2022-08-16 16:50:29

by Conor Dooley

Subject: Re: [PATCH] riscv: Ensure isa-ext static keys are writable

On 16/08/2022 17:30, Andrew Jones wrote:
> riscv_isa_ext_keys[] is an array of static keys used in the unified
> ISA extension framework. The keys added to this array may be used
> anywhere, including in modules. Ensure the keys remain writable by
> placing them in the data section.
>
> The need to change riscv_isa_ext_keys[]'s section was found when the
> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> add Zihintpause support") adds a static branch check for a newly
> added isa-ext key to cpu_relax(), which kvm uses.
>
> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")

Hey Drew,
How about adding:

Reported-by: Ron Economos <[email protected]>
Reported-by: Anup Patel <[email protected]>
Reported-by: Conor Dooley <[email protected]>

Thanks,
Conor.

> Signed-off-by: Andrew Jones <[email protected]>
> ---
> arch/riscv/kernel/cpufeature.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 553d755483ed..3b5583db9d80 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> /**

2022-08-16 16:58:36

by Andrew Jones

Subject: Re: [PATCH] riscv: Ensure isa-ext static keys are writable

On Tue, Aug 16, 2022 at 04:36:55PM +0000, [email protected] wrote:
> On 16/08/2022 17:30, Andrew Jones wrote:
> > riscv_isa_ext_keys[] is an array of static keys used in the unified
> > ISA extension framework. The keys added to this array may be used
> > anywhere, including in modules. Ensure the keys remain writable by
> > placing them in the data section.
> >
> > The need to change riscv_isa_ext_keys[]'s section was found when the
> > kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> > add Zihintpause support") adds a static branch check for a newly
> > added isa-ext key to cpu_relax(), which kvm uses.
> >
> > Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
>
> Hey Drew,
> How about adding:
>
> Reported-by: Ron Economos <[email protected]>
> Reported-by: Anup Patel <[email protected]>
> Reported-by: Conor Dooley <[email protected]>

Sure, should I repost or can those be picked up when/if the patch is
picked up?

Thanks,
drew

>
> Thanks,
> Conor.
>
> > Signed-off-by: Andrew Jones <[email protected]>
> > ---
> > arch/riscv/kernel/cpufeature.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > index 553d755483ed..3b5583db9d80 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> > /* Host ISA bitmap */
> > static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
> >
> > -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > EXPORT_SYMBOL(riscv_isa_ext_keys);
> >
> > /**

2022-08-16 17:23:49

by Conor Dooley

Subject: Re: [PATCH] riscv: Ensure isa-ext static keys are writable

On 16/08/2022 17:49, Andrew Jones wrote:
> On Tue, Aug 16, 2022 at 04:36:55PM +0000, [email protected] wrote:
>> On 16/08/2022 17:30, Andrew Jones wrote:
>>> riscv_isa_ext_keys[] is an array of static keys used in the unified
>>> ISA extension framework. The keys added to this array may be used
>>> anywhere, including in modules. Ensure the keys remain writable by
>>> placing them in the data section.
>>>
>>> The need to change riscv_isa_ext_keys[]'s section was found when the
>>> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
>>> add Zihintpause support") adds a static branch check for a newly
>>> added isa-ext key to cpu_relax(), which kvm uses.
>>>
>>> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
>>
>> Hey Drew,
>> How about adding:
>>
>> Reported-by: Ron Economos <[email protected]>
>> Reported-by: Anup Patel <[email protected]>
>> Reported-by: Conor Dooley <[email protected]>
>
> Sure, should I repost or can those be picked up when/if the patch is
> picked up?

Oh god no, don't repost for that alone.
Sorry, should've specified.
Conor.

>
> Thanks,
> drew
>
>>
>> Thanks,
>> Conor.
>>
>>> Signed-off-by: Andrew Jones <[email protected]>
>>> ---
>>> arch/riscv/kernel/cpufeature.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
>>> index 553d755483ed..3b5583db9d80 100644
>>> --- a/arch/riscv/kernel/cpufeature.c
>>> +++ b/arch/riscv/kernel/cpufeature.c
>>> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
>>> /* Host ISA bitmap */
>>> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>>>
>>> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
>>> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
>>> EXPORT_SYMBOL(riscv_isa_ext_keys);
>>>
>>> /**
>
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