From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@lists.ozlabs.org
Cc: linuxram@us.ibm.com, bauerman@linux.ibm.com
Subject: Re: [PATCH v5 19/26] powerpc/book3s64/kuap: Move KUAP related function outside radix
Date: Mon, 6 Jul 2020 20:11:45 +0530 [thread overview]
Message-ID: <d09d0150-860a-1e6a-1d4a-01ae8d7e97b9@linux.ibm.com> (raw)
In-Reply-To: <87eepo6cjm.fsf@mpe.ellerman.id.au>
On 7/6/20 6:11 PM, Michael Ellerman wrote:
> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
>> The next set of patches adds support for kuap with hash translation.
>
> That's no longer true of this series.
>
>> diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
>> index 0d72c0246052..e93b65a0e6e7 100644
>> --- a/arch/powerpc/mm/book3s64/pkeys.c
>> +++ b/arch/powerpc/mm/book3s64/pkeys.c
>> @@ -199,6 +200,24 @@ void __init pkey_early_init_devtree(void)
>> return;
>> }
>>
>> +#ifdef CONFIG_PPC_KUAP
>> +void __init setup_kuap(bool disabled)
>> +{
>> + if (disabled || !early_radix_enabled())
>> + return;
>> +
>> + if (smp_processor_id() == boot_cpuid) {
>> + pr_info("Activating Kernel Userspace Access Prevention\n");
>> + cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
>> + }
>> +
>> + /* Make sure userspace can't change the AMR */
>> + mtspr(SPRN_UAMOR, 0);
>> + mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
>> + isync();
>> +}
>> +#endif
>
> This makes this code depend on CONFIG_PPC_MEM_KEYS=y, which it didn't
> used to.
>
> That risks breaking people's existing .configs, if they have
> PPC_MEM_KEYS=n they will now lose KUAP.
>
> And I'm not convinced the two features should be tied together, at least
> at the user-visible Kconfig level.
>
That simplifies the addition of hash kuap a lot. Especially in the
exception entry and return paths. I did try to consider them as
independent options. But then the feature fixup in asm code gets
unnecessarily complicated. Also the UAMOR handling also get complicated.
-aneesh
next prev parent reply other threads:[~2020-07-06 14:47 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 13:58 [PATCH v5 00/26] powerpc/book3s/64/pkeys: Simplify the code Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 01/26] powerpc/book3s64/pkeys: Fixup bit numbering Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 02/26] powerpc/book3s64/pkeys: pkeys are supported only on hash on book3s Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 03/26] powerpc/book3s64/pkeys: Move pkey related bits in the linux page table Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 04/26] powerpc/book3s64/pkeys: Explain key 1 reservation details Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 05/26] powerpc/book3s64/pkeys: Simplify the key initialization Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 06/26] powerpc/book3s64/pkeys: Prevent key 1 modification from userspace Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 07/26] powerpc/book3s64/pkeys: kill cpu feature key CPU_FTR_PKEY Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 08/26] powerpc/book3s64/pkeys: Convert execute key support to static key Aneesh Kumar K.V
2020-07-06 7:19 ` Michael Ellerman
2020-07-06 8:47 ` Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 09/26] powerpc/book3s64/pkeys: Simplify pkey disable branch Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 10/26] powerpc/book3s64/pkeys: Convert pkey_total to max_pkey Aneesh Kumar K.V
2020-07-06 7:04 ` Michael Ellerman
2020-07-06 7:20 ` Aneesh Kumar K.V
2020-07-07 1:26 ` Michael Ellerman
2020-06-19 13:58 ` [PATCH v5 11/26] powerpc/book3s64/pkeys: Make initial_allocation_mask static Aneesh Kumar K.V
2020-07-06 7:04 ` Michael Ellerman
2020-07-06 8:48 ` Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 12/26] powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reserved Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 13/26] powerpc/book3s64/pkeys: Enable MMU_FTR_PKEY Aneesh Kumar K.V
2020-07-06 13:10 ` Michael Ellerman
2020-07-06 14:09 ` Aneesh Kumar K.V
2020-07-06 17:17 ` Aneesh Kumar K.V
2020-07-07 1:02 ` Michael Ellerman
2020-06-19 13:58 ` [PATCH v5 14/26] powerpc/book3s64/kuep: Add MMU_FTR_KUEP Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 15/26] powerpc/book3s64/pkeys: Use execute_pkey_disable static key Aneesh Kumar K.V
2020-07-06 7:20 ` Michael Ellerman
2020-07-06 8:49 ` Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 16/26] powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled " Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 17/26] powerpc/book3s64/keys: Print information during boot Aneesh Kumar K.V
2020-07-06 7:52 ` Michael Ellerman
2020-06-19 13:58 ` [PATCH v5 18/26] powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec Aneesh Kumar K.V
2020-07-06 12:29 ` Michael Ellerman
2020-07-06 14:39 ` Aneesh Kumar K.V
2020-07-07 1:07 ` Michael Ellerman
2020-06-19 13:58 ` [PATCH v5 19/26] powerpc/book3s64/kuap: Move KUAP related function outside radix Aneesh Kumar K.V
2020-07-06 12:41 ` Michael Ellerman
2020-07-06 14:41 ` Aneesh Kumar K.V [this message]
2020-07-07 1:22 ` Michael Ellerman
2020-06-19 13:58 ` [PATCH v5 20/26] powerpc/book3s64/kuep: Move KUEP " Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 21/26] powerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP to MMU_FTR_KUAP Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 22/26] powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of PPC_MEM_KEYS Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 23/26] powerpc/book3s64/kuap: Move UAMOR setup to key init function Aneesh Kumar K.V
2020-07-07 6:05 ` Michael Ellerman
2020-07-07 11:25 ` Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 24/26] powerpc/selftest/ptrave-pkey: Rename variables to make it easier to follow code Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 25/26] powerpc/selftest/ptrace-pkey: Update the test to mark an invalid pkey correctly Aneesh Kumar K.V
2020-06-19 13:58 ` [PATCH v5 26/26] powerpc/selftest/ptrace-pkey: IAMR and uamor cannot be updated by ptrace Aneesh Kumar K.V
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