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This reverts commit 3b5bbe798b2451820e74243b738268f51901e7d0.
Eric reported that systemd-shutdown gets broken by blocking the creating
of pidfds for kthreads as older versions seems to rely on being able to
create a pidfd for any process in /proc.
Reported-by: Eric Biggers <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>
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With ftrace boot-time selftest, kmemleak reported some memory leaks in
the new test case for function graph storage for multiple tracers.
unreferenced object 0xffff888005060080 (size 32):
comm "swapper/0", pid 1, jiffies 4294676440
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 20 10 06 05 80 88 ff ff ........ .......
54 0c 1e 81 ff ff ff ff 00 00 00 00 00 00 00 00 T...............
backtrace (crc 7c93416c):
[<000000000238ee6f>] __kmalloc_cache_noprof+0x11f/0x2a0
[<0000000033d2b6c5>] enter_record+0xe8/0x150
[<0000000054c38424>] match_records+0x1cd/0x230
[<00000000c775b63d>] ftrace_set_hash+0xff/0x380
[<000000007bf7208c>] ftrace_set_filter+0x70/0x90
[<00000000a5c08dda>] test_graph_storage_multi+0x2e/0xf0
[<000000006ba028ca>] trace_selftest_startup_function_graph+0x1e8/0x260
[<00000000a715d3eb>] run_tracer_selftest+0x111/0x190
[<00000000395cbf90>] register_tracer+0xdf/0x1f0
[<0000000093e67f7b>] do_one_initcall+0x141/0x3b0
[<00000000c591b682>] do_initcall_level+0x82/0xa0
[<000000004e4c6600>] do_initcalls+0x43/0x70
[<0000000034f3c4e4>] kernel_init_freeable+0x170/0x1f0
[<00000000c7a5dab2>] kernel_init+0x1a/0x1a0
[<00000000ea105947>] ret_from_fork+0x3a/0x50
[<00000000a1932e84>] ret_from_fork_asm+0x1a/0x30
...
This means filter hash allocated for the fixtures are not correctly
released after the test.
Free those hash lists after tests are done and split the loop for
initialize fixture and register fixture for rollback.
Fixes: dd120af2d5f8 ("ftrace: Add multiple fgraph storage selftest")
Cc: [email protected]
Link: https://lore.kernel.org/172411539857.28895.13119957560263401102.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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ftrace_startup_subops()
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 <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2
Fixes: c132be2c4fcc ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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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 <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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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 <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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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 <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Mark emergency sections wherever multiple lines of
rcu stall information are generated. In an emergency
section, every printk() call will attempt to directly
flush to the consoles using the EMERGENCY priority.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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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 <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Mark the full contents of __warn() as an emergency section. In
this section, every printk() call will attempt to directly
flush to the consoles using the EMERGENCY priority.
Co-developed-by: John Ogness <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Signed-off-by: Thomas Gleixner (Intel) <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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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 <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Signed-off-by: Thomas Gleixner (Intel) <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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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 <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[[email protected]: Updated the commit message.]
Signed-off-by: Petr Mladek <[email protected]>
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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 <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Add a global flag @have_nbcon_console to identify if any nbcon
consoles are registered. This will be used in follow-up commits
to preserve legacy behavior when no nbcon consoles are registered.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Currently the console lock is used to attempt legacy-type
printing even if there are no legacy or boot consoles registered.
If no such consoles are registered, the console lock does not
need to be taken.
Add tracking of legacy console registration and use it with
boot console tracking to avoid unnecessary code paths, i.e.
do not use the console lock if there are no boot consoles
and no legacy consoles.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Add nbcon_atomic_flush_unsafe() to flush all nbcon consoles
using the write_atomic() callback and allowing unsafe hostile
takeovers. Call this at the end of panic() as a final attempt
to flush any pending messages.
Note that legacy consoles use unsafe methods for flushing
from the beginning of panic (see bust_spinlocks()). Therefore,
systems using both legacy and nbcon consoles may still fail to
see panic messages due to unsafe legacy console usage.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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In console_flush_on_panic(), flush the nbcon consoles before
flushing legacy consoles. The legacy write() callbacks are not
fully safe when oops_in_progress is set.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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There may be new records that were added while a driver was
holding the nbcon context for non-printing purposes. These
new records must be flushed by the nbcon_device_release()
context because no other context will do it.
If boot consoles are registered, the legacy loop is used
(either direct or per irq_work) to handle the flushing.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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If printk has been explicitly deferred or is called from NMI
context, legacy console printing must be deferred to an irq_work
context. Introduce a helper function is_printk_legacy_deferred()
for a CPU to query if it must defer legacy console printing.
In follow-up commits this helper will be needed at other call
sites as well.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Allow nbcon consoles to print messages in the legacy printk()
caller context (printing via unlock) by integrating them into
console_flush_all(). The write_atomic() callback is used for
printing.
Provide nbcon_legacy_emit_next_record(), which acts as the
nbcon variant of console_emit_next_record(). Call this variant
within console_flush_all() for nbcon consoles. Since nbcon
consoles use their own @nbcon_seq variable to track the next
record to print, this also must be appropriately handled in
console_flush_all().
Note that the legacy printing logic uses @handover to detect
handovers for printing all consoles. For nbcon consoles,
handovers/takeovers occur on a per-console basis and thus do
not cause the console_flush_all() loop to abort.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Unfortunately it is not known if a boot console and a regular
(legacy or nbcon) console use the same hardware. For this reason
they must not be allowed to print simultaneously.
For legacy consoles this is not an issue because they are
already synchronized with the boot consoles using the console
lock. However nbcon consoles can be triggered separately.
Add a global flag @have_boot_console to identify if any boot
consoles are registered. This will be used in follow-up commits
to ensure that boot consoles and nbcon consoles cannot print
simultaneously.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Provide nbcon_atomic_flush_pending() to perform flushing of all
registered nbcon consoles using their write_atomic() callback.
Unlike console_flush_all(), nbcon_atomic_flush_pending() will
only flush up through the newest record at the time of the
call. This prevents a CPU from printing unbounded when other
CPUs are adding records. If new records are added while
flushing, it is expected that the dedicated printer threads
will print those records. If the printer thread is not
available (which is always the case at this point in the
rework), nbcon_atomic_flush_pending() _will_ flush all records
in the ringbuffer.
Unlike console_flush_all(), nbcon_atomic_flush_pending() will
fully flush one console before flushing the next. This helps to
guarantee that a block of pending records (such as a stack
trace in an emergency situation) can be printed atomically at
once before releasing console ownership.
nbcon_atomic_flush_pending() is safe in any context because it
uses write_atomic() and acquires with unsafe_takeover disabled.
Co-developed-by: John Ogness <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Signed-off-by: Thomas Gleixner (Intel) <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Add a helper function to use the current state of the CPU to
determine which priority to assign to the printing context.
The EMERGENCY priority handling is added in a follow-up commit.
It will use a per-CPU variable.
Note: nbcon_device_try_acquire(), which is used by console
drivers to acquire the nbcon console for non-printing
activities, is hard-coded to always use NORMAL priority.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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The caller of console_is_usable() usually needs @console->flags
for its own checks. Rather than having console_is_usable() read
its own copy, make the caller pass in the @flags. This also
ensures that the caller saw the same @flags value.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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The nbcon consoles use a different printing callback. For nbcon
consoles, check for the write_atomic() callback instead of
write().
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Move console_is_usable() as-is into internal.h so that it can
be used by nbcon printing functions as well.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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The headers kernel.h, serial_core.h, and console.h allow for the
definitions of many types and functions from other headers.
Rather than relying on these as proxy headers, explicitly
include all headers providing needed definitions. Also sort the
list alphabetically to be able to easily detect duplicates.
Suggested-by: Andy Shevchenko <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Provide functions nbcon_device_try_acquire() and
nbcon_device_release() which will try to acquire the nbcon
console ownership with NBCON_PRIO_NORMAL and mark it unsafe for
handover/takeover.
These functions are to be used together with the device-specific
locking when performing non-printing activities on the console
device. They will allow synchronization against the
atomic_write() callback which will be serialized, for higher
priority contexts, only by acquiring the console context
ownership.
Pitfalls:
The API requires to be called in a context with migration
disabled because it uses per-CPU variables internally.
The context is set unsafe for a takeover all the time. It
guarantees full serialization against any atomic_write() caller
except for the final flush in panic() which might try an unsafe
takeover.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Console drivers typically have to deal with access to the
hardware via user input/output (such as an interactive login
shell) and output of kernel messages via printk() calls.
They use some classic driver-specific locking mechanism in most
situations. But console->write_atomic() callbacks, used by nbcon
consoles, are synchronized only by acquiring the console
context.
The synchronization via the console context ownership is possible
only when the console driver is registered. It is when a
particular device driver is connected with a particular console
driver.
The two synchronization mechanisms must be synchronized between
each other. It is tricky because the console context ownership
is quite special. It might be taken over by a higher priority
context. Also CPU migration must be disabled. The most tricky
part is to (dis)connect these two mechanisms during the console
(un)registration.
Use the driver-specific locking callbacks: device_lock(),
device_unlock(). They allow taking the device-specific lock
while the device is being (un)registered by the related console
driver.
For example, these callbacks lock/unlock the port lock for
serial port drivers.
Note that the driver-specific locking is only needed during
(un)register if it is an nbcon console with the write_atomic()
callback implemented. If write_atomic() is not implemented, the
driver should never attempt to access the hardware without
first acquiring its driver-specific lock.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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The return value of write_atomic() does not provide any useful
information. On the contrary, it makes things more complicated
for the caller to appropriately deal with the information.
Change write_atomic() to not have a return value. If the
message did not get printed due to loss of ownership, the
caller will notice this on its own. If ownership was not lost,
it will be assumed that the driver successfully printed the
message and the sequence number for that console will be
incremented.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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The functions nbcon_owner_matches() and nbcon_waiter_matches()
use a minimal set of data to determine if a context matches.
The existing kerneldoc and comments were not clear enough and
caused the printk folks to re-prove that the functions are
indeed reliable in all cases.
Update and expand the explanations so that it is clear that the
implementations are sufficient for all cases.
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Add validation that printk_deferred_enter()/_exit() are called in
non-migration contexts.
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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If a non-boot console is registering and boot consoles exist,
the consoles are flushed before being unregistered. This allows
the non-boot console to continue where the boot console left
off.
If for whatever reason flushing fails, the lowest seq found from
any of the enabled boot consoles is used. Until now con->seq was
checked. However, if it is an nbcon boot console, the function
nbcon_seq_read() must be used to read seq because con->seq is
not updated for nbcon consoles.
Check if it is an nbcon boot console and if so call
nbcon_seq_read() to read seq.
Also, avoid usage of con->seq as temporary storage of the
starting record. Instead, rename console_init_seq() to
get_init_console_seq() and just return the value. For nbcon
consoles set the sequence via nbcon_seq_force(), for legacy
consoles set con->seq.
The cleaned design should make sure that the value stays and is
set before the console is added to the console list. It also
unifies the sequence number initialization for legacy and nbcon
consoles.
Reviewed-by: John Ogness <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Rather than splitting the nbcon allocation and initialization into
two pieces, perform all initialization in nbcon_alloc(). Later,
the initial sequence is calculated and can be explicitly set using
nbcon_seq_force(). This removes the need for the strong rules of
nbcon_init() that even included a BUG_ON().
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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kernel/printk/printk.c:284:5: sparse: sparse: context imbalance in
'console_srcu_read_lock' - wrong count at exit
include/linux/srcu.h:301:9: sparse: sparse: context imbalance in
'console_srcu_read_unlock' - unexpected unlock
Fixes: 6c4afa79147e ("printk: Prepare for SRCU console list protection")
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
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Calling va_start / va_end multiple times is undefined and causes
problems with certain compiler / platforms.
Change alloc_ordered_workqueue_lockdep_map to a macro and updated
__alloc_workqueue to take a va_list argument.
Cc: Sergey Senozhatsky <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Signed-off-by: Matthew Brost <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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Since dequeue_task() allowed to fail, there is a compile error:
kernel/sched/ext.c:3630:19: error: initialization of ‘bool (*)(struct rq*, struct task_struct *, int)’ {aka ‘_Bool (*)(struct rq *, struct task_struct *, int)’} from incompatible pointer type ‘void (*)(struct rq*, struct task_struct *, int)’
3630 | .dequeue_task = dequeue_task_scx,
| ^~~~~~~~~~~~~~~~
Allow dequeue_task_scx to fail too.
Fixes: 863ccdbb918a ("sched: Allow sched_class::dequeue_task() to fail")
Signed-off-by: Yipeng Zou <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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To receive 863ccdbb918a ("sched: Allow sched_class::dequeue_task() to fail")
which makes sched_class.dequeue_task() return bool instead of void. This
leads to compile breakage and will be fixed by a follow-up patch.
Signed-off-by: Tejun Heo <[email protected]>
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use_parent_ecpus is used to track whether the children are using the
parent's effective_cpus. When a parent's effective_cpus is changed
due to changes in a child partition's effective_xcpus, any child
using parent'effective_cpus must call update_cpumasks_hier. However,
if a child is not a valid partition, it is sufficient to determine
whether to call update_cpumasks_hier based on whether the child's
effective_cpus is going to change. To make the code more succinct,
it is suggested to remove use_parent_ecpus.
Signed-off-by: Chen Ridong <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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Both fetch_xcpus and user_xcpus functions are used to retrieve the value
of exclusive_cpus. If exclusive_cpus is not set, cpus_allowed is the
implicit value used as exclusive in a local partition. I can not imagine
a scenario where effective_xcpus is not empty when exclusive_cpus is
empty. Therefore, I suggest removing the fetch_xcpus function.
Signed-off-by: Chen Ridong <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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When enable a remote partition, I found that:
cd /sys/fs/cgroup/
mkdir test
mkdir test/test1
echo +cpuset > cgroup.subtree_control
echo +cpuset > test/cgroup.subtree_control
echo 3 > test/test1/cpuset.cpus
echo root > test/test1/cpuset.cpus.partition
cat test/test1/cpuset.cpus.partition
root invalid (Parent is not a partition root)
The parent of a remote partition could not be a root. This is due to the
emtpy effective_xcpus. It would be better to prompt the message "invalid
cpu list in cpuset.cpus.exclusive".
Signed-off-by: Chen Ridong <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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When soft interrupt actions are called, they are passed a pointer to the
struct softirq action which contains the action's function pointer.
This pointer isn't useful, as the action callback already knows what
function it is. And since each callback handles a specific soft interrupt,
the callback also knows which soft interrupt number is running.
No soft interrupt action callback actually uses this parameter, so remove
it from the function pointer signature. This clarifies that soft interrupt
actions are global routines and makes it slightly cheaper to call them.
Signed-off-by: Caleb Sander Mateos <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Jens Axboe <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
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The unification of irq_domain_create_legacy() missed the fact that
interrupts must be associated even when the Linux interrupt number provided
in the first_irq argument is 0.
This breaks all call sites of irq_domain_create_legacy() which supply 0 as
the first_irq argument.
Enforce the association for legacy domains in __irq_domain_instantiate() to
cure this.
[ tglx: Massaged it slightly. ]
Fixes: 70114e7f7585 ("irqdomain: Simplify simple and legacy domain creation")
Reported-by: Jiaxun Yang <[email protected]>
Signed-off-by Matti Vaittinen <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Jiaxun Yang <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
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iounmap() on x86 occasionally fails to unmap because the provided valid
ioremap address is not below high_memory. It turned out that this
happens due to KASLR.
KASLR uses the full address space between PAGE_OFFSET and vaddr_end to
randomize the starting points of the direct map, vmalloc and vmemmap
regions. It thereby limits the size of the direct map by using the
installed memory size plus an extra configurable margin for hot-plug
memory. This limitation is done to gain more randomization space
because otherwise only the holes between the direct map, vmalloc,
vmemmap and vaddr_end would be usable for randomizing.
The limited direct map size is not exposed to the rest of the kernel, so
the memory hot-plug and resource management related code paths still
operate under the assumption that the available address space can be
determined with MAX_PHYSMEM_BITS.
request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1
downwards. That means the first allocation happens past the end of the
direct map and if unlucky this address is in the vmalloc space, which
causes high_memory to become greater than VMALLOC_START and consequently
causes iounmap() to fail for valid ioremap addresses.
MAX_PHYSMEM_BITS cannot be changed for that because the randomization
does not align with address bit boundaries and there are other places
which actually require to know the maximum number of address bits. All
remaining usage sites of MAX_PHYSMEM_BITS have been analyzed and found
to be correct.
Cure this by exposing the end of the direct map via PHYSMEM_END and use
that for the memory hot-plug and resource management related places
instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END
maps to a variable which is initialized by the KASLR initialization and
otherwise it is based on MAX_PHYSMEM_BITS as before.
To prevent future hickups add a check into add_pages() to catch callers
trying to add memory above PHYSMEM_END.
Fixes: 0483e1fa6e09 ("x86/mm: Implement ASLR for kernel memory regions")
Reported-by: Max Ramanouski <[email protected]>
Reported-by: Alistair Popple <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-By: Max Ramanouski <[email protected]>
Tested-by: Alistair Popple <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/all/87ed6soy3z.ffs@tglx
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The helper bpf_current_task_under_cgroup() currently is only allowed for
tracing programs, allow its usage also in the BPF_CGROUP_* program types.
Move the code from kernel/trace/bpf_trace.c to kernel/bpf/helpers.c,
so it compiles also without CONFIG_BPF_EVENTS.
This will be used in systemd-networkd to monitor the sysctl writes,
and filter it's own writes from others:
https://github.com/systemd/systemd/pull/32212
Signed-off-by: Matteo Croce <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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These kfuncs are enabled even in BPF_PROG_TYPE_TRACING, so they
should be safe also in BPF_CGROUP_* programs.
Since all BPF_CGROUP_* programs share the same hook,
call register_btf_kfunc_id_set() only once.
In enum btf_kfunc_hook, rename BTF_KFUNC_HOOK_CGROUP_SKB to a more
generic BTF_KFUNC_HOOK_CGROUP, since it's used for all the cgroup
related program types.
Signed-off-by: Matteo Croce <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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The comment in cgroup_file_write is missing some interfaces, such as
'cgroup.threads'. All delegatable files are listed in
'/sys/kernel/cgroup/delegate', so update the comment in cgroup_file_write.
Besides, add a statement that files outside the namespace shouldn't be
visible from inside the delegated namespace.
tj: Reflowed text for consistency.
Signed-off-by: Chen Ridong <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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The MODULE_SIG_<type> config choice has an inconsistent prompt styled as
a question and lengthy option names.
Simplify the prompt and option names to be consistent with other module
options.
Signed-off-by: Petr Pavlu <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
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The kernel configuration allows specifying a module compression mode. If
one is selected then each module gets compressed during
'make modules_install' and additionally one can also enable support for
a respective direct in-kernel decompression support. This means that the
decompression support cannot be enabled without the automatic compression.
Some distributions, such as the (open)SUSE family, use a signer service for
modules. A build runs on a worker machine but signing is done by a separate
locked-down server that is in possession of the signing key. The build
invokes 'make modules_install' to create a modules tree, collects
information about the modules, asks the signer service for their signature,
appends each signature to the respective module and compresses all modules.
When using this arrangment, the 'make modules_install' step produces
unsigned+uncompressed modules and the distribution's own build recipe takes
care of signing and compression later.
The signing support can be currently enabled without automatically signing
modules during 'make modules_install'. However, the in-kernel decompression
support can be selected only after first enabling automatic compression
during this step.
To allow only enabling the in-kernel decompression support without the
automatic compression during 'make modules_install', separate the
compression options similarly to the signing options, as follows:
> Enable loadable module support
[*] Module compression
Module compression type (GZIP) --->
[*] Automatically compress all modules
[ ] Support in-kernel module decompression
* "Module compression" (MODULE_COMPRESS) is a new main switch for the
compression/decompression support. It replaces MODULE_COMPRESS_NONE.
* "Module compression type" (MODULE_COMPRESS_<type>) chooses the
compression type, one of GZ, XZ, ZSTD.
* "Automatically compress all modules" (MODULE_COMPRESS_ALL) is a new
option to enable module compression during 'make modules_install'. It
defaults to Y.
* "Support in-kernel module decompression" (MODULE_DECOMPRESS) enables
in-kernel decompression.
Signed-off-by: Petr Pavlu <[email protected]>
Acked-by: Masahiro Yamada <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk fix from Petr Mladek:
- Do not block printk on non-panic CPUs when they are dumping
backtraces
* tag 'printk-for-6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk/panic: Allow cpu backtraces to be written into ringbuffer during panic
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