From: Balbir Singh <bsingharora@gmail.com>
To: Ram Pai <linuxram@us.ibm.com>
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org, x86@kernel.org, linux-doc@vger.kernel.org,
arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net,
mingo@redhat.com, benh@kernel.crashing.org, paulus@samba.org,
khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com,
hbabu@us.ibm.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com,
ebiederm@xmission.com
Subject: Re: [PATCH 4/6] mm/mprotect, powerpc/mm/pkeys, x86/mm/pkeys: Add sysfs interface
Date: Fri, 22 Sep 2017 16:00:19 +1000 [thread overview]
Message-ID: <20170922160019.0d6d1eae@firefly.ozlabs.ibm.com> (raw)
In-Reply-To: <1505524870-4783-5-git-send-email-linuxram@us.ibm.com>
On Fri, 15 Sep 2017 18:21:08 -0700
Ram Pai <linuxram@us.ibm.com> wrote:
> From: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
>
> Expose useful information for programs using memory protection keys.
> Provide implementation for powerpc and x86.
>
> On a powerpc system with pkeys support, here is what is shown:
>
> $ head /sys/kernel/mm/protection_keys/*
> ==> /sys/kernel/mm/protection_keys/disable_access_supported <==
> true
>
> ==> /sys/kernel/mm/protection_keys/disable_execute_supported <==
> true
>
> ==> /sys/kernel/mm/protection_keys/disable_write_supported <==
> true
>
> ==> /sys/kernel/mm/protection_keys/total_keys <==
> 32
>
> ==> /sys/kernel/mm/protection_keys/usable_keys <==
> 29
>
> And on an x86 without pkeys support:
>
> $ head /sys/kernel/mm/protection_keys/*
> ==> /sys/kernel/mm/protection_keys/disable_access_supported <==
> false
>
> ==> /sys/kernel/mm/protection_keys/disable_execute_supported <==
> false
>
> ==> /sys/kernel/mm/protection_keys/disable_write_supported <==
> false
>
> ==> /sys/kernel/mm/protection_keys/total_keys <==
> 1
>
> ==> /sys/kernel/mm/protection_keys/usable_keys <==
> 0
>
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
Just curious, how do you see this being used? For debugging
or will applications parse these properties and use them?
It's hard for an application to partition its address space
among keys at runtime, would you agree?
Balbir Singh.
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next prev parent reply other threads:[~2017-09-22 6:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-16 1:21 [PATCH 0/6] mm, x86, powerpc: Memory Protection Keys enhancement Ram Pai
2017-09-16 1:21 ` [PATCH 1/6] mm: introduce an additional vma bit for powerpc pkey Ram Pai
2017-09-22 6:12 ` Balbir Singh
2017-09-16 1:21 ` [PATCH 2/6] mm, x86 : introduce arch_pkeys_enabled() Ram Pai
2017-09-16 1:21 ` [PATCH 3/6] mm: display pkey in smaps if arch_pkeys_enabled() is true Ram Pai
2017-09-22 6:02 ` Balbir Singh
2017-09-22 6:08 ` Balbir Singh
2017-09-16 1:21 ` [PATCH 4/6] mm/mprotect, powerpc/mm/pkeys, x86/mm/pkeys: Add sysfs interface Ram Pai
2017-09-22 6:00 ` Balbir Singh [this message]
2017-09-22 16:47 ` Ram Pai
2017-09-16 1:21 ` [PATCH 5/6] Documentation/x86: Move protecton key documentation to arch neutral directory Ram Pai
2017-09-16 1:21 ` [PATCH 6/6] Documentation/vm: PowerPC specific updates to memory protection keys Ram Pai
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