This reverts commit dad3fb67ca1cbef87ce700e83a55835e5921ce8a.
The commit converted kernfs_idr_lock to an IRQ-safe raw_spinlock because it
could be acquired while holding an rq lock through bpf_cgroup_from_id().
However, kernfs_idr_lock is held while doing GPF_NOWAIT allocations which
involves acquiring an non-IRQ-safe and non-raw lock leading to the following
lockdep warning:
=============================
[ BUG: Invalid wait context ]
6.7.0-rc5-kzm9g-00251-g655022a45b1c #578 Not tainted
-----------------------------
swapper/0/0 is trying to lock:
dfbcd488 (&c->lock){....}-{3:3}, at: local_lock_acquire+0x0/0xa4
other info that might help us debug this:
context-{5:5}
2 locks held by swapper/0/0:
#0: dfbc9c60 (lock){+.+.}-{3:3}, at: local_lock_acquire+0x0/0xa4
#1: c0c012a8 (kernfs_idr_lock){....}-{2:2}, at: __kernfs_new_node.constprop.0+0x68/0x258
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc5-kzm9g-00251-g655022a45b1c #578
Hardware name: Generic SH73A0 (Flattened Device Tree)
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x68/0x90
dump_stack_lvl from __lock_acquire+0x3cc/0x168c
__lock_acquire from lock_acquire+0x274/0x30c
lock_acquire from local_lock_acquire+0x28/0xa4
local_lock_acquire from ___slab_alloc+0x234/0x8a8
___slab_alloc from __slab_alloc.constprop.0+0x30/0x44
__slab_alloc.constprop.0 from kmem_cache_alloc+0x7c/0x148
kmem_cache_alloc from radix_tree_node_alloc.constprop.0+0x44/0xdc
radix_tree_node_alloc.constprop.0 from idr_get_free+0x110/0x2b8
idr_get_free from idr_alloc_u32+0x9c/0x108
idr_alloc_u32 from idr_alloc_cyclic+0x50/0xb8
idr_alloc_cyclic from __kernfs_new_node.constprop.0+0x88/0x258
__kernfs_new_node.constprop.0 from kernfs_create_root+0xbc/0x154
kernfs_create_root from sysfs_init+0x18/0x5c
sysfs_init from mnt_init+0xc4/0x220
mnt_init from vfs_caches_init+0x6c/0x88
vfs_caches_init from start_kernel+0x474/0x528
start_kernel from 0x0
Let's rever the commit. It's undesirable to spread out raw spinlock usage
anyway and the problem can be solved by protecting the lookup path with RCU
instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrea Righi <andrea.righi@canonical.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/CAMuHMdV=AKt+mwY7svEq5gFPx41LoSQZ_USME5_MEdWQze13ww@mail.gmail.com
Link: https://lore.kernel.org/r/20240109214828.252092-2-tj@kernel.org
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf_cgroup_from_id() is basically a wrapper to cgroup_get_from_id(),
that is relying on kernfs to determine the right cgroup associated to
the target id.
As a kfunc, it has the potential to be attached to any function through
BPF, particularly in contexts where certain locks are held.
However, kernfs is not using an irq safe spinlock for kernfs_idr_lock,
that means any kernfs function that is acquiring this lock can be
interrupted and potentially hit bpf_cgroup_from_id() in the process,
triggering a deadlock.
For example, it is really easy to trigger a lockdep splat between
kernfs_idr_lock and rq->_lock, attaching a small BPF program to
__set_cpus_allowed_ptr_locked() that just calls bpf_cgroup_from_id():
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.7.0-rc7-virtme #5 Not tainted
-----------------------------------------------------
repro/131 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffffb2dc4578 (kernfs_idr_lock){+.+.}-{2:2}, at: kernfs_find_and_get_node_by_id+0x1d/0x80
and this task is already holding:
ffff911cbecaf218 (&rq->__lock){-.-.}-{2:2}, at: task_rq_lock+0x50/0xc0
which would create a new lock dependency:
(&rq->__lock){-.-.}-{2:2} -> (kernfs_idr_lock){+.+.}-{2:2}
but this new dependency connects a HARDIRQ-irq-safe lock:
(&rq->__lock){-.-.}-{2:2}
... which became HARDIRQ-irq-safe at:
lock_acquire+0xbf/0x2b0
_raw_spin_lock_nested+0x2e/0x40
scheduler_tick+0x5d/0x170
update_process_times+0x9c/0xb0
tick_periodic+0x27/0xe0
tick_handle_periodic+0x24/0x70
__sysvec_apic_timer_interrupt+0x64/0x1a0
sysvec_apic_timer_interrupt+0x6f/0x80
asm_sysvec_apic_timer_interrupt+0x1a/0x20
memcpy+0xc/0x20
arch_dup_task_struct+0x15/0x30
copy_process+0x1ce/0x1eb0
kernel_clone+0xac/0x390
kernel_thread+0x6f/0xa0
kthreadd+0x199/0x230
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1b/0x30
to a HARDIRQ-irq-unsafe lock:
(kernfs_idr_lock){+.+.}-{2:2}
... which became HARDIRQ-irq-unsafe at:
...
lock_acquire+0xbf/0x2b0
_raw_spin_lock+0x30/0x40
__kernfs_new_node.isra.0+0x83/0x280
kernfs_create_root+0xf6/0x1d0
sysfs_init+0x1b/0x70
mnt_init+0xd9/0x2a0
vfs_caches_init+0xcf/0xe0
start_kernel+0x58a/0x6a0
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0xc5/0xe0
secondary_startup_64_no_verify+0x178/0x17b
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(kernfs_idr_lock);
local_irq_disable();
lock(&rq->__lock);
lock(kernfs_idr_lock);
<Interrupt>
lock(&rq->__lock);
*** DEADLOCK ***
Prevent this deadlock condition converting kernfs_idr_lock to a raw irq
safe spinlock.
The performance impact of this change should be negligible and it also
helps to prevent similar deadlock conditions with any other subsystems
that may depend on kernfs.
Fixes: 332ea1f697 ("bpf: Add bpf_cgroup_from_id() kfunc")
Cc: stable <stable@kernel.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231229074916.53547-1-andrea.righi@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock_class_key is still registered and can be found in
lock_keys_hash hlist after subsys_private is freed in error
handler path.A task who iterate over the lock_keys_hash
later may cause use-after-free.So fix that up and unregister
the lock_class_key before kfree(cp).
On our platform, a driver fails to kset_register because of
creating duplicate filename '/class/xxx'.With Kasan enabled,
it prints a invalid-access bug report.
KASAN bug report:
BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc
Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252
Pointer tag: [15], memory tag: [fe]
CPU: 7 PID: 252 Comm: modprobe Tainted: G W
6.6.0-mainline-maybe-dirty #1
Call trace:
dump_backtrace+0x1b0/0x1e4
show_stack+0x2c/0x40
dump_stack_lvl+0xac/0xe0
print_report+0x18c/0x4d8
kasan_report+0xe8/0x148
__hwasan_store8_noabort+0x88/0x98
lockdep_register_key+0x19c/0x1bc
class_register+0x94/0x1ec
init_module+0xbc/0xf48 [rfkill]
do_one_initcall+0x17c/0x72c
do_init_module+0x19c/0x3f8
...
Memory state around the buggy address:
ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a
ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe
>ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
^
ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03
As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access
not use-after-free here.In this case, modprobe is manipulating
the corrupted lock_keys_hash hlish where lock_class_key is already
freed before.
It's worth noting that this only can happen if lockdep is enabled,
which is not true for normal system.
Fixes: dcfbb67e48 ("driver core: class: use lock_class_key already present in struct subsys_private")
Cc: stable <stable@kernel.org>
Signed-off-by: Jing Xia <jing.xia@unisoc.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Link: https://lore.kernel.org/r/20231220024603.186078-1-jing.xia@unisoc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core wants to work with const struct bus_type, so there's no
reason that pm_clk_add_notifier() should not also do the same thing,
considering that it just passes the pointer off to the driver core which
is expecting a const *.
Cc: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023121922-triumph-exploit-f545@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In many places in the edac code, struct bus_type pointers are passed
around and then eventually sent to the driver core, which can handle a
constant pointer. So constantify all of the edac usage of these as well
because the data in them is never modified by the edac code either.
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: <linux-edac@vger.kernel.org>
Link: https://lore.kernel.org/r/2023121909-tribute-punctuate-4b22@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the @knode_class: line to prevent the kernel-doc warning:
include/linux/device.h:807: warning: Excess struct member 'knode_class' description in 'device'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20231223050532.13881-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the driver core can properly handle constant struct bus_type,
change the local driver core bus_type variables to be a constant
structure as well, placing them into read-only memory which can not be
modified at runtime.
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Len Brown <len.brown@intel.com>
Acked-by: William Breathitt Gray <william.gray@linaro.org>
Acked-by: Dave Ertman <david.m.ertman@intel.com>
Link: https://lore.kernel.org/r/2023121908-paver-follow-cc21@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the driver core can properly handle constant struct bus_type,
move the container_subsys variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023121919-chatter-grumbling-9ef3@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The functions subsys_register() and subsys_virtual_register() should be
taking a constant pointer to a struct bus_type, as they do not actually
modify anything in it, so fix up the function definitions to do so
properly.
This also changes the pointer type in struct subsys_interface to be
constant as well, as again, that's the proper signature of it.
Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/2023121908-grove-genetics-f8af@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For some reason, during the big "clean up the driver core for a const
struct bus_type" work, the bus_sort_breadthfirst() call was missed. Fix
this up by changing the type to be a const * as it should be.
Cc: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023121935-stinking-ditzy-fd5d@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Describing the usage of dev_err_probe() as being (only?) "deemed
acceptable" has a bad connotation. In fact dev_err_probe() fulfills
three tasks:
- handling of EPROBE_DEFER (even more than degrading to dev_dbg())
- symbolic output of the error code
- return err for compact error code paths
Advertise these better and claim the usage to be "fine" to get rid of
the bad connotation.
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231215174540.2438601-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
One of the last remaining users of strlcpy() in the kernel is
kernfs_path_from_node_locked(), which passes back the problematic "length
we _would_ have copied" return value to indicate truncation. Convert the
chain of all callers to use the negative return value (some of which
already doing this explicitly). All callers were already also checking
for negative return values, so the risk to missed checks looks very low.
In this analysis, it was found that cgroup1_release_agent() actually
didn't handle the "too large" condition, so this is technically also a
bug fix. :)
Here's the chain of callers, and resolution identifying each one as now
handling the correct return value:
kernfs_path_from_node_locked()
kernfs_path_from_node()
pr_cont_kernfs_path()
returns void
kernfs_path()
sysfs_warn_dup()
return value ignored
cgroup_path()
blkg_path()
bfq_bic_update_cgroup()
return value ignored
TRACE_IOCG_PATH()
return value ignored
TRACE_CGROUP_PATH()
return value ignored
perf_event_cgroup()
return value ignored
task_group_path()
return value ignored
damon_sysfs_memcg_path_eq()
return value ignored
get_mm_memcg_path()
return value ignored
lru_gen_seq_show()
return value ignored
cgroup_path_from_kernfs_id()
return value ignored
cgroup_show_path()
already converted "too large" error to negative value
cgroup_path_ns_locked()
cgroup_path_ns()
bpf_iter_cgroup_show_fdinfo()
return value ignored
cgroup1_release_agent()
wasn't checking "too large" error
proc_cgroup_show()
already converted "too large" to negative value
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <cgroups@vger.kernel.org>
Co-developed-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Link: https://lore.kernel.org/r/20231116192127.1558276-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231212211741.164376-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
strlcpy() reads the entire source buffer first. This read may exceed
the destination size limit. This is both inefficient and can lead
to linear read overflows if a source string is not NUL-terminated[1].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().
Nothing actually checks the return value coming from kernfs_name_locked(),
so this has no impact on error paths. The caller hierarchy is:
kernfs_name_locked()
kernfs_name()
pr_cont_kernfs_name()
return value ignored
cgroup_name()
current_css_set_cg_links_read()
return value ignored
print_page_owner_memcg()
return value ignored
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Link: https://lore.kernel.org/r/20231116192127.1558276-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231212211741.164376-2-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Handling of S_ISGID is usually done by inode_init_owner() in all other
filesystems, but kernfs doesn't use that function. In kernfs, struct
kernfs_node is the primary data structure, and struct inode is only
created from it on demand. Therefore, inode_init_owner() can't be
used and we need to imitate its behavior.
S_ISGID support is useful for the cgroup filesystem; it allows
subtrees managed by an unprivileged process to retain a certain owner
gid, which then enables sharing access to the subtree with another
unprivileged process.
--
v1 -> v2: minor coding style fix (comment)
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231208093310.297233-2-max.kellermann@ionos.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By passing the fsugid to kernfs_create_dir_ns(), we don't need
cgroup_kn_set_ugid() any longer. That function was added for exactly
this purpose by commit 49957f8e2a ("cgroup: newly created dirs and
files should be owned by the creator").
Eliminating this piece of duplicate code means we benefit from future
improvements to kernfs_create_dir_ns(); for example, both are lacking
S_ISGID support currently, which my next patch will add to
kernfs_create_dir_ns(). It cannot (easily) be added to
cgroup_kn_set_ugid() because we can't dereference struct kernfs_iattrs
from there.
--
v1 -> v2: 12-digit commit id
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231208093310.297233-1-max.kellermann@ionos.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For others to be able to pull from in a stable way.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'device_is_big_endian-6.8-rc1' into driver-core-next
Tag for the device_is_big_endian() addition to property.h
For others to be able to pull from in a stable way.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some users want to use the struct device pointer to see if the
device is big endian in terms of Open Firmware specifications,
i.e. if it has a "big-endian" property, or if the kernel was
compiled for BE *and* the device has a "native-endian" property.
Provide inline helper for the users.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231025184259.250588-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ending a boot log with
platform 3f202000.mmc: deferred probe pending
is already a nice hint about the problem. Sometimes there is a more
detailed error indicator available, add that to the output.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231122093332.274145-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fw_devlink=on has stabilized and is working correctly. Let's start using
device links created by fw_devlink to also enforce runtime PM ordering.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20231113220948.80089-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All three fwnode_property_get_reference_args() implemantations now allow
args argument to be NULL. Document this.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231109101010.1329587-4-sakari.ailus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fwnode_get_property_reference_args() may not be called with args argument
NULL and while OF already supports this. Add the missing NULL check.
The purpose is to be able to count the references.
Fixes: b06184acf7 ("software node: Add software_node_get_reference_args()")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231109101010.1329587-3-sakari.ailus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fwnode_get_property_reference_args() may not be called with args argument
NULL on ACPI, OF already supports this. Add the missing NULL checks and
document this.
The purpose is to be able to count the references.
Fixes: 977d5ad39f ("ACPI: Convert ACPI reference args to generic fwnode reference args")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231109101010.1329587-2-sakari.ailus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code registers the node as available in the node array
before initializing the accessor list. This makes it so that
anything which might access the accessor list as a result of
allocations will cause an undefined memory access.
In one example, an extension to access hmat data during interleave
caused this undefined access as a result of a bulk allocation
that occurs during node initialization but before the accessor
list is initialized.
Initialize the accessor list before making the node generally
available to the global system.
Fixes: 08d9dbe72b ("node: Link memory nodes to their compute nodes")
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Link: https://lore.kernel.org/r/20231030044239.971756-1-gregory.price@memverge.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert riscv to use the arch_cpu_is_hotpluggable() helper rather than
arch_register_cpu().
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com> # On HiFive Unmatched
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R4L-00Ct0d-To@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.
This allows topology_init() to be removed.
This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R4G-00Ct0M-PS@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert loongarch to use the arch_cpu_is_hotpluggable() helper rather
than arch_register_cpu(). Also remove the export as nothing should be
using arch_register_cpu() outside of the core kernel/acpi code.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R4B-00Ct0G-Kk@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch provides its own arch_unregister_cpu(). This clears the
hotpluggable flag, then unregisters the CPU.
It isn't necessary to clear the hotpluggable flag when unregistering
a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices
pointer, meaning cpu_is_hotpluggable() will return false, as
get_cpu_device() has returned NULL.
Remove arch_unregister_cpu() and use the __weak version.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R46-00Ct0A-GJ@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.
This allows topology_init() to be removed.
This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
This is a subtle change. Originally:
- on boot, topology_init() would have marked present CPUs that
io_master() is true for as hotplug-incapable.
- if a CPU is hotplugged that is an io_master(), it can later be
hot-unplugged.
The new behaviour is that any CPU that io_master() is true for will
now always be marked as hotplug-incapable, thus even if it was
hotplugged, it can no longer be hot-unplugged.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R41-00Ct04-Bg@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert x86 to use the arch_cpu_is_hotpluggable() helper rather than
arch_register_cpu().
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3w-00Cszy-6k@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the x86 version of arch_unregister_cpu() is the same as the weak
version, drop the x86 specific version.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3r-00Cszs-2R@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.
x86's struct cpus come from struct x86_cpu, which has no other members
or users. Remove this and use the version defined by common code.
This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
----
Changes since RFC:
* Fixed the second copy of arch_register_cpu() used for non-hotplug
Changes since RFC v2:
* Remove duplicate of the weak generic arch_register_cpu(), spotted
by Jonathan Cameron. Add note about initialisation order change.
Changes since RFC v3:
* Adapt to removal of EXPORT_SYMBOL()s
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3l-00Cszm-UA@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert arm64 to use the arch_cpu_is_hotpluggable() helper rather than
arch_register_cpu().
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3g-00Cszg-PP@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow ACPI's _STA value to hide CPUs that are present, but not
available to online right now due to VMM or firmware policy, the
register_cpu() call needs to be made by the ACPI machinery when ACPI
is in use. This allows it to hide CPUs that are unavailable from sysfs.
Switching to GENERIC_CPU_DEVICES is an intermediate step to allow all
five ACPI architectures to be modified at once.
Switch over to GENERIC_CPU_DEVICES, and provide an arch_register_cpu()
that populates the hotpluggable flag. arch_register_cpu() is also the
interface the ACPI machinery expects.
The struct cpu in struct cpuinfo_arm64 is never used directly, remove
it to use the one GENERIC_CPU_DEVICES provides.
This changes the CPUs visible in sysfs from possible to present, but
on arm64 smp_prepare_cpus() ensures these are the same.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3b-00Csza-Ku@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
loongarch, mips, parisc, riscv and sh all print a warning if
register_cpu() returns an error. Architectures that use
GENERIC_CPU_DEVICES call panic() instead.
Errors in this path indicate something is wrong with the firmware
description of the platform, but the kernel is able to keep running.
Downgrade this to a warning to make it easier to debug this issue.
This will allow architectures that switching over to GENERIC_CPU_DEVICES
to drop their warning, but keep the existing behaviour.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3W-00CszU-GM@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NUMA systems require the node descriptions to be ready before CPUs are
registered. This is so that the node symlinks can be created in sysfs.
Currently no NUMA platform uses GENERIC_CPU_DEVICES, meaning that CPUs
are registered by arch code, instead of cpu_dev_init().
Move cpu_dev_init() after node_dev_init() so that NUMA architectures
can use GENERIC_CPU_DEVICES.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3R-00CszO-C0@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The differences between architecture specific implementations of
arch_register_cpu() are down to whether the CPU is hotpluggable or not.
Rather than overriding the weak version of arch_register_cpu(), provide
a function that can be used to provide this detail instead.
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3M-00CszH-6r@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add arch_unregister_cpu() to allow the ACPI machinery to call
unregister_cpu(). This is enough for arm64, riscv and loongarch, but
needs to be overridden by x86 and ia64 who need to do more work.
CC: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3H-00CszC-2n@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Architectures often have extra per-cpu work that needs doing
before a CPU is registered, often to determine if a CPU is
hotpluggable.
To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move
the cpu_register() call into arch_register_cpu(), which is made __weak
so architectures with extra work can override it.
This aligns with the way x86, ia64 and loongarch register hotplug CPUs
when they become present.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3B-00Csz6-Uh@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Three of the five ACPI architectures create sysfs entries using
register_cpu() for present CPUs, whereas arm64, riscv and all
GENERIC_CPU_DEVICES do this for possible CPUs.
Registering a CPU is what causes them to show up in sysfs.
It makes very little sense to register all possible CPUs. Registering
a CPU is what triggers the udev notifications allowing user-space to
react to newly added CPUs.
To allow all five ACPI architectures to use GENERIC_CPU_DEVICES, change
it to use for_each_present_cpu().
Making the ACPI architectures use GENERIC_CPU_DEVICES is a pre-requisite
step to centralise their register_cpu() logic, before moving it into the
ACPI processor driver. When we add support for register CPUs from ACPI
in a later patch, we will avoid registering CPUs in this path.
Of the ACPI architectures that register possible CPUs, arm64 and riscv
do not support making possible CPUs present as they use the weak 'always
fails' version of arch_register_cpu().
Only two of the eight architectures that use GENERIC_CPU_DEVICES have a
distinction between present and possible CPUs.
The following architectures use GENERIC_CPU_DEVICES but are not SMP,
so possible == present:
* m68k
* microblaze
* nios2
The following architectures use GENERIC_CPU_DEVICES and consider
possible == present:
* csky: setup_smp()
* processor_probe() sets possible for all CPUs and present for all CPUs
except the boot cpu, which will have been done by
init/main.c::start_kernel().
um appears to be a subarchitecture of x86.
The remaining architecture using GENERIC_CPU_DEVICES are:
* openrisc and hexagon:
where smp_init_cpus() makes all CPUs < NR_CPUS possible,
whereas smp_prepare_cpus() only makes CPUs < setup_max_cpus present.
After this change, openrisc and hexagon systems that use the max_cpus
command line argument would not see the other CPUs present in sysfs.
This should not be a problem as these CPUs can't be brought online as
_cpu_up() checks cpu_present().
After this change, only CPUs which are present appear in sysfs.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R36-00Csz0-Px@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Neither arm64 nor riscv support physical hotadd of CPUs that were not
present at boot. For arm64 much of the platform description is in static
tables which do not have update methods. arm64 does support HOTPLUG_CPU,
which is backed by a firmware interface to turn CPUs on and off.
acpi_processor_hotadd_init() and acpi_processor_remove() are for adding
and removing CPUs that were not present at boot. arm64 systems that do this
are not supported as there is currently insufficient information in the
platform description. (e.g. did the GICR get removed too?)
arm64 currently relies on the MADT enabled flag check in map_gicc_mpidr()
to prevent CPUs that were not described as present at boot from being
added to the system. Similarly, riscv relies on the same check in
map_rintc_hartid(). Both architectures also rely on the weak 'always fails'
definitions of acpi_map_cpu() and arch_register_cpu().
Subsequent changes will redefine ACPI_HOTPLUG_CPU as making possible
CPUs present. Neither arm64 nor riscv support this.
Disable ACPI_HOTPLUG_CPU for arm64 and riscv by removing 'default y' and
selecting it on the other three ACPI architectures. This allows the weak
definitions of some symbols to be removed.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R31-00Csyt-Jq@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch_register_cpu() and arch_unregister_cpu() are not used by anything
that can be a module - they are used by drivers/base/cpu.c and
drivers/acpi/acpi_processor.c, neither of which can be a module.
Remove the exports.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R2w-00Csyn-E2@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch_register_cpu() and arch_unregister_cpu() are not used by anything
that can be a module - they are used by drivers/base/cpu.c and
drivers/acpi/acpi_processor.c, neither of which can be a module.
Remove the exports.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R2r-00Csyh-7B@rmk-PC.armlinux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
