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

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Message-ID: <88a888fe-afbf-3579-73d2-9c95bfcfda55@microchip.com>
Date:   Tue, 16 Aug 2022 16:50:56 +0000
From:   <Conor.Dooley@...rochip.com>
To:     <ajones@...tanamicro.com>, <Conor.Dooley@...rochip.com>
CC:     <linux-riscv@...ts.infradead.org>, <kvm-riscv@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <daolu@...osinc.com>,
        <jszhang@...nel.org>, <palmer@...belt.com>, <re@...z.net>,
        <apatel@...tanamicro.com>
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, Conor.Dooley@...rochip.com 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 <re@...z.net>
>> Reported-by: Anup Patel <apatel@...tanamicro.com>
>> Reported-by: Conor Dooley <conor.dooley@...rochip.com>
> 
> 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 <ajones@...tanamicro.com>
>>> ---
>>>  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);
>>>  
>>>  /**
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

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