v6.12-rt arm updates

v6.12-rt arm updates

[Daniel Wagner]

Hi,

I am about to update v6.12-rt and the arm section needs some updates.
Here is what I am going to do. Please let me know if there is something
wrong.

Thanks,
Daniel

###########################################################################
# ARM
###########################################################################
# https://lore.kernel.org/all/cover.1777964226.git.jan.kiszka@siemens.com/

# v6.12-stable material relevant for RT but no patches to drop from
# rt queue:
# 47c5d569d39d ("ARM: group is_permission_fault() with 
is_translation_fault()")
# d5e8be7bea8d ("ARM: allow __do_kernel_fault() to report execution of 
memory faults")
# 25ae6a5c473b ("ARM: fix hash_name() fault")
# fed889edca79 ("ARM: fix branch predictor hardening")

# landed in v6.12-stable, thus drop those
# (commit ids from v6.12-stable):
# 0001-arm-Disable-jump-label-on-PREEMPT_RT.patch
# 256d97d3587b ("ARM: 9459/1: Disable jump-label on PREEMPT_RT")

# arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch
# 1b645cd729ef ("ARM: 9461/1: Disable HIGHPTE on PREEMPT_RT kernels")

# Commits in upstream but not in v6.12-stable
ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
#  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")

0001-ARM-vfp-Provide-vfp_state_hold-for-VFP-locking.patch
0002-ARM-vfp-Use-vfp_state_hold-in-vfp_sync_hwstate.patch
0003-ARM-vfp-Use-vfp_state_hold-in-vfp_support_entry.patch
0004-ARM-vfp-Move-sending-signals-outside-of-vfp_state_ho.patch
#  f26bdbe1fa9f ("ARM: 9423/1: vfp: Provide vfp_state_hold() for VFP 
locking.")
   #  b54cdbad4a39 ("ARM: 9424/1: vfp: Use vfp_state_hold() in 
vfp_sync_hwstate().")
#  27035c23bad5 ("ARM: 9425/1: vfp: Use vfp_state_hold() in 
vfp_support_entry().")
#  c0b5195bad63 ("ARM: 9426/1: vfp: Move sending signals outside of 
vfp_state_hold()ed section.")

ARM__Allow_to_enable_RT.patch
#  c6e61c06d606 ("ARM: 9463/1: Allow to enable RT")

Re: v6.12-rt arm updates

[Daniel Wagner]

On 7/17/26 3:30 PM, Daniel Wagner wrote:
> ###########################################################################
> # ARM
> ###########################################################################

> # Commits in upstream but not in v6.12-stable
> ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
> #  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")

I am replacing the stable-rt patch with the upstream commit here.

Re: v6.12-rt arm updates

[bigeasy]

On 2026-07-17 13:30:15 [+0000], Daniel Wagner wrote:
> Hi,
Hi,

> I am about to update v6.12-rt and the arm section needs some updates.
> Here is what I am going to do. Please let me know if there is something
> wrong.

not sure how to read this below, I try my best.

> Thanks,
> Daniel
> 
> ###########################################################################
> # ARM
> ###########################################################################
> # https://lore.kernel.org/all/cover.1777964226.git.jan.kiszka@siemens.com/
> 
> # v6.12-stable material relevant for RT but no patches to drop from
> # rt queue:
> # 47c5d569d39d ("ARM: group is_permission_fault() with 
> is_translation_fault()")
> # d5e8be7bea8d ("ARM: allow __do_kernel_fault() to report execution of 
> memory faults")
> # 25ae6a5c473b ("ARM: fix hash_name() fault")
> # fed889edca79 ("ARM: fix branch predictor hardening")

Those few should have entered via -stable.

> # landed in v6.12-stable, thus drop those
> # (commit ids from v6.12-stable):
> # 0001-arm-Disable-jump-label-on-PREEMPT_RT.patch
> # 256d97d3587b ("ARM: 9459/1: Disable jump-label on PREEMPT_RT")
> 
> # arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch
> # 1b645cd729ef ("ARM: 9461/1: Disable HIGHPTE on PREEMPT_RT kernels")
> 
> # Commits in upstream but not in v6.12-stable
> ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
> #  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")

You should be able to drop a few of those and replace them with what I
have in v6.18
	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/?h=linux-6.18.y-rt-patches&id=73c8e8d7a75fcc8b9026385e64990f3d5ec8a40d

> 0001-ARM-vfp-Provide-vfp_state_hold-for-VFP-locking.patch
> 0002-ARM-vfp-Use-vfp_state_hold-in-vfp_sync_hwstate.patch
> 0003-ARM-vfp-Use-vfp_state_hold-in-vfp_support_entry.patch
> 0004-ARM-vfp-Move-sending-signals-outside-of-vfp_state_ho.patch
> #  f26bdbe1fa9f ("ARM: 9423/1: vfp: Provide vfp_state_hold() for VFP 
> locking.")
>    #  b54cdbad4a39 ("ARM: 9424/1: vfp: Use vfp_state_hold() in 
> vfp_sync_hwstate().")
> #  27035c23bad5 ("ARM: 9425/1: vfp: Use vfp_state_hold() in 
> vfp_support_entry().")
> #  c0b5195bad63 ("ARM: 9426/1: vfp: Move sending signals outside of 
> vfp_state_hold()ed section.")

And this needs to stay

> ARM__Allow_to_enable_RT.patch
> #  c6e61c06d606 ("ARM: 9463/1: Allow to enable RT")
> 

Sebastian

Re: v6.12-rt arm updates

[Daniel Wagner]

On 7/17/26 3:46 PM, bigeasy@linutronix.de wrote:
> not sure how to read this below, I try my best.

Yeah, sorry, it's a bit random notes.

>> # v6.12-stable material relevant for RT but no patches to drop from
>> # rt queue:
>> # 47c5d569d39d ("ARM: group is_permission_fault() with
>> is_translation_fault()")
>> # d5e8be7bea8d ("ARM: allow __do_kernel_fault() to report execution of
>> memory faults")
>> # 25ae6a5c473b ("ARM: fix hash_name() fault")
>> # fed889edca79 ("ARM: fix branch predictor hardening")
> 
> Those few should have entered via -stable.

Right, nothing to do here. I just mentioned them here, because they were 
mentioned as dependency in in Jan's backport RFC series.

>> # landed in v6.12-stable, thus drop those
>> # (commit ids from v6.12-stable):
>> # 0001-arm-Disable-jump-label-on-PREEMPT_RT.patch
>> # 256d97d3587b ("ARM: 9459/1: Disable jump-label on PREEMPT_RT")
>>
>> # arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch
>> # 1b645cd729ef ("ARM: 9461/1: Disable HIGHPTE on PREEMPT_RT kernels")

I've dropped those.

>> # Commits in upstream but not in v6.12-stable
>> ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
>> #  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")

I've replaced the downstream patch with the commit mentioned...
> You should be able to drop a few of those and replace them with what I
> have in v6.18
> 	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/?h=linux-6.18.y-rt-patches&id=73c8e8d7a75fcc8b9026385e64990f3d5ec8a40d	

... which is what you have done here as well. The main difference is 
that v6.12-stable ships 'ARM: 9459/1: Disable jump-label on PREEMPT_RT'

The resulting v6.12-rt queue is

0001-ARM-ensure-interrupts-are-enabled-in-__do_user_fault.patch
0001-ARM-vfp-Provide-vfp_state_hold-for-VFP-locking.patch
0002-ARM-vfp-Use-vfp_state_hold-in-vfp_sync_hwstate.patch
0003-ARM-vfp-Use-vfp_state_hold-in-vfp_support_entry.patch
0004-ARM-vfp-Move-sending-signals-outside-of-vfp_state_ho.patch
ARM__Allow_to_enable_RT.patch

Re: v6.12-rt arm updates

[bigeasy]

On 2026-07-17 13:54:58 [+0000], Daniel Wagner wrote:
> >> # Commits in upstream but not in v6.12-stable
> >> ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
> >> #  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")
> 
> I've replaced the downstream patch with the commit mentioned...
> > You should be able to drop a few of those and replace them with what I
> > have in v6.18
> > 	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/?h=linux-6.18.y-rt-patches&id=73c8e8d7a75fcc8b9026385e64990f3d5ec8a40d	
> 
> ... which is what you have done here as well. The main difference is 
> that v6.12-stable ships 'ARM: 9459/1: Disable jump-label on PREEMPT_RT'

It does? Not as of v6.12.95.

> The resulting v6.12-rt queue is
> 
> 0001-ARM-ensure-interrupts-are-enabled-in-__do_user_fault.patch

This looks like 59e4f3b45b96a ("ARM: ensure interrupts are enabled in __do_user_fault()")

Good.

> 0001-ARM-vfp-Provide-vfp_state_hold-for-VFP-locking.patch
> 0002-ARM-vfp-Use-vfp_state_hold-in-vfp_sync_hwstate.patch
> 0003-ARM-vfp-Use-vfp_state_hold-in-vfp_support_entry.patch
> 0004-ARM-vfp-Move-sending-signals-outside-of-vfp_state_ho.patch
> ARM__Allow_to_enable_RT.patch

Sebastian

Re: v6.12-rt arm updates

[Daniel Wagner]

On 7/17/26 4:03 PM, bigeasy@linutronix.de wrote:
> On 2026-07-17 13:54:58 [+0000], Daniel Wagner wrote:
>>>> # Commits in upstream but not in v6.12-stable
>>>> ARM__enable_irq_in_translation_section_permission_fault_handlers.patch
>>>> #  59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")
>>
>> I've replaced the downstream patch with the commit mentioned...
>>> You should be able to drop a few of those and replace them with what I
>>> have in v6.18
>>> 	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/?h=linux-6.18.y-rt-patches&id=73c8e8d7a75fcc8b9026385e64990f3d5ec8a40d
>>
>> ... which is what you have done here as well. The main difference is
>> that v6.12-stable ships 'ARM: 9459/1: Disable jump-label on PREEMPT_RT'
> 
> It does? Not as of v6.12.95.

You are right, I was looking at the wrong tree. I am adding it back.

>> The resulting v6.12-rt queue is
>>
>> 0001-ARM-ensure-interrupts-are-enabled-in-__do_user_fault.patch
> 
> This looks like 59e4f3b45b96a ("ARM: ensure interrupts are enabled in __do_user_fault()")

Correct.

So here my updated queue (the comment points to the upstream
version of the patch):

0001-ARM-ensure-interrupts-are-enabled-in-__do_user_fault.patch
# 59e4f3b45b96 ("ARM: ensure interrupts are enabled in __do_user_fault()")

0001-ARM-vfp-Provide-vfp_state_hold-for-VFP-locking.patch
0002-ARM-vfp-Use-vfp_state_hold-in-vfp_sync_hwstate.patch
0003-ARM-vfp-Use-vfp_state_hold-in-vfp_support_entry.patch
0004-ARM-vfp-Move-sending-signals-outside-of-vfp_state_ho.patch
#  f26bdbe1fa9f ("ARM: 9423/1: vfp: Provide vfp_state_hold() for VFP 
locking.")
#  b54cdbad4a39 ("ARM: 9424/1: vfp: Use vfp_state_hold() in 
vfp_sync_hwstate().")
#  27035c23bad5 ("ARM: 9425/1: vfp: Use vfp_state_hold() in 
vfp_support_entry().")
#  c0b5195bad63 ("ARM: 9426/1: vfp: Move sending signals outside of 
vfp_state_hold()ed section.")

0001-arm-Disable-jump-label-on-PREEMPT_RT.patch
# 56d97d3587b ("ARM: 9459/1: Disable jump-label on PREEMPT_RT")

ARM__Allow_to_enable_RT.patch
#  c6e61c06d606 ("ARM: 9463/1: Allow to enable RT")

Re: v6.12-rt arm updates

[bigeasy]

On 2026-07-17 14:17:54 [+0000], Daniel Wagner wrote:
> So here my updated queue (the comment points to the upstream
> version of the patch):

This looks okay. Your delta should be
	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/diff/?h=linux-6.18.y-rt&id=868deefc37dfbdfe93d760155e0c84f5f3363cc2&id2=90a16cd5d693a75843b766d0efa17f1bc0149931

Sebastian

Re: v6.12-rt arm updates

[Daniel Wagner]

On 7/17/26 4:22 PM, bigeasy@linutronix.de wrote:
> On 2026-07-17 14:17:54 [+0000], Daniel Wagner wrote:
>> So here my updated queue (the comment points to the upstream
>> version of the patch):
> 
> This looks okay. Your delta should be
> 	https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/diff/?h=linux-6.18.y-rt&id=868deefc37dfbdfe93d760155e0c84f5f3363cc2&id2=90a16cd5d693a75843b766d0efa17f1bc0149931
My diff looks a bit different, due to the backport of a bunch of arm 
cleanup patches. I've pushed the result to

   v6.12-rt-next
   v6.12-rt-patches-next

It all runs fine in my test setup. Any objections to release this?

Re: v6.12-rt arm updates

[bigeasy]

On 2026-07-21 13:06:24 [+0000], Daniel Wagner wrote:
> It all runs fine in my test setup. Any objections to release this?

No. Go ahead.

Sebastian