linux-stable.git/include/linux, branch v5.4.243

PM: domains: Restore comment indentation for generic_pm_domain.child_links

2023-05-17T09:36:04+00:00

commit afb0367a80553e795e7ad055299096544454f3f6 upstream.

The rename of generic_pm_domain.slave_links to
generic_pm_domain.child_links accidentally dropped the TAB to align the
member's comment.  Re-add the lost TAB to restore indentation.

Fixes: 8d87ae48ced2dffd ("PM: domains: Fix up terminology with parent/child")
Signed-off-by: Geert Uytterhoeven 
[ rjw: Minor subject edit ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

printk: declare printk_deferred_{enter,safe}() in include/linux/printk.h

2023-05-17T09:36:04+00:00

commit 85e3e7fbbb720b9897fba9a99659e31cbd1c082e upstream.

[This patch implements subset of original commit 85e3e7fbbb72 ("printk:
remove NMI tracking") where commit 1007843a9190 ("mm/page_alloc: fix
potential deadlock on zonelist_update_seq seqlock") depends on, for
commit 3d36424b3b58 ("mm/page_alloc: fix race condition between
build_all_zonelists and page allocation") was backported to stable.]

All NMI contexts are handled the same as the safe context: store the
message and defer printing. There is no need to have special NMI
context tracking for this. Using in_nmi() is enough.

There are several parts of the kernel that are manually calling into
the printk NMI context tracking in order to cause general printk
deferred printing:

    arch/arm/kernel/smp.c
    arch/powerpc/kexec/crash.c
    kernel/trace/trace.c

For arm/kernel/smp.c and powerpc/kexec/crash.c, provide a new
function pair printk_deferred_enter/exit that explicitly achieves the
same objective.

For ftrace, remove the printk context manipulation completely. It was
added in commit 03fc7f9c99c1 ("printk/nmi: Prevent deadlock when
accessing the main log buffer in NMI"). The purpose was to enforce
storing messages directly into the ring buffer even in NMI context.
It really should have only modified the behavior in NMI context.
There is no need for a special behavior any longer. All messages are
always stored directly now. The console deferring is handled
transparently in vprintk().

Signed-off-by: John Ogness 
[pmladek@suse.com: Remove special handling in ftrace.c completely.
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20210715193359.25946-5-john.ogness@linutronix.de
[penguin-kernel: Copy only printk_deferred_{enter,safe}() definition ]
Signed-off-by: Tetsuo Handa 
Signed-off-by: Greg Kroah-Hartman

tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH

2023-05-17T09:36:04+00:00

If userspace races tcsetattr() with a write, the drained condition
might not be guaranteed by the kernel. There is a race window after
checking Tx is empty before tty_set_termios() takes termios_rwsem for
write. During that race window, more characters can be queued by a
racing writer.

Any ongoing transmission might produce garbage during HW's
->set_termios() call. The intent of TCSADRAIN/FLUSH seems to be
preventing such a character corruption. If those flags are set, take
tty's write lock to stop any writer before performing the lower layer
Tx empty check and wait for the pending characters to be sent (if any).

The initial wait for all-writers-done must be placed outside of tty's
write lock to avoid deadlock which makes it impossible to use
tty_wait_until_sent(). The write lock is retried if a racing write is
detected.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230317113318.31327-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
(cherry picked from commit 094fb49a2d0d6827c86d2e0840873e6db0c491d2)
Signed-off-by: Ilpo Järvinen 
Signed-off-by: Greg Kroah-Hartman

tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem

2023-05-17T09:35:57+00:00

[ Upstream commit 58d7668242647e661a20efe065519abd6454287e ]

For CONFIG_NO_HZ_FULL systems, the tick_do_timer_cpu cannot be offlined.
However, cpu_is_hotpluggable() still returns true for those CPUs. This causes
torture tests that do offlining to end up trying to offline this CPU causing
test failures. Such failure happens on all architectures.

Fix the repeated error messages thrown by this (even if the hotplug errors are
harmless) by asking the opinion of the nohz subsystem on whether the CPU can be
hotplugged.

[ Apply Frederic Weisbecker feedback on refactoring tick_nohz_cpu_down(). ]

For drivers/base/ portion:
Acked-by: Greg Kroah-Hartman 
Acked-by: Frederic Weisbecker 
Cc: Frederic Weisbecker 
Cc: "Paul E. McKenney" 
Cc: Zhouyi Zhou 
Cc: Will Deacon 
Cc: Marc Zyngier 
Cc: rcu 
Cc: stable@vger.kernel.org
Fixes: 2987557f52b9 ("driver-core/cpu: Expose hotpluggability to the rest of the kernel")
Signed-off-by: Paul E. McKenney 
Signed-off-by: Joel Fernandes (Google) 
Signed-off-by: Sasha Levin

nohz: Add TICK_DEP_BIT_RCU

2023-05-17T09:35:57+00:00

[ Upstream commit 01b4c39901e087ceebae2733857248de81476bd8 ]

If a nohz_full CPU is looping in the kernel, the scheduling-clock tick
might nevertheless remain disabled.  In !PREEMPT kernels, this can
prevent RCU's attempts to enlist the aid of that CPU's executions of
cond_resched(), which can in turn result in an arbitrarily delayed grace
period and thus an OOM.  RCU therefore needs a way to enable a holdout
nohz_full CPU's scheduler-clock interrupt.

This commit therefore provides a new TICK_DEP_BIT_RCU value which RCU can
pass to tick_dep_set_cpu() and friends to force on the scheduler-clock
interrupt for a specified CPU or task.  In some cases, rcutorture needs
to turn on the scheduler-clock tick, so this commit also exports the
relevant symbols to GPL-licensed modules.

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Paul E. McKenney 
Stable-dep-of: 58d766824264 ("tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem")
Signed-off-by: Sasha Levin

mailbox: zynqmp: Fix typo in IPI documentation

2023-05-17T09:35:55+00:00

commit 79963fbfc233759bd8a43462f120d15a1bd4f4fa upstream.

Xilinx IPI message buffers allows 32-byte data transfer.
Fix documentation that says 12 bytes

Fixes: 4981b82ba2ff ("mailbox: ZynqMP IPI mailbox controller")
Signed-off-by: Tanmay Shah 
Acked-by: Michal Simek 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230311012407.1292118-4-tanmay.shah@amd.com
Signed-off-by: Mathieu Poirier 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: remove the maximum number of retries in call_bind_status

2023-05-17T09:35:52+00:00

[ Upstream commit 691d0b782066a6eeeecbfceb7910a8f6184e6105 ]

Currently call_bind_status places a hard limit of 3 to the number of
retries on EACCES error. This limit was done to prevent NLM unlock
requests from being hang forever when the server keeps returning garbage.
However this change causes problem for cases when NLM service takes
longer than 9 seconds to register with the port mapper after a restart.

This patch removes this hard coded limit and let the RPC handles
the retry based on the standard hard/soft task semantics.

Fixes: 0b760113a3a1 ("NLM: Don't hang forever on NLM unlock requests")
Reported-by: Helen Chao 
Tested-by: Helen Chao 
Signed-off-by: Dai Ngo 
Reviewed-by: Jeff Layton 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

PM: domains: Fix up terminology with parent/child

2023-05-17T09:35:47+00:00

[ Upstream commit 8d87ae48ced2dffd5e7247d19eb4c88be6f1c6f1 ]

The genpd infrastructure uses the terms master/slave, but such uses have
no external exposures (not even in Documentation/driver-api/pm/*) and are
not mandated by nor associated with any external specifications. Change
the language used through-out to parent/child.

There was one possible exception in the debugfs node
"pm_genpd/pm_genpd_summary" but its path has no hits outside of the
kernel itself when performing a code search[1], and it seems even this
single usage has been non-functional since it was introduced due to a
typo in the Python ("apend" instead of correct "append"). Fix the typo
while we're at it.

Link: https://codesearch.debian.net/ # [1]
Signed-off-by: Kees Cook 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kieran Bingham 
Signed-off-by: Rafael J. Wysocki 
Stable-dep-of: f19c3c2959e4 ("scripts/gdb: bail early if there are no generic PD")
Signed-off-by: Sasha Levin

linux/vt_buffer.h: allow either builtin or modular for macros

2023-05-17T09:35:46+00:00

[ Upstream commit 2b76ffe81e32afd6d318dc4547e2ba8c46207b77 ]

Fix build errors on ARCH=alpha when CONFIG_MDA_CONSOLE=m.
This allows the ARCH macros to be the only ones defined.

In file included from ../drivers/video/console/mdacon.c:37:
../arch/alpha/include/asm/vga.h:17:40: error: expected identifier or '(' before 'volatile'
   17 | static inline void scr_writew(u16 val, volatile u16 *addr)
      |                                        ^~~~~~~~
../include/linux/vt_buffer.h:24:34: note: in definition of macro 'scr_writew'
   24 | #define scr_writew(val, addr) (*(addr) = (val))
      |                                  ^~~~
../include/linux/vt_buffer.h:24:40: error: expected ')' before '=' token
   24 | #define scr_writew(val, addr) (*(addr) = (val))
      |                                        ^
../arch/alpha/include/asm/vga.h:17:20: note: in expansion of macro 'scr_writew'
   17 | static inline void scr_writew(u16 val, volatile u16 *addr)
      |                    ^~~~~~~~~~
../arch/alpha/include/asm/vga.h:25:29: error: expected identifier or '(' before 'volatile'
   25 | static inline u16 scr_readw(volatile const u16 *addr)
      |                             ^~~~~~~~

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Randy Dunlap 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Link: https://lore.kernel.org/r/20230329021529.16188-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()

2023-05-17T09:35:46+00:00

[ Upstream commit cbe16f35bee6880becca6f20d2ebf6b457148552 ]

Many drivers don't want interrupts enabled automatically via request_irq().
So they are handling this issue by either way of the below two:

(1)
  irq_set_status_flags(irq, IRQ_NOAUTOEN);
  request_irq(dev, irq...);

(2)
  request_irq(dev, irq...);
  disable_irq(irq);

The code in the second way is silly and unsafe. In the small time gap
between request_irq() and disable_irq(), interrupts can still come.

The code in the first way is safe though it's subobtimal.

Add a new IRQF_NO_AUTOEN flag which can be handed in by drivers to
request_irq() and request_nmi(). It prevents the automatic enabling of the
requested interrupt/nmi in the same safe way as #1 above. With that the
various usage sites of #1 and #2 above can be simplified and corrected.

Signed-off-by: Barry Song 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Cc: dmitry.torokhov@gmail.com
Link: https://lore.kernel.org/r/20210302224916.13980-2-song.bao.hua@hisilicon.com
Stable-dep-of: 39db65a0a17b ("ASoC: es8316: Handle optional IRQ assignment")
Signed-off-by: Sasha Levin