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| Started by | Ram Pai <linuxram@us.ibm.com> |
|---|---|
| First post | 2017-06-06 03:10 +0200 |
| Last post | 2017-06-06 03:10 +0200 |
| Articles | 3 — 1 participant |
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[RFC PATCH 0/7 v1] powerpc: Memory Protection Keys Ram Pai <linuxram@us.ibm.com> - 2017-06-06 03:10 +0200
[RFC PATCH 4/7 v1]powerpc: Implementation for sys_mprotect_pkey() system call. Ram Pai <linuxram@us.ibm.com> - 2017-06-06 03:10 +0200
[RFC PATCH 7/7 v1]powerpc: Deliver SEGV signal on protection key violation. Ram Pai <linuxram@us.ibm.com> - 2017-06-06 03:10 +0200
| From | Ram Pai <linuxram@us.ibm.com> |
|---|---|
| Date | 2017-06-06 03:10 +0200 |
| Subject | [RFC PATCH 0/7 v1] powerpc: Memory Protection Keys |
| Message-ID | <tPbaq-1V1-3@gated-at.bofh.it> |
Memory protection keys enable applications to protect its address space from inadvertent access or corruption from itself. The overall idea: A process allocates a key and associates it with a address range within its address space. The process than can dynamically set read/write permissions on the key without involving the kernel. Any code that violates the permissions off the address space; as defined by its associated key, will receive a segmentation fault. This patch series enables the feature on PPC64. It is enabled on HPTE 64K-page platform. ISA3.0 section 5.7.13 describes the detailed specifications. Testing: This patch series has passed all the protection key tests available in the selftests directory. Though the test are written for x86, I have updated the tests to cater to powerpc. Will send the patch separately, along with documentation updates. Thanks-to: Dave Hansen, Aneesh, Paul Mackerras, Michael Ellermen :) Ram Pai (7): Free up four PTE bits to accommadate memory keys Implement sys_pkey_alloc and sys_pkey_free system call. store and restore the key state across context switches. Implementation for sys_mprotect_pkey() system call. Program HPTE key protection bits. Handle exceptions caused by violation of key protection. Deliver SEGV signal on protection key violation. arch/powerpc/Kconfig | 15 ++ arch/powerpc/include/asm/book3s/64/hash-4k.h | 12 ++ arch/powerpc/include/asm/book3s/64/hash-64k.h | 38 ++-- arch/powerpc/include/asm/book3s/64/hash.h | 8 +- arch/powerpc/include/asm/book3s/64/mmu-hash.h | 10 + arch/powerpc/include/asm/book3s/64/mmu.h | 10 + arch/powerpc/include/asm/book3s/64/pgtable.h | 84 +++++++- arch/powerpc/include/asm/mman.h | 29 +-- arch/powerpc/include/asm/mmu_context.h | 12 ++ arch/powerpc/include/asm/pkeys.h | 159 +++++++++++++++ arch/powerpc/include/asm/processor.h | 5 + arch/powerpc/include/asm/reg.h | 10 +- arch/powerpc/include/asm/systbl.h | 3 + arch/powerpc/include/asm/unistd.h | 6 +- arch/powerpc/include/uapi/asm/ptrace.h | 5 +- arch/powerpc/include/uapi/asm/unistd.h | 3 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/exceptions-64s.S | 10 +- arch/powerpc/kernel/process.c | 18 ++ arch/powerpc/kernel/signal_32.c | 18 +- arch/powerpc/kernel/signal_64.c | 11 ++ arch/powerpc/kernel/traps.c | 49 +++++ arch/powerpc/mm/Makefile | 1 + arch/powerpc/mm/dump_linuxpagetables.c | 3 +- arch/powerpc/mm/fault.c | 21 +- arch/powerpc/mm/hash64_4k.c | 12 +- arch/powerpc/mm/hash64_64k.c | 73 +++---- arch/powerpc/mm/hash_utils_64.c | 43 ++++- arch/powerpc/mm/hugetlbpage-hash64.c | 16 +- arch/powerpc/mm/mmu_context_book3s64.c | 5 + arch/powerpc/mm/pkeys.c | 267 ++++++++++++++++++++++++++ include/linux/mm.h | 32 +-- include/uapi/asm-generic/mman-common.h | 2 +- 33 files changed, 856 insertions(+), 135 deletions(-) create mode 100644 arch/powerpc/include/asm/pkeys.h create mode 100644 arch/powerpc/mm/pkeys.c -- 1.8.3.1
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| From | Ram Pai <linuxram@us.ibm.com> |
|---|---|
| Date | 2017-06-06 03:10 +0200 |
| Subject | [RFC PATCH 4/7 v1]powerpc: Implementation for sys_mprotect_pkey() system call. |
| Message-ID | <tPbar-1V1-31@gated-at.bofh.it> |
| In reply to | #1658298 |
This system call, associates the pkey with the pte of all
pages corresponding to the given address range.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 22 ++++++-
arch/powerpc/include/asm/mman.h | 29 +++++----
arch/powerpc/include/asm/pkeys.h | 21 ++++++-
arch/powerpc/include/asm/systbl.h | 1 +
arch/powerpc/include/asm/unistd.h | 4 +-
arch/powerpc/include/uapi/asm/unistd.h | 1 +
arch/powerpc/mm/pkeys.c | 93 +++++++++++++++++++++++++++-
include/linux/mm.h | 1 +
8 files changed, 154 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 87e9a89..bc845cd 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -37,6 +37,7 @@
#define _RPAGE_RSV2 0x0800000000000000UL
#define _RPAGE_RSV3 0x0400000000000000UL
#define _RPAGE_RSV4 0x0200000000000000UL
+#define _RPAGE_RSV5 0x00040UL
#define _PAGE_PTE 0x4000000000000000UL /* distinguishes PTEs from pointers */
#define _PAGE_PRESENT 0x8000000000000000UL /* pte contains a translation */
@@ -56,6 +57,20 @@
/* Max physical address bit as per radix table */
#define _RPAGE_PA_MAX 57
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+#define H_PAGE_PKEY_BIT0 _RPAGE_RSV1
+#define H_PAGE_PKEY_BIT1 _RPAGE_RSV2
+#define H_PAGE_PKEY_BIT2 _RPAGE_RSV3
+#define H_PAGE_PKEY_BIT3 _RPAGE_RSV4
+#define H_PAGE_PKEY_BIT4 _RPAGE_RSV5
+#else /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+#define H_PAGE_PKEY_BIT0 0
+#define H_PAGE_PKEY_BIT1 0
+#define H_PAGE_PKEY_BIT2 0
+#define H_PAGE_PKEY_BIT3 0
+#define H_PAGE_PKEY_BIT4 0
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
/*
* Max physical address bit we will use for now.
*
@@ -122,7 +137,12 @@
#define PAGE_PROT_BITS (_PAGE_SAO | _PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT | \
H_PAGE_4K_PFN | _PAGE_PRIVILEGED | _PAGE_ACCESSED | \
_PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_EXEC | \
- _PAGE_SOFT_DIRTY)
+ _PAGE_SOFT_DIRTY | \
+ H_PAGE_PKEY_BIT0 | \
+ H_PAGE_PKEY_BIT1 | \
+ H_PAGE_PKEY_BIT2 | \
+ H_PAGE_PKEY_BIT3 | \
+ H_PAGE_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
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 30922f6..14cc1aa 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -13,24 +13,31 @@
#include <asm/cputable.h>
#include <linux/mm.h>
+#include <linux/pkeys.h>
#include <asm/cpu_has_feature.h>
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+
/*
* This file is included by linux/mman.h, so we can't use cacl_vm_prot_bits()
* here. How important is the optimization?
*/
-static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
- unsigned long pkey)
-{
- return (prot & PROT_SAO) ? VM_SAO : 0;
-}
-#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
+#define arch_calc_vm_prot_bits(prot, key) ( \
+ ((prot) & PROT_SAO ? VM_SAO : 0) | \
+ pkey_to_vmflag_bits(key))
+#define arch_vm_get_page_prot(vm_flags) __pgprot( \
+ ((vm_flags) & VM_SAO ? _PAGE_SAO : 0) | \
+ vmflag_to_page_pkey_bits(vm_flags))
+
+#else /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
+#define arch_calc_vm_prot_bits(prot, key) ( \
+ ((prot) & PROT_SAO ? VM_SAO : 0))
+#define arch_vm_get_page_prot(vm_flags) __pgprot( \
+ ((vm_flags) & VM_SAO ? _PAGE_SAO : 0))
+
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
- return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
static inline bool arch_validate_prot(unsigned long prot)
{
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 7bc8746..0f3dca8 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -14,6 +14,19 @@
VM_PKEY_BIT3 | \
VM_PKEY_BIT4)
+#define pkey_to_vmflag_bits(key) (((key & 0x1UL) ? VM_PKEY_BIT0 : 0x0UL) | \
+ ((key & 0x2UL) ? VM_PKEY_BIT1 : 0x0UL) | \
+ ((key & 0x4UL) ? VM_PKEY_BIT2 : 0x0UL) | \
+ ((key & 0x8UL) ? VM_PKEY_BIT3 : 0x0UL) | \
+ ((key & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL))
+
+#define vmflag_to_page_pkey_bits(vm_flags) \
+ (((vm_flags & VM_PKEY_BIT0) ? H_PAGE_PKEY_BIT4 : 0x0UL)| \
+ ((vm_flags & VM_PKEY_BIT1) ? H_PAGE_PKEY_BIT3 : 0x0UL) | \
+ ((vm_flags & VM_PKEY_BIT2) ? H_PAGE_PKEY_BIT2 : 0x0UL) | \
+ ((vm_flags & VM_PKEY_BIT3) ? H_PAGE_PKEY_BIT1 : 0x0UL) | \
+ ((vm_flags & VM_PKEY_BIT4) ? H_PAGE_PKEY_BIT0 : 0x0UL))
+
/*
* Bits are in BE format.
* NOTE: key 31, 1, 0 are not used.
@@ -42,6 +55,12 @@
#define mm_set_pkey_is_reserved(mm, pkey) (PKEY_INITIAL_ALLOCAION & \
pkeybit_mask(pkey))
+
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
+}
+
static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
{
/* a reserved key is never considered as 'explicitly allocated' */
@@ -114,7 +133,7 @@ static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
return __arch_set_user_pkey_access(tsk, pkey, init_val);
}
-static inline pkey_mm_init(struct mm_struct *mm)
+static inline void pkey_mm_init(struct mm_struct *mm)
{
mm_pkey_allocation_map(mm) = PKEY_INITIAL_ALLOCAION;
/* -1 means unallocated or invalid */
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 22dd776..b33b551 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -390,3 +390,4 @@
SYSCALL(statx)
SYSCALL(pkey_alloc)
SYSCALL(pkey_free)
+SYSCALL(pkey_mprotect)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index e0273bc..daf1ba9 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -12,12 +12,10 @@
#include <uapi/asm/unistd.h>
-#define NR_syscalls 386
+#define NR_syscalls 387
#define __NR__exit __NR_exit
-#define __IGNORE_pkey_mprotect
-
#ifndef __ASSEMBLY__
#include <linux/types.h>
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h
index 7993a07..71ae45e 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -396,5 +396,6 @@
#define __NR_statx 383
#define __NR_pkey_alloc 384
#define __NR_pkey_free 385
+#define __NR_pkey_mprotect 386
#endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index b97366e..11a32b3 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -15,6 +15,17 @@
#include <linux/pkeys.h> /* PKEY_* */
#include <uapi/asm-generic/mman-common.h>
+#define pkeyshift(pkey) ((arch_max_pkey()-pkey-1) * AMR_BITS_PER_PKEY)
+
+static inline bool pkey_allows_readwrite(int pkey)
+{
+ int pkey_shift = pkeyshift(pkey);
+
+ if (!(read_uamor() & (0x3UL << pkey_shift)))
+ return true;
+
+ return !(read_amr() & ((AMR_AD_BIT|AMR_WD_BIT) << pkey_shift));
+}
/*
* set the access right in AMR IAMR and UAMOR register
@@ -68,7 +79,60 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
int __execute_only_pkey(struct mm_struct *mm)
{
- return -1;
+ bool need_to_set_mm_pkey = false;
+ int execute_only_pkey = mm->context.execute_only_pkey;
+ int ret;
+
+ /* Do we need to assign a pkey for mm's execute-only maps? */
+ if (execute_only_pkey == -1) {
+ /* Go allocate one to use, which might fail */
+ execute_only_pkey = mm_pkey_alloc(mm);
+ if (execute_only_pkey < 0)
+ return -1;
+ need_to_set_mm_pkey = true;
+ }
+
+ /*
+ * We do not want to go through the relatively costly
+ * dance to set AMR if we do not need to. Check it
+ * first and assume that if the execute-only pkey is
+ * readwrite-disabled than we do not have to set it
+ * ourselves.
+ */
+ if (!need_to_set_mm_pkey &&
+ !pkey_allows_readwrite(execute_only_pkey))
+ return execute_only_pkey;
+
+ /*
+ * Set up AMR so that it denies access for everything
+ * other than execution.
+ */
+ ret = __arch_set_user_pkey_access(current, execute_only_pkey,
+ (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
+ /*
+ * If the AMR-set operation failed somehow, just return
+ * 0 and effectively disable execute-only support.
+ */
+ if (ret) {
+ mm_set_pkey_free(mm, execute_only_pkey);
+ return -1;
+ }
+
+ /* We got one, store it and use it from here on out */
+ if (need_to_set_mm_pkey)
+ mm->context.execute_only_pkey = execute_only_pkey;
+ return execute_only_pkey;
+}
+
+static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
+{
+ /* Do this check first since the vm_flags should be hot */
+ if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ return false;
+ if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey)
+ return false;
+
+ return true;
}
/*
@@ -84,5 +148,30 @@ int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot,
if (pkey != -1)
return pkey;
- return 0;
+ /*
+ * Look for a protection-key-drive execute-only mapping
+ * which is now being given permissions that are not
+ * execute-only. Move it back to the default pkey.
+ */
+ if (vma_is_pkey_exec_only(vma) &&
+ (prot & (PROT_READ|PROT_WRITE))) {
+ return 0;
+ }
+ /*
+ * The mapping is execute-only. Go try to get the
+ * execute-only protection key. If we fail to do that,
+ * fall through as if we do not have execute-only
+ * support.
+ */
+ if (prot == PROT_EXEC) {
+ pkey = execute_only_pkey(vma->vm_mm);
+ if (pkey > 0)
+ return pkey;
+ }
+ /*
+ * This is a vanilla, non-pkey mprotect (or we failed to
+ * setup execute-only), inherit the pkey from the VMA we
+ * are working on.
+ */
+ return vma_pkey(vma);
}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 34ddac7..5399031 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -227,6 +227,7 @@ extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
#define VM_PKEY_BIT3 VM_HIGH_ARCH_3
#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
#elif defined(CONFIG_PPC)
+#define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0
#define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 5-bit value */
#define VM_PKEY_BIT1 VM_HIGH_ARCH_1
#define VM_PKEY_BIT2 VM_HIGH_ARCH_2
--
1.8.3.1
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| From | Ram Pai <linuxram@us.ibm.com> |
|---|---|
| Date | 2017-06-06 03:10 +0200 |
| Subject | [RFC PATCH 7/7 v1]powerpc: Deliver SEGV signal on protection key violation. |
| Message-ID | <tPbar-1V1-33@gated-at.bofh.it> |
| In reply to | #1658298 |
The value of the AMR register at the time of the exception
is made available in gp_regs[PT_AMR] of the siginfo.
This field can be used to reprogram the permission bits of
any valid protection key.
Similarly the value of the key, whose protection got violated,
is made available at si_pkey field of the siginfo structure.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/include/uapi/asm/ptrace.h | 5 +++-
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kernel/exceptions-64s.S | 8 ++++++
arch/powerpc/kernel/signal_32.c | 18 ++++++++++---
arch/powerpc/kernel/signal_64.c | 11 ++++++++
arch/powerpc/kernel/traps.c | 49 ++++++++++++++++++++++++++++++++++
6 files changed, 88 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h
index 8036b38..109d0c2 100644
--- a/arch/powerpc/include/uapi/asm/ptrace.h
+++ b/arch/powerpc/include/uapi/asm/ptrace.h
@@ -49,6 +49,8 @@ struct pt_regs {
unsigned long dar; /* Fault registers */
unsigned long dsisr; /* on 4xx/Book-E used for ESR */
unsigned long result; /* Result of a system call */
+ unsigned long dscr; /* contents of the DSCR register */
+ unsigned long amr; /* contents of AMR register */
};
#endif /* __ASSEMBLY__ */
@@ -109,7 +111,8 @@ struct pt_regs {
#define PT_DSISR 42
#define PT_RESULT 43
#define PT_DSCR 44
-#define PT_REGS_COUNT 44
+#define PT_AMR 45
+#define PT_REGS_COUNT 45
#define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 709e234..3818dc5 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -301,6 +301,7 @@ int main(void)
STACK_PT_REGS_OFFSET(ORIG_GPR3, orig_gpr3);
STACK_PT_REGS_OFFSET(RESULT, result);
STACK_PT_REGS_OFFSET(_TRAP, trap);
+ STACK_PT_REGS_OFFSET(_AMR, amr);
#ifndef CONFIG_PPC64
/*
* The PowerPC 400-class & Book-E processors have neither the DAR
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 5226a9d..9872dd3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -493,6 +493,10 @@ EXC_COMMON_BEGIN(data_access_common)
ld r12,_MSR(r1)
ld r3,PACA_EXGEN+EX_DAR(r13)
lwz r4,PACA_EXGEN+EX_DSISR(r13)
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ mfspr r5,SPRN_AMR
+ std r5,_AMR(r1)
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
li r5,0x300
std r3,_DAR(r1)
std r4,_DSISR(r1)
@@ -561,6 +565,10 @@ EXC_COMMON_BEGIN(instruction_access_common)
ld r12,_MSR(r1)
ld r3,_NIP(r1)
andis. r4,r12,0x5820
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ mfspr r5,SPRN_AMR
+ std r5,_AMR(r1)
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
li r5,0x400
std r3,_DAR(r1)
std r4,_DSISR(r1)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 97bb138..f317638 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -141,9 +141,11 @@ static inline int save_general_regs(struct pt_regs *regs,
WARN_ON(!FULL_REGS(regs));
- for (i = 0; i <= PT_RESULT; i ++) {
+ for (i = 0; i <= PT_REGS_COUNT; i++) {
if (i == 14 && !FULL_REGS(regs))
i = 32;
+ if (i == PT_DSCR)
+ continue;
if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
return -EFAULT;
}
@@ -156,8 +158,8 @@ static inline int restore_general_regs(struct pt_regs *regs,
elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i;
- for (i = 0; i <= PT_RESULT; i++) {
- if ((i == PT_MSR) || (i == PT_SOFTE))
+ for (i = 0; i <= PT_REGS_COUNT; i++) {
+ if ((i == PT_MSR) || (i == PT_SOFTE) || (i == PT_DSCR))
continue;
if (__get_user(gregs[i], &sr->mc_gregs[i]))
return -EFAULT;
@@ -661,6 +663,9 @@ static long restore_user_regs(struct pt_regs *regs,
long err;
unsigned int save_r2 = 0;
unsigned long msr;
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ unsigned long amr;
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
#ifdef CONFIG_VSX
int i;
#endif
@@ -750,6 +755,13 @@ static long restore_user_regs(struct pt_regs *regs,
return 1;
#endif /* CONFIG_SPE */
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ amr = regs->amr;
+ err |= __get_user(regs->amr, &sr->mc_gregs[PT_AMR]);
+ if (!err && amr != regs->amr)
+ mtspr(SPRN_AMR, regs->amr);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
return 0;
}
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index c83c115..d86d232 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -327,6 +327,9 @@ static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
unsigned long save_r13 = 0;
unsigned long msr;
struct pt_regs *regs = tsk->thread.regs;
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ unsigned long amr;
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
#ifdef CONFIG_VSX
int i;
#endif
@@ -406,6 +409,14 @@ static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
}
#endif
+
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ amr = regs->amr;
+ err |= __get_user(regs->amr, &sc->gp_regs[PT_AMR]);
+ if (!err && amr != regs->amr)
+ mtspr(SPRN_AMR, regs->amr);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
return err;
}
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d4e545d..cc4bde8b 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -20,6 +20,7 @@
#include <linux/sched/debug.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/pkeys.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
@@ -247,6 +248,49 @@ void user_single_step_siginfo(struct task_struct *tsk,
info->si_addr = (void __user *)regs->nip;
}
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+static void fill_sig_info_pkey(int si_code, siginfo_t *info, unsigned long addr)
+{
+ struct vm_area_struct *vma;
+
+ /* Fault not from Protection Keys: nothing to do */
+ if (si_code != SEGV_PKUERR)
+ return;
+
+ down_read(¤t->mm->mmap_sem);
+ /*
+ * we could be racing with pkey_mprotect().
+ * If pkey_mprotect() wins the key value could
+ * get modified...xxx
+ */
+ vma = find_vma(current->mm, addr);
+ up_read(¤t->mm->mmap_sem);
+
+ /*
+ * force_sig_info_fault() is called from a number of
+ * contexts, some of which have a VMA and some of which
+ * do not. The Pkey-fault handing happens after we have a
+ * valid VMA, so we should never reach this without a
+ * valid VMA.
+ */
+ if (!vma) {
+ WARN_ONCE(1, "Pkey fault with no VMA passed in");
+ info->si_pkey = 0;
+ return;
+ }
+
+ /*
+ * We could report the incorrect key because of the reason
+ * explained above.
+ *
+ * si_pkey should be thought off as a strong hint, but not
+ * an absolutely guarantee because of the race explained
+ * above.
+ */
+ info->si_pkey = vma_pkey(vma);
+}
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
siginfo_t info;
@@ -274,6 +318,11 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
info.si_signo = signr;
info.si_code = code;
info.si_addr = (void __user *) addr;
+
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+ fill_sig_info_pkey(code, &info, addr);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
force_sig_info(signr, &info, current);
}
--
1.8.3.1
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