From: Ram Pai <linuxram@us.ibm.com>
To: 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,
linuxram@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org,
corbet@lwn.net, mingo@redhat.com
Subject: [RFC v5 21/38] powerpc: implementation for arch_override_mprotect_pkey()
Date: Wed, 5 Jul 2017 14:21:58 -0700 [thread overview]
Message-ID: <1499289735-14220-22-git-send-email-linuxram@us.ibm.com> (raw)
In-Reply-To: <1499289735-14220-1-git-send-email-linuxram@us.ibm.com>
arch independent code calls arch_override_mprotect_pkey()
to return a pkey that best matches the requested protection.
This patch provides the implementation.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 10 ++++++-
arch/powerpc/mm/pkeys.c | 47 ++++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index f148e84..20846c2 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -13,6 +13,11 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey)
((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL));
}
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
+}
+
#define arch_max_pkey() 32
#define AMR_AD_BIT 0x1UL
#define AMR_WD_BIT 0x2UL
@@ -102,11 +107,12 @@ static inline int execute_only_pkey(struct mm_struct *mm)
return __execute_only_pkey(mm);
}
-
+extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
+ int prot, int pkey);
static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
int prot, int pkey)
{
- return 0;
+ return __arch_override_mprotect_pkey(vma, prot, pkey);
}
extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index 6c90317..c60a045 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -123,3 +123,50 @@ int __execute_only_pkey(struct mm_struct *mm)
mm->context.execute_only_pkey = execute_only_pkey;
return execute_only_pkey;
}
+
+static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
+{
+ /* Do this check first since the vm_flags should be hot */
+ if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ return false;
+
+ return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
+}
+
+/*
+ * This should only be called for *plain* mprotect calls.
+ */
+int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot,
+ int pkey)
+{
+ /*
+ * Is this an mprotect_pkey() call? If so, never
+ * override the value that came from the user.
+ */
+ if (pkey != -1)
+ return pkey;
+
+ /*
+ * If the currently associated pkey is execute-only,
+ * but the requested protection requires read or write,
+ * move it back to the default pkey.
+ */
+ if (vma_is_pkey_exec_only(vma) &&
+ (prot & (PROT_READ|PROT_WRITE)))
+ return 0;
+
+ /*
+ * the requested protection is execute-only. Hence
+ * lets use a execute-only pkey.
+ */
+ if (prot == PROT_EXEC) {
+ pkey = execute_only_pkey(vma->vm_mm);
+ if (pkey > 0)
+ return pkey;
+ }
+
+ /*
+ * nothing to override.
+ */
+ return vma_pkey(vma);
+}
--
1.7.1
--
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next prev parent reply other threads:[~2017-07-05 21:23 UTC|newest]
Thread overview: 92+ 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 ` [RFC v5 01/38] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai
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
2017-07-11 5:59 ` Balbir Singh
2017-07-11 15:44 ` Ram Pai
2017-07-12 3:10 ` Balbir Singh
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 ` [RFC v5 04/38] powerpc: introduce pte_get_hash_gslot() helper 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 ` [RFC v5 06/38] powerpc: use helper functions in __hash_page_64K() for 64K PTE 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 ` [RFC v5 08/38] powerpc: use helper functions in __hash_page_4K() " 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 ` [RFC v5 10/38] powerpc: use helper functions in flush_hash_page() Ram Pai
2017-07-05 21:21 ` [RFC v5 11/38] mm: introduce an additional vma bit for powerpc pkey Ram Pai
2017-07-11 18:10 ` Dave Hansen
2017-07-12 22:23 ` Ram Pai
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
2017-07-11 18:11 ` Dave Hansen
2017-07-11 21:29 ` Benjamin Herrenschmidt
2017-07-11 21:51 ` Ram Pai
2017-07-11 21:57 ` Dave Hansen
2017-07-11 22:14 ` Ram Pai
2017-07-11 22:19 ` Dave Hansen
2017-07-11 22:08 ` Benjamin Herrenschmidt
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
2017-07-11 18:12 ` Dave Hansen
2017-07-05 21:21 ` [RFC v5 14/38] powerpc: initial plumbing for key management Ram Pai
2017-07-12 3:28 ` Balbir Singh
2017-07-13 7:45 ` Ram Pai
2017-07-13 20:37 ` Ram Pai
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
2017-07-12 5:26 ` Balbir Singh
2017-07-13 7:55 ` Ram Pai
2017-07-13 9:49 ` Balbir Singh
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 ` [RFC v5 17/38] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls 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 ` [RFC v5 19/38] powerpc: introduce execute-only pkey 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 [this message]
2017-07-05 21:21 ` [RFC v5 22/38] powerpc: map vma key-protection bits to pte key bits Ram Pai
2017-07-05 21:22 ` [RFC v5 23/38] powerpc: sys_pkey_mprotect() system call Ram Pai
2017-07-05 21:22 ` [RFC v5 24/38] powerpc: Program HPTE key protection bits 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 ` [RFC v5 26/38] powerpc: check key protection for user page access 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 ` [RFC v5 28/38] powerpc: implementation for arch_vma_access_permitted() 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 ` [RFC v5 30/38] powerpc: capture AMR register content on " Ram Pai
2017-07-05 21:22 ` [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper Ram Pai
2017-07-10 3:11 ` Anshuman Khandual
2017-07-10 5:55 ` Ram Pai
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
2017-07-10 3:10 ` Anshuman Khandual
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
2017-07-10 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
2017-07-10 3:07 ` Anshuman Khandual
2017-07-10 6:01 ` Ram Pai
2017-07-11 18:13 ` Dave Hansen
2017-07-13 8:03 ` Ram Pai
2017-07-13 14:07 ` Dave Hansen
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 ` [RFC v5 36/38] selftest: PowerPC specific test updates to memory protection keys Ram Pai
2017-07-11 17:33 ` Dave Hansen
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 ` [RFC v5 38/38] Documentation: PowerPC specific updates to memory protection keys Ram Pai
2017-07-10 3:07 ` Anshuman Khandual
2017-07-10 5:59 ` Ram Pai
2017-07-11 18:23 ` Dave Hansen
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 6:05 ` Ram Pai
2017-07-10 17:15 ` Ram Pai
2017-07-11 14:52 ` Michal Hocko
2017-07-11 19:32 ` Ram Pai
2017-07-11 21:30 ` Benjamin Herrenschmidt
2017-07-12 7:23 ` Michal Hocko
2017-07-12 7:39 ` Michal Hocko
2017-07-12 22:53 ` Benjamin Herrenschmidt
2017-07-13 6:20 ` Michal Hocko
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