The kernel already knows at the time of interrupt allocation whether
affinity of an interrupt can be controlled by userspace or not.
It still creates all related procfs control files with read/write
permissions. That's inconsistent and non-intuitive for system
administrators and tools.
Therefore set the file permissions to read-only for such interrupts.
[ tglx: Massage change log, fixed UP build ]
Signed-off-by: Jeff Xie <jeff.xie@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240825131911.107119-1-jeff.xie@linux.dev
msleep() and msleep_interruptible() add a jiffie to the requested timeout.
This extra jiffie was introduced to ensure that the timeout will not happen
earlier than specified.
Since the rework of the timer wheel, the enqueue path already takes care of
this. So the extra jiffie added by msleep*() is pointless now.
Remove this extra jiffie in msleep() and msleep_interruptible().
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/all/20240829074133.4547-1-anna-maria@linutronix.de
In a few audit records, PIDs were being recorded with task_pid_nr()
instead of task_tgid_nr().
$ grep "task_pid_nr" kernel/audit*.c
audit.c: task_pid_nr(current),
auditfilter.c: pid = task_pid_nr(current);
auditsc.c: audit_log_format(ab, " pid=%u", task_pid_nr(current));
For single-thread applications, the process id (pid) and the thread
group id (tgid) are the same. However, on multi-thread applications,
task_pid_nr() returns the current thread id (user-space's TID), while
task_tgid_nr() returns the main thread id (user-space's PID). Since
the users are more interested in the process id (pid), rather than the
thread id (tid), this patch converts these callers to the correct method.
Link: https://github.com/linux-audit/audit-kernel/issues/126
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Ricardo Robaina <rrobaina@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Add a kvfree_rcu_barrier() function. It waits until all
in-flight pointers are freed over RCU machinery. It does
not wait any GP completion and it is within its right to
return immediately if there are no outstanding pointers.
This function is useful when there is a need to guarantee
that a memory is fully freed before destroying memory caches.
For example, during unloading a kernel module.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
amdgpu pr conconflicts due to patches cherry-picked to -fixes, I might
as well catch up with a backmerge and handle them all. Plus both misc
and intel maintainers asked for a backmerge anyway.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Kunkun Jiang reports that for a workload involving the simultaneous startup
of a large number of VMs (for a total of about 200 vcpus), a lot of CPU
time gets spent on spinning on the tmp_mask_lock that exists as a static
raw spinlock in irq_do_set_affinity(). This lock protects a global cpumask
(tmp_mask) that is used as a temporary variable to compute the resulting
affinity.
While this is triggered by KVM issuing a irq_set_affinity() call each time
a vcpu is about to execute, it is obvious that having a single global
resource is not very scalable.
Since a cpumask can be a fairly large structure on systems with a high core
count, a stack allocation is not really appropriate. Instead, turn the
global cpumask into a per-CPU variable, removing the need for locking
altogether as the code is executed with preemption and interrupts disabled.
[ tglx: Moved the per CPU variable declaration outside of the function ]
Reported-by: Kunkun Jiang <jiangkunkun@huawei.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kunkun Jiang <jiangkunkun@huawei.com>
Link: https://lore.kernel.org/all/20240826080618.3886694-1-maz@kernel.org
Link: https://lore.kernel.org/all/a7fc58e4-64c2-77fc-c1dc-f5eb78dbbb01@huawei.com
Pull vfs fixes from Christian Brauner:
"VFS:
- Ensure that backing files uses file->f_ops->splice_write() for
splice
netfs:
- Revert the removal of PG_private_2 from netfs_release_folio() as
cephfs still relies on this
- When AS_RELEASE_ALWAYS is set on a mapping the folio needs to
always be invalidated during truncation
- Fix losing untruncated data in a folio by making letting
netfs_release_folio() return false if the folio is dirty
- Fix trimming of streaming-write folios in netfs_inval_folio()
- Reset iterator before retrying a short read
- Fix interaction of streaming writes with zero-point tracker
afs:
- During truncation afs currently calls truncate_setsize() which sets
i_size, expands the pagecache and truncates it. The first two
operations aren't needed because they will have already been done.
So call truncate_pagecache() instead and skip the redundant parts
overlayfs:
- Fix checking of the number of allowed lower layers so 500 layers
can actually be used instead of just 499
- Add missing '\n' to pr_err() output
- Pass string to ovl_parse_layer() and thus allow it to be used for
Opt_lowerdir as well
pidfd:
- Revert blocking the creation of pidfds for kthread as apparently
userspace relies on this. Specifically, it breaks systemd during
shutdown
romfs:
- Fix romfs_read_folio() to use the correct offset with
folio_zero_tail()"
* tag 'vfs-6.11-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
netfs: Fix interaction of streaming writes with zero-point tracker
netfs: Fix missing iterator reset on retry of short read
netfs: Fix trimming of streaming-write folios in netfs_inval_folio()
netfs: Fix netfs_release_folio() to say no if folio dirty
afs: Fix post-setattr file edit to do truncation correctly
mm: Fix missing folio invalidation calls during truncation
ovl: ovl_parse_param_lowerdir: Add missed '\n' for pr_err
ovl: fix wrong lowerdir number check for parameter Opt_lowerdir
ovl: pass string to ovl_parse_layer()
backing-file: convert to using fops->splice_write
Revert "pidfd: prevent creation of pidfds for kthreads"
romfs: fix romfs_read_folio()
netfs, ceph: Partially revert "netfs: Replace PG_fscache by setting folio->private and marking dirty"
Previously, the mapped ring-buffer layout caused misalignment between
the meta-page and sub-buffers when the sub-buffer size was not a
multiple of PAGE_SIZE. This prevented hardware with larger TLB entries
from utilizing them effectively.
Add a padding with the zero-page between the meta-page and sub-buffers.
Also update the ring-buffer map_test to verify that padding.
Link: https://lore.kernel.org/20240628104611.1443542-1-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The text and data address is saved in the meta data so that it can be used
to know the delta of the text and data addresses of the last boot compared
to the text and data addresses of the current boot. The delta is used to
convert function pointer entries in the ring buffer to something that can
be used by kallsyms (note this only works for built-in functions).
But the saved addresses get reset on boot up. If the buffer is not used
and there's another reboot, then the saved text and data addresses will be
of the last boot and not that of the boot that created the content in the
ring buffer.
To get an idea of the issue:
# trace-cmd start -B boot_mapped -p function
# reboot
# trace-cmd show -B boot_mapped | tail
<...>-1 [000] d..1. 461.983243: native_apic_msr_write <-native_kick_ap
<...>-1 [000] d..1. 461.983244: __pfx_native_apic_msr_eoi <-native_kick_ap
<...>-1 [000] d..1. 461.983244: reserve_irq_vector_locked <-native_kick_ap
<...>-1 [000] d..1. 461.983262: branch_emulate_op <-native_kick_ap
<...>-1 [000] d..1. 461.983262: __ia32_sys_ia32_pread64 <-native_kick_ap
<...>-1 [000] d..1. 461.983263: native_kick_ap <-__smpboot_create_thread
<...>-1 [000] d..1. 461.983263: store_cache_disable <-native_kick_ap
<...>-1 [000] d..1. 461.983279: acpi_power_off_prepare <-native_kick_ap
<...>-1 [000] d..1. 461.983280: __pfx_acpi_ns_delete_node <-acpi_suspend_enter
<...>-1 [000] d..1. 461.983280: __pfx_acpi_os_release_lock <-acpi_suspend_enter
# reboot
# trace-cmd show -B boot_mapped |tail
<...>-1 [000] d..1. 461.983243: 0xffffffffa9669220 <-0xffffffffa965f3db
<...>-1 [000] d..1. 461.983244: 0xffffffffa96690f0 <-0xffffffffa965f3db
<...>-1 [000] d..1. 461.983244: 0xffffffffa9663fa0 <-0xffffffffa965f3db
<...>-1 [000] d..1. 461.983262: 0xffffffffa9672e80 <-0xffffffffa965f3e0
<...>-1 [000] d..1. 461.983262: 0xffffffffa962b940 <-0xffffffffa965f3ec
<...>-1 [000] d..1. 461.983263: 0xffffffffa965f540 <-0xffffffffa96e1362
<...>-1 [000] d..1. 461.983263: 0xffffffffa963c940 <-0xffffffffa965f55b
<...>-1 [000] d..1. 461.983279: 0xffffffffa9ee30c0 <-0xffffffffa965f59b
<...>-1 [000] d..1. 461.983280: 0xffffffffa9f16c10 <-0xffffffffa9ee3157
<...>-1 [000] d..1. 461.983280: 0xffffffffa9ee02e0 <-0xffffffffa9ee3157
By not updating the saved text and data addresses in the meta data at
every boot up and only updating them when the buffer is reset, it
allows multiple boots to see the same data.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20240815113629.0dc90af8@rorschach.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull cgroup fixes from Tejun Heo:
"Three patches addressing cpuset corner cases"
* tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Eliminate unncessary sched domains rebuilds in hotplug
cgroup/cpuset: Clear effective_xcpus on cpus_allowed clearing only if cpus.exclusive not set
cgroup/cpuset: fix panic caused by partcmd_update
Pull workqueue fixes from Tejun Heo:
"Nothing too interesting. One patch to remove spurious warning and
others to address static checker warnings"
* tag 'wq-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Correct declaration of cpu_pwq in struct workqueue_struct
workqueue: Fix spruious data race in __flush_work()
workqueue: Remove incorrect "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker
workqueue: Fix UBSAN 'subtraction overflow' error in shift_and_mask()
workqueue: doc: Fix function name, remove markers
This adds a kfunc wrapper around strncpy_from_user,
which can be called from sleepable BPF programs.
This matches the non-sleepable 'bpf_probe_read_user_str'
helper except it includes an additional 'flags'
param, which allows consumers to clear the entire
destination buffer on success or failure.
Signed-off-by: Jordan Rome <linux@jordanrome.com>
Link: https://lore.kernel.org/r/20240823195101.3621028-1-linux@jordanrome.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, users can only stash kptr into map values with bpf_kptr_xchg().
This patch further supports stashing kptr into local kptr by adding local
kptr as a valid destination type.
When stashing into local kptr, btf_record in program BTF is used instead
of btf_record in map to search for the btf_field of the local kptr.
The local kptr specific checks in check_reg_type() only apply when the
source argument of bpf_kptr_xchg() is local kptr. Therefore, we make the
scope of the check explicit as the destination now can also be local kptr.
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Link: https://lore.kernel.org/r/20240813212424.2871455-5-amery.hung@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ARG_PTR_TO_KPTR is currently only used by the bpf_kptr_xchg helper.
Although it limits reg types for that helper's first arg to
PTR_TO_MAP_VALUE, any arbitrary mapval won't do: further custom
verification logic ensures that the mapval reg being xchgd-into is
pointing to a kptr field. If this is not the case, it's not safe to xchg
into that reg's pointee.
Let's rename the bpf_arg_type to more accurately describe the fairly
specific expectations that this arg type encodes.
This is a nonfunctional change.
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Link: https://lore.kernel.org/r/20240813212424.2871455-4-amery.hung@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently btf_parse_fields is used in two places to create struct
btf_record's for structs: when looking at mapval type, and when looking
at any struct in program BTF. The former looks for kptr fields while the
latter does not. This patch modifies the btf_parse_fields call made when
looking at prog BTF struct types to search for kptrs as well.
Before this series there was no reason to search for kptrs in non-mapval
types: a referenced kptr needs some owner to guarantee resource cleanup,
and map values were the only owner that supported this. If a struct with
a kptr field were to have some non-kptr-aware owner, the kptr field
might not be properly cleaned up and result in resources leaking. Only
searching for kptr fields in mapval was a simple way to avoid this
problem.
In practice, though, searching for BPF_KPTR when populating
struct_meta_tab does not expose us to this risk, as struct_meta_tab is
only accessed through btf_find_struct_meta helper, and that helper is
only called in contexts where recognizing the kptr field is safe:
* PTR_TO_BTF_ID reg w/ MEM_ALLOC flag
* Such a reg is a local kptr and must be free'd via bpf_obj_drop,
which will correctly handle kptr field
* When handling specific kfuncs which either expect MEM_ALLOC input or
return MEM_ALLOC output (obj_{new,drop}, percpu_obj_{new,drop},
list+rbtree funcs, refcount_acquire)
* Will correctly handle kptr field for same reasons as above
* When looking at kptr pointee type
* Called by functions which implement "correct kptr resource
handling"
* In btf_check_and_fixup_fields
* Helper that ensures no ownership loops for lists and rbtrees,
doesn't care about kptr field existence
So we should be able to find BPF_KPTR fields in all prog BTF structs
without leaking resources.
Further patches in the series will build on this change to support
kptr_xchg into non-mapval local kptr. Without this change there would be
no kptr field found in such a type.
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Link: https://lore.kernel.org/r/20240813212424.2871455-3-amery.hung@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
btf_parse_kptr() and btf_record_free() do btf_get() and btf_put()
respectively when working on btf_record in program and map if there are
kptr fields. If the kptr is from program BTF, since both callers has
already tracked the life cycle of program BTF, it is safe to remove the
btf_get() and btf_put().
This change prevents memory leak of program BTF later when we start
searching for kptr fields when building btf_record for program. It can
happen when the btf fd is closed. The btf_put() corresponding to the
btf_get() in btf_parse_kptr() was supposed to be called by
btf_record_free() in btf_free_struct_meta_tab() in btf_free(). However,
it will never happen since the invocation of btf_free() depends on the
refcount of the btf to become 0 in the first place.
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Link: https://lore.kernel.org/r/20240813212424.2871455-2-amery.hung@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The timerslack_ns setting is used to specify how much the hardware
timers should be delayed, to potentially dispatch multiple timers in a
single interrupt. This is a performance optimization. Timers of
realtime tasks (having a realtime scheduling policy) should not be
delayed.
This logic was inconsitently applied to the hrtimers, leading to delays
of realtime tasks which used timed waits for events (e.g. condition
variables). Due to the downstream override of the slack for rt tasks,
the procfs reported incorrect (non-zero) timerslack_ns values.
This is changed by setting the timer_slack_ns task attribute to 0 for
all tasks with a rt policy. By that, downstream users do not need to
specially handle rt tasks (w.r.t. the slack), and the procfs entry
shows the correct value of "0". Setting non-zero slack values (either
via procfs or PR_SET_TIMERSLACK) on tasks with a rt policy is ignored,
as stated in "man 2 PR_SET_TIMERSLACK":
Timer slack is not applied to threads that are scheduled under a
real-time scheduling policy (see sched_setscheduler(2)).
The special handling of timerslack on rt tasks in downstream users
is removed as well.
Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240814121032.368444-2-felix.moessbauer@siemens.com
do_misc_fixups() relaces bpf_cast_to_kern_ctx() and bpf_rdonly_cast()
by a single instruction "r0 = r1". This follows bpf_fastcall contract.
This commit allows bpf_fastcall pattern rewrite for these two
functions in order to use them in bpf_fastcall selftests.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240822084112.3257995-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In case of malformed relocation record of kind BPF_CORE_TYPE_ID_LOCAL
referencing a non-existing BTF type, function bpf_core_calc_relo_insn
would cause a null pointer deference.
Fix this by adding a proper check upper in call stack, as malformed
relocation records could be passed from user space.
Simplest reproducer is a program:
r0 = 0
exit
With a single relocation record:
.insn_off = 0, /* patch first instruction */
.type_id = 100500, /* this type id does not exist */
.access_str_off = 6, /* offset of string "0" */
.kind = BPF_CORE_TYPE_ID_LOCAL,
See the link for original reproducer or next commit for a test case.
Fixes: 74753e1462 ("libbpf: Replace btf__type_by_id() with btf_type_by_id().")
Reported-by: Liu RuiTong <cnitlrt@gmail.com>
Closes: https://lore.kernel.org/bpf/CAK55_s6do7C+DVwbwY_7nKfUz0YLDoiA1v6X3Y9+p0sWzipFSA@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240822080124.2995724-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Directly call into dma-iommu just like we have been doing for dma-direct
for a while. This avoids the indirect call overhead for IOMMU ops and
removes the need to have DMA ops entirely for many common configurations.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Almost all instances of the dma_map_ops ->map_page()/map_sg() methods
implement ->unmap_page()/unmap_sg() too. The once instance which doesn't
dma_dummy_ops which is used to fail the DMA mapping and thus there won't
be any calls to ->unmap_page()/unmap_sg().
Remove the checks for ->unmap_page()/unmap_sg() and call them directly to
create an interface that is symmetrical to ->map_page()/map_sg().
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high
bit can not encode this limit.
Use a plain address for the DMA zone limit instead.
Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In dma_common_find_pages(), area->flags are compared directly with
VM_DMA_COHERENT. This works because VM_DMA_COHERENT is the only set
flag.
During development of a new feature (ASI [1]), a new VM flag is
introduced, and that flag can be injected into VM_DMA_COHERENT mappings
(among others). The presence of that flag caused
dma_common_find_pages() to return NULL for VM_DMA_COHERENT addresses,
leading to a lot of problems ending in crashing during boot. It took a
bit of time to figure this problem out.
It was a mistake to inject a VM flag to begin with, but it took a
significant amount of debugging to figure out the problem. Most users of
area->flags use bitmasking rather than equivalency to check for flags.
Update dma_common_find_pages() and dma_common_free_remap() to do the
same, which would have avoided the boot crashing. Instead, add a warning
in dma_common_find_pages() if any extra VM flags are set to catch such
problems more easily during development.
No functional change intended.
[1]https://lore.kernel.org/lkml/20240712-asi-rfc-24-v1-0-144b319a40d8@google.com/
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Since the register_ftrace_graph() assigns a new fgraph_ops to
fgraph_array before registring it by ftrace_startup_subops(), the new
fgraph_ops can be used in function_graph_enter().
In most cases, it is still OK because those fgraph_ops's hashtable is
already initialized by ftrace_set_filter*() etc.
But if a user registers a new fgraph_ops which does not initialize the
hash list, ftrace_ops_test() in function_graph_enter() causes a NULL
pointer dereference BUG because fgraph_ops->ops.func_hash is NULL.
This can be reproduced by the below commands because function profiler's
fgraph_ops does not initialize the hash list;
# cd /sys/kernel/tracing
# echo function_graph > current_tracer
# echo 1 > function_profile_enabled
To fix this problem, add a new fgraph_ops to fgraph_array after
ftrace_startup_subops(). Thus, until the new fgraph_ops is initialized,
we will see fgraph_stub on the corresponding fgraph_array entry.
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2
Fixes: c132be2c4f ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There are potentially useful cases where a specific iterator type might
need to be passed into some kfunc. So, in addition to existing
bpf_iter_<type>_{new,next,destroy}() kfuncs, allow to pass iterator
pointer to any kfunc.
We employ "__iter" naming suffix for arguments that are meant to accept
iterators. We also enforce that they accept PTR -> STRUCT btf_iter_<type>
type chain and point to a valid initialized on-the-stack iterator state.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240808232230.2848712-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Verifier enforces that all iterator structs are named `bpf_iter_<name>`
and that whenever iterator is passed to a kfunc it's passed as a valid PTR ->
STRUCT chain (with potentially const modifiers in between).
We'll need this check for upcoming changes, so instead of duplicating
the logic, extract it into a helper function.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240808232230.2848712-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
wq->lockdep_map is set only after __alloc_workqueue()
successfully returns. However, on its error path
__alloc_workqueue() may call destroy_workqueue() which
expects wq->lockdep_map to be already set, which results
in a null-ptr-deref in touch_wq_lockdep_map().
Add a simple NULL-check to touch_wq_lockdep_map().
Oops: general protection fault, probably for non-canonical address
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:__lock_acquire+0x81/0x7800
[..]
Call Trace:
<TASK>
? __die_body+0x66/0xb0
? die_addr+0xb2/0xe0
? exc_general_protection+0x300/0x470
? asm_exc_general_protection+0x22/0x30
? __lock_acquire+0x81/0x7800
? mark_lock+0x94/0x330
? __lock_acquire+0x12fd/0x7800
? __lock_acquire+0x3439/0x7800
lock_acquire+0x14c/0x3e0
? __flush_workqueue+0x167/0x13a0
? __init_swait_queue_head+0xaf/0x150
? __flush_workqueue+0x167/0x13a0
__flush_workqueue+0x17d/0x13a0
? __flush_workqueue+0x167/0x13a0
? lock_release+0x50f/0x830
? drain_workqueue+0x94/0x300
drain_workqueue+0xe3/0x300
destroy_workqueue+0xac/0xc40
? workqueue_sysfs_register+0x159/0x2f0
__alloc_workqueue+0x1506/0x1760
alloc_workqueue+0x61/0x150
...
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Mark emergency sections wherever multiple lines of
lock debugging output are generated. In an emergency
section, every printk() call will attempt to directly
flush to the consoles using the EMERGENCY priority.
Note that debug_show_all_locks() and
lockdep_print_held_locks() rely on their callers to
enter the emergency section. This is because these
functions can also be called in non-emergency
situations (such as sysrq).
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-36-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
Mark an emergency section beginning with oops_enter() until the
end of oops_exit(). In this section, every printk() call will
attempt to directly flush to the consoles using the EMERGENCY
priority.
The very end of oops_exit() performs a kmsg_dump(). This is not
included in the emergency section because it is another
flushing mechanism that should occur after the consoles have
flushed the oops messages.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-34-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
In emergency situations (something has gone wrong but the
system continues to operate), usually important information
(such as a backtrace) is generated via printk(). This
information should be pushed out to the consoles ASAP.
Add per-CPU emergency nesting tracking because an emergency
can arise while in an emergency situation.
Add functions to mark the beginning and end of emergency
sections where the urgent messages are generated.
Perform direct console flushing at the emergency priority if
the current CPU is in an emergency state and it is safe to do
so.
Note that the emergency state is not system-wide. While one CPU
is in an emergency state, another CPU may attempt to print
console messages at normal priority.
Also note that printk() already attempts to flush consoles in
the caller context for normal priority. However, follow-up
changes will introduce printing kthreads, in which case the
normal priority printk() calls will offload to the kthreads.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-32-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
There are many call sites where console flushing occur.
Depending on the system state and types of consoles, the flush
methods to use are different. A flush call site generally must
consider:
@have_boot_console
@have_nbcon_console
@have_legacy_console
@legacy_allow_panic_sync
is_printk_preferred()
and take into account the current CPU state:
NBCON_PRIO_NORMAL
NBCON_PRIO_EMERGENCY
NBCON_PRIO_PANIC
in order to decide if it should:
flush nbcon directly via atomic_write() callback
flush legacy directly via console_unlock
flush legacy via offload to irq_work
All of these call sites use their own logic to make this
decision, which is complicated and error prone. Especially
later when two more flush methods will be introduced:
flush nbcon via offload to kthread
flush legacy via offload to kthread
Introduce a new internal struct console_flush_type that specifies
which console flushing methods should be used in the context of
the caller.
Introduce a helper function to fill out console_flush_type to
be used for flushing call sites.
Replace the logic of all flushing call sites to use the new
helper.
This change standardizes behavior, leading to both fixes and
optimizations across various call sites. For instance, in
console_cpu_notify(), the new logic ensures that nbcon consoles
are flushed when they aren’t managed by the legacy loop.
Similarly, in console_flush_on_panic(), the system no longer
needs to flush nbcon consoles if none are present.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-31-john.ogness@linutronix.de
[pmladek@suse.com: Updated the commit message.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
If legacy and nbcon consoles are registered and the nbcon
consoles are allowed to flush (i.e. no boot consoles
registered), the legacy consoles will no longer perform
direct printing on the panic CPU until after the backtrace
has been stored. This will give the safe nbcon consoles a
chance to print the panic messages before allowing the
unsafe legacy consoles to print.
If no nbcon consoles are registered or they are not allowed
to flush because boot consoles are registered, there is no
change in behavior (i.e. legacy consoles will always attempt
to print from the printk() caller context).
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-30-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
