From: Anshuman Khandual <khandual@linux.vnet.ibm.com> To: Ram Pai <linuxram@us.ibm.com>, 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 Cc: 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, dave.hansen@intel.com, hbabu@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com Subject: Re: [RFC v5 32/38] powerpc: capture the violated protection key on fault Date: Mon, 10 Jul 2017 08:40:19 +0530 [thread overview] Message-ID: <5fa43f48-d3b3-89f2-0bbd-58be3e07f4b8@linux.vnet.ibm.com> (raw) In-Reply-To: <1499289735-14220-33-git-send-email-linuxram@us.ibm.com> On 07/06/2017 02:52 AM, Ram Pai wrote: > Capture the protection key that got violated in paca. > This value will be used by used to inform the signal > handler. > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > --- > arch/powerpc/include/asm/paca.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/mm/fault.c | 3 +++ > 3 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h > index c8bd1fc..0c06188 100644 > --- a/arch/powerpc/include/asm/paca.h > +++ b/arch/powerpc/include/asm/paca.h > @@ -94,6 +94,7 @@ struct paca_struct { > u64 dscr_default; /* per-CPU default DSCR */ > #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > u64 paca_amr; /* value of amr at exception */ > + u16 paca_pkey; /* exception causing pkey */ > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > #ifdef CONFIG_PPC_STD_MMU_64 > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c > index 17f5d8a..7dff862 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -244,6 +244,7 @@ int main(void) > > #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > OFFSET(PACA_AMR, paca_struct, paca_amr); > + OFFSET(PACA_PKEY, paca_struct, paca_pkey); > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > OFFSET(ACCOUNT_STARTTIME, paca_struct, accounting.starttime); > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index a6710f5..c8674a7 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -265,6 +265,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > if (error_code & DSISR_KEYFAULT) { > code = SEGV_PKUERR; > get_paca()->paca_amr = read_amr(); > + get_paca()->paca_pkey = get_pte_pkey(current->mm, address); > goto bad_area_nosemaphore; > } > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > @@ -290,6 +291,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > > perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); > > + Stray empty line addition here. > /* > * We want to do this outside mmap_sem, because reading code around nip > * can result in fault, which will cause a deadlock when called with > @@ -453,6 +455,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, > is_exec, 0)) { > get_paca()->paca_amr = read_amr(); > + get_paca()->paca_pkey = vma_pkey(vma); Why not get_pte_pkey() here as well ? IIUC both these function would give us the same pkey, then why is the difference when we process a page fault for real protection key violation in HW compared to cross checking of VMA protection key in SW for regular page faults.
WARNING: multiple messages have this Message-ID (diff)
From: Anshuman Khandual <khandual@linux.vnet.ibm.com> To: Ram Pai <linuxram@us.ibm.com>, 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 Cc: 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, dave.hansen@intel.com, hbabu@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com Subject: Re: [RFC v5 32/38] powerpc: capture the violated protection key on fault Date: Mon, 10 Jul 2017 08:40:19 +0530 [thread overview] Message-ID: <5fa43f48-d3b3-89f2-0bbd-58be3e07f4b8@linux.vnet.ibm.com> (raw) In-Reply-To: <1499289735-14220-33-git-send-email-linuxram@us.ibm.com> On 07/06/2017 02:52 AM, Ram Pai wrote: > Capture the protection key that got violated in paca. > This value will be used by used to inform the signal > handler. > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > --- > arch/powerpc/include/asm/paca.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/mm/fault.c | 3 +++ > 3 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h > index c8bd1fc..0c06188 100644 > --- a/arch/powerpc/include/asm/paca.h > +++ b/arch/powerpc/include/asm/paca.h > @@ -94,6 +94,7 @@ struct paca_struct { > u64 dscr_default; /* per-CPU default DSCR */ > #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > u64 paca_amr; /* value of amr at exception */ > + u16 paca_pkey; /* exception causing pkey */ > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > #ifdef CONFIG_PPC_STD_MMU_64 > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c > index 17f5d8a..7dff862 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -244,6 +244,7 @@ int main(void) > > #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS > OFFSET(PACA_AMR, paca_struct, paca_amr); > + OFFSET(PACA_PKEY, paca_struct, paca_pkey); > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > > OFFSET(ACCOUNT_STARTTIME, paca_struct, accounting.starttime); > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index a6710f5..c8674a7 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -265,6 +265,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > if (error_code & DSISR_KEYFAULT) { > code = SEGV_PKUERR; > get_paca()->paca_amr = read_amr(); > + get_paca()->paca_pkey = get_pte_pkey(current->mm, address); > goto bad_area_nosemaphore; > } > #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ > @@ -290,6 +291,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > > perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); > > + Stray empty line addition here. > /* > * We want to do this outside mmap_sem, because reading code around nip > * can result in fault, which will cause a deadlock when called with > @@ -453,6 +455,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, > if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, > is_exec, 0)) { > get_paca()->paca_amr = read_amr(); > + get_paca()->paca_pkey = vma_pkey(vma); Why not get_pte_pkey() here as well ? IIUC both these function would give us the same pkey, then why is the difference when we process a page fault for real protection key violation in HW compared to cross checking of VMA protection key in SW for regular page faults. -- 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:[~2017-07-10 3:11 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 [this message] 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 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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