* [PATCH v2 05/28] powerpc/book3s64/kuap: Move KUAP related function outside radix
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 | 18 ++++++++++++++++++
arch/powerpc/mm/book3s64/radix_pgtable.c | 18 ------------------
5 files changed, 23 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 e82df54f5681..21de441762d5 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>
@@ -184,4 +184,4 @@ 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 92bcd1a26d73..248438dff74a 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -13,7 +13,7 @@
#define KUAP_CURRENT 4
#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 bfb161a3a0ea..f704f657e1f7 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..e923be3b52e7 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -198,6 +198,24 @@ 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 8f9edf07063a..74558ce6b5cb 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -526,24 +526,6 @@ 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 v2 06/28] powerpc/book3s64/kuep: Move KUEP related function outside radix
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 21de441762d5..21008cc7af6f 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 e923be3b52e7..b6ea4fec787b 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -198,6 +198,27 @@ 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 74558ce6b5cb..3fb088eecece 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -508,24 +508,6 @@ 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 v2 07/28] powerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP to MMU_FTR_KUAP
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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>
---
arch/powerpc/include/asm/book3s/64/kup.h | 18 +++++++++---------
arch/powerpc/include/asm/mmu.h | 6 +++---
arch/powerpc/mm/book3s64/pkeys.c | 2 +-
3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 21008cc7af6f..f4fb651f5850 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -24,7 +24,7 @@
mtspr SPRN_AMR, \gpr2
/* No isync required, see kuap_restore_amr() */
998:
- END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
#endif
.endm
@@ -36,7 +36,7 @@
sldi \gpr2, \gpr2, AMR_KUAP_SHIFT
999: tdne \gpr1, \gpr2
EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
- END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
#endif
.endm
@@ -56,7 +56,7 @@
mtspr SPRN_AMR, \gpr2
isync
99:
- END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
+ END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
#endif
.endm
@@ -69,7 +69,7 @@
static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
{
- if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) {
+ if (mmu_has_feature(MMU_FTR_KUAP)) {
if (unlikely(regs->kuap != amr)) {
isync();
mtspr(SPRN_AMR, regs->kuap);
@@ -84,7 +84,7 @@ static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
static inline unsigned long kuap_get_and_check_amr(void)
{
- if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) {
+ if (mmu_has_feature(MMU_FTR_KUAP)) {
unsigned long amr = mfspr(SPRN_AMR);
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) /* kuap_check_amr() */
WARN_ON_ONCE(amr != AMR_KUAP_BLOCKED);
@@ -95,7 +95,7 @@ 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_RADIX_KUAP))
+ if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_KUAP))
WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
}
@@ -106,7 +106,7 @@ static inline void kuap_check_amr(void)
static inline unsigned long get_kuap(void)
{
- if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP))
+ if (!early_mmu_has_feature(MMU_FTR_KUAP))
return 0;
return mfspr(SPRN_AMR);
@@ -114,7 +114,7 @@ static inline unsigned long get_kuap(void)
static inline void set_kuap(unsigned long value)
{
- if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP))
+ if (!early_mmu_has_feature(MMU_FTR_KUAP))
return;
/*
@@ -164,7 +164,7 @@ static inline void restore_user_access(unsigned long flags)
static inline bool
bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
{
- return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) &&
+ return WARN(mmu_has_feature(MMU_FTR_KUAP) &&
(regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
"Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
}
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index b26af5aac5a6..a7cc2b83836f 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -112,7 +112,7 @@
/*
* Supports KUAP (key 0 controlling userspace addresses) on radix
*/
-#define MMU_FTR_RADIX_KUAP ASM_CONST(0x80000000)
+#define MMU_FTR_KUAP ASM_CONST(0x80000000)
/* MMU feature bit sets for various CPUs */
#define MMU_FTRS_DEFAULT_HPTE_ARCH_V2 \
@@ -174,10 +174,10 @@ enum {
#endif
#ifdef CONFIG_PPC_RADIX_MMU
MMU_FTR_TYPE_RADIX |
+#endif /* CONFIG_PPC_RADIX_MMU */
#ifdef CONFIG_PPC_KUAP
- MMU_FTR_RADIX_KUAP |
+ MMU_FTR_KUAP |
#endif /* CONFIG_PPC_KUAP */
-#endif /* CONFIG_PPC_RADIX_MMU */
#ifdef CONFIG_PPC_MEM_KEYS
MMU_FTR_PKEY |
#endif
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index b6ea4fec787b..7498c9a8ef74 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -227,7 +227,7 @@ void __init setup_kuap(bool disabled)
if (smp_processor_id() == boot_cpuid) {
pr_info("Activating Kernel Userspace Access Prevention\n");
- cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
+ cur_cpu_spec->mmu_features |= MMU_FTR_KUAP;
}
/* Make sure userspace can't change the AMR */
--
2.26.2
^ permalink raw reply related
* [PATCH v2 08/28] powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of PPC_MEM_KEYS
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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/platforms/Kconfig.cputype | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 27a81c291be8..eb36a6007a94 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 v2 09/28] powerpc/book3s64/kuap: Move UAMOR setup to key init function
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 f4fb651f5850..1b350bf781ec 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)) {
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 6d2a3a3666f0..4cd5b620c08c 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 7498c9a8ef74..12a9ac169f5d 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -23,7 +23,7 @@ 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.
@@ -112,8 +112,16 @@ 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;
@@ -195,6 +203,12 @@ 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;
}
@@ -230,8 +244,9 @@ 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 v2 10/28] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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..fc75b815c9ca 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)) {
+ 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 6fc4520092c7..12b65d3d79aa 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 64733b9cb20a..6c43aaf1c713 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -454,7 +454,7 @@ 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 8ed2411c3f39..bdd4f1792c76 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -183,7 +183,7 @@ 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;
@@ -237,7 +237,7 @@ 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;
}
@@ -252,7 +252,7 @@ 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);
@@ -1295,12 +1295,14 @@ 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:
/*
@@ -1894,7 +1896,7 @@ 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 12a9ac169f5d..976f65f27324 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -189,6 +189,10 @@ 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 v2 11/28] powerpc/exec: Set thread.regs early during exec
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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/kernel/process.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 8479c762aef2..abbe545ed88c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1462,9 +1462,18 @@ 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;
+ }
+
}
#endif
@@ -1689,15 +1698,6 @@ 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 v2 12/28] powerpc/book3s64/pkeys: Store/restore userspace AMR correctly on entry and exit from kernel
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 | 129 +++++++++++++++++++----
arch/powerpc/kernel/entry_64.S | 6 +-
arch/powerpc/kernel/exceptions-64s.S | 4 +-
arch/powerpc/kernel/syscall_64.c | 25 ++++-
4 files changed, 136 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 1b350bf781ec..82bef3901672 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
@@ -40,38 +69,89 @@
#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
#else /* !__ASSEMBLY__ */
-#ifdef CONFIG_PPC_KUAP
+#ifdef CONFIG_PPC_MEM_KEYS
#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)
+static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
- if (mmu_has_feature(MMU_FTR_KUAP)) {
+ 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);
@@ -86,7 +166,7 @@ static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
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);
@@ -97,7 +177,8 @@ 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);
}
@@ -170,8 +251,12 @@ 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)
+#else /* CONFIG_PPC_MEM_KEYS */
+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)
{
}
@@ -183,7 +268,7 @@ static inline unsigned long kuap_get_and_check_amr(void)
{
return 0;
}
-#endif /* CONFIG_PPC_KUAP */
+#endif /* CONFIG_PPC_MEM_KEYS */
#endif /* __ASSEMBLY__ */
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 ef4a90212664..11abe8fbf0ba 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
@@ -2757,7 +2757,7 @@ 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 f704f657e1f7..4d417fdadb2a 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -35,7 +35,20 @@ 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;
+ mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ isync();
+ } else
+#endif
+ kuap_check_amr();
account_cpu_user_entry();
@@ -208,6 +221,10 @@ 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;
}
@@ -300,6 +317,10 @@ 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;
}
@@ -378,7 +399,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
* mtmsr, which would cause RAW 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 v2 13/28] powerpc/book3s64/kuep: Store/restore userspace IAMR correctly on entry and exit from kernel
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 | 7 ++--
4 files changed, 58 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 82bef3901672..67320a990f3f 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 KUAP 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 e0195e6b892b..2bfd2b6a72ab 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_KUAP
unsigned long kuap;
#endif
+#ifdef CONFIG_PPC_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 fcf24a365fc0..6c7326fc73b9 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -353,6 +353,10 @@ int main(void)
#ifdef CONFIG_PPC_KUAP
STACK_PT_REGS_OFFSET(STACK_REGS_KUAP, kuap);
#endif
+#ifdef CONFIG_PPC_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 4d417fdadb2a..faac67d04a70 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -37,14 +37,17 @@ 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;
mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+ mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED);
isync();
} else
#endif
--
2.26.2
^ permalink raw reply related
* [PATCH v2 14/28] powerpc/book3s64/pkeys: Inherit correctly on fork.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index abbe545ed88c..9ef95a1217ef 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1677,6 +1677,13 @@ 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)
+ kregs->kuap = AMR_KUAP_BLOCKED;
+ kregs->kuep = AMR_KUEP_BLOCKED;
#endif
kregs->nip = ppc_function_entry(f);
return 0;
--
2.26.2
^ permalink raw reply related
* [PATCH v2 15/28] powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-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 | 19 ++++++++++++++++++-
arch/powerpc/mm/book3s64/pkeys.c | 18 ++----------------
3 files changed, 22 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 67320a990f3f..fe1818954e51 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 9ef95a1217ef..0ab9a8cf1bcb 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1474,7 +1474,25 @@ 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)
+{
+ /*
+ * 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
@@ -1809,7 +1827,6 @@ 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 976f65f27324..5012b57af808 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -20,8 +20,8 @@ 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;
/*
@@ -387,20 +387,6 @@ 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
* [PATCH v2 16/28] powerpc/ptrace-view: Use pt_regs values instead of thread_struct based one.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
We will remove thread.amr/iamr/uamor in a later patch
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/kernel/ptrace/ptrace-view.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c
index 15e3b79b6395..5b7bea41c699 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -488,14 +488,25 @@ static int pkey_active(struct task_struct *target, const struct user_regset *reg
static int pkey_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf)
{
- BUILD_BUG_ON(TSO(amr) + sizeof(unsigned long) != TSO(iamr));
- BUILD_BUG_ON(TSO(iamr) + sizeof(unsigned long) != TSO(uamor));
+ int ret;
if (!arch_pkeys_enabled())
return -ENODEV;
- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.amr,
- 0, ELF_NPKEY * sizeof(unsigned long));
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.regs->kuap,
+ 0, 1 * sizeof(unsigned long));
+ if (ret)
+ goto err_out;
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.regs->kuep,
+ 1 * sizeof(unsigned long), 2 * sizeof(unsigned long));
+ if (ret)
+ goto err_out;
+
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &default_uamor,
+ 2 * sizeof(unsigned long), 3 * sizeof(unsigned long));
+err_out:
+ return ret;
}
static int pkey_set(struct task_struct *target, const struct user_regset *regset,
@@ -518,8 +529,8 @@ static int pkey_set(struct task_struct *target, const struct user_regset *regset
return ret;
/* UAMOR determines which bits of the AMR can be set from userspace. */
- target->thread.amr = (new_amr & target->thread.uamor) |
- (target->thread.amr & ~target->thread.uamor);
+ target->thread.regs->kuap = (new_amr & default_uamor) |
+ (target->thread.regs->kuap & ~default_uamor);
return 0;
}
--
2.26.2
^ permalink raw reply related
* [PATCH v2 17/28] powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Now that kernel correctly store/restore userspace AMR/IAMR values, avoid
manipulating AMR and IAMR from the kernel on behalf of userspace.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 23 ++++++++
arch/powerpc/include/asm/processor.h | 5 --
arch/powerpc/kernel/process.c | 4 --
arch/powerpc/kernel/traps.c | 6 --
arch/powerpc/mm/book3s64/pkeys.c | 71 ++++--------------------
5 files changed, 34 insertions(+), 75 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index fe1818954e51..31eb0acddea9 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -174,6 +174,29 @@ extern u64 default_uamor;
extern u64 default_amr;
extern u64 default_iamr;
+/*
+ * For kernel thread that doesn't have thread.regs return
+ * default AMR/IAMR values.
+ */
+static inline u64 current_thread_amr(void)
+{
+ if (current->thread.regs)
+ return current->thread.regs->kuap;
+ return AMR_KUAP_BLOCKED;
+}
+
+static inline u64 current_thread_iamr(void)
+{
+ if (current->thread.regs)
+ return current->thread.regs->kuep;
+ return AMR_KUEP_BLOCKED;
+}
+
+static inline u64 read_uamor(void)
+{
+ return default_uamor;
+}
+
static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
if (!mmu_has_feature(MMU_FTR_PKEY))
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index a51964b4ec42..591987da44e2 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -234,11 +234,6 @@ struct thread_struct {
struct thread_vr_state ckvr_state; /* Checkpointed VR state */
unsigned long ckvrsave; /* Checkpointed VRSAVE */
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-#ifdef CONFIG_PPC_MEM_KEYS
- unsigned long amr;
- unsigned long iamr;
- unsigned long uamor;
-#endif
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
void* kvm_shadow_vcpu; /* KVM internal data */
#endif /* CONFIG_KVM_BOOK3S_32_HANDLER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0ab9a8cf1bcb..682deeee421f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -585,7 +585,6 @@ static void save_all(struct task_struct *tsk)
__giveup_spe(tsk);
msr_check_and_clear(msr_all_available);
- thread_pkey_regs_save(&tsk->thread);
}
void flush_all_to_thread(struct task_struct *tsk)
@@ -1097,8 +1096,6 @@ static inline void save_sprs(struct thread_struct *t)
t->tar = mfspr(SPRN_TAR);
}
#endif
-
- thread_pkey_regs_save(t);
}
static inline void restore_sprs(struct thread_struct *old_thread,
@@ -1139,7 +1136,6 @@ static inline void restore_sprs(struct thread_struct *old_thread,
mtspr(SPRN_TIDR, new_thread->tidr);
#endif
- thread_pkey_regs_restore(new_thread, old_thread);
}
struct task_struct *__switch_to(struct task_struct *prev,
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 3fca22276bb1..a47fb49b7af8 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -348,12 +348,6 @@ static bool exception_common(int signr, struct pt_regs *regs, int code,
current->thread.trap_nr = code;
- /*
- * Save all the pkey registers AMR/IAMR/UAMOR. Eg: Core dumps need
- * to capture the content, if the task gets killed.
- */
- thread_pkey_regs_save(¤t->thread);
-
return true;
}
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 5012b57af808..0f4fc2876fc8 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -264,40 +264,17 @@ void pkey_mm_init(struct mm_struct *mm)
mm->context.execute_only_pkey = execute_only_key;
}
-static inline u64 read_amr(void)
+static inline void update_current_thread_amr(u64 value)
{
- return mfspr(SPRN_AMR);
+ current->thread.regs->kuap = value;
}
-static inline void write_amr(u64 value)
-{
- mtspr(SPRN_AMR, value);
-}
-
-static inline u64 read_iamr(void)
-{
- if (static_branch_unlikely(&execute_pkey_disabled))
- return 0x0UL;
-
- return mfspr(SPRN_IAMR);
-}
-
-static inline void write_iamr(u64 value)
+static inline void update_current_thread_iamr(u64 value)
{
if (static_branch_unlikely(&execute_pkey_disabled))
return;
- mtspr(SPRN_IAMR, value);
-}
-
-static inline u64 read_uamor(void)
-{
- return mfspr(SPRN_UAMOR);
-}
-
-static inline void write_uamor(u64 value)
-{
- mtspr(SPRN_UAMOR, value);
+ current->thread.regs->kuep = value;
}
static bool is_pkey_enabled(int pkey)
@@ -314,20 +291,21 @@ static bool is_pkey_enabled(int pkey)
return !!(uamor_pkey_bits);
}
+/* FIXME!! what happens to other threads AMR value? */
static inline void init_amr(int pkey, u8 init_bits)
{
u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
- u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+ u64 old_amr = current_thread_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
- write_amr(old_amr | new_amr_bits);
+ update_current_thread_amr(old_amr | new_amr_bits);
}
static inline void init_iamr(int pkey, u8 init_bits)
{
u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
- u64 old_iamr = read_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
+ u64 old_iamr = current_thread_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
- write_iamr(old_iamr | new_iamr_bits);
+ update_current_thread_iamr(old_iamr | new_iamr_bits);
}
/*
@@ -360,33 +338,6 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
return 0;
}
-void thread_pkey_regs_save(struct thread_struct *thread)
-{
- if (!mmu_has_feature(MMU_FTR_PKEY))
- return;
-
- /*
- * TODO: Skip saving registers if @thread hasn't used any keys yet.
- */
- thread->amr = read_amr();
- thread->iamr = read_iamr();
- thread->uamor = read_uamor();
-}
-
-void thread_pkey_regs_restore(struct thread_struct *new_thread,
- struct thread_struct *old_thread)
-{
- if (!mmu_has_feature(MMU_FTR_PKEY))
- return;
-
- if (old_thread->amr != new_thread->amr)
- write_amr(new_thread->amr);
- if (old_thread->iamr != new_thread->iamr)
- write_iamr(new_thread->iamr);
- if (old_thread->uamor != new_thread->uamor)
- write_uamor(new_thread->uamor);
-}
-
int execute_only_pkey(struct mm_struct *mm)
{
if (static_branch_likely(&execute_pkey_disabled))
@@ -440,10 +391,10 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
return true;
pkey_shift = pkeyshift(pkey);
- if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift)))
+ if (execute && !(current_thread_iamr() & (IAMR_EX_BIT << pkey_shift)))
return true;
- amr = read_amr(); /* Delay reading amr until absolutely needed */
+ amr = current_thread_amr();
return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) ||
(write && !(amr & (AMR_WR_BIT << pkey_shift))));
}
--
2.26.2
^ permalink raw reply related
* [PATCH v2 18/28] powerpc/book3s64/kuap: Restrict access to userspace based on userspace AMR
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
If an application has configured address protection such that read/write is
denied using pkey even the kernel should receive a FAULT on accessing the same.
This patch use user AMR value stored in pt_regs.kuap to achieve the same.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 31eb0acddea9..f097d69ec2c8 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -279,14 +279,20 @@ static inline void set_kuap(unsigned long value)
static __always_inline void allow_user_access(void __user *to, const void __user *from,
unsigned long size, unsigned long dir)
{
+ unsigned long thread_amr = 0;
+
// This is written so we can resolve to a single case at build time
BUILD_BUG_ON(!__builtin_constant_p(dir));
+
+ if (mmu_has_feature(MMU_FTR_PKEY))
+ thread_amr = current_thread_amr();
+
if (dir == KUAP_READ)
- set_kuap(AMR_KUAP_BLOCK_WRITE);
+ set_kuap(thread_amr | AMR_KUAP_BLOCK_WRITE);
else if (dir == KUAP_WRITE)
- set_kuap(AMR_KUAP_BLOCK_READ);
+ set_kuap(thread_amr | AMR_KUAP_BLOCK_READ);
else if (dir == KUAP_READ_WRITE)
- set_kuap(0);
+ set_kuap(thread_amr);
else
BUILD_BUG();
}
--
2.26.2
^ permalink raw reply related
* [PATCH v2 19/28] powerpc/book3s64/kuap: Improve error reporting with KUAP
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
With hash translation use DSISR_KEYFAULT to identify a wrong access.
With Radix we look at the AMR value and type of fault.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/32/kup.h | 4 +--
arch/powerpc/include/asm/book3s/64/kup.h | 28 ++++++++++++++++----
arch/powerpc/include/asm/kup.h | 4 +--
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 4 +--
arch/powerpc/mm/fault.c | 2 +-
5 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 3c0ba22dc360..213d3ab40d2d 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -176,8 +176,8 @@ static inline void restore_user_access(unsigned long flags)
allow_user_access(to, to, end - addr, KUAP_READ_WRITE);
}
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+ bool is_write, unsigned long error_code)
{
unsigned long begin = regs->kuap & 0xf0000000;
unsigned long end = regs->kuap << 28;
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index f097d69ec2c8..66c97d9d2ed8 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -317,13 +317,31 @@ static inline void restore_user_access(unsigned long flags)
set_kuap(flags);
}
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+#define RADIX_KUAP_BLOCK_READ UL(0x4000000000000000)
+#define RADIX_KUAP_BLOCK_WRITE UL(0x8000000000000000)
+
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+ bool is_write, unsigned long error_code)
{
- return WARN(mmu_has_feature(MMU_FTR_KUAP) &&
- (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
- "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+ if (!mmu_has_feature(MMU_FTR_KUAP))
+ return false;
+
+ if (radix_enabled()) {
+ /*
+ * Will be a storage protection fault.
+ * Only check the details of AMR[0]
+ */
+ return WARN((regs->kuap & (is_write ? RADIX_KUAP_BLOCK_WRITE : RADIX_KUAP_BLOCK_READ)),
+ "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+ }
+ /*
+ * We don't want to WARN here because userspace can setup
+ * keys such that a kernel access to user address can cause
+ * fault
+ */
+ return !!(error_code & DSISR_KEYFAULT);
}
+
#else /* CONFIG_PPC_MEM_KEYS */
static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 248438dff74a..249eed77a06b 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -57,8 +57,8 @@ static inline void prevent_user_access(void __user *to, const void __user *from,
unsigned long size, unsigned long dir) { }
static inline unsigned long prevent_user_access_return(void) { return 0UL; }
static inline void restore_user_access(unsigned long flags) { }
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+ bool is_write, unsigned long error_code)
{
return false;
}
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 85ed2390fb99..c401e4e404d4 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -60,8 +60,8 @@ static inline void restore_user_access(unsigned long flags)
mtspr(SPRN_MD_AP, flags);
}
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+ bool is_write, unsigned long error_code)
{
return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xf0000000),
"Bug: fault blocked by AP register !");
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 84af6c8eecf7..4e6e7e0fea21 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -233,7 +233,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code,
// Read/write fault in a valid region (the exception table search passed
// above), but blocked by KUAP is bad, it can never succeed.
- if (bad_kuap_fault(regs, address, is_write))
+ if (bad_kuap_fault(regs, address, is_write, error_code))
return true;
// What's left? Kernel fault on user in well defined regions (extable
--
2.26.2
^ permalink raw reply related
* [PATCH v2 20/28] powerpc/book3s64/kuap: Use Key 3 to implement KUAP with hash translation.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Radix use AMR Key 0 and hash translation use AMR key 3.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 66c97d9d2ed8..f704fb615dd5 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -5,11 +5,10 @@
#include <linux/const.h>
#include <asm/reg.h>
-#define AMR_KUAP_BLOCK_READ UL(0x4000000000000000)
-#define AMR_KUAP_BLOCK_WRITE UL(0x8000000000000000)
+#define AMR_KUAP_BLOCK_READ UL(0x5455555555555555)
+#define AMR_KUAP_BLOCK_WRITE UL(0xa8aaaaaaaaaaaaaa)
#define AMR_KUEP_BLOCKED (1UL << 62)
#define AMR_KUAP_BLOCKED (AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE)
-#define AMR_KUAP_SHIFT 62
#ifdef __ASSEMBLY__
@@ -75,8 +74,8 @@
#ifdef CONFIG_PPC_KUAP_DEBUG
BEGIN_MMU_FTR_SECTION_NESTED(67)
mfspr \gpr1, SPRN_AMR
- li \gpr2, (AMR_KUAP_BLOCKED >> AMR_KUAP_SHIFT)
- sldi \gpr2, \gpr2, AMR_KUAP_SHIFT
+ /* Prevent access to userspace using any key values */
+ LOAD_REG_IMMEDIATE(\gpr2, AMR_KUAP_BLOCKED)
999: tdne \gpr1, \gpr2
EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
--
2.26.2
^ permalink raw reply related
* [PATCH v2 21/28] powerpc/book3s64/kuep: Use Key 3 to implement KUEP with hash translation.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Radix use IAMR Key 0 and hash translation use IAMR key 3.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index f704fb615dd5..5b00592479d1 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -7,7 +7,7 @@
#define AMR_KUAP_BLOCK_READ UL(0x5455555555555555)
#define AMR_KUAP_BLOCK_WRITE UL(0xa8aaaaaaaaaaaaaa)
-#define AMR_KUEP_BLOCKED (1UL << 62)
+#define AMR_KUEP_BLOCKED UL(0x5455555555555555)
#define AMR_KUAP_BLOCKED (AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE)
#ifdef __ASSEMBLY__
--
2.26.2
^ permalink raw reply related
* [PATCH v2 22/28] powerpc/book3s64/hash/kuap: Enable kuap on hash
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 0f4fc2876fc8..e94585fad5c4 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -240,7 +240,12 @@ void __init setup_kuep(bool disabled)
#ifdef CONFIG_PPC_KUAP
void __init setup_kuap(bool disabled)
{
- if (disabled || !early_radix_enabled())
+ if (disabled)
+ return;
+ /*
+ * On hash if PKEY feature is not enabled, disable KUAP too.
+ */
+ if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
return;
if (smp_processor_id() == boot_cpuid) {
--
2.26.2
^ permalink raw reply related
* [PATCH v2 23/28] powerpc/book3s64/hash/kuep: Enable KUEP on hash
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/pkeys.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index e94585fad5c4..bb127e4e2dd2 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -219,7 +219,12 @@ void __init pkey_early_init_devtree(void)
#ifdef CONFIG_PPC_KUEP
void __init setup_kuep(bool disabled)
{
- if (disabled || !early_radix_enabled())
+ if (disabled)
+ return;
+ /*
+ * On hash if PKEY feature is not enabled, disable KUAP too.
+ */
+ if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
return;
if (smp_processor_id() == boot_cpuid) {
--
2.26.2
^ permalink raw reply related
* [PATCH v2 24/28] powerpc/book3s64/keys: Print information during boot.
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
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 bb127e4e2dd2..5d320ac2ba04 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -207,6 +207,7 @@ void __init pkey_early_init_devtree(void)
*/
initial_allocation_mask |= reserved_allocation_mask;
+ pr_info("Enabling Memory keys with max key count %d", max_pkey);
err_out:
/*
* Setup uamor on boot cpu
--
2.26.2
^ permalink raw reply related
* [PATCH v2 25/28] powerpc/selftest/ptrave-pkey: Rename variables to make it easier to follow code
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Rename variable to indicate that they are invalid values which we will use to
test ptrace update of pkeys.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
.../selftests/powerpc/ptrace/ptrace-pkey.c | 26 +++++++++----------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index bdbbbe8431e0..f9216c7a1829 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -44,7 +44,7 @@ struct shared_info {
unsigned long amr2;
/* AMR value that ptrace should refuse to write to the child. */
- unsigned long amr3;
+ unsigned long invalid_amr;
/* IAMR value the parent expects to read from the child. */
unsigned long expected_iamr;
@@ -57,8 +57,8 @@ struct shared_info {
* (even though they're valid ones) because userspace doesn't have
* access to those registers.
*/
- unsigned long new_iamr;
- unsigned long new_uamor;
+ unsigned long invalid_iamr;
+ unsigned long invalid_uamor;
};
static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
@@ -100,7 +100,7 @@ static int child(struct shared_info *info)
info->amr1 |= 3ul << pkeyshift(pkey1);
info->amr2 |= 3ul << pkeyshift(pkey2);
- info->amr3 |= info->amr2 | 3ul << pkeyshift(pkey3);
+ info->invalid_amr |= info->amr2 | 3ul << pkeyshift(pkey3);
if (disable_execute)
info->expected_iamr |= 1ul << pkeyshift(pkey1);
@@ -111,8 +111,8 @@ static int child(struct shared_info *info)
info->expected_uamor |= 3ul << pkeyshift(pkey1) |
3ul << pkeyshift(pkey2);
- info->new_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
- info->new_uamor |= 3ul << pkeyshift(pkey1);
+ info->invalid_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
+ info->invalid_uamor |= 3ul << pkeyshift(pkey1);
/*
* We won't use pkey3. We just want a plausible but invalid key to test
@@ -196,9 +196,9 @@ static int parent(struct shared_info *info, pid_t pid)
PARENT_SKIP_IF_UNSUPPORTED(ret, &info->child_sync);
PARENT_FAIL_IF(ret, &info->child_sync);
- info->amr1 = info->amr2 = info->amr3 = regs[0];
- info->expected_iamr = info->new_iamr = regs[1];
- info->expected_uamor = info->new_uamor = regs[2];
+ info->amr1 = info->amr2 = info->invalid_amr = regs[0];
+ info->expected_iamr = info->invalid_iamr = regs[1];
+ info->expected_uamor = info->invalid_uamor = regs[2];
/* Wake up child so that it can set itself up. */
ret = prod_child(&info->child_sync);
@@ -234,10 +234,10 @@ static int parent(struct shared_info *info, pid_t pid)
return ret;
/* Write invalid AMR value in child. */
- ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr3, 1);
+ ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->invalid_amr, 1);
PARENT_FAIL_IF(ret, &info->child_sync);
- printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr3);
+ printf("%-30s AMR: %016lx\n", ptrace_write_running, info->invalid_amr);
/* Wake up child so that it can verify it didn't change. */
ret = prod_child(&info->child_sync);
@@ -249,7 +249,7 @@ static int parent(struct shared_info *info, pid_t pid)
/* Try to write to IAMR. */
regs[0] = info->amr1;
- regs[1] = info->new_iamr;
+ regs[1] = info->invalid_iamr;
ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);
PARENT_FAIL_IF(!ret, &info->child_sync);
@@ -257,7 +257,7 @@ static int parent(struct shared_info *info, pid_t pid)
ptrace_write_running, regs[0], regs[1]);
/* Try to write to IAMR and UAMOR. */
- regs[2] = info->new_uamor;
+ regs[2] = info->invalid_uamor;
ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);
PARENT_FAIL_IF(!ret, &info->child_sync);
--
2.26.2
^ permalink raw reply related
* [PATCH v2 26/28] powerpc/selftest/ptrace-pkey: Update the test to mark an invalid pkey correctly
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
.../selftests/powerpc/ptrace/ptrace-pkey.c | 30 ++++++++-----------
1 file changed, 12 insertions(+), 18 deletions(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index f9216c7a1829..bc33d748d95b 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -66,11 +66,6 @@ static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
return syscall(__NR_pkey_alloc, flags, init_access_rights);
}
-static int sys_pkey_free(int pkey)
-{
- return syscall(__NR_pkey_free, pkey);
-}
-
static int child(struct shared_info *info)
{
unsigned long reg;
@@ -100,7 +95,11 @@ static int child(struct shared_info *info)
info->amr1 |= 3ul << pkeyshift(pkey1);
info->amr2 |= 3ul << pkeyshift(pkey2);
- info->invalid_amr |= info->amr2 | 3ul << pkeyshift(pkey3);
+ /*
+ * invalid amr value where we try to force write
+ * things which are deined by a uamor setting.
+ */
+ info->invalid_amr = info->amr2 | (~0x0UL & ~info->expected_uamor);
if (disable_execute)
info->expected_iamr |= 1ul << pkeyshift(pkey1);
@@ -111,17 +110,12 @@ static int child(struct shared_info *info)
info->expected_uamor |= 3ul << pkeyshift(pkey1) |
3ul << pkeyshift(pkey2);
- info->invalid_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
- info->invalid_uamor |= 3ul << pkeyshift(pkey1);
-
/*
- * We won't use pkey3. We just want a plausible but invalid key to test
- * whether ptrace will let us write to AMR bits we are not supposed to.
- *
- * This also tests whether the kernel restores the UAMOR permissions
- * after a key is freed.
+ * Create an IAMR value different from expected value.
+ * Kernel will reject an IAMR and UAMOR change.
*/
- sys_pkey_free(pkey3);
+ info->invalid_iamr = info->expected_iamr | (1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2));
+ info->invalid_uamor = info->expected_uamor & ~(0x3ul << pkeyshift(pkey1));
printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
user_write, info->amr1, pkey1, pkey2, pkey3);
@@ -196,9 +190,9 @@ static int parent(struct shared_info *info, pid_t pid)
PARENT_SKIP_IF_UNSUPPORTED(ret, &info->child_sync);
PARENT_FAIL_IF(ret, &info->child_sync);
- info->amr1 = info->amr2 = info->invalid_amr = regs[0];
- info->expected_iamr = info->invalid_iamr = regs[1];
- info->expected_uamor = info->invalid_uamor = regs[2];
+ info->amr1 = info->amr2 = regs[0];
+ info->expected_iamr = regs[1];
+ info->expected_uamor = regs[2];
/* Wake up child so that it can set itself up. */
ret = prod_child(&info->child_sync);
--
2.26.2
^ permalink raw reply related
* [PATCH v2 27/28] powerpc/selftest/ptrace-pkey: IAMR and uamor cannot be updated by ptrace
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
Both IAMR and uamor are privileged and cannot be updated by userspace. Hence
we also don't allow ptrace interface to update them. Don't update them in the
test. Also expected_iamr is only changed if we can allocate a DISABLE_EXECUTE
pkey.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index bc33d748d95b..5c3c8222de46 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -101,15 +101,12 @@ static int child(struct shared_info *info)
*/
info->invalid_amr = info->amr2 | (~0x0UL & ~info->expected_uamor);
+ /*
+ * if PKEY_DISABLE_EXECUTE succeeded we should update the expected_iamr
+ */
if (disable_execute)
info->expected_iamr |= 1ul << pkeyshift(pkey1);
- else
- info->expected_iamr &= ~(1ul << pkeyshift(pkey1));
-
- info->expected_iamr &= ~(1ul << pkeyshift(pkey2) | 1ul << pkeyshift(pkey3));
- info->expected_uamor |= 3ul << pkeyshift(pkey1) |
- 3ul << pkeyshift(pkey2);
/*
* Create an IAMR value different from expected value.
* Kernel will reject an IAMR and UAMOR change.
--
2.26.2
^ permalink raw reply related
* [PATCH v2 28/28] powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec
From: Aneesh Kumar K.V @ 2020-05-02 11:22 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman, npiggin
In-Reply-To: <20200502112229.545331-1-aneesh.kumar@linux.ibm.com>
We can kexec into a kernel that doesn't use memory keys for kernel
mapping (such as an older kernel which doesn't support kuap/kuep with hash
translation). We need to make sure we reset the AMR/IAMR value on kexec
otherwise, the new kernel will use key 0 for kernel mapping and the old
AMR value prevents access to key 0.
This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR
is not needed and the IAMR reset is partial (it doesn't do the reset
on secondary cpus) and is redundant with this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/kup.h | 20 ++++++++++++++++++++
arch/powerpc/include/asm/kup.h | 14 ++++++++++++++
arch/powerpc/kernel/misc_64.S | 14 --------------
arch/powerpc/kexec/core_64.c | 3 +++
arch/powerpc/mm/book3s64/pgtable.c | 3 +++
5 files changed, 40 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 5b00592479d1..1cd0d849bd1b 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -341,6 +341,26 @@ static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
return !!(error_code & DSISR_KEYFAULT);
}
+#define reset_kuap reset_kuap
+static inline void reset_kuap(void)
+{
+ if (mmu_has_feature(MMU_FTR_KUAP)) {
+ mtspr(SPRN_AMR, 0);
+ /* Do we need isync()? We are going via a kexec reset */
+ isync();
+ }
+}
+
+#define reset_kuep reset_kuep
+static inline void reset_kuep(void)
+{
+ if (mmu_has_feature(MMU_FTR_KUEP)) {
+ mtspr(SPRN_IAMR, 0);
+ /* Do we need isync()? We are going via a kexec reset */
+ isync();
+ }
+}
+
#else /* CONFIG_PPC_MEM_KEYS */
static inline void kuap_restore_user_amr(struct pt_regs *regs)
{
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 249eed77a06b..b22becc1705c 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -101,6 +101,20 @@ static inline void prevent_current_access_user(void)
prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
}
+#ifndef reset_kuap
+#define reset_kuap reset_kuap
+static inline void reset_kuap(void)
+{
+}
+#endif
+
+#ifndef reset_kuep
+#define reset_kuep reset_kuep
+static inline void reset_kuep(void)
+{
+}
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_POWERPC_KUAP_H_ */
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 1864605eca29..7bb46ad98207 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -413,20 +413,6 @@ _GLOBAL(kexec_sequence)
li r0,0
std r0,16(r1)
-BEGIN_FTR_SECTION
- /*
- * This is the best time to turn AMR/IAMR off.
- * key 0 is used in radix for supervisor<->user
- * protection, but on hash key 0 is reserved
- * ideally we want to enter with a clean state.
- * NOTE, we rely on r0 being 0 from above.
- */
- mtspr SPRN_IAMR,r0
-BEGIN_FTR_SECTION_NESTED(42)
- mtspr SPRN_AMOR,r0
-END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
/* save regs for local vars on new stack.
* yes, we won't go back, but ...
*/
diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c
index b4184092172a..a124715f33ea 100644
--- a/arch/powerpc/kexec/core_64.c
+++ b/arch/powerpc/kexec/core_64.c
@@ -152,6 +152,9 @@ static void kexec_smp_down(void *arg)
if (ppc_md.kexec_cpu_down)
ppc_md.kexec_cpu_down(0, 1);
+ reset_kuap();
+ reset_kuep();
+
kexec_smp_wait();
/* NOTREACHED */
}
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index e0bb69c616e4..cf3d65067d48 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -168,6 +168,9 @@ void mmu_cleanup_all(void)
radix__mmu_cleanup_all();
else if (mmu_hash_ops.hpte_clear_all)
mmu_hash_ops.hpte_clear_all();
+
+ reset_kuap();
+ reset_kuep();
}
#ifdef CONFIG_MEMORY_HOTPLUG
--
2.26.2
^ permalink raw reply related
* [powerpc:topic/uaccess] BUILD SUCCESS b44f687386875b714dae2afa768e73401e45c21c
From: kbuild test robot @ 2020-05-02 11:38 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git topic/uaccess
branch HEAD: b44f687386875b714dae2afa768e73401e45c21c drm/i915/gem: Replace user_access_begin by user_write_access_begin
elapsed time: 695m
configs tested: 193
configs skipped: 0
The following configs have been built successfully.
More configs may be tested in the coming days.
arm64 allyesconfig
arm allyesconfig
arm64 allmodconfig
arm allmodconfig
arm64 allnoconfig
arm allnoconfig
arm efm32_defconfig
arm at91_dt_defconfig
arm shmobile_defconfig
arm64 defconfig
arm exynos_defconfig
arm multi_v5_defconfig
arm sunxi_defconfig
arm multi_v7_defconfig
sparc allyesconfig
arc allyesconfig
powerpc defconfig
ia64 defconfig
i386 alldefconfig
openrisc simple_smp_defconfig
arc defconfig
mips ar7_defconfig
s390 allnoconfig
mips allnoconfig
mips allmodconfig
sparc64 defconfig
csky defconfig
sh rsk7269_defconfig
ia64 allnoconfig
powerpc mpc512x_defconfig
sh sh7785lcr_32bit_defconfig
xtensa iss_defconfig
um defconfig
nds32 allnoconfig
m68k sun3_defconfig
i386 allnoconfig
i386 allyesconfig
i386 defconfig
i386 debian-10.3
ia64 allmodconfig
ia64 generic_defconfig
ia64 tiger_defconfig
ia64 bigsur_defconfig
ia64 allyesconfig
ia64 alldefconfig
m68k m5475evb_defconfig
m68k allmodconfig
m68k bvme6000_defconfig
m68k multi_defconfig
nios2 3c120_defconfig
nios2 10m50_defconfig
c6x evmc6678_defconfig
c6x allyesconfig
openrisc or1ksim_defconfig
nds32 defconfig
alpha defconfig
h8300 h8s-sim_defconfig
h8300 edosk2674_defconfig
h8300 h8300h-sim_defconfig
xtensa common_defconfig
microblaze mmu_defconfig
microblaze nommu_defconfig
mips fuloong2e_defconfig
mips malta_kvm_defconfig
mips allyesconfig
mips 64r6el_defconfig
mips 32r2_defconfig
mips malta_kvm_guest_defconfig
mips tb0287_defconfig
mips capcella_defconfig
mips ip32_defconfig
mips decstation_64_defconfig
mips loongson3_defconfig
mips ath79_defconfig
mips bcm63xx_defconfig
parisc allnoconfig
parisc generic-64bit_defconfig
parisc generic-32bit_defconfig
parisc allyesconfig
parisc allmodconfig
powerpc chrp32_defconfig
powerpc holly_defconfig
powerpc ppc64_defconfig
powerpc rhel-kconfig
powerpc allnoconfig
powerpc mpc866_ads_defconfig
powerpc amigaone_defconfig
powerpc adder875_defconfig
powerpc ep8248e_defconfig
powerpc g5_defconfig
m68k randconfig-a001-20200502
mips randconfig-a001-20200502
nds32 randconfig-a001-20200502
alpha randconfig-a001-20200502
parisc randconfig-a001-20200502
riscv randconfig-a001-20200502
h8300 randconfig-a001-20200502
nios2 randconfig-a001-20200502
microblaze randconfig-a001-20200502
c6x randconfig-a001-20200502
sparc64 randconfig-a001-20200502
s390 randconfig-a001-20200502
xtensa randconfig-a001-20200502
sh randconfig-a001-20200502
openrisc randconfig-a001-20200502
csky randconfig-a001-20200502
x86_64 randconfig-a003-20200502
x86_64 randconfig-a001-20200502
x86_64 randconfig-a002-20200502
i386 randconfig-a002-20200502
i386 randconfig-a003-20200502
i386 randconfig-a001-20200502
i386 randconfig-b003-20200502
i386 randconfig-b001-20200502
x86_64 randconfig-b003-20200502
x86_64 randconfig-b001-20200502
i386 randconfig-b002-20200502
i386 randconfig-b003-20200501
x86_64 randconfig-b002-20200501
i386 randconfig-b001-20200501
x86_64 randconfig-b003-20200501
x86_64 randconfig-b001-20200501
i386 randconfig-b002-20200501
x86_64 randconfig-c002-20200502
i386 randconfig-c002-20200502
i386 randconfig-c001-20200502
i386 randconfig-c003-20200502
i386 randconfig-d003-20200502
i386 randconfig-d001-20200502
x86_64 randconfig-d002-20200502
i386 randconfig-d002-20200502
x86_64 randconfig-e003-20200502
i386 randconfig-e003-20200502
x86_64 randconfig-e001-20200502
i386 randconfig-e002-20200502
i386 randconfig-e001-20200502
i386 randconfig-f003-20200502
x86_64 randconfig-f001-20200502
x86_64 randconfig-f003-20200502
x86_64 randconfig-f002-20200502
i386 randconfig-f001-20200502
i386 randconfig-f002-20200502
x86_64 randconfig-g003-20200502
i386 randconfig-g003-20200502
i386 randconfig-g002-20200502
x86_64 randconfig-g001-20200502
x86_64 randconfig-g002-20200502
i386 randconfig-g001-20200502
i386 randconfig-h001-20200502
i386 randconfig-h002-20200502
i386 randconfig-h003-20200502
x86_64 randconfig-h002-20200502
x86_64 randconfig-h001-20200502
x86_64 randconfig-h003-20200502
ia64 randconfig-a001-20200502
arm64 randconfig-a001-20200502
arc randconfig-a001-20200502
powerpc randconfig-a001-20200502
arm randconfig-a001-20200502
sparc randconfig-a001-20200502
ia64 randconfig-a001-20200501
arc randconfig-a001-20200501
powerpc randconfig-a001-20200501
arm randconfig-a001-20200501
sparc randconfig-a001-20200501
riscv allyesconfig
riscv nommu_virt_defconfig
riscv allnoconfig
riscv defconfig
riscv rv32_defconfig
riscv allmodconfig
s390 zfcpdump_defconfig
s390 debug_defconfig
s390 allyesconfig
s390 allmodconfig
s390 alldefconfig
s390 defconfig
sh allmodconfig
sh titan_defconfig
sh allnoconfig
sparc defconfig
sparc64 allnoconfig
sparc64 allyesconfig
sparc64 allmodconfig
um x86_64_defconfig
um i386_defconfig
x86_64 rhel
x86_64 rhel-7.6
x86_64 rhel-7.6-kselftests
x86_64 rhel-7.2-clear
x86_64 lkp
x86_64 fedora-25
x86_64 kexec
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply
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