From: Ram Pai <linuxram@us.ibm.com> To: Dave Hansen <dave.hansen@intel.com> Cc: 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, linux-kselftest@vger.kernel.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, hbabu@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com Subject: Re: [RFC v5 34/38] procfs: display the protection-key number associated with a vma Date: Thu, 13 Jul 2017 10:04:11 -0700 [thread overview] Message-ID: <20170713170411.GI5525@ram.oc3035372033.ibm.com> (raw) In-Reply-To: <e3355a7a-8899-b69d-968a-6862c29633a2@intel.com> On Thu, Jul 13, 2017 at 07:07:48AM -0700, Dave Hansen wrote: > On 07/13/2017 01:03 AM, Ram Pai wrote: > > On Tue, Jul 11, 2017 at 11:13:56AM -0700, Dave Hansen wrote: > >> On 07/05/2017 02:22 PM, Ram Pai wrote: > >>> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > >>> +void arch_show_smap(struct seq_file *m, struct vm_area_struct *vma) > >>> +{ > >>> + seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > >>> +} > >>> +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > >> > >> This seems like kinda silly unnecessary duplication. Could we just put > >> this in the fs/proc/ code and #ifdef it on ARCH_HAS_PKEYS? > > > > Well x86 predicates it based on availability of X86_FEATURE_OSPKE. > > > > powerpc doesn't need that check or any similar check. So trying to > > generalize the code does not save much IMHO. > > I know all your hardware doesn't support it. :) Wow! you bring a good point which I had not considered yet. I need some runtime checks for RPT. But regardless, my above statement is still partially true. x86 predicates it based on availability of X86_FEATURE_OSPKE, and powerpc should predicate it based on HPT. So we have our own customized checks. Hence a unified function won't suffice. > > So, for instance, if you are running on a new POWER9 with radix page > tables, you will just always output "ProtectionKey: 0" in every VMA, > regardless? > > > maybe have a seperate inline function that does > > seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > > and is called from x86 and powerpc's arch_show_smap()? > > At least will keep the string format captured in > > one single place. > > Now that we have two architectures, is there a strong reason we can't > just have an arch_pkeys_enabled(), and stick the seq_printf() back in > generic code? correct. that looks like the correct approach. Was trying to avoid touching arch neutral code. But this approach will force me do so. Will do. -- Ram Pai
WARNING: multiple messages have this Message-ID (diff)
From: Ram Pai <linuxram@us.ibm.com> To: Dave Hansen <dave.hansen@intel.com> Cc: 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, linux-kselftest@vger.kernel.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, hbabu@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com Subject: Re: [RFC v5 34/38] procfs: display the protection-key number associated with a vma Date: Thu, 13 Jul 2017 10:04:11 -0700 [thread overview] Message-ID: <20170713170411.GI5525@ram.oc3035372033.ibm.com> (raw) In-Reply-To: <e3355a7a-8899-b69d-968a-6862c29633a2@intel.com> On Thu, Jul 13, 2017 at 07:07:48AM -0700, Dave Hansen wrote: > On 07/13/2017 01:03 AM, Ram Pai wrote: > > On Tue, Jul 11, 2017 at 11:13:56AM -0700, Dave Hansen wrote: > >> On 07/05/2017 02:22 PM, Ram Pai wrote: > >>> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > >>> +void arch_show_smap(struct seq_file *m, struct vm_area_struct *vma) > >>> +{ > >>> + seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > >>> +} > >>> +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > >> > >> This seems like kinda silly unnecessary duplication. Could we just put > >> this in the fs/proc/ code and #ifdef it on ARCH_HAS_PKEYS? > > > > Well x86 predicates it based on availability of X86_FEATURE_OSPKE. > > > > powerpc doesn't need that check or any similar check. So trying to > > generalize the code does not save much IMHO. > > I know all your hardware doesn't support it. :) Wow! you bring a good point which I had not considered yet. I need some runtime checks for RPT. But regardless, my above statement is still partially true. x86 predicates it based on availability of X86_FEATURE_OSPKE, and powerpc should predicate it based on HPT. So we have our own customized checks. Hence a unified function won't suffice. > > So, for instance, if you are running on a new POWER9 with radix page > tables, you will just always output "ProtectionKey: 0" in every VMA, > regardless? > > > maybe have a seperate inline function that does > > seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > > and is called from x86 and powerpc's arch_show_smap()? > > At least will keep the string format captured in > > one single place. > > Now that we have two architectures, is there a strong reason we can't > just have an arch_pkeys_enabled(), and stick the seq_printf() back in > generic code? correct. that looks like the correct approach. Was trying to avoid touching arch neutral code. But this approach will force me do so. Will do. -- Ram Pai -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-07-13 17:04 UTC|newest] Thread overview: 191+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-07-05 21:21 [RFC v5 00/38] powerpc: Memory Protection Keys Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 01/38] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-07 7:25 ` Balbir Singh 2017-07-07 7:25 ` Balbir Singh 2017-07-07 7:25 ` Balbir Singh 2017-07-05 21:21 ` [RFC v5 02/38] powerpc: Free up four 64K PTE bits in 64K " Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-11 5:59 ` Balbir Singh 2017-07-11 5:59 ` Balbir Singh 2017-07-11 15:44 ` Ram Pai 2017-07-11 15:44 ` Ram Pai 2017-07-12 3:10 ` Balbir Singh 2017-07-12 3:10 ` Balbir Singh 2017-07-13 7:39 ` Ram Pai 2017-07-13 7:39 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 03/38] powerpc: introduce pte_set_hash_slot() helper Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 04/38] powerpc: introduce pte_get_hash_gslot() helper Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 05/38] powerpc: capture the PTE format changes in the dump pte report Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 06/38] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 07/38] powerpc: use helper functions in __hash_page_huge() " Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 08/38] powerpc: use helper functions in __hash_page_4K() " Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 09/38] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 10/38] powerpc: use helper functions in flush_hash_page() Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 11/38] mm: introduce an additional vma bit for powerpc pkey Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-11 18:10 ` Dave Hansen 2017-07-11 18:10 ` Dave Hansen 2017-07-12 22:23 ` Ram Pai 2017-07-12 22:23 ` Ram Pai 2017-07-12 22:40 ` Benjamin Herrenschmidt 2017-07-12 22:40 ` Benjamin Herrenschmidt 2017-07-05 21:21 ` [RFC v5 12/38] mm: ability to disable execute permission on a key at creation Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-11 18:11 ` Dave Hansen 2017-07-11 18:11 ` Dave Hansen 2017-07-11 21:29 ` Benjamin Herrenschmidt 2017-07-11 21:29 ` Benjamin Herrenschmidt 2017-07-11 21:51 ` Ram Pai 2017-07-11 21:51 ` Ram Pai 2017-07-11 21:57 ` Dave Hansen 2017-07-11 21:57 ` Dave Hansen 2017-07-11 22:14 ` Ram Pai 2017-07-11 22:14 ` Ram Pai 2017-07-11 22:19 ` Dave Hansen 2017-07-11 22:19 ` Dave Hansen 2017-07-11 22:08 ` Benjamin Herrenschmidt 2017-07-11 22:08 ` Benjamin Herrenschmidt 2017-07-11 22:19 ` Ram Pai 2017-07-11 22:19 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 13/38] x86: disallow pkey creation with PKEY_DISABLE_EXECUTE Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-11 18:12 ` Dave Hansen 2017-07-11 18:12 ` Dave Hansen 2017-07-05 21:21 ` [RFC v5 14/38] powerpc: initial plumbing for key management Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-12 3:28 ` Balbir Singh 2017-07-12 3:28 ` Balbir Singh 2017-07-13 7:45 ` Ram Pai 2017-07-13 7:45 ` Ram Pai 2017-07-13 20:37 ` Ram Pai 2017-07-13 20:37 ` Ram Pai 2017-07-13 21:30 ` Balbir Singh 2017-07-13 21:30 ` Balbir Singh 2017-07-13 21:30 ` Balbir Singh 2017-07-13 21:30 ` Balbir Singh 2017-07-05 21:21 ` [RFC v5 15/38] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai 2017-07-05 21:21 ` [RFC v5 15/38] powerpc: helper function to read, write AMR, IAMR, UAMOR registers Ram Pai 2017-07-05 21:21 ` [RFC v5 15/38] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai 2017-07-12 5:26 ` Balbir Singh 2017-07-12 5:26 ` Balbir Singh 2017-07-13 7:55 ` Ram Pai 2017-07-13 7:55 ` Ram Pai 2017-07-13 9:49 ` Balbir Singh 2017-07-13 9:49 ` Balbir Singh 2017-07-13 9:49 ` Balbir Singh 2017-07-13 23:29 ` Ram Pai 2017-07-13 23:29 ` Ram Pai 2017-07-13 23:29 ` Ram Pai 2017-07-13 23:29 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 16/38] powerpc: implementation for arch_set_user_pkey_access() Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 17/38] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 18/38] powerpc: store and restore the pkey state across context switches Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 19/38] powerpc: introduce execute-only pkey Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 20/38] powerpc: ability to associate pkey to a vma Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 21/38] powerpc: implementation for arch_override_mprotect_pkey() Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:21 ` [RFC v5 22/38] powerpc: map vma key-protection bits to pte key bits Ram Pai 2017-07-05 21:21 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 23/38] powerpc: sys_pkey_mprotect() system call Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 24/38] powerpc: Program HPTE key protection bits Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 25/38] powerpc: helper to validate key-access permissions of a pte Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 26/38] powerpc: check key protection for user page access Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 27/38] powerpc: Macro the mask used for checking DSI exception Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 28/38] powerpc: implementation for arch_vma_access_permitted() Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 29/38] powerpc: Handle exceptions caused by pkey violation Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 30/38] powerpc: capture AMR register content on " Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-10 3:11 ` Anshuman Khandual 2017-07-10 3:11 ` Anshuman Khandual 2017-07-10 5:55 ` Ram Pai 2017-07-10 5:55 ` Ram Pai 2017-07-11 11:22 ` Anshuman Khandual 2017-07-11 11:22 ` Anshuman Khandual 2017-07-05 21:22 ` [RFC v5 32/38] powerpc: capture the violated protection key on fault Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-10 3:10 ` Anshuman Khandual 2017-07-10 3:10 ` Anshuman Khandual 2017-07-10 5:49 ` Ram Pai 2017-07-10 5:49 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 33/38] powerpc: Deliver SEGV signal on pkey violation Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-10 3:08 ` Anshuman Khandual 2017-07-10 3:08 ` Anshuman Khandual 2017-07-05 21:22 ` [RFC v5 34/38] procfs: display the protection-key number associated with a vma Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-10 3:07 ` Anshuman Khandual 2017-07-10 3:07 ` Anshuman Khandual 2017-07-10 6:01 ` Ram Pai 2017-07-10 6:01 ` Ram Pai 2017-07-11 18:13 ` Dave Hansen 2017-07-11 18:13 ` Dave Hansen 2017-07-13 8:03 ` Ram Pai 2017-07-13 8:03 ` Ram Pai 2017-07-13 14:07 ` Dave Hansen 2017-07-13 14:07 ` Dave Hansen 2017-07-13 17:04 ` Ram Pai [this message] 2017-07-13 17:04 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 35/38] selftest: Move protecton key selftest to arch neutral directory Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 36/38] selftest: PowerPC specific test updates to memory protection keys Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-11 17:33 ` Dave Hansen 2017-07-11 17:33 ` Dave Hansen 2017-07-12 21:57 ` Ram Pai 2017-07-12 21:57 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 37/38] Documentation: Move protecton key documentation to arch neutral directory Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-05 21:22 ` [RFC v5 38/38] Documentation: PowerPC specific updates to memory protection keys Ram Pai 2017-07-05 21:22 ` Ram Pai 2017-07-10 3:07 ` Anshuman Khandual 2017-07-10 3:07 ` Anshuman Khandual 2017-07-10 5:59 ` Ram Pai 2017-07-10 5:59 ` Ram Pai 2017-07-11 18:23 ` Dave Hansen 2017-07-11 18:23 ` Dave Hansen 2017-07-13 19:56 ` Ram Pai 2017-07-13 19:56 ` Ram Pai 2017-07-10 5:43 ` [RFC v5 00/38] powerpc: Memory Protection Keys Anshuman Khandual 2017-07-10 5:43 ` Anshuman Khandual 2017-07-10 6:05 ` Ram Pai 2017-07-10 6:05 ` Ram Pai 2017-07-10 17:15 ` Ram Pai 2017-07-10 17:15 ` Ram Pai 2017-07-11 14:52 ` Michal Hocko 2017-07-11 14:52 ` Michal Hocko 2017-07-11 19:32 ` Ram Pai 2017-07-11 19:32 ` Ram Pai 2017-07-11 21:30 ` Benjamin Herrenschmidt 2017-07-11 21:30 ` Benjamin Herrenschmidt 2017-07-12 7:23 ` Michal Hocko 2017-07-12 7:23 ` Michal Hocko 2017-07-12 7:39 ` Michal Hocko 2017-07-12 7:39 ` Michal Hocko 2017-07-12 22:53 ` Benjamin Herrenschmidt 2017-07-12 22:53 ` Benjamin Herrenschmidt 2017-07-13 6:20 ` Michal Hocko 2017-07-13 6:20 ` Michal Hocko
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