Xe driver, but even if that ends up
the case, let's make that all part of the "GCC_NO_STRINGOP_OVERFLOW"
logic.
For now, we just disable it for all gcc versions while the exact cause
is unknown.
Link: https://lore.kernel.org/all/202401161031.hjGJHMiJ-lkp@intel.com/T/
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If initrd_start cpio extraction fails, CONFIG_BLK_DEV_RAM triggers
fallback to initrd.image handling via populate_initrd_image().
The populate_initrd_image() call follows successful extraction of any
built-in cpio archive at __initramfs_start, but currently performs
built-in archive extraction a second time.
Prior to commit b2a74d5f9d ("initramfs: remove clean_rootfs"),
the second built-in initramfs unpack call was used to repopulate entries
removed by clean_rootfs(), but it's no longer necessary now the contents
of the previous extraction are retained.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Link: https://lore.kernel.org/r/20240111062240.9362-1-ddiss@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull driver core updates from Greg KH:
"Here are the set of driver core and kernfs changes for 6.8-rc1.
Nothing major in here this release cycle, just lots of small cleanups
and some tweaks on kernfs that in the very end, got reverted and will
come back in a safer way next release cycle.
Included in here are:
- more driver core 'const' cleanups and fixes
- fw_devlink=rpm is now the default behavior
- kernfs tiny changes to remove some string functions
- cpu handling in the driver core is updated to work better on many
systems that add topologies and cpus after booting
- other minor changes and cleanups
All of the cpu handling patches have been acked by the respective
maintainers and are coming in here in one series. Everything has been
in linux-next for a while with no reported issues"
* tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits)
Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock"
kernfs: convert kernfs_idr_lock to an irq safe raw spinlock
class: fix use-after-free in class_register()
PM: clk: make pm_clk_add_notifier() take a const pointer
EDAC: constantify the struct bus_type usage
kernfs: fix reference to renamed function
driver core: device.h: fix Excess kernel-doc description warning
driver core: class: fix Excess kernel-doc description warning
driver core: mark remaining local bus_type variables as const
driver core: container: make container_subsys const
driver core: bus: constantify subsys_register() calls
driver core: bus: make bus_sort_breadthfirst() take a const pointer
kernfs: d_obtain_alias(NULL) will do the right thing...
driver core: Better advertise dev_err_probe()
kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()
kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy()
kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy()
initramfs: Expose retained initrd as sysfs file
fs/kernfs/dir: obey S_ISGID
kernel/cgroup: use kernfs_create_dir_ns()
...
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem changes
for 6.8-rc1.
Other than lots of binder driver changes (as you can see by the merge
conflicts) included in here are:
- lots of iio driver updates and additions
- spmi driver updates
- eeprom driver updates
- firmware driver updates
- ocxl driver updates
- mhi driver updates
- w1 driver updates
- nvmem driver updates
- coresight driver updates
- platform driver remove callback api changes
- tags.sh script updates
- bus_type constant marking cleanups
- lots of other small driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (341 commits)
android: removed duplicate linux/errno
uio: Fix use-after-free in uio_open
drivers: soc: xilinx: add check for platform
firmware: xilinx: Export function to use in other module
scripts/tags.sh: remove find_sources
scripts/tags.sh: use -n to test archinclude
scripts/tags.sh: add local annotation
scripts/tags.sh: use more portable -path instead of -wholename
scripts/tags.sh: Update comment (addition of gtags)
firmware: zynqmp: Convert to platform remove callback returning void
firmware: turris-mox-rwtm: Convert to platform remove callback returning void
firmware: stratix10-svc: Convert to platform remove callback returning void
firmware: stratix10-rsu: Convert to platform remove callback returning void
firmware: raspberrypi: Convert to platform remove callback returning void
firmware: qemu_fw_cfg: Convert to platform remove callback returning void
firmware: mtk-adsp-ipc: Convert to platform remove callback returning void
firmware: imx-dsp: Convert to platform remove callback returning void
firmware: coreboot_table: Convert to platform remove callback returning void
firmware: arm_scpi: Convert to platform remove callback returning void
firmware: arm_scmi: Convert to platform remove callback returning void
...
Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
When the kernel command line option "retain_initrd" is set, we do not
free the initrd memory. However, we also don't expose it to anyone for
consumption. That leaves us in a weird situation where the only user of
this feature is ppc64 and arm64 specific kexec tooling.
To make it more generally useful, this patch adds a kobject to the
firmware object that contains the initrd context when "retain_initrd"
is set. That way, we can access the initrd any time after boot from
user space and for example hand it into kexec as --initrd parameter
if we want to reboot the same initrd. Or inspect it directly locally.
With this patch applied, there is a new /sys/firmware/initrd file when
the kernel was booted with an initrd and "retain_initrd" command line
option is set.
Signed-off-by: Alexander Graf <graf@amazon.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20231207235654.16622-1-graf@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ON_STACK.
IA-64 was removed with commit cf8e865810 ("arch: Remove Itanium (IA-64)
architecture"). Therefore remove support for ARCH_TASK_STRUCT_ON_STACK
as well.
Note: this also reveals a potential bug in powerpc code, which makes use of
__init_task_data without selecting ARCH_TASK_STRUCT_ON_STACK which makes
__init_task_data a no-op. This is broken since commit d11ed3ab31 ("Expand
INIT_TASK() in init/init_task.c and remove") from 2018 and needs to be
addressed separately.
Link: https://lkml.kernel.org/r/20231116133638.1636277-4-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Documentation/filesystems/ramfs-rootfs-initramfs.rst states:
If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
default. To force ramfs, add "rootfstype=ramfs" to the kernel command
line.
This currently does not work when root= is provided since then
saved_root_name contains a string and rootfstype= is ignored. Therefore,
ramfs is currently always chosen when root= is provided.
The current behavior for rootfs's filesystem is:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs
unspecified | tmpfs | tmpfs
unspecified | ramfs | ramfs
provided | ignored | ramfs
rootfstype= should be respected regardless whether root= is given,
as shown below:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs (as before)
unspecified | tmpfs | tmpfs (as before)
unspecified | ramfs | ramfs (as before)
provided | unspecified | ramfs (compatibility with before)
provided | tmpfs | tmpfs (new)
provided | ramfs | ramfs (new)
This table represents the new behavior.
Fixes: 6e19eded36 ("initmpfs: use initramfs if rootfstype= or root= specified")
Cc: <stable@vger.kernel.org>
Signed-off-by: Rob Landley <rob@landley.net>
Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/
Reviewed-and-Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull non-MM updates from Andrew Morton:
"As usual, lots of singleton and doubleton patches all over the tree
and there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- 'kdump: use generic functions to simplify crashkernel reservation
in arch', from Baoquan He. This is mainly cleanups and
consolidation of the 'crashkernel=' kernel parameter handling
- After much discussion, David Laight's 'minmax: Relax type checks in
min() and max()' is here. Hopefully reduces some typecasting and
the use of min_t() and max_t()
- A group of patches from Oleg Nesterov which clean up and slightly
fix our handling of reads from /proc/PID/task/... and which remove
task_struct.thread_group"
* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
scripts/gdb/vmalloc: disable on no-MMU
scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
.mailmap: add address mapping for Tomeu Vizoso
mailmap: update email address for Claudiu Beznea
tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
.mailmap: map Benjamin Poirier's address
scripts/gdb: add lx_current support for riscv
ocfs2: fix a spelling typo in comment
proc: test ProtectionKey in proc-empty-vm test
proc: fix proc-empty-vm test with vsyscall
fs/proc/base.c: remove unneeded semicolon
do_io_accounting: use sig->stats_lock
do_io_accounting: use __for_each_thread()
ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
ocfs2: fix a typo in a comment
scripts/show_delta: add __main__ judgement before main code
treewide: mark stuff as __ro_after_init
fs: ocfs2: check status values
proc: test /proc/${pid}/statm
compiler.h: move __is_constexpr() to compiler.h
...
Pull sysctl updates from Luis Chamberlain:
"To help make the move of sysctls out of kernel/sysctl.c not incur a
size penalty sysctl has been changed to allow us to not require the
sentinel, the final empty element on the sysctl array. Joel Granados
has been doing all this work. On the v6.6 kernel we got the major
infrastructure changes required to support this. For v6.7-rc1 we have
all arch/ and drivers/ modified to remove the sentinel. Both arch and
driver changes have been on linux-next for a bit less than a month. It
is worth re-iterating the value:
- this helps reduce the overall build time size of the kernel and run
time memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move
sysctls out from kernel/sysctl.c to their own files
For v6.8-rc1 expect removal of all the sentinels and also then the
unneeded check for procname == NULL.
The last two patches are fixes recently merged by Krister Johansen
which allow us again to use softlockup_panic early on boot. This used
to work but the alias work broke it. This is useful for folks who want
to detect softlockups super early rather than wait and spend money on
cloud solutions with nothing but an eventual hung kernel. Although
this hadn't gone through linux-next it's also a stable fix, so we
might as well roll through the fixes now"
* tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits)
watchdog: move softlockup_panic back to early_param
proc: sysctl: prevent aliased sysctls from getting passed to init
intel drm: Remove now superfluous sentinel element from ctl_table array
Drivers: hv: Remove now superfluous sentinel element from ctl_table array
raid: Remove now superfluous sentinel element from ctl_table array
fw loader: Remove the now superfluous sentinel element from ctl_table array
sgi-xp: Remove the now superfluous sentinel element from ctl_table array
vrf: Remove the now superfluous sentinel element from ctl_table array
char-misc: Remove the now superfluous sentinel element from ctl_table array
infiniband: Remove the now superfluous sentinel element from ctl_table array
macintosh: Remove the now superfluous sentinel element from ctl_table array
parport: Remove the now superfluous sentinel element from ctl_table array
scsi: Remove now superfluous sentinel element from ctl_table array
tty: Remove now superfluous sentinel element from ctl_table array
xen: Remove now superfluous sentinel element from ctl_table array
hpet: Remove now superfluous sentinel element from ctl_table array
c-sky: Remove now superfluous sentinel element from ctl_talbe array
powerpc: Remove now superfluous sentinel element from ctl_table arrays
riscv: Remove now superfluous sentinel element from ctl_table array
x86/vdso: Remove now superfluous sentinel element from ctl_table array
...
Pull ia64 removal and asm-generic updates from Arnd Bergmann:
- The ia64 architecture gets its well-earned retirement as planned,
now that there is one last (mostly) working release that will be
maintained as an LTS kernel.
- The architecture specific system call tables are updated for the
added map_shadow_stack() syscall and to remove references to the
long-gone sys_lookup_dcookie() syscall.
* tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
hexagon: Remove unusable symbols from the ptrace.h uapi
asm-generic: Fix spelling of architecture
arch: Reserve map_shadow_stack() syscall number for all architectures
syscalls: Cleanup references to sys_lookup_dcookie()
Documentation: Drop or replace remaining mentions of IA64
lib/raid6: Drop IA64 support
Documentation: Drop IA64 from feature descriptions
kernel: Drop IA64 support from sig_fault handlers
arch: Remove Itanium (IA-64) architecture
The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values. If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init. Fix by checking for the existence of aliased parameters in the
unknown boot parameter code. If an alias exists, don't return an error
or pass the value to init.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae2 ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Pull hardening updates from Kees Cook:
"One of the more voluminous set of changes is for adding the new
__counted_by annotation[1] to gain run-time bounds checking of
dynamically sized arrays with UBSan.
- Add LKDTM test for stuck CPUs (Mark Rutland)
- Improve LKDTM selftest behavior under UBSan (Ricardo Cañuelo)
- Refactor more 1-element arrays into flexible arrays (Gustavo A. R.
Silva)
- Analyze and replace strlcpy and strncpy uses (Justin Stitt, Azeem
Shaikh)
- Convert group_info.usage to refcount_t (Elena Reshetova)
- Add __counted_by annotations (Kees Cook, Gustavo A. R. Silva)
- Add Kconfig fragment for basic hardening options (Kees Cook, Lukas
Bulwahn)
- Fix randstruct GCC plugin performance mode to stay in groups (Kees
Cook)
- Fix strtomem() compile-time check for small sources (Kees Cook)"
* tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (56 commits)
hwmon: (acpi_power_meter) replace open-coded kmemdup_nul
reset: Annotate struct reset_control_array with __counted_by
kexec: Annotate struct crash_mem with __counted_by
virtio_console: Annotate struct port_buffer with __counted_by
ima: Add __counted_by for struct modsig and use struct_size()
MAINTAINERS: Include stackleak paths in hardening entry
string: Adjust strtomem() logic to allow for smaller sources
hardening: x86: drop reference to removed config AMD_IOMMU_V2
randstruct: Fix gcc-plugin performance mode to stay in group
mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
irqchip/imx-intmux: Annotate struct intmux_data with __counted_by
KVM: Annotate struct kvm_irq_routing_table with __counted_by
virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by
sparc: Annotate struct cpuinfo_tree with __counted_by
isdn: kcapi: replace deprecated strncpy with strscpy_pad
isdn: replace deprecated strncpy with strscpy
NFS/flexfiles: Annotate struct nfs4_ff_layout_segment with __counted_by
nfs41: Annotate struct nfs4_file_layout_dsaddr with __counted_by
...
Pull x86 hw mitigation updates from Borislav Petkov:
- A bunch of improvements, cleanups and fixlets to the SRSO mitigation
machinery and other, general cleanups to the hw mitigations code, by
Josh Poimboeuf
- Improve the return thunk detection by objtool as it is absolutely
important that the default return thunk is not used after returns
have been patched. Future work to detect and report this better is
pending
- Other misc cleanups and fixes
* tag 'x86_bugs_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/retpoline: Document some thunk handling aspects
x86/retpoline: Make sure there are no unconverted return thunks due to KCSAN
x86/callthunks: Delete unused "struct thunk_desc"
x86/vdso: Run objtool on vdso32-setup.o
objtool: Fix return thunk patching in retpolines
x86/srso: Remove unnecessary semicolon
x86/pti: Fix kernel warnings for pti= and nopti cmdline options
x86/calldepth: Rename __x86_return_skl() to call_depth_return_thunk()
x86/nospec: Refactor UNTRAIN_RET[_*]
x86/rethunk: Use SYM_CODE_START[_LOCAL]_NOALIGN macros
x86/srso: Disentangle rethunk-dependent options
x86/srso: Move retbleed IBPB check into existing 'has_microcode' code block
x86/bugs: Remove default case for fully switched enums
x86/srso: Remove 'pred_cmd' label
x86/srso: Unexport untraining functions
x86/srso: Improve i-cache locality for alias mitigation
x86/srso: Fix unret validation dependencies
x86/srso: Fix vulnerability reporting for missing microcode
x86/srso: Print mitigation for retbleed IBPB case
x86/srso: Print actual mitigation if requested mitigation isn't possible
...
Pull initial bcachefs updates from Kent Overstreet:
"Here's the bcachefs filesystem pull request.
One new patch since last week: the exportfs constants ended up
conflicting with other filesystems that are also getting added to the
global enum, so switched to new constants picked by Amir.
The only new non fs/bcachefs/ patch is the objtool patch that adds
bcachefs functions to the list of noreturns. The patch that exports
osq_lock() has been dropped for now, per Ingo"
* tag 'bcachefs-2023-10-30' of https://evilpiepirate.org/git/bcachefs: (2781 commits)
exportfs: Change bcachefs fid_type enum to avoid conflicts
bcachefs: Refactor memcpy into direct assignment
bcachefs: Fix drop_alloc_keys()
bcachefs: snapshot_create_lock
bcachefs: Fix snapshot skiplists during snapshot deletion
bcachefs: bch2_sb_field_get() refactoring
bcachefs: KEY_TYPE_error now counts towards i_sectors
bcachefs: Fix handling of unknown bkey types
bcachefs: Switch to unsafe_memcpy() in a few places
bcachefs: Use struct_size()
bcachefs: Correctly initialize new buckets on device resize
bcachefs: Fix another smatch complaint
bcachefs: Use strsep() in split_devs()
bcachefs: Add iops fields to bch_member
bcachefs: Rename bch_sb_field_members -> bch_sb_field_members_v1
bcachefs: New superblock section members_v2
bcachefs: Add new helper to retrieve bch_member from sb
bcachefs: bucket_lock() is now a sleepable lock
bcachefs: fix crc32c checksum merge byte order problem
bcachefs: Fix bch2_inode_delete_keys()
...
Enabling CONFIG_KCSAN leads to unconverted, default return thunks to
remain after patching.
As David Kaplan describes in his debugging of the issue, it is caused by
a couple of KCSAN-generated constructors which aren't processed by
objtool:
"When KCSAN is enabled, GCC generates lots of constructor functions
named _sub_I_00099_0 which call __tsan_init and then return. The
returns in these are generally annotated normally by objtool and fixed
up at runtime. But objtool runs on vmlinux.o and vmlinux.o does not
include a couple of object files that are in vmlinux, like
init/version-timestamp.o and .vmlinux.export.o, both of which contain
_sub_I_00099_0 functions. As a result, the returns in these functions
are not annotated, and the panic occurs when we call one of them in
do_ctors and it uses the default return thunk.
This difference can be seen by counting the number of these functions in the object files:
$ objdump -d vmlinux.o|grep -c "<_sub_I_00099_0>:"
2601
$ objdump -d vmlinux|grep -c "<_sub_I_00099_0>:"
2603
If these functions are only run during kernel boot, there is no
speculation concern."
Fix it by disabling KCSAN on version-timestamp.o and .vmlinux.export.o
so the extra functions don't get generated. KASAN and GCOV are already
disabled for those files.
[ bp: Massage commit message. ]
Closes: https://lore.kernel.org/lkml/20231016214810.GA3942238@dev-arch.thelio-3990X/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Marco Elver <elver@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20231017165946.v4i2d4exyqwqq3bx@treble
Given a wrong root device, current log may not give the pretty name
which is useful to locate root cause.
For example, there are 2 blk devs in a VM, /dev/vda which has 2 partitials
/dev/vda1 and /dev/vda2 and /dev/vdb which is blank. /dev/vda2 is the
right root dev. When set "root=/dev/vdb", we get error log:
[ 0.635575] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(254,16)
It's not straightforward to find out the root cause as there is lack of
the root devive name therefore hard for people to get those info from the
device number, in the example, (254,16).
It is more comprehensive way to hint the root cause if pretty name is
given here, like:
[ 0.559887] Kernel panic - not syncing: VFS: Unable to mount root fs on "/dev/vdb" or unknown-block(254,16)
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Message-Id: <20230907091025.3436878-1-jianyong.wu@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
There has been a long standing page cache coherence bug with direct IO.
This provides part of a mechanism to fix it, currently just used by
bcachefs but potentially worth promoting to the VFS.
Direct IO evicts the range of the pagecache being read or written to.
For reads, we need dirty pages to be written to disk, so that the read
doesn't return stale data. For writes, we need to evict that range of
the pagecache so that it's not stale after the write completes.
However, without a locking mechanism to prevent those pages from being
re-added to the pagecache - by a buffered read or page fault - page
cache inconsistency is still possible.
This isn't necessarily just an issue for userspace when they're playing
games; filesystems may hang arbitrary state off the pagecache, and so
page cache inconsistency may cause real filesystem bugs, depending on
the filesystem. This is less of an issue for iomap based filesystems,
but e.g. buffer heads caches disk block mappings (!) and attaches them
to the pagecache, and bcachefs attaches disk reservations to pagecache
pages.
This issue has been hard to fix, because
- we need to add a lock (henceforth called pagecache_add_lock), which
would be held for the duration of the direct IO
- page faults add pages to the page cache, thus need to take the same
lock
- dio -> gup -> page fault thus can deadlock
And we cannot enforce a lock ordering with this lock, since userspace
will be controlling the lock ordering (via the fd and buffer arguments
to direct IOs), so we need a different method of deadlock avoidance.
We need to tell the page fault handler that we're already holding a
pagecache_add_lock, and since plumbing it through the entire gup() path
would be highly impractical this adds a field to task_struct.
Then the full method is:
- in the dio path, when we first take the pagecache_add_lock, note the
mapping in the current task_struct
- in the page fault handler, if faults_disabled_mapping is set, we
check if it's the same mapping as the one we're taking a page fault
for, and if so return an error.
Then we check lock ordering: if there's a lock ordering violation and
trylock fails, we'll have to cycle the locks and return an error that
tells the DIO path to retry: faults_disabled_mapping is also used for
signalling "locks were dropped, please retry".
Also relevant to this patch: mapping->invalidate_lock.
mapping->invalidate_lock provides most of the required semantics - it's
used by truncate/fallocate to block pages being added to the pagecache.
However, since it's a rwsem, direct IOs would need to take the write
side in order to block page cache adds, and would then be exclusive with
each other - we'll need a new type of lock to pair with this approach.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Jan Kara <jack@suse.cz>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Andreas Grünbacher <andreas.gruenbacher@gmail.com>
The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.
None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.
While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.
There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.
So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.
[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
