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, mhocko@kernel.org
Subject: [RFC v6 23/62] powerpc: implementation for arch_override_mprotect_pkey()
Date: Sat, 15 Jul 2017 20:56:25 -0700 [thread overview]
Message-ID: <1500177424-13695-24-git-send-email-linuxram@us.ibm.com> (raw)
In-Reply-To: <1500177424-13695-1-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/mmu_context.h | 5 +++
arch/powerpc/include/asm/pkeys.h | 14 ++++++++-
arch/powerpc/mm/pkeys.c | 47 ++++++++++++++++++++++++++++++++
3 files changed, 64 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 4705dab..7232484 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -185,6 +185,11 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
#ifndef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
#define pkey_initialize()
#define pkey_mm_init(mm)
+
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ return 0;
+}
#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
#endif /* __KERNEL__ */
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index c92b049..94013af 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -29,6 +29,13 @@ 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)
+{
+ if (!pkey_inited)
+ return 0;
+ return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
+}
+
#define arch_max_pkey() 32
#define AMR_RD_BIT 0x1UL
#define AMR_WR_BIT 0x2UL
@@ -138,11 +145,14 @@ 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;
+ if (!pkey_inited)
+ 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 34e8557..403f5ae 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -154,3 +154,50 @@ 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:[~2017-07-16 3:58 UTC|newest]
Thread overview: 103+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-16 3:56 [RFC v6 00/62] powerpc: Memory Protection Keys Ram Pai
2017-07-16 3:56 ` [RFC v6 01/62] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai
2017-07-20 5:51 ` Aneesh Kumar K.V
2017-07-20 22:03 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 02/62] powerpc: Free up four 64K PTE bits in 64K " Ram Pai
2017-07-20 5:53 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper Ram Pai
2017-07-20 5:56 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 04/62] powerpc: introduce pte_get_hash_gslot() helper Ram Pai
2017-07-20 5:57 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 05/62] powerpc: capture the PTE format changes in the dump pte report Ram Pai
2017-07-20 5:56 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 06/62] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai
2017-07-20 5:58 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 07/62] powerpc: use helper functions in __hash_page_huge() " Ram Pai
2017-07-20 5:58 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 08/62] powerpc: use helper functions in __hash_page_4K() " Ram Pai
2017-07-16 3:56 ` [RFC v6 09/62] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai
2017-07-16 3:56 ` [RFC v6 10/62] powerpc: use helper functions in flush_hash_page() Ram Pai
2017-07-16 3:56 ` [RFC v6 11/62] powerpc: initial pkey plumbing Ram Pai
2017-07-20 6:04 ` Aneesh Kumar K.V
2017-07-20 22:11 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 12/62] mm: introduce an additional vma bit for powerpc pkey Ram Pai
2017-07-16 3:56 ` [RFC v6 13/62] powerpc: track allocation status of all pkeys Ram Pai
2017-07-27 14:01 ` Thiago Jung Bauermann
2017-07-29 22:43 ` Ram Pai
2017-07-31 18:15 ` Thiago Jung Bauermann
2017-07-16 3:56 ` [RFC v6 14/62] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai
2017-07-16 3:56 ` [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers Ram Pai
2017-07-27 20:40 ` Thiago Jung Bauermann
2017-07-30 0:38 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 16/62] powerpc: cleaup AMR,iAMR when a key is allocated or freed Ram Pai
2017-07-16 3:56 ` [RFC v6 17/62] powerpc: implementation for arch_set_user_pkey_access() Ram Pai
2017-07-27 14:15 ` Thiago Jung Bauermann
2017-07-29 22:59 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 18/62] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai
2017-07-16 3:56 ` [RFC v6 19/62] powerpc: ability to create execute-disabled pkeys Ram Pai
2017-07-27 14:54 ` Thiago Jung Bauermann
2017-07-27 15:34 ` Thiago Jung Bauermann
2017-07-29 23:24 ` Ram Pai
2017-07-31 12:59 ` Michael Ellerman
2017-07-16 3:56 ` [RFC v6 20/62] powerpc: store and restore the pkey state across context switches Ram Pai
2017-07-27 17:32 ` Thiago Jung Bauermann
2017-07-29 23:31 ` Ram Pai
2017-07-31 13:00 ` Michael Ellerman
2017-07-16 3:56 ` [RFC v6 21/62] powerpc: introduce execute-only pkey Ram Pai
2017-07-28 22:17 ` Thiago Jung Bauermann
2017-07-30 0:51 ` Ram Pai
2017-07-31 16:19 ` Thiago Jung Bauermann
2017-08-01 6:46 ` Michael Ellerman
2017-08-01 16:14 ` Thiago Jung Bauermann
2017-08-02 9:40 ` Michael Ellerman
[not found] ` <20170817233555.GC5427@ram.oc3035372033.ibm.com>
2017-08-17 23:42 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 22/62] powerpc: ability to associate pkey to a vma Ram Pai
2017-07-16 3:56 ` Ram Pai [this message]
2017-07-16 3:56 ` [RFC v6 24/62] powerpc: map vma key-protection bits to pte key bits Ram Pai
2017-07-16 3:56 ` [RFC v6 25/62] powerpc: sys_pkey_mprotect() system call Ram Pai
2017-07-16 3:56 ` [RFC v6 26/62] powerpc: Program HPTE key protection bits Ram Pai
2017-07-20 6:28 ` Aneesh Kumar K.V
2017-07-16 3:56 ` [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte Ram Pai
2017-07-20 6:42 ` Aneesh Kumar K.V
2017-07-20 22:15 ` Ram Pai
2017-07-21 6:51 ` Aneesh Kumar K.V
2017-07-21 16:42 ` Ram Pai
2017-07-28 21:00 ` Thiago Jung Bauermann
2017-07-30 0:39 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 28/62] powerpc: check key protection for user page access Ram Pai
2017-07-16 3:56 ` [RFC v6 29/62] powerpc: Macro the mask used for checking DSI exception Ram Pai
2017-07-16 3:56 ` [RFC v6 30/62] powerpc: implementation for arch_vma_access_permitted() Ram Pai
2017-07-16 3:56 ` [RFC v6 31/62] powerpc: Handle exceptions caused by pkey violation Ram Pai
2017-07-16 3:56 ` [RFC v6 32/62] powerpc: capture AMR register content on " Ram Pai
2017-07-16 3:56 ` [RFC v6 33/62] powerpc: introduce get_pte_pkey() helper Ram Pai
2017-07-16 3:56 ` [RFC v6 34/62] powerpc: capture the violated protection key on fault Ram Pai
2017-07-16 3:56 ` [RFC v6 35/62] powerpc: Deliver SEGV signal on pkey violation Ram Pai
2017-08-19 19:09 ` Eric W. Biederman
2017-08-22 18:06 ` Ram Pai
2017-07-16 3:56 ` [RFC v6 36/62] mm: introduce arch_pkeys_enabled() Ram Pai
2017-07-16 3:56 ` [RFC v6 37/62] x86: implementation for arch_pkeys_enabled() Ram Pai
2017-07-16 3:56 ` [RFC v6 38/62] powerpc: " Ram Pai
2017-07-16 3:56 ` [RFC v6 39/62] mm: display pkey in smaps if arch_pkeys_enabled() is true Ram Pai
2017-07-16 3:56 ` [RFC v6 40/62] x86: delete arch_show_smap() Ram Pai
2017-07-16 3:56 ` [RFC v6 41/62] selftest/x86: Move protecton key selftest to arch neutral directory Ram Pai
2017-07-16 3:56 ` [RFC v6 42/62] selftest/vm: rename all references to pkru to a generic name Ram Pai
2017-07-16 3:56 ` [RFC v6 43/62] selftest/vm: move generic definitions to header file Ram Pai
2017-07-16 3:56 ` [RFC v6 44/62] selftest/vm: typecast the pkey register Ram Pai
2017-07-16 3:56 ` [RFC v6 45/62] selftest/vm: generics function to handle shadow key register Ram Pai
2017-07-16 3:56 ` [RFC v6 46/62] selftest/vm: fix the wrong assert in pkey_disable_set() Ram Pai
2017-07-16 3:56 ` [RFC v6 47/62] selftest/vm: fixed bugs in pkey_disable_clear() Ram Pai
2017-07-16 3:56 ` [RFC v6 48/62] selftest/vm: clear the bits in shadow reg when a pkey is freed Ram Pai
2017-07-16 3:56 ` [RFC v6 49/62] selftest/vm: fix alloc_random_pkey() to make it really random Ram Pai
2017-07-16 3:56 ` [RFC v6 50/62] selftest/vm: introduce two arch independent abstraction Ram Pai
2017-07-16 3:56 ` [RFC v6 51/62] selftest/vm: pkey register should match shadow pkey Ram Pai
2017-07-16 3:56 ` [RFC v6 52/62] selftest/vm: generic cleanup Ram Pai
2017-07-16 3:56 ` [RFC v6 53/62] selftest/vm: powerpc implementation for generic abstraction Ram Pai
2017-07-16 3:56 ` [RFC v6 54/62] selftest/vm: fix an assertion in test_pkey_alloc_exhaust() Ram Pai
2017-07-16 3:56 ` [RFC v6 55/62] selftest/vm: associate key on a mapped page and detect access violation Ram Pai
2017-07-16 3:56 ` [RFC v6 56/62] selftest/vm: detect no key violation on a freed key Ram Pai
2017-07-16 3:56 ` [RFC v6 57/62] selftest/vm: associate key on a mapped page and detect write violation Ram Pai
2017-07-16 3:57 ` [RFC v6 58/62] selftest/vm: detect no write key-violation on a freed key Ram Pai
2017-07-16 3:57 ` [RFC v6 59/62] selftest/vm: detect write violation on a mapped access-denied-key page Ram Pai
2017-07-16 3:57 ` [RFC v6 60/62] selftest/vm: sub-page allocator Ram Pai
2017-07-16 3:57 ` [RFC v6 61/62] Documentation/x86: Move protecton key documentation to arch neutral directory Ram Pai
2017-07-16 3:57 ` [RFC v6 62/62] Documentation/vm: PowerPC specific updates to memory protection keys Ram Pai
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