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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2020-11-27 10:14:10 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2020-12-04 01:01:25 +1100
commitd94b827e89dc3f92cd871d10f4992a6bd3c861e5 (patch)
treecf3fd6317c4c6b93f539381c2bd0d081f272b88c /arch/powerpc/include
parentpowerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP and MMU_FTR_KUEP (diff)
downloadlinux-dev-d94b827e89dc3f92cd871d10f4992a6bd3c861e5.tar.xz
linux-dev-d94b827e89dc3f92cd871d10f4992a6bd3c861e5.zip
powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
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> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201127044424.40686-9-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include')
-rw-r--r--arch/powerpc/include/asm/book3s/64/hash-pkey.h25
-rw-r--r--arch/powerpc/include/asm/book3s/64/hash.h2
-rw-r--r--arch/powerpc/include/asm/book3s/64/mmu-hash.h1
-rw-r--r--arch/powerpc/include/asm/mmu_context.h2
4 files changed, 22 insertions, 8 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..f1e60d579f6c 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 +14,23 @@ 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_BOOK3S_KUAP) ||
+ mmu_has_feature(MMU_FTR_BOOK3S_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..d959b0195ad9 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -145,7 +145,7 @@ 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);
+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 683a9c7d1b03..9192cb05a6ab 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 e5a5e3cb7724..033d2f39ed28 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;
}