* [PATCH v4 02/41] powerpc/book3s64/pkeys: pkeys are supported only on hash on book3s.
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Move them to hash specific file and add BUG() for radix path.
---
.../powerpc/include/asm/book3s/64/hash-pkey.h | 32 ++++++++++++++++
arch/powerpc/include/asm/book3s/64/pkeys.h | 25 +++++++++++++
arch/powerpc/include/asm/pkeys.h | 37 ++++---------------
3 files changed, 64 insertions(+), 30 deletions(-)
create mode 100644 arch/powerpc/include/asm/book3s/64/hash-pkey.h
create mode 100644 arch/powerpc/include/asm/book3s/64/pkeys.h
diff --git a/arch/powerpc/include/asm/book3s/64/hash-pkey.h b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
new file mode 100644
index 000000000000..795010897e5d
--- /dev/null
+++ b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
+#define _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
+
+static inline u64 hash__vmflag_to_pte_pkey_bits(u64 vm_flags)
+{
+ return (((vm_flags & VM_PKEY_BIT0) ? H_PTE_PKEY_BIT0 : 0x0UL) |
+ ((vm_flags & VM_PKEY_BIT1) ? H_PTE_PKEY_BIT1 : 0x0UL) |
+ ((vm_flags & VM_PKEY_BIT2) ? H_PTE_PKEY_BIT2 : 0x0UL) |
+ ((vm_flags & VM_PKEY_BIT3) ? H_PTE_PKEY_BIT3 : 0x0UL) |
+ ((vm_flags & VM_PKEY_BIT4) ? H_PTE_PKEY_BIT4 : 0x0UL));
+}
+
+static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
+{
+ return (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
+}
+
+static inline u16 hash__pte_to_pkey_bits(u64 pteflags)
+{
+ return (((pteflags & H_PTE_PKEY_BIT4) ? 0x10 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT3) ? 0x8 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT2) ? 0x4 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT1) ? 0x2 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT0) ? 0x1 : 0x0UL));
+}
+
+#endif
diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h
new file mode 100644
index 000000000000..8174662a9173
--- /dev/null
+++ b/arch/powerpc/include/asm/book3s/64/pkeys.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef _ASM_POWERPC_BOOK3S_64_PKEYS_H
+#define _ASM_POWERPC_BOOK3S_64_PKEYS_H
+
+#include <asm/book3s/64/hash-pkey.h>
+
+static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
+{
+ if (static_branch_likely(&pkey_disabled))
+ return 0x0UL;
+
+ if (radix_enabled())
+ BUG();
+ return hash__vmflag_to_pte_pkey_bits(vm_flags);
+}
+
+static inline u16 pte_to_pkey_bits(u64 pteflags)
+{
+ if (radix_enabled())
+ BUG();
+ return hash__pte_to_pkey_bits(pteflags);
+}
+
+#endif /*_ASM_POWERPC_KEYS_H */
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index f8f4d0793789..5dd0a79d1809 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -25,23 +25,18 @@ extern u32 reserved_allocation_mask; /* bits set for reserved keys */
PKEY_DISABLE_WRITE | \
PKEY_DISABLE_EXECUTE)
+#ifdef CONFIG_PPC_BOOK3S_64
+#include <asm/book3s/64/pkeys.h>
+#else
+#error "Not supported"
+#endif
+
+
static inline u64 pkey_to_vmflag_bits(u16 pkey)
{
return (((u64)pkey << VM_PKEY_SHIFT) & ARCH_VM_PKEY_FLAGS);
}
-static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
-{
- if (static_branch_likely(&pkey_disabled))
- return 0x0UL;
-
- return (((vm_flags & VM_PKEY_BIT0) ? H_PTE_PKEY_BIT0 : 0x0UL) |
- ((vm_flags & VM_PKEY_BIT1) ? H_PTE_PKEY_BIT1 : 0x0UL) |
- ((vm_flags & VM_PKEY_BIT2) ? H_PTE_PKEY_BIT2 : 0x0UL) |
- ((vm_flags & VM_PKEY_BIT3) ? H_PTE_PKEY_BIT3 : 0x0UL) |
- ((vm_flags & VM_PKEY_BIT4) ? H_PTE_PKEY_BIT4 : 0x0UL));
-}
-
static inline int vma_pkey(struct vm_area_struct *vma)
{
if (static_branch_likely(&pkey_disabled))
@@ -51,24 +46,6 @@ static inline int vma_pkey(struct vm_area_struct *vma)
#define arch_max_pkey() pkeys_total
-static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
-{
- return (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
-}
-
-static inline u16 pte_to_pkey_bits(u64 pteflags)
-{
- return (((pteflags & H_PTE_PKEY_BIT4) ? 0x10 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT3) ? 0x8 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT2) ? 0x4 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT1) ? 0x2 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT0) ? 0x1 : 0x0UL));
-}
-
#define pkey_alloc_mask(pkey) (0x1 << pkey)
#define mm_pkey_allocation_map(mm) (mm->context.pkey_allocation_map)
--
2.26.2
^ permalink raw reply related
* [PATCH v4 03/41] powerpc/book3s64/pkeys: Move pkey related bits in the linux page table
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
To keep things simple, all the pkey related bits are kept together
in linux page table for 64K config with hash translation. With hash-4k
kernel requires 4 bits to store slots details. This is done by overloading
some of the RPN bits for storing the slot details. Due to this PKEY_BIT0 on
the 4K config is used for storing hash slot details.
64K before
|....|RSV1| RSV2| RSV3 | RSV4 | RPN44| RPN43 |.... | RSV5|
|....| P4 | P3 | P2 | P1 | Busy | HASHPTE |.... | P0 |
after
|....|RSV1| RSV2| RSV3 | RSV4 | RPN44 | RPN43 |.... | RSV5 |
|....| P4 | P3 | P2 | P1 | P0 | HASHPTE |.... | Busy |
4k before
|....| RSV1 | RSV2 | RSV3 | RSV4 | RPN44| RPN43.... | RSV5|
|....| Busy | HASHPTE | P2 | P1 | F_SEC| F_GIX.... | P0 |
after
|....| RSV1 | RSV2| RSV3 | RSV4 | Free | RPN43.... | RSV5 |
|....| HASHPTE | P2 | P1 | P0 | F_SEC| F_GIX.... | BUSY |
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hash-4k.h | 16 ++++++++--------
arch/powerpc/include/asm/book3s/64/hash-64k.h | 12 ++++++------
arch/powerpc/include/asm/book3s/64/pgtable.h | 17 ++++++++---------
3 files changed, 22 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index f889d56bf8cf..082b98808701 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -34,11 +34,11 @@
#define H_PUD_TABLE_SIZE (sizeof(pud_t) << H_PUD_INDEX_SIZE)
#define H_PGD_TABLE_SIZE (sizeof(pgd_t) << H_PGD_INDEX_SIZE)
-#define H_PAGE_F_GIX_SHIFT 53
-#define H_PAGE_F_SECOND _RPAGE_RPN44 /* HPTE is in 2ndary HPTEG */
-#define H_PAGE_F_GIX (_RPAGE_RPN43 | _RPAGE_RPN42 | _RPAGE_RPN41)
-#define H_PAGE_BUSY _RPAGE_RSV1 /* software: PTE & hash are busy */
-#define H_PAGE_HASHPTE _RPAGE_RSV2 /* software: PTE & hash are busy */
+#define H_PAGE_F_GIX_SHIFT _PAGE_PA_MAX
+#define H_PAGE_F_SECOND _RPAGE_PKEY_BIT0 /* HPTE is in 2ndary HPTEG */
+#define H_PAGE_F_GIX (_RPAGE_RPN43 | _RPAGE_RPN42 | _RPAGE_RPN41)
+#define H_PAGE_BUSY _RPAGE_RSV1
+#define H_PAGE_HASHPTE _RPAGE_PKEY_BIT4
/* PTE flags to conserve for HPTE identification */
#define _PAGE_HPTEFLAGS (H_PAGE_BUSY | H_PAGE_HASHPTE | \
@@ -59,9 +59,9 @@
/* memory key bits, only 8 keys supported */
#define H_PTE_PKEY_BIT4 0
#define H_PTE_PKEY_BIT3 0
-#define H_PTE_PKEY_BIT2 _RPAGE_RSV3
-#define H_PTE_PKEY_BIT1 _RPAGE_RSV4
-#define H_PTE_PKEY_BIT0 _RPAGE_RSV5
+#define H_PTE_PKEY_BIT2 _RPAGE_PKEY_BIT3
+#define H_PTE_PKEY_BIT1 _RPAGE_PKEY_BIT2
+#define H_PTE_PKEY_BIT0 _RPAGE_PKEY_BIT1
/*
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 0a15fd14cf72..f20de1149ebe 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -32,15 +32,15 @@
*/
#define H_PAGE_COMBO _RPAGE_RPN0 /* this is a combo 4k page */
#define H_PAGE_4K_PFN _RPAGE_RPN1 /* PFN is for a single 4k page */
-#define H_PAGE_BUSY _RPAGE_RPN44 /* software: PTE & hash are busy */
+#define H_PAGE_BUSY _RPAGE_RSV1 /* software: PTE & hash are busy */
#define H_PAGE_HASHPTE _RPAGE_RPN43 /* PTE has associated HPTE */
/* memory key bits. */
-#define H_PTE_PKEY_BIT4 _RPAGE_RSV1
-#define H_PTE_PKEY_BIT3 _RPAGE_RSV2
-#define H_PTE_PKEY_BIT2 _RPAGE_RSV3
-#define H_PTE_PKEY_BIT1 _RPAGE_RSV4
-#define H_PTE_PKEY_BIT0 _RPAGE_RSV5
+#define H_PTE_PKEY_BIT4 _RPAGE_PKEY_BIT4
+#define H_PTE_PKEY_BIT3 _RPAGE_PKEY_BIT3
+#define H_PTE_PKEY_BIT2 _RPAGE_PKEY_BIT2
+#define H_PTE_PKEY_BIT1 _RPAGE_PKEY_BIT1
+#define H_PTE_PKEY_BIT0 _RPAGE_PKEY_BIT0
/*
* We need to differentiate between explicit huge page and THP huge
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index f17442c3a092..b7c0ba977d6a 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -32,11 +32,13 @@
#define _RPAGE_SW1 0x00800
#define _RPAGE_SW2 0x00400
#define _RPAGE_SW3 0x00200
-#define _RPAGE_RSV1 0x1000000000000000UL
-#define _RPAGE_RSV2 0x0800000000000000UL
-#define _RPAGE_RSV3 0x0400000000000000UL
-#define _RPAGE_RSV4 0x0200000000000000UL
-#define _RPAGE_RSV5 0x00040UL
+#define _RPAGE_RSV1 0x00040UL
+
+#define _RPAGE_PKEY_BIT4 0x1000000000000000UL
+#define _RPAGE_PKEY_BIT3 0x0800000000000000UL
+#define _RPAGE_PKEY_BIT2 0x0400000000000000UL
+#define _RPAGE_PKEY_BIT1 0x0200000000000000UL
+#define _RPAGE_PKEY_BIT0 0x0100000000000000UL
#define _PAGE_PTE 0x4000000000000000UL /* distinguishes PTEs from pointers */
#define _PAGE_PRESENT 0x8000000000000000UL /* pte contains a translation */
@@ -58,13 +60,12 @@
*/
#define _RPAGE_RPN0 0x01000
#define _RPAGE_RPN1 0x02000
-#define _RPAGE_RPN44 0x0100000000000000UL
#define _RPAGE_RPN43 0x0080000000000000UL
#define _RPAGE_RPN42 0x0040000000000000UL
#define _RPAGE_RPN41 0x0020000000000000UL
/* Max physical address bit as per radix table */
-#define _RPAGE_PA_MAX 57
+#define _RPAGE_PA_MAX 56
/*
* Max physical address bit we will use for now.
@@ -125,8 +126,6 @@
_PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE | \
_PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
-#define H_PTE_PKEY (H_PTE_PKEY_BIT0 | H_PTE_PKEY_BIT1 | H_PTE_PKEY_BIT2 | \
- H_PTE_PKEY_BIT3 | H_PTE_PKEY_BIT4)
/*
* We define 2 sets of base prot bits, one for basic pages (ie,
* cacheable kernel and user pages) and one for non cacheable
--
2.26.2
^ permalink raw reply related
* [PATCH v4 04/41] powerpc/book3s64/pkeys: Explain key 1 reservation details
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
This explains the details w.r.t key 1.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 1199fc2bfaec..d60e6bfa3e03 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -124,7 +124,10 @@ static int pkey_initialize(void)
#else
os_reserved = 0;
#endif
- /* Bits are in LE format. */
+ /*
+ * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
+ * programming note.
+ */
reserved_allocation_mask = (0x1 << 1) | (0x1 << execute_only_key);
/* register mask is in BE format */
--
2.26.2
^ permalink raw reply related
* [PATCH v4 05/41] powerpc/book3s64/pkeys: Simplify the key initialization
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Add documentation explaining the execute_only_key. The reservation and initialization mask
details are also explained in this patch.
No functional change in this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 186 ++++++++++++++++++-------------
1 file changed, 107 insertions(+), 79 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index d60e6bfa3e03..3db0b3cfc322 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -15,48 +15,71 @@
DEFINE_STATIC_KEY_TRUE(pkey_disabled);
int pkeys_total; /* Total pkeys as per device tree */
u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
-u32 reserved_allocation_mask; /* Bits set for reserved keys */
+/*
+ * Keys marked in the reservation list cannot be allocated by userspace
+ */
+u32 reserved_allocation_mask;
static bool pkey_execute_disable_supported;
-static bool pkeys_devtree_defined; /* property exported by device tree */
-static u64 pkey_amr_mask; /* Bits in AMR not to be touched */
-static u64 pkey_iamr_mask; /* Bits in AMR not to be touched */
-static u64 pkey_uamor_mask; /* Bits in UMOR not to be touched */
+static u64 default_amr;
+static u64 default_iamr;
+/* Allow all keys to be modified by default */
+static u64 default_uamor = ~0x0UL;
+/*
+ * Key used to implement PROT_EXEC mmap. Denies READ/WRITE
+ * We pick key 2 because 0 is special key and 1 is reserved as per ISA.
+ */
static int execute_only_key = 2;
+
#define AMR_BITS_PER_PKEY 2
#define AMR_RD_BIT 0x1UL
#define AMR_WR_BIT 0x2UL
#define IAMR_EX_BIT 0x1UL
-#define PKEY_REG_BITS (sizeof(u64)*8)
+#define PKEY_REG_BITS (sizeof(u64) * 8)
#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
-static void scan_pkey_feature(void)
+static int scan_pkey_feature(void)
{
u32 vals[2];
+ int pkeys_total = 0;
struct device_node *cpu;
+ /*
+ * Pkey is not supported with Radix translation.
+ */
+ if (radix_enabled())
+ return 0;
+
cpu = of_find_node_by_type(NULL, "cpu");
if (!cpu)
- return;
+ return 0;
if (of_property_read_u32_array(cpu,
- "ibm,processor-storage-keys", vals, 2))
- return;
+ "ibm,processor-storage-keys", vals, 2) == 0) {
+ /*
+ * Since any pkey can be used for data or execute, we will
+ * just treat all keys as equal and track them as one entity.
+ */
+ pkeys_total = vals[0];
+ /* Should we check for IAMR support FIXME!! */
+ } else {
+ /*
+ * Let's assume 32 pkeys on P8 bare metal, if its not defined by device
+ * tree. We make this exception since skiboot forgot to expose this
+ * property on power8.
+ */
+ if (!firmware_has_feature(FW_FEATURE_LPAR) &&
+ cpu_has_feature(CPU_FTRS_POWER8))
+ pkeys_total = 32;
+ }
/*
- * Since any pkey can be used for data or execute, we will just treat
- * all keys as equal and track them as one entity.
+ * Adjust the upper limit, based on the number of bits supported by
+ * arch-neutral code.
*/
- pkeys_total = vals[0];
- pkeys_devtree_defined = true;
-}
-
-static inline bool pkey_mmu_enabled(void)
-{
- if (firmware_has_feature(FW_FEATURE_LPAR))
- return pkeys_total;
- else
- return cpu_has_feature(CPU_FTR_PKEY);
+ pkeys_total = min_t(int, pkeys_total,
+ ((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) + 1));
+ return pkeys_total;
}
static int pkey_initialize(void)
@@ -80,31 +103,13 @@ static int pkey_initialize(void)
!= (sizeof(u64) * BITS_PER_BYTE));
/* scan the device tree for pkey feature */
- scan_pkey_feature();
-
- /*
- * Let's assume 32 pkeys on P8 bare metal, if its not defined by device
- * tree. We make this exception since skiboot forgot to expose this
- * property on power8.
- */
- if (!pkeys_devtree_defined && !firmware_has_feature(FW_FEATURE_LPAR) &&
- cpu_has_feature(CPU_FTRS_POWER8))
- pkeys_total = 32;
-
- /*
- * Adjust the upper limit, based on the number of bits supported by
- * arch-neutral code.
- */
- pkeys_total = min_t(int, pkeys_total,
- ((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)+1));
-
- if (!pkey_mmu_enabled() || radix_enabled() || !pkeys_total)
- static_branch_enable(&pkey_disabled);
- else
+ pkeys_total = scan_pkey_feature();
+ if (pkeys_total)
static_branch_disable(&pkey_disabled);
-
- if (static_branch_likely(&pkey_disabled))
+ else {
+ static_branch_enable(&pkey_disabled);
return 0;
+ }
/*
* The device tree cannot be relied to indicate support for
@@ -118,48 +123,71 @@ static int pkey_initialize(void)
#ifdef CONFIG_PPC_4K_PAGES
/*
* The OS can manage only 8 pkeys due to its inability to represent them
- * in the Linux 4K PTE.
+ * in the Linux 4K PTE. Mark all other keys reserved.
*/
os_reserved = pkeys_total - 8;
#else
os_reserved = 0;
#endif
- /*
- * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
- * programming note.
- */
- reserved_allocation_mask = (0x1 << 1) | (0x1 << execute_only_key);
-
- /* register mask is in BE format */
- pkey_amr_mask = ~0x0ul;
- pkey_amr_mask &= ~(0x3ul << pkeyshift(0));
-
- pkey_iamr_mask = ~0x0ul;
- pkey_iamr_mask &= ~(0x3ul << pkeyshift(0));
- pkey_iamr_mask &= ~(0x3ul << pkeyshift(execute_only_key));
-
- pkey_uamor_mask = ~0x0ul;
- pkey_uamor_mask &= ~(0x3ul << pkeyshift(0));
- pkey_uamor_mask &= ~(0x3ul << pkeyshift(execute_only_key));
-
- /* mark the rest of the keys as reserved and hence unavailable */
- for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
- reserved_allocation_mask |= (0x1 << i);
- pkey_uamor_mask &= ~(0x3ul << pkeyshift(i));
- }
- initial_allocation_mask = reserved_allocation_mask | (0x1 << 0);
if (unlikely((pkeys_total - os_reserved) <= execute_only_key)) {
/*
* Insufficient number of keys to support
* execute only key. Mark it unavailable.
- * Any AMR, UAMOR, IAMR bit set for
- * this key is irrelevant since this key
- * can never be allocated.
*/
execute_only_key = -1;
+ } else {
+ /*
+ * Mark the execute_only_pkey as not available for
+ * user allocation via pkey_alloc.
+ */
+ reserved_allocation_mask |= (0x1 << execute_only_key);
+
+ /*
+ * Deny READ/WRITE for execute_only_key.
+ * Allow execute in IAMR.
+ */
+ default_amr |= (0x3ul << pkeyshift(execute_only_key));
+ default_iamr &= ~(0x3ul << pkeyshift(execute_only_key));
+
+ /*
+ * Clear the uamor bits for this key.
+ */
+ default_uamor &= ~(0x3ul << pkeyshift(execute_only_key));
}
+ /*
+ * Allow access for only key 0. And prevent any other modification.
+ */
+ default_amr &= ~(0x3ul << pkeyshift(0));
+ default_iamr &= ~(0x3ul << pkeyshift(0));
+ default_uamor &= ~(0x3ul << pkeyshift(0));
+ /*
+ * key 0 is special in that we want to consider it an allocated
+ * key which is preallocated. We don't allow changing AMR bits
+ * w.r.t key 0. But one can pkey_free(key0)
+ */
+ initial_allocation_mask |= (0x1 << 0);
+
+ /*
+ * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
+ * programming note.
+ */
+ reserved_allocation_mask |= (0x1 << 1);
+
+ /*
+ * Prevent the usage of OS reserved the keys. Update UAMOR
+ * for those keys.
+ */
+ for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
+ reserved_allocation_mask |= (0x1 << i);
+ default_uamor &= ~(0x3ul << pkeyshift(i));
+ }
+ /*
+ * Prevent the allocation of reserved keys too.
+ */
+ initial_allocation_mask |= reserved_allocation_mask;
+
return 0;
}
@@ -301,13 +329,13 @@ void thread_pkey_regs_init(struct thread_struct *thread)
if (static_branch_likely(&pkey_disabled))
return;
- thread->amr = pkey_amr_mask;
- thread->iamr = pkey_iamr_mask;
- thread->uamor = pkey_uamor_mask;
+ thread->amr = default_amr;
+ thread->iamr = default_iamr;
+ thread->uamor = default_uamor;
- write_uamor(pkey_uamor_mask);
- write_amr(pkey_amr_mask);
- write_iamr(pkey_iamr_mask);
+ write_amr(default_amr);
+ write_iamr(default_iamr);
+ write_uamor(default_uamor);
}
int __execute_only_pkey(struct mm_struct *mm)
--
2.26.2
^ permalink raw reply related
* [PATCH v4 06/41] powerpc/book3s64/pkeys: Prevent key 1 modification from userspace.
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Key 1 is marked reserved by ISA. Setup uamor to prevent userspace modification
of the same.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 3db0b3cfc322..9e68a08799ee 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -174,6 +174,7 @@ static int pkey_initialize(void)
* programming note.
*/
reserved_allocation_mask |= (0x1 << 1);
+ default_uamor &= ~(0x3ul << pkeyshift(1));
/*
* Prevent the usage of OS reserved the keys. Update UAMOR
--
2.26.2
^ permalink raw reply related
* [PATCH v4 08/41] powerpc/book3s64/pkeys: Convert execute key support to static key
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Convert the bool to a static key like pkey_disabled.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 9e68a08799ee..7d400d5a4076 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -13,13 +13,13 @@
#include <linux/of_device.h>
DEFINE_STATIC_KEY_TRUE(pkey_disabled);
+DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
int pkeys_total; /* Total pkeys as per device tree */
u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
/*
* Keys marked in the reservation list cannot be allocated by userspace
*/
u32 reserved_allocation_mask;
-static bool pkey_execute_disable_supported;
static u64 default_amr;
static u64 default_iamr;
/* Allow all keys to be modified by default */
@@ -116,9 +116,7 @@ static int pkey_initialize(void)
* execute_disable support. Instead we use a PVR check.
*/
if (pvr_version_is(PVR_POWER7) || pvr_version_is(PVR_POWER7p))
- pkey_execute_disable_supported = false;
- else
- pkey_execute_disable_supported = true;
+ static_branch_enable(&execute_pkey_disabled);
#ifdef CONFIG_PPC_4K_PAGES
/*
@@ -214,7 +212,7 @@ static inline void write_amr(u64 value)
static inline u64 read_iamr(void)
{
- if (!likely(pkey_execute_disable_supported))
+ if (static_branch_unlikely(&execute_pkey_disabled))
return 0x0UL;
return mfspr(SPRN_IAMR);
@@ -222,7 +220,7 @@ static inline u64 read_iamr(void)
static inline void write_iamr(u64 value)
{
- if (!likely(pkey_execute_disable_supported))
+ if (static_branch_unlikely(&execute_pkey_disabled))
return;
mtspr(SPRN_IAMR, value);
@@ -282,7 +280,7 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
return -EINVAL;
if (init_val & PKEY_DISABLE_EXECUTE) {
- if (!pkey_execute_disable_supported)
+ if (static_branch_unlikely(&execute_pkey_disabled))
return -EINVAL;
new_iamr_bits |= IAMR_EX_BIT;
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 09/41] powerpc/book3s64/pkeys: Simplify pkey disable branch
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Make the default value FALSE (pkey enabled) and set to TRUE when we
find the total number of keys supported to be zero.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 2 +-
arch/powerpc/mm/book3s64/pkeys.c | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 5dd0a79d1809..75d2a2c19c04 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -11,7 +11,7 @@
#include <linux/jump_label.h>
#include <asm/firmware.h>
-DECLARE_STATIC_KEY_TRUE(pkey_disabled);
+DECLARE_STATIC_KEY_FALSE(pkey_disabled);
extern int pkeys_total; /* total pkeys as per device tree */
extern u32 initial_allocation_mask; /* bits set for the initially allocated keys */
extern u32 reserved_allocation_mask; /* bits set for reserved keys */
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 7d400d5a4076..87d882a9aaf2 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -12,7 +12,7 @@
#include <linux/pkeys.h>
#include <linux/of_device.h>
-DEFINE_STATIC_KEY_TRUE(pkey_disabled);
+DEFINE_STATIC_KEY_FALSE(pkey_disabled);
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
int pkeys_total; /* Total pkeys as per device tree */
u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
@@ -104,9 +104,8 @@ static int pkey_initialize(void)
/* scan the device tree for pkey feature */
pkeys_total = scan_pkey_feature();
- if (pkeys_total)
- static_branch_disable(&pkey_disabled);
- else {
+ if (!pkeys_total) {
+ /* No support for pkey. Mark it disabled */
static_branch_enable(&pkey_disabled);
return 0;
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 10/41] powerpc/book3s64/pkeys: Convert pkey_total to max_pkey
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
max_pkey now represents max key value that userspace can allocate.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 7 +++++--
arch/powerpc/mm/book3s64/pkeys.c | 14 +++++++-------
2 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 75d2a2c19c04..652bad7334f3 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -12,7 +12,7 @@
#include <asm/firmware.h>
DECLARE_STATIC_KEY_FALSE(pkey_disabled);
-extern int pkeys_total; /* total pkeys as per device tree */
+extern int max_pkey;
extern u32 initial_allocation_mask; /* bits set for the initially allocated keys */
extern u32 reserved_allocation_mask; /* bits set for reserved keys */
@@ -44,7 +44,10 @@ 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() pkeys_total
+static inline int arch_max_pkey(void)
+{
+ return max_pkey;
+}
#define pkey_alloc_mask(pkey) (0x1 << pkey)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 87d882a9aaf2..a4d7287082a8 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -14,7 +14,7 @@
DEFINE_STATIC_KEY_FALSE(pkey_disabled);
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
-int pkeys_total; /* Total pkeys as per device tree */
+int max_pkey; /* Maximum key value supported */
u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
/*
* Keys marked in the reservation list cannot be allocated by userspace
@@ -84,7 +84,7 @@ static int scan_pkey_feature(void)
static int pkey_initialize(void)
{
- int os_reserved, i;
+ int pkeys_total, i;
/*
* We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral
@@ -122,12 +122,12 @@ static int pkey_initialize(void)
* The OS can manage only 8 pkeys due to its inability to represent them
* in the Linux 4K PTE. Mark all other keys reserved.
*/
- os_reserved = pkeys_total - 8;
+ max_pkey = min(8, pkeys_total);
#else
- os_reserved = 0;
+ max_pkey = pkeys_total;
#endif
- if (unlikely((pkeys_total - os_reserved) <= execute_only_key)) {
+ if (unlikely(max_pkey <= execute_only_key)) {
/*
* Insufficient number of keys to support
* execute only key. Mark it unavailable.
@@ -174,10 +174,10 @@ static int pkey_initialize(void)
default_uamor &= ~(0x3ul << pkeyshift(1));
/*
- * Prevent the usage of OS reserved the keys. Update UAMOR
+ * Prevent the usage of OS reserved keys. Update UAMOR
* for those keys.
*/
- for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
+ for (i = max_pkey; i < pkeys_total; i++) {
reserved_allocation_mask |= (0x1 << i);
default_uamor &= ~(0x3ul << pkeyshift(i));
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 11/41] powerpc/book3s64/pkeys: Make initial_allocation_mask static
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
initial_allocation_mask is not used outside this file.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 1 -
arch/powerpc/mm/book3s64/pkeys.c | 2 +-
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 652bad7334f3..47c81d41ea9a 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -13,7 +13,6 @@
DECLARE_STATIC_KEY_FALSE(pkey_disabled);
extern int max_pkey;
-extern u32 initial_allocation_mask; /* bits set for the initially allocated keys */
extern u32 reserved_allocation_mask; /* bits set for reserved keys */
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index a4d7287082a8..73b5ef1490c8 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -15,11 +15,11 @@
DEFINE_STATIC_KEY_FALSE(pkey_disabled);
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
int max_pkey; /* Maximum key value supported */
-u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
/*
* Keys marked in the reservation list cannot be allocated by userspace
*/
u32 reserved_allocation_mask;
+static u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
static u64 default_amr;
static u64 default_iamr;
/* Allow all keys to be modified by default */
--
2.26.2
^ permalink raw reply related
* [PATCH v4 12/41] powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reserved
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
The hypervisor can return less than max allowed pkey (for ex: 31) instead
of 32. We should mark all the pkeys above max allowed as reserved so
that we avoid the allocation of the wrong pkey(for ex: key 31 in the above
case) by userspace.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 73b5ef1490c8..0ff59acdbb84 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -175,9 +175,10 @@ static int pkey_initialize(void)
/*
* Prevent the usage of OS reserved keys. Update UAMOR
- * for those keys.
+ * for those keys. Also mark the rest of the bits in the
+ * 32 bit mask as reserved.
*/
- for (i = max_pkey; i < pkeys_total; i++) {
+ for (i = max_pkey; i < 32 ; i++) {
reserved_allocation_mask |= (0x1 << i);
default_uamor &= ~(0x3ul << pkeyshift(i));
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 13/41] powerpc/book3s64/pkeys: Enable MMU_FTR_PKEY
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Parse storage keys related device tree entry in early_init_devtree
and enable MMU feature MMU_FTR_PKEY if pkeys are supported.
MMU feature is used instead of CPU feature because this enables us
to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/mmu.h | 6 +++
arch/powerpc/include/asm/mmu.h | 6 +++
arch/powerpc/kernel/prom.c | 5 +++
arch/powerpc/mm/book3s64/pkeys.c | 54 ++++++++++++++----------
4 files changed, 48 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index 5393a535240c..3371ea05b7d3 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -209,6 +209,12 @@ extern int mmu_io_psize;
void mmu_early_init_devtree(void);
void hash__early_init_devtree(void);
void radix__early_init_devtree(void);
+#ifdef CONFIG_PPC_MEM_KEYS
+void pkey_early_init_devtree(void);
+#else
+static inline void pkey_early_init_devtree(void) {}
+#endif
+
extern void hash__early_init_mmu(void);
extern void radix__early_init_mmu(void);
static inline void __init early_init_mmu(void)
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index f4ac25d4df05..72966d3d8f64 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -23,6 +23,7 @@
/* Radix page table supported and enabled */
#define MMU_FTR_TYPE_RADIX ASM_CONST(0x00000040)
+#define MMU_FTR_PKEY ASM_CONST(0x00000080)
/*
* Individual features below.
@@ -177,6 +178,9 @@ enum {
MMU_FTR_RADIX_KUAP |
#endif /* CONFIG_PPC_KUAP */
#endif /* CONFIG_PPC_RADIX_MMU */
+#ifdef CONFIG_PPC_MEM_KEYS
+ MMU_FTR_PKEY |
+#endif
0,
};
@@ -356,6 +360,8 @@ extern void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size);
static inline void mmu_early_init_devtree(void) { }
+static inline void pkey_early_init_devtree(void) {}
+
extern void *abatron_pteptrs[2];
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 6a3bac357e24..6d70797352d8 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -815,6 +815,11 @@ void __init early_init_devtree(void *params)
/* Now try to figure out if we are running on LPAR and so on */
pseries_probe_fw_features();
+ /*
+ * Initialize pkey features and default AMR/IAMR values
+ */
+ pkey_early_init_devtree();
+
#ifdef CONFIG_PPC_PS3
/* Identify PS3 firmware */
if (of_flat_dt_is_compatible(of_get_flat_dt_root(), "sony,ps3"))
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 0ff59acdbb84..bbba9c601e14 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -10,7 +10,8 @@
#include <asm/mmu.h>
#include <asm/setup.h>
#include <linux/pkeys.h>
-#include <linux/of_device.h>
+#include <linux/of_fdt.h>
+
DEFINE_STATIC_KEY_FALSE(pkey_disabled);
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
@@ -38,38 +39,45 @@ static int execute_only_key = 2;
#define PKEY_REG_BITS (sizeof(u64) * 8)
#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
+static int __init dt_scan_storage_keys(unsigned long node,
+ const char *uname, int depth,
+ void *data)
+{
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ const __be32 *prop;
+ int pkeys_total;
+
+ /* We are scanning "cpu" nodes only */
+ if (type == NULL || strcmp(type, "cpu") != 0)
+ return 0;
+
+ prop = of_get_flat_dt_prop(node, "ibm,processor-storage-keys", NULL);
+ if (!prop)
+ return 0;
+ pkeys_total = be32_to_cpu(prop[0]);
+ return pkeys_total;
+}
+
static int scan_pkey_feature(void)
{
- u32 vals[2];
- int pkeys_total = 0;
- struct device_node *cpu;
+ int pkeys_total;
/*
* Pkey is not supported with Radix translation.
*/
- if (radix_enabled())
+ if (early_radix_enabled())
return 0;
- cpu = of_find_node_by_type(NULL, "cpu");
- if (!cpu)
- return 0;
+ pkeys_total = of_scan_flat_dt(dt_scan_storage_keys, NULL);
+ if (pkeys_total == 0) {
- if (of_property_read_u32_array(cpu,
- "ibm,processor-storage-keys", vals, 2) == 0) {
- /*
- * Since any pkey can be used for data or execute, we will
- * just treat all keys as equal and track them as one entity.
- */
- pkeys_total = vals[0];
- /* Should we check for IAMR support FIXME!! */
- } else {
/*
* Let's assume 32 pkeys on P8 bare metal, if its not defined by device
* tree. We make this exception since skiboot forgot to expose this
* property on power8.
*/
if (!firmware_has_feature(FW_FEATURE_LPAR) &&
- cpu_has_feature(CPU_FTRS_POWER8))
+ early_cpu_has_feature(CPU_FTRS_POWER8))
pkeys_total = 32;
}
@@ -82,7 +90,7 @@ static int scan_pkey_feature(void)
return pkeys_total;
}
-static int pkey_initialize(void)
+void __init pkey_early_init_devtree(void)
{
int pkeys_total, i;
@@ -107,9 +115,11 @@ static int pkey_initialize(void)
if (!pkeys_total) {
/* No support for pkey. Mark it disabled */
static_branch_enable(&pkey_disabled);
- return 0;
+ return;
}
+ cur_cpu_spec->mmu_features |= MMU_FTR_PKEY;
+
/*
* The device tree cannot be relied to indicate support for
* execute_disable support. Instead we use a PVR check.
@@ -187,11 +197,9 @@ static int pkey_initialize(void)
*/
initial_allocation_mask |= reserved_allocation_mask;
- return 0;
+ return;
}
-arch_initcall(pkey_initialize);
-
void pkey_mm_init(struct mm_struct *mm)
{
if (static_branch_likely(&pkey_disabled))
--
2.26.2
^ permalink raw reply related
* [PATCH v4 14/41] powerpc/book3s64/kuep: Add MMU_FTR_KUEP
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
This will be used to enable/disable Kernel Userspace Execution
Prevention (KUEP).
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/mmu.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 72966d3d8f64..94435f85e3bc 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -24,6 +24,7 @@
/* Radix page table supported and enabled */
#define MMU_FTR_TYPE_RADIX ASM_CONST(0x00000040)
#define MMU_FTR_PKEY ASM_CONST(0x00000080)
+#define MMU_FTR_KUEP ASM_CONST(0x00000100)
/*
* Individual features below.
@@ -181,6 +182,10 @@ enum {
#ifdef CONFIG_PPC_MEM_KEYS
MMU_FTR_PKEY |
#endif
+#ifdef CONFIG_PPC_KUEP
+ MMU_FTR_KUEP |
+#endif /* CONFIG_PPC_KUAP */
+
0,
};
--
2.26.2
^ permalink raw reply related
* [PATCH v4 15/41] powerpc/book3s64/pkeys: Use execute_pkey_disable static key
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Use execute_pkey_disabled static key to check for execute key support instead
of pkey_disabled.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 10 +---------
arch/powerpc/mm/book3s64/pkeys.c | 5 ++++-
2 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 47c81d41ea9a..09fbaa409ac4 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -126,15 +126,7 @@ static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
* Try to dedicate one of the protection keys to be used as an
* execute-only protection key.
*/
-extern int __execute_only_pkey(struct mm_struct *mm);
-static inline int execute_only_pkey(struct mm_struct *mm)
-{
- if (static_branch_likely(&pkey_disabled))
- return -1;
-
- return __execute_only_pkey(mm);
-}
-
+extern int execute_only_pkey(struct mm_struct *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,
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index bbba9c601e14..fed4f159011b 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -345,8 +345,11 @@ void thread_pkey_regs_init(struct thread_struct *thread)
write_uamor(default_uamor);
}
-int __execute_only_pkey(struct mm_struct *mm)
+int execute_only_pkey(struct mm_struct *mm)
{
+ if (static_branch_likely(&execute_pkey_disabled))
+ return -1;
+
return mm->context.execute_only_pkey;
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 16/41] powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled static key
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/pkeys.h | 2 +-
arch/powerpc/include/asm/pkeys.h | 14 ++++++--------
arch/powerpc/mm/book3s64/pkeys.c | 16 +++++++---------
3 files changed, 14 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h
index 8174662a9173..5b178139f3c0 100644
--- a/arch/powerpc/include/asm/book3s/64/pkeys.h
+++ b/arch/powerpc/include/asm/book3s/64/pkeys.h
@@ -7,7 +7,7 @@
static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return 0x0UL;
if (radix_enabled())
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 09fbaa409ac4..b1d448c53209 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -11,7 +11,6 @@
#include <linux/jump_label.h>
#include <asm/firmware.h>
-DECLARE_STATIC_KEY_FALSE(pkey_disabled);
extern int max_pkey;
extern u32 reserved_allocation_mask; /* bits set for reserved keys */
@@ -38,7 +37,7 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey)
static inline int vma_pkey(struct vm_area_struct *vma)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return 0;
return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
}
@@ -93,9 +92,8 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
u32 all_pkeys_mask = (u32)(~(0x0));
int ret;
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return -1;
-
/*
* Are we out of pkeys? We must handle this specially because ffz()
* behavior is undefined if there are no zeros.
@@ -111,7 +109,7 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return -1;
if (!mm_pkey_is_allocated(mm, pkey))
@@ -132,7 +130,7 @@ extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
int prot, int pkey)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return 0;
/*
@@ -150,7 +148,7 @@ extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
unsigned long init_val)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return -EINVAL;
/*
@@ -167,7 +165,7 @@ static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
static inline bool arch_pkeys_enabled(void)
{
- return !static_branch_likely(&pkey_disabled);
+ return mmu_has_feature(MMU_FTR_PKEY);
}
extern void pkey_mm_init(struct mm_struct *mm);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index fed4f159011b..810118123e70 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -13,7 +13,6 @@
#include <linux/of_fdt.h>
-DEFINE_STATIC_KEY_FALSE(pkey_disabled);
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
int max_pkey; /* Maximum key value supported */
/*
@@ -114,7 +113,6 @@ void __init pkey_early_init_devtree(void)
pkeys_total = scan_pkey_feature();
if (!pkeys_total) {
/* No support for pkey. Mark it disabled */
- static_branch_enable(&pkey_disabled);
return;
}
@@ -202,7 +200,7 @@ void __init pkey_early_init_devtree(void)
void pkey_mm_init(struct mm_struct *mm)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return;
mm_pkey_allocation_map(mm) = initial_allocation_mask;
mm->context.execute_only_pkey = execute_only_key;
@@ -306,7 +304,7 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
void thread_pkey_regs_save(struct thread_struct *thread)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return;
/*
@@ -320,7 +318,7 @@ void thread_pkey_regs_save(struct thread_struct *thread)
void thread_pkey_regs_restore(struct thread_struct *new_thread,
struct thread_struct *old_thread)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return;
if (old_thread->amr != new_thread->amr)
@@ -333,7 +331,7 @@ void thread_pkey_regs_restore(struct thread_struct *new_thread,
void thread_pkey_regs_init(struct thread_struct *thread)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return;
thread->amr = default_amr;
@@ -408,7 +406,7 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return true;
return pkey_access_permitted(pte_to_pkey_bits(pte), write, execute);
@@ -425,7 +423,7 @@ bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
bool execute, bool foreign)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return true;
/*
* Do not enforce our key-permissions on a foreign vma.
@@ -438,7 +436,7 @@ bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm)
{
- if (static_branch_likely(&pkey_disabled))
+ if (!mmu_has_feature(MMU_FTR_PKEY))
return;
/* Duplicate the oldmm pkey state in mm: */
--
2.26.2
^ permalink raw reply related
* [PATCH v4 17/41] powerpc/book3s64/kuap: Move KUAP related function outside radix
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
The next set of patches adds support for kuap with hash translation.
In preparation for that rename/move kuap related functions to
non radix names.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
.../asm/book3s/64/{kup-radix.h => kup.h} | 6 +++---
arch/powerpc/include/asm/kup.h | 2 +-
arch/powerpc/kernel/syscall_64.c | 2 +-
arch/powerpc/mm/book3s64/pkeys.c | 19 +++++++++++++++++++
arch/powerpc/mm/book3s64/radix_pgtable.c | 18 ------------------
5 files changed, 24 insertions(+), 23 deletions(-)
rename arch/powerpc/include/asm/book3s/64/{kup-radix.h => kup.h} (97%)
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup.h
similarity index 97%
rename from arch/powerpc/include/asm/book3s/64/kup-radix.h
rename to arch/powerpc/include/asm/book3s/64/kup.h
index 3ee1ec60be84..dff1fef765fa 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H
-#define _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H
+#ifndef _ASM_POWERPC_BOOK3S_64_KUP_H
+#define _ASM_POWERPC_BOOK3S_64_KUP_H
#include <linux/const.h>
#include <asm/reg.h>
@@ -182,4 +182,4 @@ static inline unsigned long kuap_get_and_check_amr(void)
#endif /* __ASSEMBLY__ */
-#endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */
+#endif /* _ASM_POWERPC_BOOK3S_64_KUP_H */
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index c745ee41ad66..015f51b02741 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -15,7 +15,7 @@
#define KUAP_CURRENT (KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
#ifdef CONFIG_PPC64
-#include <asm/book3s/64/kup-radix.h>
+#include <asm/book3s/64/kup.h>
#endif
#ifdef CONFIG_PPC_8xx
#include <asm/nohash/32/kup-8xx.h>
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 79edba3ab312..7e560a01afa4 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -2,7 +2,7 @@
#include <linux/err.h>
#include <asm/asm-prototypes.h>
-#include <asm/book3s/64/kup-radix.h>
+#include <asm/book3s/64/kup.h>
#include <asm/cputime.h>
#include <asm/hw_irq.h>
#include <asm/kprobes.h>
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 810118123e70..cdd200441b58 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -12,6 +12,7 @@
#include <linux/pkeys.h>
#include <linux/of_fdt.h>
+#include <asm/smp.h>
DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
int max_pkey; /* Maximum key value supported */
@@ -198,6 +199,24 @@ void __init pkey_early_init_devtree(void)
return;
}
+#ifdef CONFIG_PPC_KUAP
+void __init setup_kuap(bool disabled)
+{
+ if (disabled || !early_radix_enabled())
+ return;
+
+ if (smp_processor_id() == boot_cpuid) {
+ pr_info("Activating Kernel Userspace Access Prevention\n");
+ cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
+ }
+
+ /* Make sure userspace can't change the AMR */
+ mtspr(SPRN_UAMOR, 0);
+ mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ isync();
+}
+#endif
+
void pkey_mm_init(struct mm_struct *mm)
{
if (!mmu_has_feature(MMU_FTR_PKEY))
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 8acb96de0e48..7ebaf35ec21d 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -532,24 +532,6 @@ void setup_kuep(bool disabled)
}
#endif
-#ifdef CONFIG_PPC_KUAP
-void setup_kuap(bool disabled)
-{
- if (disabled || !early_radix_enabled())
- return;
-
- if (smp_processor_id() == boot_cpuid) {
- pr_info("Activating Kernel Userspace Access Prevention\n");
- cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
- }
-
- /* Make sure userspace can't change the AMR */
- mtspr(SPRN_UAMOR, 0);
- mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
- isync();
-}
-#endif
-
void __init radix__early_init_mmu(void)
{
unsigned long lpcr;
--
2.26.2
^ permalink raw reply related
* [PATCH v4 18/41] powerpc/book3s64/kuep: Move KUEP related function outside radix
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
The next set of patches adds support for kuep with hash translation.
In preparation for that rename/move kuap related functions to
non radix names.
Also set MMU_FTR_KUEP and add the missing isync().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 1 +
arch/powerpc/mm/book3s64/pkeys.c | 21 +++++++++++++++++++++
arch/powerpc/mm/book3s64/radix_pgtable.c | 18 ------------------
3 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index dff1fef765fa..bbac8b47df13 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -7,6 +7,7 @@
#define AMR_KUAP_BLOCK_READ UL(0x4000000000000000)
#define AMR_KUAP_BLOCK_WRITE UL(0x8000000000000000)
+#define AMR_KUEP_BLOCKED (1UL << 62)
#define AMR_KUAP_BLOCKED (AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE)
#define AMR_KUAP_SHIFT 62
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index cdd200441b58..3c048a8d238f 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -199,6 +199,27 @@ void __init pkey_early_init_devtree(void)
return;
}
+#ifdef CONFIG_PPC_KUEP
+void __init setup_kuep(bool disabled)
+{
+ if (disabled || !early_radix_enabled())
+ return;
+
+ if (smp_processor_id() == boot_cpuid) {
+ pr_info("Activating Kernel Userspace Execution Prevention\n");
+ cur_cpu_spec->mmu_features |= MMU_FTR_KUEP;
+ }
+
+ /*
+ * Radix always uses key0 of the IAMR to determine if an access is
+ * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction
+ * fetch.
+ */
+ mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED);
+ isync();
+}
+#endif
+
#ifdef CONFIG_PPC_KUAP
void __init setup_kuap(bool disabled)
{
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 7ebaf35ec21d..2f641e1d7e82 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -514,24 +514,6 @@ static void radix_init_amor(void)
mtspr(SPRN_AMOR, (3ul << 62));
}
-#ifdef CONFIG_PPC_KUEP
-void setup_kuep(bool disabled)
-{
- if (disabled || !early_radix_enabled())
- return;
-
- if (smp_processor_id() == boot_cpuid)
- pr_info("Activating Kernel Userspace Execution Prevention\n");
-
- /*
- * Radix always uses key0 of the IAMR to determine if an access is
- * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction
- * fetch.
- */
- mtspr(SPRN_IAMR, (1ul << 62));
-}
-#endif
-
void __init radix__early_init_mmu(void)
{
unsigned long lpcr;
--
2.26.2
^ permalink raw reply related
* [PATCH v4 20/41] powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of PPC_MEM_KEYS
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
The next set of patches adds support for kuap with hash translation.
Hence make KUAP a BOOK3S_64 feature. Also make it a subfeature of
PPC_MEM_KEYS. Hash translation is going to use pkeys to support
KUAP/KUEP. Adding this dependency reduces the code complexity and
enables us to move some of the initialization code to pkeys.c
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 33 ++++++++++++++----------
arch/powerpc/include/asm/ptrace.h | 2 +-
arch/powerpc/kernel/asm-offsets.c | 2 +-
arch/powerpc/platforms/Kconfig.cputype | 4 +--
4 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 476bcd7b0e8b..aa2787c8b12a 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -62,7 +62,7 @@
#else /* !__ASSEMBLY__ */
-#ifdef CONFIG_PPC_KUAP
+#ifdef CONFIG_PPC_MEM_KEYS
#include <asm/mmu.h>
#include <asm/ptrace.h>
@@ -97,6 +97,24 @@ static inline void kuap_check_amr(void)
WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
}
+#else /* CONFIG_PPC_MEM_KEYS */
+
+static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
+{
+}
+
+static inline void kuap_check_amr(void)
+{
+}
+
+static inline unsigned long kuap_get_and_check_amr(void)
+{
+ return 0;
+}
+#endif /* CONFIG_PPC_MEM_KEYS */
+
+
+#ifdef CONFIG_PPC_KUAP
/*
* We support individually allowing read or write, but we don't support nesting
* because that would require an expensive read/modify write of the AMR.
@@ -166,19 +184,6 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
(regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
"Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
}
-#else /* CONFIG_PPC_KUAP */
-static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
-{
-}
-
-static inline void kuap_check_amr(void)
-{
-}
-
-static inline unsigned long kuap_get_and_check_amr(void)
-{
- return 0;
-}
#endif /* CONFIG_PPC_KUAP */
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index ac3970fff0d5..1a6cadf63d14 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -53,7 +53,7 @@ struct pt_regs
#ifdef CONFIG_PPC64
unsigned long ppr;
#endif
-#ifdef CONFIG_PPC_KUAP
+#ifdef CONFIG_PPC_HAVE_KUAP
unsigned long kuap;
#endif
};
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 9b9cde07e396..1694c4f531b9 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -354,7 +354,7 @@ int main(void)
STACK_PT_REGS_OFFSET(_PPR, ppr);
#endif /* CONFIG_PPC64 */
-#ifdef CONFIG_PPC_KUAP
+#ifdef CONFIG_PPC_HAVE_KUAP
STACK_PT_REGS_OFFSET(STACK_REGS_KUAP, kuap);
#endif
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index d349603fb889..053c46aecf80 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -99,6 +99,8 @@ config PPC_BOOK3S_64
select ARCH_SUPPORTS_NUMA_BALANCING
select IRQ_WORK
select PPC_MM_SLICES
+ select PPC_HAVE_KUAP if PPC_MEM_KEYS
+ select PPC_HAVE_KUEP if PPC_MEM_KEYS
config PPC_BOOK3E_64
bool "Embedded processors"
@@ -350,8 +352,6 @@ config PPC_RADIX_MMU
bool "Radix MMU Support"
depends on PPC_BOOK3S_64
select ARCH_HAS_GIGANTIC_PAGE
- select PPC_HAVE_KUEP
- select PPC_HAVE_KUAP
default y
help
Enable support for the Power ISA 3.0 Radix style MMU. Currently this
--
2.26.2
^ permalink raw reply related
* [PATCH v4 21/41] powerpc/book3s64/kuap: Move UAMOR setup to key init function
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
With hash translation, the kernel will use key 3 for implementing
KUAP feature. Hence the default UAMOR value depends on what other
keys are marked reserved. Move the UAMOR initialization to pkeys init.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 2 ++
arch/powerpc/kernel/smp.c | 5 +++++
arch/powerpc/mm/book3s64/pkeys.c | 25 +++++++++++++++++++-----
3 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index aa2787c8b12a..e6ee1c34842f 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -67,6 +67,8 @@
#include <asm/mmu.h>
#include <asm/ptrace.h>
+extern u64 default_uamor;
+
static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
{
if (mmu_has_feature(MMU_FTR_KUAP) && unlikely(regs->kuap != amr)) {
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index c820c95162ff..eec40082599f 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -59,6 +59,7 @@
#include <asm/asm-prototypes.h>
#include <asm/cpu_has_feature.h>
#include <asm/ftrace.h>
+#include <asm/kup.h>
#ifdef DEBUG
#include <asm/udbg.h>
@@ -1256,6 +1257,10 @@ void start_secondary(void *unused)
mmgrab(&init_mm);
current->active_mm = &init_mm;
+#ifdef CONFIG_PPC_MEM_KEYS
+ mtspr(SPRN_UAMOR, default_uamor);
+#endif
+
smp_store_cpu_info(cpu);
set_dec(tb_ticks_per_jiffy);
preempt_disable();
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index ad3348b7e25c..4a7d05c1a9c7 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -24,7 +24,7 @@ static u32 initial_allocation_mask; /* Bits set for the initially allocated k
static u64 default_amr;
static u64 default_iamr;
/* Allow all keys to be modified by default */
-static u64 default_uamor = ~0x0UL;
+u64 default_uamor = ~0x0UL;
/*
* Key used to implement PROT_EXEC mmap. Denies READ/WRITE
* We pick key 2 because 0 is special key and 1 is reserved as per ISA.
@@ -113,8 +113,16 @@ void __init pkey_early_init_devtree(void)
/* scan the device tree for pkey feature */
pkeys_total = scan_pkey_feature();
if (!pkeys_total) {
- /* No support for pkey. Mark it disabled */
- return;
+ /*
+ * No key support but on radix we can use key 0
+ * to implement kuap.
+ */
+ if (early_radix_enabled())
+ /*
+ * Make sure userspace can't change the AMR
+ */
+ default_uamor = 0;
+ goto err_out;
}
cur_cpu_spec->mmu_features |= MMU_FTR_PKEY;
@@ -196,6 +204,12 @@ void __init pkey_early_init_devtree(void)
*/
initial_allocation_mask |= reserved_allocation_mask;
+err_out:
+ /*
+ * Setup uamor on boot cpu
+ */
+ mtspr(SPRN_UAMOR, default_uamor);
+
return;
}
@@ -231,8 +245,9 @@ void __init setup_kuap(bool disabled)
cur_cpu_spec->mmu_features |= MMU_FTR_KUAP;
}
- /* Make sure userspace can't change the AMR */
- mtspr(SPRN_UAMOR, 0);
+ /*
+ * Set the default kernel AMR values on all cpus.
+ */
mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
isync();
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 22/41] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
This patch updates kernel hash page table entries to use storage key 3
for its mapping. This implies all kernel access will now use key 3 to
control READ/WRITE. The patch also prevents the allocation of key 3 from
userspace and UAMOR value is updated such that userspace cannot modify key 3.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
.../powerpc/include/asm/book3s/64/hash-pkey.h | 24 ++++++++++++++-----
arch/powerpc/include/asm/book3s/64/hash.h | 3 ++-
arch/powerpc/include/asm/book3s/64/mmu-hash.h | 1 +
arch/powerpc/include/asm/mmu_context.h | 2 +-
arch/powerpc/mm/book3s64/hash_4k.c | 2 +-
arch/powerpc/mm/book3s64/hash_64k.c | 4 ++--
arch/powerpc/mm/book3s64/hash_hugepage.c | 2 +-
arch/powerpc/mm/book3s64/hash_hugetlbpage.c | 2 +-
arch/powerpc/mm/book3s64/hash_pgtable.c | 2 +-
arch/powerpc/mm/book3s64/hash_utils.c | 10 ++++----
arch/powerpc/mm/book3s64/pkeys.c | 4 ++++
11 files changed, 38 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-pkey.h b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
index 795010897e5d..9f44e208f036 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-pkey.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
@@ -2,6 +2,9 @@
#ifndef _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
#define _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
+/* We use key 3 for KERNEL */
+#define HASH_DEFAULT_KERNEL_KEY (HPTE_R_KEY_BIT0 | HPTE_R_KEY_BIT1)
+
static inline u64 hash__vmflag_to_pte_pkey_bits(u64 vm_flags)
{
return (((vm_flags & VM_PKEY_BIT0) ? H_PTE_PKEY_BIT0 : 0x0UL) |
@@ -11,13 +14,22 @@ static inline u64 hash__vmflag_to_pte_pkey_bits(u64 vm_flags)
((vm_flags & VM_PKEY_BIT4) ? H_PTE_PKEY_BIT4 : 0x0UL));
}
-static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
+static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
{
- return (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
- ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
+ unsigned long pte_pkey;
+
+ pte_pkey = (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
+ ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
+
+ if (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_KUEP)) {
+ if ((pte_pkey == 0) && (flags & HPTE_USE_KERNEL_KEY))
+ return HASH_DEFAULT_KERNEL_KEY;
+ }
+
+ return pte_pkey;
}
static inline u16 hash__pte_to_pkey_bits(u64 pteflags)
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 73ad038ed10b..a3c0f93d2768 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -145,7 +145,8 @@ extern void hash__mark_initmem_nx(void);
extern void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, unsigned long pte, int huge);
-extern unsigned long htab_convert_pte_flags(unsigned long pteflags);
+extern unsigned long htab_convert_pte_flags(unsigned long pteflags,
+ unsigned long flags);
/* Atomic PTE updates */
static inline unsigned long hash__pte_update(struct mm_struct *mm,
unsigned long addr,
diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index 58fcc959f9d5..eb9950043b78 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -452,6 +452,7 @@ static inline unsigned long hpt_hash(unsigned long vpn,
#define HPTE_LOCAL_UPDATE 0x1
#define HPTE_NOHPTE_UPDATE 0x2
+#define HPTE_USE_KERNEL_KEY 0x4
extern int __hash_page_4K(unsigned long ea, unsigned long access,
unsigned long vsid, pte_t *ptep, unsigned long trap,
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 1a474f6b1992..2d85e0ea5f1c 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -286,7 +286,7 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
#define thread_pkey_regs_init(thread)
#define arch_dup_pkeys(oldmm, mm)
-static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
+static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
{
return 0x0UL;
}
diff --git a/arch/powerpc/mm/book3s64/hash_4k.c b/arch/powerpc/mm/book3s64/hash_4k.c
index 22e787123cdf..7de1a8a0c62a 100644
--- a/arch/powerpc/mm/book3s64/hash_4k.c
+++ b/arch/powerpc/mm/book3s64/hash_4k.c
@@ -54,7 +54,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
* PP bits. _PAGE_USER is already PP bit 0x2, so we only
* need to add in 0x1 if it's a read-only user page
*/
- rflags = htab_convert_pte_flags(new_pte);
+ rflags = htab_convert_pte_flags(new_pte, flags);
rpte = __real_pte(__pte(old_pte), ptep, PTRS_PER_PTE);
if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
diff --git a/arch/powerpc/mm/book3s64/hash_64k.c b/arch/powerpc/mm/book3s64/hash_64k.c
index 7084ce2951e6..998c6817ed47 100644
--- a/arch/powerpc/mm/book3s64/hash_64k.c
+++ b/arch/powerpc/mm/book3s64/hash_64k.c
@@ -72,7 +72,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
* Handle the subpage protection bits
*/
subpg_pte = new_pte & ~subpg_prot;
- rflags = htab_convert_pte_flags(subpg_pte);
+ rflags = htab_convert_pte_flags(subpg_pte, flags);
if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
@@ -260,7 +260,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
new_pte |= _PAGE_DIRTY;
} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
- rflags = htab_convert_pte_flags(new_pte);
+ rflags = htab_convert_pte_flags(new_pte, flags);
rpte = __real_pte(__pte(old_pte), ptep, PTRS_PER_PTE);
if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
diff --git a/arch/powerpc/mm/book3s64/hash_hugepage.c b/arch/powerpc/mm/book3s64/hash_hugepage.c
index 440823797de7..c0fabe6c5a12 100644
--- a/arch/powerpc/mm/book3s64/hash_hugepage.c
+++ b/arch/powerpc/mm/book3s64/hash_hugepage.c
@@ -57,7 +57,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
if (!(old_pmd & (H_PAGE_THP_HUGE | _PAGE_DEVMAP)))
return 0;
- rflags = htab_convert_pte_flags(new_pmd);
+ rflags = htab_convert_pte_flags(new_pmd, flags);
#if 0
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
diff --git a/arch/powerpc/mm/book3s64/hash_hugetlbpage.c b/arch/powerpc/mm/book3s64/hash_hugetlbpage.c
index eefa89c6117b..8ce8fc327af4 100644
--- a/arch/powerpc/mm/book3s64/hash_hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/hash_hugetlbpage.c
@@ -72,7 +72,7 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
if (old_pte & (H_PAGE_THP_HUGE | _PAGE_DEVMAP))
return 0;
- rflags = htab_convert_pte_flags(new_pte);
+ rflags = htab_convert_pte_flags(new_pte, flags);
if (unlikely(mmu_psize == MMU_PAGE_16G))
offset = PTRS_PER_PUD;
else
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index 8b4b0a602158..6a213e3ddd35 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -445,7 +445,7 @@ void hash__mark_initmem_nx(void)
start = (unsigned long)__init_begin;
end = (unsigned long)__init_end;
- pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
+ pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY);
WARN_ON(!hash__change_memory_range(start, end, pp));
}
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 0124003e60d0..9686caf36be9 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -186,7 +186,7 @@ static struct mmu_psize_def mmu_psize_defaults_gp[] = {
* - We make sure R is always set and never lost
* - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
*/
-unsigned long htab_convert_pte_flags(unsigned long pteflags)
+unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags)
{
unsigned long rflags = 0;
@@ -240,7 +240,7 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags)
*/
rflags |= HPTE_R_M;
- rflags |= pte_to_hpte_pkey_bits(pteflags);
+ rflags |= pte_to_hpte_pkey_bits(pteflags, flags);
return rflags;
}
@@ -255,7 +255,7 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
shift = mmu_psize_defs[psize].shift;
step = 1 << shift;
- prot = htab_convert_pte_flags(prot);
+ prot = htab_convert_pte_flags(prot, HPTE_USE_KERNEL_KEY);
DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
vstart, vend, pstart, prot, psize, ssize);
@@ -1301,12 +1301,14 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
psize = mmu_vmalloc_psize;
ssize = mmu_kernel_ssize;
+ flags |= HPTE_USE_KERNEL_KEY;
break;
case IO_REGION_ID:
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
psize = mmu_io_psize;
ssize = mmu_kernel_ssize;
+ flags |= HPTE_USE_KERNEL_KEY;
break;
default:
/*
@@ -1864,7 +1866,7 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
unsigned long hash;
unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
- unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
+ unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY);
long ret;
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 4a7d05c1a9c7..7980b013d161 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -190,6 +190,10 @@ void __init pkey_early_init_devtree(void)
reserved_allocation_mask |= (0x1 << 1);
default_uamor &= ~(0x3ul << pkeyshift(1));
+ /* handle key 3 which is used by kernel for KAUP */
+ reserved_allocation_mask |= (0x1 << 3);
+ default_uamor &= ~(0x3ul << pkeyshift(3));
+
/*
* Prevent the usage of OS reserved keys. Update UAMOR
* for those keys. Also mark the rest of the bits in the
--
2.26.2
^ permalink raw reply related
* [PATCH v4 00/41] Kernel userspace access/execution prevention with hash translation
From: Aneesh Kumar K.V @ 2020-06-15 6:13 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
This patch series implements KUAP and KUEP with hash translation mode using
memory keys. The kernel now uses memory protection key 3 to control access
to the kernel. Kernel page table entries are now configured with key 3.
Access to locations configured with any other key value is denied when in
kernel mode (MSR_PR=0). This includes userspace which is by default configured
with key 0.
Changes from v3:
* Fix build error reported by kernel test robot <lkp@intel.com>
Changes from v2:
* Rebase to the latest kernel.
* Fixed a bug with disabling KUEP/KUAP on kernel command line
* Added a patch to make kup key dynamic.
Changes from V1:
* Rebased on latest kernel
Aneesh Kumar K.V (41):
powerpc/book3s64/pkeys: Fixup bit numbering
powerpc/book3s64/pkeys: pkeys are supported only on hash on book3s.
powerpc/book3s64/pkeys: Move pkey related bits in the linux page table
powerpc/book3s64/pkeys: Explain key 1 reservation details
powerpc/book3s64/pkeys: Simplify the key initialization
powerpc/book3s64/pkeys: Prevent key 1 modification from userspace.
powerpc/book3s64/pkeys: kill cpu feature key CPU_FTR_PKEY
powerpc/book3s64/pkeys: Convert execute key support to static key
powerpc/book3s64/pkeys: Simplify pkey disable branch
powerpc/book3s64/pkeys: Convert pkey_total to max_pkey
powerpc/book3s64/pkeys: Make initial_allocation_mask static
powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reserved
powerpc/book3s64/pkeys: Enable MMU_FTR_PKEY
powerpc/book3s64/kuep: Add MMU_FTR_KUEP
powerpc/book3s64/pkeys: Use execute_pkey_disable static key
powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled
static key
powerpc/book3s64/kuap: Move KUAP related function outside radix
powerpc/book3s64/kuep: Move KUEP related function outside radix
powerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP to MMU_FTR_KUAP
powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of
PPC_MEM_KEYS
powerpc/book3s64/kuap: Move UAMOR setup to key init function
powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash
translation
powerpc/exec: Set thread.regs early during exec
powerpc/book3s64/pkeys: Store/restore userspace AMR correctly on entry
and exit from kernel
powerpc/book3s64/kuep: Store/restore userspace IAMR correctly on entry
and exit from kernel
powerpc/book3s64/pkeys: Inherit correctly on fork.
powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec
powerpc/ptrace-view: Use pt_regs values instead of thread_struct based
one.
powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode.
powerpc/book3s64/kuap: Restrict access to userspace based on userspace
AMR
powerpc/book3s64/kuap: Improve error reporting with KUAP
powerpc/book3s64/kuap: Use Key 3 to implement KUAP with hash
translation.
powerpc/book3s64/kuep: Use Key 3 to implement KUEP with hash
translation.
powerpc/book3s64/hash/kuap: Enable kuap on hash
powerpc/book3s64/hash/kuep: Enable KUEP on hash
powerpc/book3s64/keys: Print information during boot.
powerpc/selftest/ptrave-pkey: Rename variables to make it easier to
follow code
powerpc/selftest/ptrace-pkey: Update the test to mark an invalid pkey
correctly
powerpc/selftest/ptrace-pkey: IAMR and uamor cannot be updated by
ptrace
powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec
powerpc/book3s64/hash/kup: Don't hardcode kup key
arch/powerpc/include/asm/book3s/32/kup.h | 4 +-
arch/powerpc/include/asm/book3s/64/hash-4k.h | 21 +-
arch/powerpc/include/asm/book3s/64/hash-64k.h | 12 +-
.../powerpc/include/asm/book3s/64/hash-pkey.h | 24 +
arch/powerpc/include/asm/book3s/64/hash.h | 3 +-
.../powerpc/include/asm/book3s/64/kup-radix.h | 185 --------
arch/powerpc/include/asm/book3s/64/kup.h | 391 +++++++++++++++++
arch/powerpc/include/asm/book3s/64/mmu-hash.h | 9 +-
arch/powerpc/include/asm/book3s/64/mmu.h | 6 +
arch/powerpc/include/asm/book3s/64/pgtable.h | 17 +-
arch/powerpc/include/asm/book3s/64/pkeys.h | 25 ++
arch/powerpc/include/asm/cputable.h | 13 +-
arch/powerpc/include/asm/kup.h | 20 +-
arch/powerpc/include/asm/mmu.h | 17 +-
arch/powerpc/include/asm/mmu_context.h | 2 +-
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 4 +-
arch/powerpc/include/asm/pkeys.h | 65 +--
arch/powerpc/include/asm/processor.h | 5 -
arch/powerpc/include/asm/ptrace.h | 8 +-
arch/powerpc/include/asm/thread_info.h | 2 -
arch/powerpc/kernel/asm-offsets.c | 6 +-
arch/powerpc/kernel/dt_cpu_ftrs.c | 6 -
arch/powerpc/kernel/entry_64.S | 6 +-
arch/powerpc/kernel/exceptions-64s.S | 4 +-
arch/powerpc/kernel/misc_64.S | 14 -
arch/powerpc/kernel/process.c | 56 ++-
arch/powerpc/kernel/prom.c | 5 +
arch/powerpc/kernel/ptrace/ptrace-view.c | 23 +-
arch/powerpc/kernel/smp.c | 5 +
arch/powerpc/kernel/syscall_64.c | 32 +-
arch/powerpc/kernel/traps.c | 6 -
arch/powerpc/kexec/core_64.c | 3 +
arch/powerpc/mm/book3s64/hash_4k.c | 2 +-
arch/powerpc/mm/book3s64/hash_64k.c | 4 +-
arch/powerpc/mm/book3s64/hash_hugepage.c | 2 +-
arch/powerpc/mm/book3s64/hash_hugetlbpage.c | 2 +-
arch/powerpc/mm/book3s64/hash_pgtable.c | 2 +-
arch/powerpc/mm/book3s64/hash_utils.c | 10 +-
arch/powerpc/mm/book3s64/pgtable.c | 3 +
arch/powerpc/mm/book3s64/pkeys.c | 412 +++++++++++-------
arch/powerpc/mm/book3s64/radix_pgtable.c | 36 --
arch/powerpc/mm/fault.c | 2 +-
arch/powerpc/platforms/Kconfig.cputype | 4 +-
.../selftests/powerpc/ptrace/ptrace-pkey.c | 53 +--
44 files changed, 939 insertions(+), 592 deletions(-)
create mode 100644 arch/powerpc/include/asm/book3s/64/hash-pkey.h
delete mode 100644 arch/powerpc/include/asm/book3s/64/kup-radix.h
create mode 100644 arch/powerpc/include/asm/book3s/64/kup.h
create mode 100644 arch/powerpc/include/asm/book3s/64/pkeys.h
--
2.26.2
^ permalink raw reply
* [PATCH v4 23/41] powerpc/exec: Set thread.regs early during exec
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
In later patches during exec, we would like to access default regs.kuap to
control access to the user mapping. Having thread.regs set early makes the
code changes simpler.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/thread_info.h | 2 --
arch/powerpc/kernel/process.c | 37 +++++++++++++++++---------
2 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index ca6c97025704..9418dff1cfe1 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -77,10 +77,8 @@ struct thread_info {
/* how to get the thread information struct from C */
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-#ifdef CONFIG_PPC_BOOK3S_64
void arch_setup_new_exec(void);
#define arch_setup_new_exec arch_setup_new_exec
-#endif
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 048d64c4e115..14599c7e4a37 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1473,10 +1473,32 @@ void flush_thread(void)
#ifdef CONFIG_PPC_BOOK3S_64
void arch_setup_new_exec(void)
{
- if (radix_enabled())
- return;
- hash__setup_new_exec();
+ if (!radix_enabled())
+ hash__setup_new_exec();
+
+ /*
+ * If we exec out of a kernel thread then thread.regs will not be
+ * set. Do it now.
+ */
+ if (!current->thread.regs) {
+ struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
+ current->thread.regs = regs - 1;
+ }
+
}
+#else
+void arch_setup_new_exec(void)
+{
+ /*
+ * If we exec out of a kernel thread then thread.regs will not be
+ * set. Do it now.
+ */
+ if (!current->thread.regs) {
+ struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
+ current->thread.regs = regs - 1;
+ }
+}
+
#endif
#ifdef CONFIG_PPC64
@@ -1704,15 +1726,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
#endif
#endif
- /*
- * If we exec out of a kernel thread then thread.regs will not be
- * set. Do it now.
- */
- if (!current->thread.regs) {
- struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
- current->thread.regs = regs - 1;
- }
-
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* Clear any transactional state, we're exec()ing. The cause is
--
2.26.2
^ permalink raw reply related
* [PATCH v4 24/41] powerpc/book3s64/pkeys: Store/restore userspace AMR correctly on entry and exit from kernel
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
This prepare kernel to operate with a different value than userspace AMR.
For this, AMR needs to be saved and restored on entry and return from the
kernel.
With KUAP we modify kernel AMR when accessing user address from the kernel
via copy_to/from_user interfaces.
If MMU_FTR_KEY is enabled we always use the key mechanism to implement KUAP
feature. If MMU_FTR_KEY is not supported and if we support MMU_FTR_KUAP
(radix translation on POWER9), we can skip restoring AMR on return
to userspace. Userspace won't be using AMR in that specific config.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 141 ++++++++++++++++++-----
arch/powerpc/kernel/entry_64.S | 6 +-
arch/powerpc/kernel/exceptions-64s.S | 4 +-
arch/powerpc/kernel/syscall_64.c | 26 ++++-
4 files changed, 144 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index e6ee1c34842f..6979cd1a0003 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -13,18 +13,47 @@
#ifdef __ASSEMBLY__
-.macro kuap_restore_amr gpr1, gpr2
-#ifdef CONFIG_PPC_KUAP
+.macro kuap_restore_user_amr gpr1
+#if defined(CONFIG_PPC_MEM_KEYS)
BEGIN_MMU_FTR_SECTION_NESTED(67)
- mfspr \gpr1, SPRN_AMR
+ /*
+ * AMR is going to be different when
+ * returning to userspace.
+ */
+ ld \gpr1, STACK_REGS_KUAP(r1)
+ isync
+ mtspr SPRN_AMR, \gpr1
+
+ /* No isync required, see kuap_restore_user_amr() */
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_PKEY , 67)
+#endif
+.endm
+
+.macro kuap_restore_kernel_amr gpr1, gpr2
+#if defined(CONFIG_PPC_MEM_KEYS)
+ BEGIN_MMU_FTR_SECTION_NESTED(67)
+ b 99f // handle_pkey_restore_amr
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_PKEY , 67)
+
+ BEGIN_MMU_FTR_SECTION_NESTED(68)
+ b 99f // handle_kuap_restore_amr
+ MMU_FTR_SECTION_ELSE_NESTED(68)
+ b 100f // skip_restore_amr
+ ALT_MMU_FTR_SECTION_END_NESTED_IFSET(MMU_FTR_KUAP, 68)
+
+99:
+ /*
+ * AMR is going to be mostly the same since we are
+ * returning to the kernel. Compare and do a mtspr.
+ */
ld \gpr2, STACK_REGS_KUAP(r1)
+ mfspr \gpr1, SPRN_AMR
cmpd \gpr1, \gpr2
- beq 998f
+ beq 100f
isync
mtspr SPRN_AMR, \gpr2
/* No isync required, see kuap_restore_amr() */
-998:
- END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
+100: // skip_restore_amr
#endif
.endm
@@ -40,23 +69,58 @@
#endif
.endm
+/*
+ * MMU_FTR_PKEY and MMU_FTR_KUAP can both be enabled on a platform. We prefer
+ * PKEY over KUAP if both can be enabled on the platform.
+ *
+ * With KUAP only enabled on exception if we are coming from userspace we don't
+ * save the AMR at all, because the expectation is that userspace can't change
+ * the AMR if KUAP feature is enabled.
+ */
.macro kuap_save_amr_and_lock gpr1, gpr2, use_cr, msr_pr_cr
-#ifdef CONFIG_PPC_KUAP
+#if defined(CONFIG_PPC_MEM_KEYS)
+
BEGIN_MMU_FTR_SECTION_NESTED(67)
+ b 101f // handle_pkey_save_amr
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_PKEY , 67)
+
+ BEGIN_MMU_FTR_SECTION_NESTED(68)
+ b 99f // handle_kuap_save_amr
+ MMU_FTR_SECTION_ELSE_NESTED(68)
+ b 100f // skip_save_amr
+ ALT_MMU_FTR_SECTION_END_NESTED_IFSET(MMU_FTR_KUAP, 68)
+
+
+99: // handle_kuap_save_amr
.ifnb \msr_pr_cr
- bne \msr_pr_cr, 99f
+ /*
+ * We avoid changing AMR outside the kernel
+ * hence skip this completely.
+ */
+ bne \msr_pr_cr, 100f // from userspace
.endif
+
+101: // handle_pkey_save_amr
mfspr \gpr1, SPRN_AMR
std \gpr1, STACK_REGS_KUAP(r1)
- li \gpr2, (AMR_KUAP_BLOCKED >> AMR_KUAP_SHIFT)
- sldi \gpr2, \gpr2, AMR_KUAP_SHIFT
+
+ /*
+ * update kernel AMR with AMR_KUAP_BLOCKED only
+ * if KUAP feature is enabled
+ */
+ BEGIN_MMU_FTR_SECTION_NESTED(69)
+ LOAD_REG_IMMEDIATE(\gpr2, AMR_KUAP_BLOCKED)
cmpd \use_cr, \gpr1, \gpr2
- beq \use_cr, 99f
- // We don't isync here because we very recently entered via rfid
+ beq \use_cr, 102f
+ /*
+ * We don't isync here because we very recently entered via an interrupt
+ */
mtspr SPRN_AMR, \gpr2
isync
-99:
- END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
+102:
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 69)
+
+100: // skip_save_amr
#endif
.endm
@@ -69,22 +133,40 @@
extern u64 default_uamor;
-static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
+static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
- if (mmu_has_feature(MMU_FTR_KUAP) && unlikely(regs->kuap != amr)) {
- isync();
- mtspr(SPRN_AMR, regs->kuap);
- /*
- * No isync required here because we are about to RFI back to
- * previous context before any user accesses would be made,
- * which is a CSI.
- */
+ if (!mmu_has_feature(MMU_FTR_PKEY))
+ return;
+
+ isync();
+ mtspr(SPRN_AMR, regs->kuap);
+ /*
+ * No isync required here because we are about to rfi
+ * back to previous context before any user accesses
+ * would be made, which is a CSI.
+ */
+}
+
+static inline void kuap_restore_kernel_amr(struct pt_regs *regs,
+ unsigned long amr)
+{
+ if (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_PKEY)) {
+
+ if (unlikely(regs->kuap != amr)) {
+ isync();
+ mtspr(SPRN_AMR, regs->kuap);
+ /*
+ * No isync required here because we are about to rfi
+ * back to previous context before any user accesses
+ * would be made, which is a CSI.
+ */
+ }
}
}
static inline unsigned long kuap_get_and_check_amr(void)
{
- if (mmu_has_feature(MMU_FTR_KUAP)) {
+ if (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_PKEY)) {
unsigned long amr = mfspr(SPRN_AMR);
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
@@ -95,13 +177,18 @@ static inline unsigned long kuap_get_and_check_amr(void)
static inline void kuap_check_amr(void)
{
- if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_KUAP))
+ if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) &&
+ (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_PKEY)))
WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
}
#else /* CONFIG_PPC_MEM_KEYS */
-static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
+static inline void kuap_restore_user_amr(struct pt_regs *regs)
+{
+}
+
+static inline void kuap_restore_kernel_amr(struct pt_regs *regs, unsigned long amr)
{
}
@@ -113,6 +200,7 @@ static inline unsigned long kuap_get_and_check_amr(void)
{
return 0;
}
+
#endif /* CONFIG_PPC_MEM_KEYS */
@@ -187,7 +275,6 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
"Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
}
#endif /* CONFIG_PPC_KUAP */
-
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_BOOK3S_64_KUP_H */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9d49338e0c85..a087cbe0b17d 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -481,8 +481,8 @@ _ASM_NOKPROBE_SYMBOL(fast_interrupt_return)
kuap_check_amr r3, r4
ld r5,_MSR(r1)
andi. r0,r5,MSR_PR
- bne .Lfast_user_interrupt_return
- kuap_restore_amr r3, r4
+ bne .Lfast_user_interrupt_return_amr
+ kuap_restore_kernel_amr r3, r4
andi. r0,r5,MSR_RI
li r3,0 /* 0 return value, no EMULATE_STACK_STORE */
bne+ .Lfast_kernel_interrupt_return
@@ -502,6 +502,8 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return)
cmpdi r3,0
bne- .Lrestore_nvgprs
+.Lfast_user_interrupt_return_amr:
+ kuap_restore_user_amr r3
.Lfast_user_interrupt_return:
ld r11,_NIP(r1)
ld r12,_MSR(r1)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e70ebb5c318c..8226af444d77 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -971,7 +971,7 @@ EXC_COMMON_BEGIN(system_reset_common)
ld r10,SOFTE(r1)
stb r10,PACAIRQSOFTMASK(r13)
- kuap_restore_amr r9, r10
+ kuap_restore_kernel_amr r9, r10
EXCEPTION_RESTORE_REGS
RFI_TO_USER_OR_KERNEL
@@ -2784,7 +2784,7 @@ EXC_COMMON_BEGIN(soft_nmi_common)
ld r10,SOFTE(r1)
stb r10,PACAIRQSOFTMASK(r13)
- kuap_restore_amr r9, r10
+ kuap_restore_kernel_amr r9, r10
EXCEPTION_RESTORE_REGS hsrr=0
RFI_TO_KERNEL
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 7e560a01afa4..fded67982fbe 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -35,7 +35,21 @@ notrace long system_call_exception(long r3, long r4, long r5,
BUG_ON(!FULL_REGS(regs));
BUG_ON(regs->softe != IRQS_ENABLED);
- kuap_check_amr();
+#ifdef CONFIG_PPC_MEM_KEYS
+ if (mmu_has_feature(MMU_FTR_PKEY)) {
+ unsigned long amr;
+ /*
+ * When entering from userspace we mostly have the AMR
+ * different from kernel default values. Hence don't compare.
+ */
+ amr = mfspr(SPRN_AMR);
+ regs->kuap = amr;
+ if (mmu_has_feature(MMU_FTR_KUAP))
+ mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ isync();
+ } else
+#endif
+ kuap_check_amr();
account_cpu_user_entry();
@@ -222,6 +236,10 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
account_cpu_user_exit();
+ /*
+ * We do this at the end so that we do context switch with KERNEL AMR
+ */
+ kuap_restore_user_amr(regs);
return ret;
}
@@ -306,6 +324,10 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
account_cpu_user_exit();
+ /*
+ * We do this at the end so that we do context switch with KERNEL AMR
+ */
+ kuap_restore_user_amr(regs);
return ret;
}
@@ -376,7 +398,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
* which would cause Read-After-Write stalls. Hence, we take the AMR
* value from the check above.
*/
- kuap_restore_amr(regs, amr);
+ kuap_restore_kernel_amr(regs, amr);
return ret;
}
--
2.26.2
^ permalink raw reply related
* [PATCH v4 26/41] powerpc/book3s64/pkeys: Inherit correctly on fork.
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
Child thread.kuap value is inherited from the parent in copy_thread_tls. We still
need to make sure when the child returns from a fork in the kernel we start with the kernel
default AMR value.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/kernel/process.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 14599c7e4a37..dbce0b1daf2f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1705,6 +1705,15 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
childregs->ppr = DEFAULT_PPR;
p->thread.tidr = 0;
+#endif
+ /*
+ * Run with the current AMR value of the kernel
+ */
+#if defined(CONFIG_PPC_MEM_KEYS)
+ if (mmu_has_feature(MMU_FTR_KUAP))
+ kregs->kuap = AMR_KUAP_BLOCKED;
+ if (mmu_has_feature(MMU_FTR_KUEP))
+ kregs->kuep = AMR_KUEP_BLOCKED;
#endif
kregs->nip = ppc_function_entry(f);
return 0;
--
2.26.2
^ permalink raw reply related
* [PATCH v4 25/41] powerpc/book3s64/kuep: Store/restore userspace IAMR correctly on entry and exit from kernel
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
This prepare kernel to operate with a different value than userspace IAMR.
For this, IAMR needs to be saved and restored on entry and return from the
kernel.
If MMU_FTR_KEY is enabled we always use the key mechanism to implement KUEP
feature. If MMU_FTR_KEY is not supported and if we support MMU_FTR_KUEP
(radix translation on POWER9), we can skip restoring IAMR on return
to userspace. Userspace won't be using IAMR in that specific config.
We don't need to save/restore IAMR on reentry into the kernel due to interrupt
because the kernel doesn't modify IAMR internally.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 46 ++++++++++++++++++++++--
arch/powerpc/include/asm/ptrace.h | 6 +++-
arch/powerpc/kernel/asm-offsets.c | 4 +++
arch/powerpc/kernel/syscall_64.c | 8 +++--
4 files changed, 59 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 6979cd1a0003..49182efea945 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -17,15 +17,26 @@
#if defined(CONFIG_PPC_MEM_KEYS)
BEGIN_MMU_FTR_SECTION_NESTED(67)
/*
- * AMR is going to be different when
+ * AMR and IAMR are going to be different when
* returning to userspace.
*/
ld \gpr1, STACK_REGS_KUAP(r1)
isync
mtspr SPRN_AMR, \gpr1
+ /*
+ * Restore IAMR only when returning to userspace
+ */
+ ld \gpr1, STACK_REGS_KUEP(r1)
+ mtspr SPRN_IAMR, \gpr1
/* No isync required, see kuap_restore_user_amr() */
END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_PKEY , 67)
+
+ /*
+ * We don't check KUEP feature here, because if FTR_PKEY
+ * is not enabled we don't need to restore IAMR on
+ * return to usespace.
+ */
#endif
.endm
@@ -53,6 +64,9 @@
isync
mtspr SPRN_AMR, \gpr2
/* No isync required, see kuap_restore_amr() */
+ /*
+ * No need to restore IAMR when returning to kernel space.
+ */
100: // skip_restore_amr
#endif
.endm
@@ -90,6 +104,12 @@
b 100f // skip_save_amr
ALT_MMU_FTR_SECTION_END_NESTED_IFSET(MMU_FTR_KUAP, 68)
+ /*
+ * We don't check KUEP feature here, because if FTR_PKEY
+ * is not enabled we don't need to save IAMR on
+ * entry from usespace. That is handled by either
+ * handle_kuap_save_amr or skip_save_amr
+ */
99: // handle_kuap_save_amr
.ifnb \msr_pr_cr
@@ -120,6 +140,25 @@
102:
END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 69)
+ .ifnb \msr_pr_cr
+ beq \msr_pr_cr, 103f // from kernel space
+ mfspr \gpr1, SPRN_IAMR
+ std \gpr1, STACK_REGS_KUEP(r1)
+
+ /*
+ * update kernel IAMR with AMR_KUEP_BLOCKED only
+ * if KUEP feature is enabled
+ */
+ BEGIN_MMU_FTR_SECTION_NESTED(70)
+ LOAD_REG_IMMEDIATE(\gpr2, AMR_KUEP_BLOCKED)
+ cmpd \use_cr, \gpr1, \gpr2
+ beq \use_cr, 103f
+ mtspr SPRN_IAMR, \gpr2
+ isync
+103:
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUEP, 70)
+ .endif
+
100: // skip_save_amr
#endif
.endm
@@ -140,13 +179,13 @@ static inline void kuap_restore_user_amr(struct pt_regs *regs)
isync();
mtspr(SPRN_AMR, regs->kuap);
+ mtspr(SPRN_IAMR, regs->kuep);
/*
* No isync required here because we are about to rfi
* back to previous context before any user accesses
* would be made, which is a CSI.
*/
}
-
static inline void kuap_restore_kernel_amr(struct pt_regs *regs,
unsigned long amr)
{
@@ -162,6 +201,9 @@ static inline void kuap_restore_kernel_amr(struct pt_regs *regs,
*/
}
}
+ /*
+ * No need to restore IAMR when returning to kernel space.
+ */
}
static inline unsigned long kuap_get_and_check_amr(void)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 1a6cadf63d14..2b610dc20426 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -56,8 +56,12 @@ struct pt_regs
#ifdef CONFIG_PPC_HAVE_KUAP
unsigned long kuap;
#endif
+#ifdef CONFIG_PPC_HAVE_KUEP
+ unsigned long kuep;
+#endif
+
};
- unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */
+ unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */
};
};
#endif
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 1694c4f531b9..5b68970a52a7 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -357,6 +357,10 @@ int main(void)
#ifdef CONFIG_PPC_HAVE_KUAP
STACK_PT_REGS_OFFSET(STACK_REGS_KUAP, kuap);
#endif
+#ifdef CONFIG_PPC_HAVE_KUEP
+ STACK_PT_REGS_OFFSET(STACK_REGS_KUEP, kuep);
+#endif
+
#if defined(CONFIG_PPC32)
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index fded67982fbe..8229730c6cb5 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -37,15 +37,19 @@ notrace long system_call_exception(long r3, long r4, long r5,
#ifdef CONFIG_PPC_MEM_KEYS
if (mmu_has_feature(MMU_FTR_PKEY)) {
- unsigned long amr;
+ unsigned long amr, iamr;
/*
- * When entering from userspace we mostly have the AMR
+ * When entering from userspace we mostly have the AMR/IAMR
* different from kernel default values. Hence don't compare.
*/
amr = mfspr(SPRN_AMR);
+ iamr = mfspr(SPRN_IAMR);
regs->kuap = amr;
+ regs->kuep = iamr;
if (mmu_has_feature(MMU_FTR_KUAP))
mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ if (mmu_has_feature(MMU_FTR_KUEP))
+ mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED);
isync();
} else
#endif
--
2.26.2
^ permalink raw reply related
* [PATCH v4 27/41] powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec
From: Aneesh Kumar K.V @ 2020-06-15 6:14 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200615061430.770174-1-aneesh.kumar@linux.ibm.com>
On fork, we inherit from the parent and on exec, we should switch to default_amr values.
Also, avoid changing the AMR register value within the kernel. The kernel now runs with
different AMR values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 2 ++
arch/powerpc/kernel/process.c | 6 +++++-
arch/powerpc/mm/book3s64/pkeys.c | 18 ++----------------
3 files changed, 9 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 49182efea945..23d6f212d39c 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -171,6 +171,8 @@
#include <asm/ptrace.h>
extern u64 default_uamor;
+extern u64 default_amr;
+extern u64 default_iamr;
static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dbce0b1daf2f..340e473e8738 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1485,6 +1485,11 @@ void arch_setup_new_exec(void)
current->thread.regs = regs - 1;
}
+#ifdef CONFIG_PPC_MEM_KEYS
+ current->thread.regs->kuap = default_amr;
+ current->thread.regs->kuep = default_iamr;
+#endif
+
}
#else
void arch_setup_new_exec(void)
@@ -1839,7 +1844,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
current->thread.load_tm = 0;
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
- thread_pkey_regs_init(¤t->thread);
}
EXPORT_SYMBOL(start_thread);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 7980b013d161..95e972d6bbfa 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -21,8 +21,8 @@ int max_pkey; /* Maximum key value supported */
*/
u32 reserved_allocation_mask;
static u32 initial_allocation_mask; /* Bits set for the initially allocated keys */
-static u64 default_amr;
-static u64 default_iamr;
+u64 default_amr;
+u64 default_iamr;
/* Allow all keys to be modified by default */
u64 default_uamor = ~0x0UL;
/*
@@ -388,20 +388,6 @@ void thread_pkey_regs_restore(struct thread_struct *new_thread,
write_uamor(new_thread->uamor);
}
-void thread_pkey_regs_init(struct thread_struct *thread)
-{
- if (!mmu_has_feature(MMU_FTR_PKEY))
- return;
-
- thread->amr = default_amr;
- thread->iamr = default_iamr;
- thread->uamor = default_uamor;
-
- write_amr(default_amr);
- write_iamr(default_iamr);
- write_uamor(default_uamor);
-}
-
int execute_only_pkey(struct mm_struct *mm)
{
if (static_branch_likely(&execute_pkey_disabled))
--
2.26.2
^ permalink raw reply related
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