[PATCH -next v6 00/10]arm64: add machine check safe support

[PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

With the increase of memory capacity and density, the probability of
memory error increases. The increasing size and density of server RAM
in the data center and cloud have shown increased uncorrectable memory
errors.

Currently, the kernel has a mechanism to recover from hardware memory
errors. This patchset provides an new recovery mechanism.

For arm64, the hardware memory error handling is do_sea() which divided
into two cases:
 1. The user state consumed the memory errors, the solution is kill the
    user process and isolate the error page.
 2. The kernel state consumed the memory errors, the solution is panic.

For case 2, Undifferentiated panic maybe not the optimal choice, it can be
handled better, in some scenarios, we can avoid panic, such as uaccess, if the
uaccess fails due to memory error, only the user process will be affected,
kill the user process and isolate the user page with hardware memory errors
is a better choice.

This patchset can be divided into two parts:
 1. Patch 1~6    - do some restructuring to arm64 extable.
 2. Patch 7~10   - arm64 add support for machine check safe framework,
 then ,add two specific scenarios(uaccess/cow) to machine check safe.

Since V5:
 1. Add patch2/3 to add uaccess assembly helpers.
 2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
 3. Remove kernel access fixup in patch9.
 All suggestion are from Mark. 

Since V4:
 1. According Michael's suggestion, add patch5.
 2. According Mark's suggestiog, do some restructuring to arm64
 extable, then a new adaptation of machine check safe support is made based
 on this.
 3. According Mark's suggestion, support machine check safe in do_mte() in
 cow scene.
 4. In V4, two patches have been merged into -next, so V5 not send these
 two patches.

Since V3:
 1. According to Robin's suggestion, direct modify user_ldst and
 user_ldp in asm-uaccess.h and modify mte.S.
 2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
 and copy_to_user.S.
 3. According to Robin's suggestion, using micro in copy_page_mc.S to
 simplify code.
 4. According to KeFeng's suggestion, modify powerpc code in patch1.
 5. According to KeFeng's suggestion, modify mm/extable.c and some code
 optimization.

Since V2:
 1. According to Mark's suggestion, all uaccess can be recovered due to
    memory error.
 2. Scenario pagecache reading is also supported as part of uaccess
    (copy_to_user()) and duplication code problem is also solved. 
    Thanks for Robin's suggestion.
 3. According Mark's suggestion, update commit message of patch 2/5.
 4. According Borisllav's suggestion, update commit message of patch 1/5.

Since V1:
 1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
   ARM64_UCE_KERNEL_RECOVERY.
 2.Add two new scenes, cow and pagecache reading.
 3.Fix two small bug(the first two patch).

V1 in here:
https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/

Tong Tiangen (10):
  arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
  arm64: asm-extable: move data fields
  arm64: asm-extable: add asm uacess helpers
  arm64: extable: make uaaccess helper use extable type
    EX_TYPE_UACCESS_ERR_ZERO
  arm64: extable: move _cond_extable to _cond_uaccess_extable
  arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
  Add generic fallback version of copy_mc_to_user()
  arm64: add support for machine check error safe
  arm64: add uaccess to machine check safe
  arm64: add cow to machine check safe

 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
 arch/arm64/include/asm/asm-uaccess.h | 12 ++--
 arch/arm64/include/asm/assembler.h   |  8 ++-
 arch/arm64/include/asm/extable.h     |  1 +
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 +++
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 ++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++---
 arch/arm64/mm/extable.c              | 21 ++++++-
 arch/arm64/mm/fault.c                | 29 ++++++++-
 arch/powerpc/include/asm/uaccess.h   |  1 +
 arch/x86/include/asm/uaccess.h       |  1 +
 include/linux/highmem.h              |  8 +++
 include/linux/uaccess.h              |  9 +++
 mm/memory.c                          |  2 +-
 19 files changed, 339 insertions(+), 90 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

-- 
2.25.1

[PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

With the increase of memory capacity and density, the probability of
memory error increases. The increasing size and density of server RAM
in the data center and cloud have shown increased uncorrectable memory
errors.

Currently, the kernel has a mechanism to recover from hardware memory
errors. This patchset provides an new recovery mechanism.

For arm64, the hardware memory error handling is do_sea() which divided
into two cases:
 1. The user state consumed the memory errors, the solution is kill the
    user process and isolate the error page.
 2. The kernel state consumed the memory errors, the solution is panic.

For case 2, Undifferentiated panic maybe not the optimal choice, it can be
handled better, in some scenarios, we can avoid panic, such as uaccess, if the
uaccess fails due to memory error, only the user process will be affected,
kill the user process and isolate the user page with hardware memory errors
is a better choice.

This patchset can be divided into two parts:
 1. Patch 1~6    - do some restructuring to arm64 extable.
 2. Patch 7~10   - arm64 add support for machine check safe framework,
 then ,add two specific scenarios(uaccess/cow) to machine check safe.

Since V5:
 1. Add patch2/3 to add uaccess assembly helpers.
 2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
 3. Remove kernel access fixup in patch9.
 All suggestion are from Mark. 

Since V4:
 1. According Michael's suggestion, add patch5.
 2. According Mark's suggestiog, do some restructuring to arm64
 extable, then a new adaptation of machine check safe support is made based
 on this.
 3. According Mark's suggestion, support machine check safe in do_mte() in
 cow scene.
 4. In V4, two patches have been merged into -next, so V5 not send these
 two patches.

Since V3:
 1. According to Robin's suggestion, direct modify user_ldst and
 user_ldp in asm-uaccess.h and modify mte.S.
 2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
 and copy_to_user.S.
 3. According to Robin's suggestion, using micro in copy_page_mc.S to
 simplify code.
 4. According to KeFeng's suggestion, modify powerpc code in patch1.
 5. According to KeFeng's suggestion, modify mm/extable.c and some code
 optimization.

Since V2:
 1. According to Mark's suggestion, all uaccess can be recovered due to
    memory error.
 2. Scenario pagecache reading is also supported as part of uaccess
    (copy_to_user()) and duplication code problem is also solved. 
    Thanks for Robin's suggestion.
 3. According Mark's suggestion, update commit message of patch 2/5.
 4. According Borisllav's suggestion, update commit message of patch 1/5.

Since V1:
 1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
   ARM64_UCE_KERNEL_RECOVERY.
 2.Add two new scenes, cow and pagecache reading.
 3.Fix two small bug(the first two patch).

V1 in here:
https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/

Tong Tiangen (10):
  arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
  arm64: asm-extable: move data fields
  arm64: asm-extable: add asm uacess helpers
  arm64: extable: make uaaccess helper use extable type
    EX_TYPE_UACCESS_ERR_ZERO
  arm64: extable: move _cond_extable to _cond_uaccess_extable
  arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
  Add generic fallback version of copy_mc_to_user()
  arm64: add support for machine check error safe
  arm64: add uaccess to machine check safe
  arm64: add cow to machine check safe

 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
 arch/arm64/include/asm/asm-uaccess.h | 12 ++--
 arch/arm64/include/asm/assembler.h   |  8 ++-
 arch/arm64/include/asm/extable.h     |  1 +
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 +++
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 ++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++---
 arch/arm64/mm/extable.c              | 21 ++++++-
 arch/arm64/mm/fault.c                | 29 ++++++++-
 arch/powerpc/include/asm/uaccess.h   |  1 +
 arch/x86/include/asm/uaccess.h       |  1 +
 include/linux/highmem.h              |  8 +++
 include/linux/uaccess.h              |  9 +++
 mm/memory.c                          |  2 +-
 19 files changed, 339 insertions(+), 90 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

-- 
2.25.1


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[PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

With the increase of memory capacity and density, the probability of
memory error increases. The increasing size and density of server RAM
in the data center and cloud have shown increased uncorrectable memory
errors.

Currently, the kernel has a mechanism to recover from hardware memory
errors. This patchset provides an new recovery mechanism.

For arm64, the hardware memory error handling is do_sea() which divided
into two cases:
 1. The user state consumed the memory errors, the solution is kill the
    user process and isolate the error page.
 2. The kernel state consumed the memory errors, the solution is panic.

For case 2, Undifferentiated panic maybe not the optimal choice, it can be
handled better, in some scenarios, we can avoid panic, such as uaccess, if the
uaccess fails due to memory error, only the user process will be affected,
kill the user process and isolate the user page with hardware memory errors
is a better choice.

This patchset can be divided into two parts:
 1. Patch 1~6    - do some restructuring to arm64 extable.
 2. Patch 7~10   - arm64 add support for machine check safe framework,
 then ,add two specific scenarios(uaccess/cow) to machine check safe.

Since V5:
 1. Add patch2/3 to add uaccess assembly helpers.
 2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
 3. Remove kernel access fixup in patch9.
 All suggestion are from Mark. 

Since V4:
 1. According Michael's suggestion, add patch5.
 2. According Mark's suggestiog, do some restructuring to arm64
 extable, then a new adaptation of machine check safe support is made based
 on this.
 3. According Mark's suggestion, support machine check safe in do_mte() in
 cow scene.
 4. In V4, two patches have been merged into -next, so V5 not send these
 two patches.

Since V3:
 1. According to Robin's suggestion, direct modify user_ldst and
 user_ldp in asm-uaccess.h and modify mte.S.
 2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
 and copy_to_user.S.
 3. According to Robin's suggestion, using micro in copy_page_mc.S to
 simplify code.
 4. According to KeFeng's suggestion, modify powerpc code in patch1.
 5. According to KeFeng's suggestion, modify mm/extable.c and some code
 optimization.

Since V2:
 1. According to Mark's suggestion, all uaccess can be recovered due to
    memory error.
 2. Scenario pagecache reading is also supported as part of uaccess
    (copy_to_user()) and duplication code problem is also solved. 
    Thanks for Robin's suggestion.
 3. According Mark's suggestion, update commit message of patch 2/5.
 4. According Borisllav's suggestion, update commit message of patch 1/5.

Since V1:
 1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
   ARM64_UCE_KERNEL_RECOVERY.
 2.Add two new scenes, cow and pagecache reading.
 3.Fix two small bug(the first two patch).

V1 in here:
https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/

Tong Tiangen (10):
  arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
  arm64: asm-extable: move data fields
  arm64: asm-extable: add asm uacess helpers
  arm64: extable: make uaaccess helper use extable type
    EX_TYPE_UACCESS_ERR_ZERO
  arm64: extable: move _cond_extable to _cond_uaccess_extable
  arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
  Add generic fallback version of copy_mc_to_user()
  arm64: add support for machine check error safe
  arm64: add uaccess to machine check safe
  arm64: add cow to machine check safe

 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
 arch/arm64/include/asm/asm-uaccess.h | 12 ++--
 arch/arm64/include/asm/assembler.h   |  8 ++-
 arch/arm64/include/asm/extable.h     |  1 +
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 +++
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 ++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++---
 arch/arm64/mm/extable.c              | 21 ++++++-
 arch/arm64/mm/fault.c                | 29 ++++++++-
 arch/powerpc/include/asm/uaccess.h   |  1 +
 arch/x86/include/asm/uaccess.h       |  1 +
 include/linux/highmem.h              |  8 +++
 include/linux/uaccess.h              |  9 +++
 mm/memory.c                          |  2 +-
 19 files changed, 339 insertions(+), 90 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

-- 
2.25.1

[PATCH -next v6 01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support

[Tong Tiangen]

Currently, The extable type EX_TYPE_UACCESS_ERR_ZERO is used by
__get/put_kernel_nofault(), but those helpers are not uaccess type, so we
add a new extable type EX_TYPE_KACCESS_ERR_ZERO which can be used by
__get/put_kernel_no_fault().

This is also to prepare for distinguishing the two types in machine check
safe process.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 15 ++++-
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/mm/extable.c              |  1 +
 3 files changed, 62 insertions(+), 48 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index c39f2437e08e..1717fc4cfeb5 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,7 +6,8 @@
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
 #define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_KACCESS_ERR_ZERO	4
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
 #ifdef __ASSEMBLY__
 
@@ -73,9 +74,21 @@
 			    EX_DATA_REG(ZERO, zero)			\
 			  ")")
 
+#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__DEFINE_ASM_GPR_NUMS						\
+	__ASM_EXTABLE_RAW(#insn, #fixup, 				\
+			  __stringify(EX_TYPE_KACCESS_ERR_ZERO),	\
+			  "("						\
+			    EX_DATA_REG(ERR, err) " | "			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ")")
+
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
 #define EX_DATA_REG_DATA_SHIFT	0
 #define EX_DATA_REG_DATA	GENMASK(4, 0)
 #define EX_DATA_REG_ADDR_SHIFT	5
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 63f9c828f1a7..2fc9f0861769 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -232,34 +232,34 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
  * The "__xxx_error" versions set the third argument to -EFAULT if an error
  * occurs, and leave it unchanged on success.
  */
-#define __get_mem_asm(load, reg, x, addr, err)				\
+#define __get_mem_asm(load, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" load "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %w0, %w1)			\
+	_ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %w0, %w1)		\
 	: "+r" (err), "=&r" (x)						\
 	: "r" (addr))
 
-#define __raw_get_mem(ldr, x, ptr, err)					\
-do {									\
-	unsigned long __gu_val;						\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
-	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
+#define __raw_get_mem(ldr, x, ptr, err, type)					\
+do {										\
+	unsigned long __gu_val;							\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err), type);	\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
+	(x) = (__force __typeof__(*(ptr)))__gu_val;				\
 } while (0)
 
 /*
@@ -274,7 +274,7 @@ do {									\
 	__chk_user_ptr(ptr);						\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err);		\
+	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 									\
 	(x) = __rgu_val;						\
@@ -314,40 +314,40 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_get_mem("ldr", *((type *)(__gkn_dst)),			\
-		      (__force type *)(__gkn_src), __gkn_err);		\
+		      (__force type *)(__gkn_src), __gkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__gkn_err))					\
 		goto err_label;						\
 } while (0)
 
-#define __put_mem_asm(store, reg, x, addr, err)				\
+#define __put_mem_asm(store, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" store "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0)				\
+	_ASM_EXTABLE_##type##ACCESS_ERR(1b, 2b, %w0)			\
 	: "+r" (err)							\
 	: "r" (x), "r" (addr))
 
-#define __raw_put_mem(str, x, ptr, err)					\
-do {									\
-	__typeof__(*(ptr)) __pu_val = (x);				\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__put_mem_asm(str, "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__put_mem_asm(str, "%x", __pu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
+#define __raw_put_mem(str, x, ptr, err, type)					\
+do {										\
+	__typeof__(*(ptr)) __pu_val = (x);					\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__put_mem_asm(str, "%w", __pu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__put_mem_asm(str, "%x", __pu_val, (ptr), (err), type);		\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
 } while (0)
 
 /*
@@ -362,7 +362,7 @@ do {									\
 	__chk_user_ptr(__rpu_ptr);					\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err);		\
+	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 } while (0)
 
@@ -400,7 +400,7 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_put_mem("str", *((type *)(__pkn_src)),			\
-		      (__force type *)(__pkn_dst), __pkn_err);		\
+		      (__force type *)(__pkn_dst), __pkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__pkn_err))					\
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 489455309695..056591e5ca80 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -77,6 +77,7 @@ bool fixup_exception(struct pt_regs *regs)
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
+	case EX_TYPE_KACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
 	case EX_TYPE_LOAD_UNALIGNED_ZEROPAD:
 		return ex_handler_load_unaligned_zeropad(ex, regs);
-- 
2.25.1

[PATCH -next v6 01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support

[Tong Tiangen]

Currently, The extable type EX_TYPE_UACCESS_ERR_ZERO is used by
__get/put_kernel_nofault(), but those helpers are not uaccess type, so we
add a new extable type EX_TYPE_KACCESS_ERR_ZERO which can be used by
__get/put_kernel_no_fault().

This is also to prepare for distinguishing the two types in machine check
safe process.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 15 ++++-
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/mm/extable.c              |  1 +
 3 files changed, 62 insertions(+), 48 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index c39f2437e08e..1717fc4cfeb5 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,7 +6,8 @@
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
 #define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_KACCESS_ERR_ZERO	4
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
 #ifdef __ASSEMBLY__
 
@@ -73,9 +74,21 @@
 			    EX_DATA_REG(ZERO, zero)			\
 			  ")")
 
+#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__DEFINE_ASM_GPR_NUMS						\
+	__ASM_EXTABLE_RAW(#insn, #fixup, 				\
+			  __stringify(EX_TYPE_KACCESS_ERR_ZERO),	\
+			  "("						\
+			    EX_DATA_REG(ERR, err) " | "			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ")")
+
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
 #define EX_DATA_REG_DATA_SHIFT	0
 #define EX_DATA_REG_DATA	GENMASK(4, 0)
 #define EX_DATA_REG_ADDR_SHIFT	5
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 63f9c828f1a7..2fc9f0861769 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -232,34 +232,34 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
  * The "__xxx_error" versions set the third argument to -EFAULT if an error
  * occurs, and leave it unchanged on success.
  */
-#define __get_mem_asm(load, reg, x, addr, err)				\
+#define __get_mem_asm(load, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" load "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %w0, %w1)			\
+	_ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %w0, %w1)		\
 	: "+r" (err), "=&r" (x)						\
 	: "r" (addr))
 
-#define __raw_get_mem(ldr, x, ptr, err)					\
-do {									\
-	unsigned long __gu_val;						\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
-	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
+#define __raw_get_mem(ldr, x, ptr, err, type)					\
+do {										\
+	unsigned long __gu_val;							\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err), type);	\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
+	(x) = (__force __typeof__(*(ptr)))__gu_val;				\
 } while (0)
 
 /*
@@ -274,7 +274,7 @@ do {									\
 	__chk_user_ptr(ptr);						\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err);		\
+	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 									\
 	(x) = __rgu_val;						\
@@ -314,40 +314,40 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_get_mem("ldr", *((type *)(__gkn_dst)),			\
-		      (__force type *)(__gkn_src), __gkn_err);		\
+		      (__force type *)(__gkn_src), __gkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__gkn_err))					\
 		goto err_label;						\
 } while (0)
 
-#define __put_mem_asm(store, reg, x, addr, err)				\
+#define __put_mem_asm(store, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" store "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0)				\
+	_ASM_EXTABLE_##type##ACCESS_ERR(1b, 2b, %w0)			\
 	: "+r" (err)							\
 	: "r" (x), "r" (addr))
 
-#define __raw_put_mem(str, x, ptr, err)					\
-do {									\
-	__typeof__(*(ptr)) __pu_val = (x);				\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__put_mem_asm(str, "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__put_mem_asm(str, "%x", __pu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
+#define __raw_put_mem(str, x, ptr, err, type)					\
+do {										\
+	__typeof__(*(ptr)) __pu_val = (x);					\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__put_mem_asm(str, "%w", __pu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__put_mem_asm(str, "%x", __pu_val, (ptr), (err), type);		\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
 } while (0)
 
 /*
@@ -362,7 +362,7 @@ do {									\
 	__chk_user_ptr(__rpu_ptr);					\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err);		\
+	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 } while (0)
 
@@ -400,7 +400,7 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_put_mem("str", *((type *)(__pkn_src)),			\
-		      (__force type *)(__pkn_dst), __pkn_err);		\
+		      (__force type *)(__pkn_dst), __pkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__pkn_err))					\
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 489455309695..056591e5ca80 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -77,6 +77,7 @@ bool fixup_exception(struct pt_regs *regs)
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
+	case EX_TYPE_KACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
 	case EX_TYPE_LOAD_UNALIGNED_ZEROPAD:
 		return ex_handler_load_unaligned_zeropad(ex, regs);
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support

[Tong Tiangen]

Currently, The extable type EX_TYPE_UACCESS_ERR_ZERO is used by
__get/put_kernel_nofault(), but those helpers are not uaccess type, so we
add a new extable type EX_TYPE_KACCESS_ERR_ZERO which can be used by
__get/put_kernel_no_fault().

This is also to prepare for distinguishing the two types in machine check
safe process.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 15 ++++-
 arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
 arch/arm64/mm/extable.c              |  1 +
 3 files changed, 62 insertions(+), 48 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index c39f2437e08e..1717fc4cfeb5 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,7 +6,8 @@
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
 #define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_KACCESS_ERR_ZERO	4
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
 #ifdef __ASSEMBLY__
 
@@ -73,9 +74,21 @@
 			    EX_DATA_REG(ZERO, zero)			\
 			  ")")
 
+#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__DEFINE_ASM_GPR_NUMS						\
+	__ASM_EXTABLE_RAW(#insn, #fixup, 				\
+			  __stringify(EX_TYPE_KACCESS_ERR_ZERO),	\
+			  "("						\
+			    EX_DATA_REG(ERR, err) " | "			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ")")
+
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
 #define EX_DATA_REG_DATA_SHIFT	0
 #define EX_DATA_REG_DATA	GENMASK(4, 0)
 #define EX_DATA_REG_ADDR_SHIFT	5
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 63f9c828f1a7..2fc9f0861769 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -232,34 +232,34 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
  * The "__xxx_error" versions set the third argument to -EFAULT if an error
  * occurs, and leave it unchanged on success.
  */
-#define __get_mem_asm(load, reg, x, addr, err)				\
+#define __get_mem_asm(load, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" load "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %w0, %w1)			\
+	_ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %w0, %w1)		\
 	: "+r" (err), "=&r" (x)						\
 	: "r" (addr))
 
-#define __raw_get_mem(ldr, x, ptr, err)					\
-do {									\
-	unsigned long __gu_val;						\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
-	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
+#define __raw_get_mem(ldr, x, ptr, err, type)					\
+do {										\
+	unsigned long __gu_val;							\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err), type);	\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
+	(x) = (__force __typeof__(*(ptr)))__gu_val;				\
 } while (0)
 
 /*
@@ -274,7 +274,7 @@ do {									\
 	__chk_user_ptr(ptr);						\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err);		\
+	__raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 									\
 	(x) = __rgu_val;						\
@@ -314,40 +314,40 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_get_mem("ldr", *((type *)(__gkn_dst)),			\
-		      (__force type *)(__gkn_src), __gkn_err);		\
+		      (__force type *)(__gkn_src), __gkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__gkn_err))					\
 		goto err_label;						\
 } while (0)
 
-#define __put_mem_asm(store, reg, x, addr, err)				\
+#define __put_mem_asm(store, reg, x, addr, err, type)			\
 	asm volatile(							\
 	"1:	" store "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	_ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0)				\
+	_ASM_EXTABLE_##type##ACCESS_ERR(1b, 2b, %w0)			\
 	: "+r" (err)							\
 	: "r" (x), "r" (addr))
 
-#define __raw_put_mem(str, x, ptr, err)					\
-do {									\
-	__typeof__(*(ptr)) __pu_val = (x);				\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 2:								\
-		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 4:								\
-		__put_mem_asm(str, "%w", __pu_val, (ptr), (err));	\
-		break;							\
-	case 8:								\
-		__put_mem_asm(str, "%x", __pu_val, (ptr), (err));	\
-		break;							\
-	default:							\
-		BUILD_BUG();						\
-	}								\
+#define __raw_put_mem(str, x, ptr, err, type)					\
+do {										\
+	__typeof__(*(ptr)) __pu_val = (x);					\
+	switch (sizeof(*(ptr))) {						\
+	case 1:									\
+		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 2:									\
+		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err), type);	\
+		break;								\
+	case 4:									\
+		__put_mem_asm(str, "%w", __pu_val, (ptr), (err), type);		\
+		break;								\
+	case 8:									\
+		__put_mem_asm(str, "%x", __pu_val, (ptr), (err), type);		\
+		break;								\
+	default:								\
+		BUILD_BUG();							\
+	}									\
 } while (0)
 
 /*
@@ -362,7 +362,7 @@ do {									\
 	__chk_user_ptr(__rpu_ptr);					\
 									\
 	uaccess_ttbr0_enable();						\
-	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err);		\
+	__raw_put_mem("sttr", __rpu_val, __rpu_ptr, err, U);		\
 	uaccess_ttbr0_disable();					\
 } while (0)
 
@@ -400,7 +400,7 @@ do {									\
 									\
 	__uaccess_enable_tco_async();					\
 	__raw_put_mem("str", *((type *)(__pkn_src)),			\
-		      (__force type *)(__pkn_dst), __pkn_err);		\
+		      (__force type *)(__pkn_dst), __pkn_err, K);	\
 	__uaccess_disable_tco_async();					\
 									\
 	if (unlikely(__pkn_err))					\
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 489455309695..056591e5ca80 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -77,6 +77,7 @@ bool fixup_exception(struct pt_regs *regs)
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
+	case EX_TYPE_KACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
 	case EX_TYPE_LOAD_UNALIGNED_ZEROPAD:
 		return ex_handler_load_unaligned_zeropad(ex, regs);
-- 
2.25.1

[PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Tong Tiangen]

In subsequent patches we'll need to fill in extable data fields in
regular assembly files. In preparation for this, move the definitions of
the extable data fields earlier in asm-extable.h so that they are
defined for both assembly and C files.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 1717fc4cfeb5..204b30bf78b3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -9,6 +9,18 @@
 #define EX_TYPE_KACCESS_ERR_ZERO	4
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
+/* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
+#define EX_DATA_REG_ERR_SHIFT	0
+#define EX_DATA_REG_ERR		GENMASK(4, 0)
+#define EX_DATA_REG_ZERO_SHIFT	5
+#define EX_DATA_REG_ZERO	GENMASK(9, 5)
+
+/* Data fields for EX_TYPE_LOAD_UNALIGNED_ZEROPAD */
+#define EX_DATA_REG_DATA_SHIFT	0
+#define EX_DATA_REG_DATA	GENMASK(4, 0)
+#define EX_DATA_REG_ADDR_SHIFT	5
+#define EX_DATA_REG_ADDR	GENMASK(9, 5)
+
 #ifdef __ASSEMBLY__
 
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
@@ -57,11 +69,6 @@
 #define _ASM_EXTABLE(insn, fixup) \
 	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
 
-#define EX_DATA_REG_ERR_SHIFT	0
-#define EX_DATA_REG_ERR		GENMASK(4, 0)
-#define EX_DATA_REG_ZERO_SHIFT	5
-#define EX_DATA_REG_ZERO	GENMASK(9, 5)
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
@@ -89,11 +96,6 @@
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-#define EX_DATA_REG_DATA_SHIFT	0
-#define EX_DATA_REG_DATA	GENMASK(4, 0)
-#define EX_DATA_REG_ADDR_SHIFT	5
-#define EX_DATA_REG_ADDR	GENMASK(9, 5)
-
 #define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr)		\
 	__DEFINE_ASM_GPR_NUMS							\
 	__ASM_EXTABLE_RAW(#insn, #fixup,					\
-- 
2.25.1

[PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Tong Tiangen]

In subsequent patches we'll need to fill in extable data fields in
regular assembly files. In preparation for this, move the definitions of
the extable data fields earlier in asm-extable.h so that they are
defined for both assembly and C files.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 1717fc4cfeb5..204b30bf78b3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -9,6 +9,18 @@
 #define EX_TYPE_KACCESS_ERR_ZERO	4
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
+/* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
+#define EX_DATA_REG_ERR_SHIFT	0
+#define EX_DATA_REG_ERR		GENMASK(4, 0)
+#define EX_DATA_REG_ZERO_SHIFT	5
+#define EX_DATA_REG_ZERO	GENMASK(9, 5)
+
+/* Data fields for EX_TYPE_LOAD_UNALIGNED_ZEROPAD */
+#define EX_DATA_REG_DATA_SHIFT	0
+#define EX_DATA_REG_DATA	GENMASK(4, 0)
+#define EX_DATA_REG_ADDR_SHIFT	5
+#define EX_DATA_REG_ADDR	GENMASK(9, 5)
+
 #ifdef __ASSEMBLY__
 
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
@@ -57,11 +69,6 @@
 #define _ASM_EXTABLE(insn, fixup) \
 	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
 
-#define EX_DATA_REG_ERR_SHIFT	0
-#define EX_DATA_REG_ERR		GENMASK(4, 0)
-#define EX_DATA_REG_ZERO_SHIFT	5
-#define EX_DATA_REG_ZERO	GENMASK(9, 5)
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
@@ -89,11 +96,6 @@
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-#define EX_DATA_REG_DATA_SHIFT	0
-#define EX_DATA_REG_DATA	GENMASK(4, 0)
-#define EX_DATA_REG_ADDR_SHIFT	5
-#define EX_DATA_REG_ADDR	GENMASK(9, 5)
-
 #define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr)		\
 	__DEFINE_ASM_GPR_NUMS							\
 	__ASM_EXTABLE_RAW(#insn, #fixup,					\
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Tong Tiangen]

In subsequent patches we'll need to fill in extable data fields in
regular assembly files. In preparation for this, move the definitions of
the extable data fields earlier in asm-extable.h so that they are
defined for both assembly and C files.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 1717fc4cfeb5..204b30bf78b3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -9,6 +9,18 @@
 #define EX_TYPE_KACCESS_ERR_ZERO	4
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
 
+/* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
+#define EX_DATA_REG_ERR_SHIFT	0
+#define EX_DATA_REG_ERR		GENMASK(4, 0)
+#define EX_DATA_REG_ZERO_SHIFT	5
+#define EX_DATA_REG_ZERO	GENMASK(9, 5)
+
+/* Data fields for EX_TYPE_LOAD_UNALIGNED_ZEROPAD */
+#define EX_DATA_REG_DATA_SHIFT	0
+#define EX_DATA_REG_DATA	GENMASK(4, 0)
+#define EX_DATA_REG_ADDR_SHIFT	5
+#define EX_DATA_REG_ADDR	GENMASK(9, 5)
+
 #ifdef __ASSEMBLY__
 
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
@@ -57,11 +69,6 @@
 #define _ASM_EXTABLE(insn, fixup) \
 	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
 
-#define EX_DATA_REG_ERR_SHIFT	0
-#define EX_DATA_REG_ERR		GENMASK(4, 0)
-#define EX_DATA_REG_ZERO_SHIFT	5
-#define EX_DATA_REG_ZERO	GENMASK(9, 5)
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
@@ -89,11 +96,6 @@
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-#define EX_DATA_REG_DATA_SHIFT	0
-#define EX_DATA_REG_DATA	GENMASK(4, 0)
-#define EX_DATA_REG_ADDR_SHIFT	5
-#define EX_DATA_REG_ADDR	GENMASK(9, 5)
-
 #define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr)		\
 	__DEFINE_ASM_GPR_NUMS							\
 	__ASM_EXTABLE_RAW(#insn, #fixup,					\
-- 
2.25.1

Re: [PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Will Deacon]

On Tue, Jun 21, 2022 at 07:26:30AM +0000, Tong Tiangen wrote:
> In subsequent patches we'll need to fill in extable data fields in
> regular assembly files. In preparation for this, move the definitions of
> the extable data fields earlier in asm-extable.h so that they are
> defined for both assembly and C files.
> 
> There should be no functional change as a result of this patch.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> ---
>  arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)

This (and the following) patch should retain Mark's authorship information
as they are taken from his git tree:

https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/extable/asm-uaccess

I plan to apply the first six patches for now, so I'll fix that up at the
same time.

Will

Re: [PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Will Deacon]

On Tue, Jun 21, 2022 at 07:26:30AM +0000, Tong Tiangen wrote:
> In subsequent patches we'll need to fill in extable data fields in
> regular assembly files. In preparation for this, move the definitions of
> the extable data fields earlier in asm-extable.h so that they are
> defined for both assembly and C files.
> 
> There should be no functional change as a result of this patch.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> ---
>  arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)

This (and the following) patch should retain Mark's authorship information
as they are taken from his git tree:

https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/extable/asm-uaccess

I plan to apply the first six patches for now, so I'll fix that up at the
same time.

Will

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH -next v6 02/10] arm64: asm-extable: move data fields

[Will Deacon]

On Tue, Jun 21, 2022 at 07:26:30AM +0000, Tong Tiangen wrote:
> In subsequent patches we'll need to fill in extable data fields in
> regular assembly files. In preparation for this, move the definitions of
> the extable data fields earlier in asm-extable.h so that they are
> defined for both assembly and C files.
> 
> There should be no functional change as a result of this patch.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> ---
>  arch/arm64/include/asm/asm-extable.h | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)

This (and the following) patch should retain Mark's authorship information
as they are taken from his git tree:

https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/extable/asm-uaccess

I plan to apply the first six patches for now, so I'll fix that up at the
same time.

Will

[PATCH -next v6 03/10] arm64: asm-extable: add asm uacess helpers

[Tong Tiangen]

In subsequent patches we want to explciitly annotate uaccess fixups in
assembly files.

We have existing helpers for this for inline assembly, but due to
differing stringification requirements it's not possible to have a
single definition that we can use for both inline asm and plain asm
files. So as with other cases (e.g. gpr-regnum.h), we must prove
separate helprs for plain asm and inline asm.

So that we can do so, this patch adds helpers to define
EX_TYPE_UACCESS_ERR_ZERO fixups in plain assembly. These correspond 1-1
with the inline assembly versions except for the absence of
stringification. No plain assmebly heleprs are added for
EX_TYPE_LOAD_UNALIGNED_ZEROPAD fixups as these only exist for a single C
function.

For copy_{to,from}_user() we'll need fixups with regs and err, so I've
added _ASM_EXTABLE_UACCESS(insn, fixup), where both the error and zero
registers are WZR.

For clarity, the existing `_asm_extable` assemgbly maco is now defined
in terms of the _ASM_EXTABLE() CPP macro, making the CPP macros
canonical in all cases.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 31 ++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 204b30bf78b3..2e1e6bc33bcd 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -2,6 +2,9 @@
 #ifndef __ASM_ASM_EXTABLE_H
 #define __ASM_ASM_EXTABLE_H
 
+#include <linux/bits.h>
+#include <asm/gpr-num.h>
+
 #define EX_TYPE_NONE			0
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
@@ -32,12 +35,32 @@
 	.short		(data);				\
 	.popsection;
 
+#define _ASM_EXTABLE(insn, fixup)	\
+	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
+
+#define EX_DATA_REG(reg, gpr)	\
+	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
+
+#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__ASM_EXTABLE_RAW(insn, fixup, 					\
+			  EX_TYPE_UACCESS_ERR_ZERO,			\
+			  (						\
+			    EX_DATA_REG(ERR, err) |			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ))
+
+#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 /*
  * Create an exception table entry for `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
  */
 	.macro		_asm_extable, insn, fixup
-	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
+	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
 /*
@@ -52,11 +75,8 @@
 
 #else /* __ASSEMBLY__ */
 
-#include <linux/bits.h>
 #include <linux/stringify.h>
 
-#include <asm/gpr-num.h>
-
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
 	".pushsection	__ex_table, \"a\"\n"		\
 	".align		2\n"				\
@@ -93,6 +113,9 @@
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-- 
2.25.1

[PATCH -next v6 03/10] arm64: asm-extable: add asm uacess helpers

[Tong Tiangen]

In subsequent patches we want to explciitly annotate uaccess fixups in
assembly files.

We have existing helpers for this for inline assembly, but due to
differing stringification requirements it's not possible to have a
single definition that we can use for both inline asm and plain asm
files. So as with other cases (e.g. gpr-regnum.h), we must prove
separate helprs for plain asm and inline asm.

So that we can do so, this patch adds helpers to define
EX_TYPE_UACCESS_ERR_ZERO fixups in plain assembly. These correspond 1-1
with the inline assembly versions except for the absence of
stringification. No plain assmebly heleprs are added for
EX_TYPE_LOAD_UNALIGNED_ZEROPAD fixups as these only exist for a single C
function.

For copy_{to,from}_user() we'll need fixups with regs and err, so I've
added _ASM_EXTABLE_UACCESS(insn, fixup), where both the error and zero
registers are WZR.

For clarity, the existing `_asm_extable` assemgbly maco is now defined
in terms of the _ASM_EXTABLE() CPP macro, making the CPP macros
canonical in all cases.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 31 ++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 204b30bf78b3..2e1e6bc33bcd 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -2,6 +2,9 @@
 #ifndef __ASM_ASM_EXTABLE_H
 #define __ASM_ASM_EXTABLE_H
 
+#include <linux/bits.h>
+#include <asm/gpr-num.h>
+
 #define EX_TYPE_NONE			0
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
@@ -32,12 +35,32 @@
 	.short		(data);				\
 	.popsection;
 
+#define _ASM_EXTABLE(insn, fixup)	\
+	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
+
+#define EX_DATA_REG(reg, gpr)	\
+	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
+
+#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__ASM_EXTABLE_RAW(insn, fixup, 					\
+			  EX_TYPE_UACCESS_ERR_ZERO,			\
+			  (						\
+			    EX_DATA_REG(ERR, err) |			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ))
+
+#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 /*
  * Create an exception table entry for `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
  */
 	.macro		_asm_extable, insn, fixup
-	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
+	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
 /*
@@ -52,11 +75,8 @@
 
 #else /* __ASSEMBLY__ */
 
-#include <linux/bits.h>
 #include <linux/stringify.h>
 
-#include <asm/gpr-num.h>
-
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
 	".pushsection	__ex_table, \"a\"\n"		\
 	".align		2\n"				\
@@ -93,6 +113,9 @@
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 03/10] arm64: asm-extable: add asm uacess helpers

[Tong Tiangen]

In subsequent patches we want to explciitly annotate uaccess fixups in
assembly files.

We have existing helpers for this for inline assembly, but due to
differing stringification requirements it's not possible to have a
single definition that we can use for both inline asm and plain asm
files. So as with other cases (e.g. gpr-regnum.h), we must prove
separate helprs for plain asm and inline asm.

So that we can do so, this patch adds helpers to define
EX_TYPE_UACCESS_ERR_ZERO fixups in plain assembly. These correspond 1-1
with the inline assembly versions except for the absence of
stringification. No plain assmebly heleprs are added for
EX_TYPE_LOAD_UNALIGNED_ZEROPAD fixups as these only exist for a single C
function.

For copy_{to,from}_user() we'll need fixups with regs and err, so I've
added _ASM_EXTABLE_UACCESS(insn, fixup), where both the error and zero
registers are WZR.

For clarity, the existing `_asm_extable` assemgbly maco is now defined
in terms of the _ASM_EXTABLE() CPP macro, making the CPP macros
canonical in all cases.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h | 31 ++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 204b30bf78b3..2e1e6bc33bcd 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -2,6 +2,9 @@
 #ifndef __ASM_ASM_EXTABLE_H
 #define __ASM_ASM_EXTABLE_H
 
+#include <linux/bits.h>
+#include <asm/gpr-num.h>
+
 #define EX_TYPE_NONE			0
 #define EX_TYPE_FIXUP			1
 #define EX_TYPE_BPF			2
@@ -32,12 +35,32 @@
 	.short		(data);				\
 	.popsection;
 
+#define _ASM_EXTABLE(insn, fixup)	\
+	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
+
+#define EX_DATA_REG(reg, gpr)	\
+	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
+
+#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__ASM_EXTABLE_RAW(insn, fixup, 					\
+			  EX_TYPE_UACCESS_ERR_ZERO,			\
+			  (						\
+			    EX_DATA_REG(ERR, err) |			\
+			    EX_DATA_REG(ZERO, zero)			\
+			  ))
+
+#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
+
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 /*
  * Create an exception table entry for `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
  */
 	.macro		_asm_extable, insn, fixup
-	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
+	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
 /*
@@ -52,11 +75,8 @@
 
 #else /* __ASSEMBLY__ */
 
-#include <linux/bits.h>
 #include <linux/stringify.h>
 
-#include <asm/gpr-num.h>
-
 #define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
 	".pushsection	__ex_table, \"a\"\n"		\
 	".align		2\n"				\
@@ -93,6 +113,9 @@
 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
+#define _ASM_EXTABLE_UACCESS(insn, fixup)				\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
+
 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)			\
 	_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
 
-- 
2.25.1

[PATCH -next v6 04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

[Tong Tiangen]

Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  8 ++++++++
 arch/arm64/include/asm/asm-uaccess.h | 12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 2e1e6bc33bcd..73266553f8a2 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -63,6 +63,14 @@
 	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
+/*
+ * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
+ * when an unhandled fault is taken.
+ */
+	.macro          _asm_extable_uaccess, insn, fixup
+	_ASM_EXTABLE_UACCESS(\insn, \fixup)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index 0557af834e03..75b211c98dea 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -61,7 +61,7 @@ alternative_else_nop_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable_uaccess	9999b, l
 
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif
 8889:		ldtr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b, \l;
+		_asm_extable_uaccess	8889b, \l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif
 8889:		sttr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b,\l;
+		_asm_extable_uaccess	8889b,\l;
 	.endm
 
 	.macro user_ldst l, inst, reg, addr, post_inc
 8888:		\inst		\reg, [\addr];
 		add		\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
+		_asm_extable_uaccess	8888b, \l;
 	.endm
 #endif
-- 
2.25.1

[PATCH -next v6 04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

[Tong Tiangen]

Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  8 ++++++++
 arch/arm64/include/asm/asm-uaccess.h | 12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 2e1e6bc33bcd..73266553f8a2 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -63,6 +63,14 @@
 	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
+/*
+ * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
+ * when an unhandled fault is taken.
+ */
+	.macro          _asm_extable_uaccess, insn, fixup
+	_ASM_EXTABLE_UACCESS(\insn, \fixup)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index 0557af834e03..75b211c98dea 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -61,7 +61,7 @@ alternative_else_nop_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable_uaccess	9999b, l
 
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif
 8889:		ldtr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b, \l;
+		_asm_extable_uaccess	8889b, \l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif
 8889:		sttr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b,\l;
+		_asm_extable_uaccess	8889b,\l;
 	.endm
 
 	.macro user_ldst l, inst, reg, addr, post_inc
 8888:		\inst		\reg, [\addr];
 		add		\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
+		_asm_extable_uaccess	8888b, \l;
 	.endm
 #endif
-- 
2.25.1


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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

[Tong Tiangen]

Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  8 ++++++++
 arch/arm64/include/asm/asm-uaccess.h | 12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 2e1e6bc33bcd..73266553f8a2 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -63,6 +63,14 @@
 	_ASM_EXTABLE(\insn, \fixup)
 	.endm
 
+/*
+ * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
+ * when an unhandled fault is taken.
+ */
+	.macro          _asm_extable_uaccess, insn, fixup
+	_ASM_EXTABLE_UACCESS(\insn, \fixup)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index 0557af834e03..75b211c98dea 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -61,7 +61,7 @@ alternative_else_nop_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable_uaccess	9999b, l
 
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif
 8889:		ldtr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b, \l;
+		_asm_extable_uaccess	8889b, \l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif
 8889:		sttr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b,\l;
+		_asm_extable_uaccess	8889b,\l;
 	.endm
 
 	.macro user_ldst l, inst, reg, addr, post_inc
 8888:		\inst		\reg, [\addr];
 		add		\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
+		_asm_extable_uaccess	8888b, \l;
 	.endm
 #endif
-- 
2.25.1

[PATCH -next v6 05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable

[Tong Tiangen]

Currently, We use _cond_extable for cache maintenance uaccess helper
caches_clean_inval_user_pou(), so this should be moved over to
EX_TYPE_UACCESS_ERR_ZERO and rename _cond_extable to _cond_uaccess_extable
for clarity.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 6 +++---
 arch/arm64/include/asm/assembler.h   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 73266553f8a2..b97213d292ce 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -75,9 +75,9 @@
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
  */
-	.macro		_cond_extable, insn, fixup
-	.ifnc		\fixup,
-	_asm_extable	\insn, \fixup
+	.macro		_cond_uaccess_extable, insn, fixup
+	.ifnc			\fixup,
+	_asm_extable_uaccess	\insn, \fixup
 	.endif
 	.endm
 
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 8c5a61aeaf8e..dc422fa437c2 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -423,7 +423,7 @@ alternative_endif
 	b.lo	.Ldcache_op\@
 	dsb	\domain
 
-	_cond_extable .Ldcache_op\@, \fixup
+	_cond_uaccess_extable .Ldcache_op\@, \fixup
 	.endm
 
 /*
@@ -462,7 +462,7 @@ alternative_endif
 	dsb	ish
 	isb
 
-	_cond_extable .Licache_op\@, \fixup
+	_cond_uaccess_extable .Licache_op\@, \fixup
 	.endm
 
 /*
-- 
2.25.1

[PATCH -next v6 05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable

[Tong Tiangen]

Currently, We use _cond_extable for cache maintenance uaccess helper
caches_clean_inval_user_pou(), so this should be moved over to
EX_TYPE_UACCESS_ERR_ZERO and rename _cond_extable to _cond_uaccess_extable
for clarity.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 6 +++---
 arch/arm64/include/asm/assembler.h   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 73266553f8a2..b97213d292ce 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -75,9 +75,9 @@
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
  */
-	.macro		_cond_extable, insn, fixup
-	.ifnc		\fixup,
-	_asm_extable	\insn, \fixup
+	.macro		_cond_uaccess_extable, insn, fixup
+	.ifnc			\fixup,
+	_asm_extable_uaccess	\insn, \fixup
 	.endif
 	.endm
 
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 8c5a61aeaf8e..dc422fa437c2 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -423,7 +423,7 @@ alternative_endif
 	b.lo	.Ldcache_op\@
 	dsb	\domain
 
-	_cond_extable .Ldcache_op\@, \fixup
+	_cond_uaccess_extable .Ldcache_op\@, \fixup
 	.endm
 
 /*
@@ -462,7 +462,7 @@ alternative_endif
 	dsb	ish
 	isb
 
-	_cond_extable .Licache_op\@, \fixup
+	_cond_uaccess_extable .Licache_op\@, \fixup
 	.endm
 
 /*
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable

[Tong Tiangen]

Currently, We use _cond_extable for cache maintenance uaccess helper
caches_clean_inval_user_pou(), so this should be moved over to
EX_TYPE_UACCESS_ERR_ZERO and rename _cond_extable to _cond_uaccess_extable
for clarity.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 6 +++---
 arch/arm64/include/asm/assembler.h   | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 73266553f8a2..b97213d292ce 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -75,9 +75,9 @@
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
  */
-	.macro		_cond_extable, insn, fixup
-	.ifnc		\fixup,
-	_asm_extable	\insn, \fixup
+	.macro		_cond_uaccess_extable, insn, fixup
+	.ifnc			\fixup,
+	_asm_extable_uaccess	\insn, \fixup
 	.endif
 	.endm
 
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 8c5a61aeaf8e..dc422fa437c2 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -423,7 +423,7 @@ alternative_endif
 	b.lo	.Ldcache_op\@
 	dsb	\domain
 
-	_cond_extable .Ldcache_op\@, \fixup
+	_cond_uaccess_extable .Ldcache_op\@, \fixup
 	.endm
 
 /*
@@ -462,7 +462,7 @@ alternative_endif
 	dsb	ish
 	isb
 
-	_cond_extable .Licache_op\@, \fixup
+	_cond_uaccess_extable .Licache_op\@, \fixup
 	.endm
 
 /*
-- 
2.25.1

[PATCH -next v6 06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP

[Tong Tiangen]

Currently, extable type EX_TYPE_FIXUP is no place to use, We can safely
remove it.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 23 ++++-------------------
 arch/arm64/mm/extable.c              |  9 ---------
 2 files changed, 4 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index b97213d292ce..980d1dd8e1a3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,11 +6,10 @@
 #include <asm/gpr-num.h>
 
 #define EX_TYPE_NONE			0
-#define EX_TYPE_FIXUP			1
-#define EX_TYPE_BPF			2
-#define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_KACCESS_ERR_ZERO	4
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
+#define EX_TYPE_BPF			1
+#define EX_TYPE_UACCESS_ERR_ZERO	2
+#define EX_TYPE_KACCESS_ERR_ZERO	3
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -35,9 +34,6 @@
 	.short		(data);				\
 	.popsection;
 
-#define _ASM_EXTABLE(insn, fixup)	\
-	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
-
 #define EX_DATA_REG(reg, gpr)	\
 	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
 
@@ -55,14 +51,6 @@
 #define _ASM_EXTABLE_UACCESS(insn, fixup)				\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
 
-/*
- * Create an exception table entry for `insn`, which will branch to `fixup`
- * when an unhandled fault is taken.
- */
-	.macro		_asm_extable, insn, fixup
-	_ASM_EXTABLE(\insn, \fixup)
-	.endm
-
 /*
  * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
@@ -94,9 +82,6 @@
 	".short		(" data ")\n"			\
 	".popsection\n"
 
-#define _ASM_EXTABLE(insn, fixup) \
-	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 056591e5ca80..228d681a8715 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,13 +16,6 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
-static bool ex_handler_fixup(const struct exception_table_entry *ex,
-			     struct pt_regs *regs)
-{
-	regs->pc = get_ex_fixup(ex);
-	return true;
-}
-
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -72,8 +65,6 @@ bool fixup_exception(struct pt_regs *regs)
 		return false;
 
 	switch (ex->type) {
-	case EX_TYPE_FIXUP:
-		return ex_handler_fixup(ex, regs);
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
-- 
2.25.1

[PATCH -next v6 06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP

[Tong Tiangen]

Currently, extable type EX_TYPE_FIXUP is no place to use, We can safely
remove it.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 23 ++++-------------------
 arch/arm64/mm/extable.c              |  9 ---------
 2 files changed, 4 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index b97213d292ce..980d1dd8e1a3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,11 +6,10 @@
 #include <asm/gpr-num.h>
 
 #define EX_TYPE_NONE			0
-#define EX_TYPE_FIXUP			1
-#define EX_TYPE_BPF			2
-#define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_KACCESS_ERR_ZERO	4
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
+#define EX_TYPE_BPF			1
+#define EX_TYPE_UACCESS_ERR_ZERO	2
+#define EX_TYPE_KACCESS_ERR_ZERO	3
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -35,9 +34,6 @@
 	.short		(data);				\
 	.popsection;
 
-#define _ASM_EXTABLE(insn, fixup)	\
-	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
-
 #define EX_DATA_REG(reg, gpr)	\
 	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
 
@@ -55,14 +51,6 @@
 #define _ASM_EXTABLE_UACCESS(insn, fixup)				\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
 
-/*
- * Create an exception table entry for `insn`, which will branch to `fixup`
- * when an unhandled fault is taken.
- */
-	.macro		_asm_extable, insn, fixup
-	_ASM_EXTABLE(\insn, \fixup)
-	.endm
-
 /*
  * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
@@ -94,9 +82,6 @@
 	".short		(" data ")\n"			\
 	".popsection\n"
 
-#define _ASM_EXTABLE(insn, fixup) \
-	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 056591e5ca80..228d681a8715 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,13 +16,6 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
-static bool ex_handler_fixup(const struct exception_table_entry *ex,
-			     struct pt_regs *regs)
-{
-	regs->pc = get_ex_fixup(ex);
-	return true;
-}
-
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -72,8 +65,6 @@ bool fixup_exception(struct pt_regs *regs)
 		return false;
 
 	switch (ex->type) {
-	case EX_TYPE_FIXUP:
-		return ex_handler_fixup(ex, regs);
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
-- 
2.25.1


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[PATCH -next v6 06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP

[Tong Tiangen]

Currently, extable type EX_TYPE_FIXUP is no place to use, We can safely
remove it.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/asm-extable.h | 23 ++++-------------------
 arch/arm64/mm/extable.c              |  9 ---------
 2 files changed, 4 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index b97213d292ce..980d1dd8e1a3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,11 +6,10 @@
 #include <asm/gpr-num.h>
 
 #define EX_TYPE_NONE			0
-#define EX_TYPE_FIXUP			1
-#define EX_TYPE_BPF			2
-#define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_KACCESS_ERR_ZERO	4
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
+#define EX_TYPE_BPF			1
+#define EX_TYPE_UACCESS_ERR_ZERO	2
+#define EX_TYPE_KACCESS_ERR_ZERO	3
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -35,9 +34,6 @@
 	.short		(data);				\
 	.popsection;
 
-#define _ASM_EXTABLE(insn, fixup)	\
-	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
-
 #define EX_DATA_REG(reg, gpr)	\
 	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
 
@@ -55,14 +51,6 @@
 #define _ASM_EXTABLE_UACCESS(insn, fixup)				\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
 
-/*
- * Create an exception table entry for `insn`, which will branch to `fixup`
- * when an unhandled fault is taken.
- */
-	.macro		_asm_extable, insn, fixup
-	_ASM_EXTABLE(\insn, \fixup)
-	.endm
-
 /*
  * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
@@ -94,9 +82,6 @@
 	".short		(" data ")\n"			\
 	".popsection\n"
 
-#define _ASM_EXTABLE(insn, fixup) \
-	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 056591e5ca80..228d681a8715 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,13 +16,6 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
-static bool ex_handler_fixup(const struct exception_table_entry *ex,
-			     struct pt_regs *regs)
-{
-	regs->pc = get_ex_fixup(ex);
-	return true;
-}
-
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -72,8 +65,6 @@ bool fixup_exception(struct pt_regs *regs)
 		return false;
 
 	switch (ex->type) {
-	case EX_TYPE_FIXUP:
-		return ex_handler_fixup(ex, regs);
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
-- 
2.25.1

[PATCH -next v6 07/10] Add generic fallback version of copy_mc_to_user()

[Tong Tiangen]

x86/powerpc has it's implementation of copy_mc_to_user(), we add generic
fallback in include/linux/uaccess.h prepare for other architechures to
enable CONFIG_ARCH_HAS_COPY_MC.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/uaccess.h | 1 +
 arch/x86/include/asm/uaccess.h     | 1 +
 include/linux/uaccess.h            | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 9b82b38ff867..58dbe8e2e318 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -358,6 +358,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n)
 
 	return n;
 }
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 913e593a3b45..64ba7f723ddf 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -512,6 +512,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);
 
 unsigned long __must_check
 copy_mc_to_user(void *to, const void *from, unsigned len);
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 /*
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5a328cf02b75..07e9faeb14b5 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -174,6 +174,15 @@ copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
 }
 #endif
 
+#ifndef copy_mc_to_user
+static inline unsigned long __must_check
+copy_mc_to_user(void *dst, const void *src, size_t cnt)
+{
+	check_object_size(src, cnt, true);
+	return raw_copy_to_user(dst, src, cnt);
+}
+#endif
+
 static __always_inline void pagefault_disabled_inc(void)
 {
 	current->pagefault_disabled++;
-- 
2.25.1

[PATCH -next v6 07/10] Add generic fallback version of copy_mc_to_user()

[Tong Tiangen]

x86/powerpc has it's implementation of copy_mc_to_user(), we add generic
fallback in include/linux/uaccess.h prepare for other architechures to
enable CONFIG_ARCH_HAS_COPY_MC.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/uaccess.h | 1 +
 arch/x86/include/asm/uaccess.h     | 1 +
 include/linux/uaccess.h            | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 9b82b38ff867..58dbe8e2e318 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -358,6 +358,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n)
 
 	return n;
 }
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 913e593a3b45..64ba7f723ddf 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -512,6 +512,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);
 
 unsigned long __must_check
 copy_mc_to_user(void *to, const void *from, unsigned len);
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 /*
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5a328cf02b75..07e9faeb14b5 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -174,6 +174,15 @@ copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
 }
 #endif
 
+#ifndef copy_mc_to_user
+static inline unsigned long __must_check
+copy_mc_to_user(void *dst, const void *src, size_t cnt)
+{
+	check_object_size(src, cnt, true);
+	return raw_copy_to_user(dst, src, cnt);
+}
+#endif
+
 static __always_inline void pagefault_disabled_inc(void)
 {
 	current->pagefault_disabled++;
-- 
2.25.1


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[PATCH -next v6 07/10] Add generic fallback version of copy_mc_to_user()

[Tong Tiangen]

x86/powerpc has it's implementation of copy_mc_to_user(), we add generic
fallback in include/linux/uaccess.h prepare for other architechures to
enable CONFIG_ARCH_HAS_COPY_MC.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/uaccess.h | 1 +
 arch/x86/include/asm/uaccess.h     | 1 +
 include/linux/uaccess.h            | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 9b82b38ff867..58dbe8e2e318 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -358,6 +358,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n)
 
 	return n;
 }
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 913e593a3b45..64ba7f723ddf 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -512,6 +512,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned len);
 
 unsigned long __must_check
 copy_mc_to_user(void *to, const void *from, unsigned len);
+#define copy_mc_to_user copy_mc_to_user
 #endif
 
 /*
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5a328cf02b75..07e9faeb14b5 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -174,6 +174,15 @@ copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
 }
 #endif
 
+#ifndef copy_mc_to_user
+static inline unsigned long __must_check
+copy_mc_to_user(void *dst, const void *src, size_t cnt)
+{
+	check_object_size(src, cnt, true);
+	return raw_copy_to_user(dst, src, cnt);
+}
+#endif
+
 static __always_inline void pagefault_disabled_inc(void)
 {
 	current->pagefault_disabled++;
-- 
2.25.1

[PATCH -next v6 08/10] arm64: add support for machine check error safe

[Tong Tiangen]

During the processing of arm64 kernel hardware memory errors(do_sea()), if
the errors is consumed in the kernel, the current processing is panic.
However, it is not optimal.

Take uaccess for example, if the uaccess operation fails due to memory
error, only the user process will be affected, kill the user process
and isolate the user page with hardware memory errors is a better choice.

This patch only enable machine error check framework, it add exception
fixup before kernel panic in do_sea() and only limit the consumption of
hardware memory errors in kernel mode triggered by user mode processes.
If fixup successful, panic can be avoided.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/Kconfig               |  1 +
 arch/arm64/include/asm/extable.h |  1 +
 arch/arm64/mm/extable.c          | 16 ++++++++++++++++
 arch/arm64/mm/fault.c            | 29 ++++++++++++++++++++++++++++-
 4 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9728103a13aa..a636e5ce02b5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
 	select ARCH_HAS_CACHE_LINE_SIZE
+	select ARCH_HAS_COPY_MC if ACPI_APEI_GHES
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE
diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/extable.h
index 72b0e71cc3de..f80ebd0addfd 100644
--- a/arch/arm64/include/asm/extable.h
+++ b/arch/arm64/include/asm/extable.h
@@ -46,4 +46,5 @@ bool ex_handler_bpf(const struct exception_table_entry *ex,
 #endif /* !CONFIG_BPF_JIT */
 
 bool fixup_exception(struct pt_regs *regs);
+bool fixup_exception_mc(struct pt_regs *regs);
 #endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 228d681a8715..478e639f8680 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -76,3 +76,19 @@ bool fixup_exception(struct pt_regs *regs)
 
 	BUG();
 }
+
+bool fixup_exception_mc(struct pt_regs *regs)
+{
+	const struct exception_table_entry *ex;
+
+	ex = search_exception_tables(instruction_pointer(regs));
+	if (!ex)
+		return false;
+
+	/*
+	 * This is not complete, More Machine check safe extable type can
+	 * be processed here.
+	 */
+
+	return false;
+}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index de166cdeb89a..bd6dd67c9ead 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -700,6 +700,31 @@ static int do_bad(unsigned long far, unsigned long esr, struct pt_regs *regs)
 	return 1; /* "fault" */
 }
 
+static bool arm64_do_kernel_sea(unsigned long addr, unsigned int esr,
+				     struct pt_regs *regs, int sig, int code)
+{
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC))
+		return false;
+
+	if (user_mode(regs))
+		return false;
+
+	if (apei_claim_sea(regs) < 0)
+		return false;
+
+	if (!fixup_exception_mc(regs))
+		return false;
+
+	if (current->flags & PF_KTHREAD)
+		return true;
+
+	set_thread_esr(0, esr);
+	arm64_force_sig_fault(sig, code, addr,
+		"Uncorrected memory error on access to user memory\n");
+
+	return true;
+}
+
 static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 {
 	const struct fault_info *inf;
@@ -725,7 +750,9 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 		 */
 		siaddr  = untagged_addr(far);
 	}
-	arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
+
+	if (!arm64_do_kernel_sea(siaddr, esr, regs, inf->sig, inf->code))
+		arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
 
 	return 0;
 }
-- 
2.25.1

[PATCH -next v6 08/10] arm64: add support for machine check error safe

[Tong Tiangen]

During the processing of arm64 kernel hardware memory errors(do_sea()), if
the errors is consumed in the kernel, the current processing is panic.
However, it is not optimal.

Take uaccess for example, if the uaccess operation fails due to memory
error, only the user process will be affected, kill the user process
and isolate the user page with hardware memory errors is a better choice.

This patch only enable machine error check framework, it add exception
fixup before kernel panic in do_sea() and only limit the consumption of
hardware memory errors in kernel mode triggered by user mode processes.
If fixup successful, panic can be avoided.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/Kconfig               |  1 +
 arch/arm64/include/asm/extable.h |  1 +
 arch/arm64/mm/extable.c          | 16 ++++++++++++++++
 arch/arm64/mm/fault.c            | 29 ++++++++++++++++++++++++++++-
 4 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9728103a13aa..a636e5ce02b5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
 	select ARCH_HAS_CACHE_LINE_SIZE
+	select ARCH_HAS_COPY_MC if ACPI_APEI_GHES
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE
diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/extable.h
index 72b0e71cc3de..f80ebd0addfd 100644
--- a/arch/arm64/include/asm/extable.h
+++ b/arch/arm64/include/asm/extable.h
@@ -46,4 +46,5 @@ bool ex_handler_bpf(const struct exception_table_entry *ex,
 #endif /* !CONFIG_BPF_JIT */
 
 bool fixup_exception(struct pt_regs *regs);
+bool fixup_exception_mc(struct pt_regs *regs);
 #endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 228d681a8715..478e639f8680 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -76,3 +76,19 @@ bool fixup_exception(struct pt_regs *regs)
 
 	BUG();
 }
+
+bool fixup_exception_mc(struct pt_regs *regs)
+{
+	const struct exception_table_entry *ex;
+
+	ex = search_exception_tables(instruction_pointer(regs));
+	if (!ex)
+		return false;
+
+	/*
+	 * This is not complete, More Machine check safe extable type can
+	 * be processed here.
+	 */
+
+	return false;
+}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index de166cdeb89a..bd6dd67c9ead 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -700,6 +700,31 @@ static int do_bad(unsigned long far, unsigned long esr, struct pt_regs *regs)
 	return 1; /* "fault" */
 }
 
+static bool arm64_do_kernel_sea(unsigned long addr, unsigned int esr,
+				     struct pt_regs *regs, int sig, int code)
+{
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC))
+		return false;
+
+	if (user_mode(regs))
+		return false;
+
+	if (apei_claim_sea(regs) < 0)
+		return false;
+
+	if (!fixup_exception_mc(regs))
+		return false;
+
+	if (current->flags & PF_KTHREAD)
+		return true;
+
+	set_thread_esr(0, esr);
+	arm64_force_sig_fault(sig, code, addr,
+		"Uncorrected memory error on access to user memory\n");
+
+	return true;
+}
+
 static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 {
 	const struct fault_info *inf;
@@ -725,7 +750,9 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 		 */
 		siaddr  = untagged_addr(far);
 	}
-	arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
+
+	if (!arm64_do_kernel_sea(siaddr, esr, regs, inf->sig, inf->code))
+		arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
 
 	return 0;
 }
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 08/10] arm64: add support for machine check error safe

[Tong Tiangen]

During the processing of arm64 kernel hardware memory errors(do_sea()), if
the errors is consumed in the kernel, the current processing is panic.
However, it is not optimal.

Take uaccess for example, if the uaccess operation fails due to memory
error, only the user process will be affected, kill the user process
and isolate the user page with hardware memory errors is a better choice.

This patch only enable machine error check framework, it add exception
fixup before kernel panic in do_sea() and only limit the consumption of
hardware memory errors in kernel mode triggered by user mode processes.
If fixup successful, panic can be avoided.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/Kconfig               |  1 +
 arch/arm64/include/asm/extable.h |  1 +
 arch/arm64/mm/extable.c          | 16 ++++++++++++++++
 arch/arm64/mm/fault.c            | 29 ++++++++++++++++++++++++++++-
 4 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9728103a13aa..a636e5ce02b5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
 	select ARCH_HAS_CACHE_LINE_SIZE
+	select ARCH_HAS_COPY_MC if ACPI_APEI_GHES
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE
diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/extable.h
index 72b0e71cc3de..f80ebd0addfd 100644
--- a/arch/arm64/include/asm/extable.h
+++ b/arch/arm64/include/asm/extable.h
@@ -46,4 +46,5 @@ bool ex_handler_bpf(const struct exception_table_entry *ex,
 #endif /* !CONFIG_BPF_JIT */
 
 bool fixup_exception(struct pt_regs *regs);
+bool fixup_exception_mc(struct pt_regs *regs);
 #endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 228d681a8715..478e639f8680 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -76,3 +76,19 @@ bool fixup_exception(struct pt_regs *regs)
 
 	BUG();
 }
+
+bool fixup_exception_mc(struct pt_regs *regs)
+{
+	const struct exception_table_entry *ex;
+
+	ex = search_exception_tables(instruction_pointer(regs));
+	if (!ex)
+		return false;
+
+	/*
+	 * This is not complete, More Machine check safe extable type can
+	 * be processed here.
+	 */
+
+	return false;
+}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index de166cdeb89a..bd6dd67c9ead 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -700,6 +700,31 @@ static int do_bad(unsigned long far, unsigned long esr, struct pt_regs *regs)
 	return 1; /* "fault" */
 }
 
+static bool arm64_do_kernel_sea(unsigned long addr, unsigned int esr,
+				     struct pt_regs *regs, int sig, int code)
+{
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC))
+		return false;
+
+	if (user_mode(regs))
+		return false;
+
+	if (apei_claim_sea(regs) < 0)
+		return false;
+
+	if (!fixup_exception_mc(regs))
+		return false;
+
+	if (current->flags & PF_KTHREAD)
+		return true;
+
+	set_thread_esr(0, esr);
+	arm64_force_sig_fault(sig, code, addr,
+		"Uncorrected memory error on access to user memory\n");
+
+	return true;
+}
+
 static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 {
 	const struct fault_info *inf;
@@ -725,7 +750,9 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
 		 */
 		siaddr  = untagged_addr(far);
 	}
-	arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
+
+	if (!arm64_do_kernel_sea(siaddr, esr, regs, inf->sig, inf->code))
+		arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
 
 	return 0;
 }
-- 
2.25.1

[PATCH -next v6 09/10] arm64: add uaccess to machine check safe

[Tong Tiangen]

If user access fail due to hardware memory error, only the relevant
processes are affected, so killing the user process and isolate the
error page with hardware memory errors is a more reasonable choice
than kernel panic.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/mm/extable.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 478e639f8680..28ec35e3d210 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -85,10 +85,10 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	if (!ex)
 		return false;
 
-	/*
-	 * This is not complete, More Machine check safe extable type can
-	 * be processed here.
-	 */
+	switch (ex->type) {
+	case EX_TYPE_UACCESS_ERR_ZERO:
+		return ex_handler_uaccess_err_zero(ex, regs);
+	}
 
 	return false;
 }
-- 
2.25.1

[PATCH -next v6 09/10] arm64: add uaccess to machine check safe

[Tong Tiangen]

If user access fail due to hardware memory error, only the relevant
processes are affected, so killing the user process and isolate the
error page with hardware memory errors is a more reasonable choice
than kernel panic.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/mm/extable.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 478e639f8680..28ec35e3d210 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -85,10 +85,10 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	if (!ex)
 		return false;
 
-	/*
-	 * This is not complete, More Machine check safe extable type can
-	 * be processed here.
-	 */
+	switch (ex->type) {
+	case EX_TYPE_UACCESS_ERR_ZERO:
+		return ex_handler_uaccess_err_zero(ex, regs);
+	}
 
 	return false;
 }
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 09/10] arm64: add uaccess to machine check safe

[Tong Tiangen]

If user access fail due to hardware memory error, only the relevant
processes are affected, so killing the user process and isolate the
error page with hardware memory errors is a more reasonable choice
than kernel panic.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/mm/extable.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 478e639f8680..28ec35e3d210 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -85,10 +85,10 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	if (!ex)
 		return false;
 
-	/*
-	 * This is not complete, More Machine check safe extable type can
-	 * be processed here.
-	 */
+	switch (ex->type) {
+	case EX_TYPE_UACCESS_ERR_ZERO:
+		return ex_handler_uaccess_err_zero(ex, regs);
+	}
 
 	return false;
 }
-- 
2.25.1

[PATCH -next v6 10/10] arm64: add cow to machine check safe

[Tong Tiangen]

In the cow(copy on write) processing, the data of the user process is
copied, when hardware memory error is encountered during copy, only the
relevant processes are affected, so killing the user process and isolate
the user page with hardware memory errors is a more reasonable choice than
kernel panic.

Add new helper copy_page_mc() which provide a page copy implementation with
machine check safe. At present, only used in cow. In future, we can expand
more scenes. As long as the consequences of page copy failure are not
fatal(eg: only affect user process), we can use this helper.

The copy_page_mc() in copy_page_mc.S is largely borrows from copy_page()
in copy_page.S and the main difference is copy_page_mc() add extable entry
to every load/store insn to support machine check safe. largely to keep the
patch simple. If needed those optimizations can be folded in.

Add new extable type EX_TYPE_COPY_PAGE_MC which used in copy_page_mc().

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  5 ++
 arch/arm64/include/asm/assembler.h   |  4 ++
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 ++++
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 +++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++++---
 arch/arm64/mm/extable.c              |  9 +++
 include/linux/highmem.h              |  8 +++
 mm/memory.c                          |  2 +-
 11 files changed, 178 insertions(+), 8 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 980d1dd8e1a3..969e2848ca13 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -10,6 +10,7 @@
 #define EX_TYPE_UACCESS_ERR_ZERO	2
 #define EX_TYPE_KACCESS_ERR_ZERO	3
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_COPY_PAGE_MC		5
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -59,6 +60,10 @@
 	_ASM_EXTABLE_UACCESS(\insn, \fixup)
 	.endm
 
+	.macro          _asm_extable_copy_page_mc, insn, fixup
+	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_COPY_PAGE_MC, 0)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index dc422fa437c2..44927fa3a844 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -168,6 +168,10 @@ lr	.req	x30		// link register
 #define CPU_LE(code...) code
 #endif
 
+#define CPY_MC(l, x...)		\
+9999:   x;			\
+	_asm_extable_copy_page_mc    9999b, l
+
 /*
  * Define a macro that constructs a 64-bit value by concatenating two
  * 32-bit registers. Note that on big endian systems the order of the
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..b8129f64cfea 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -40,6 +40,7 @@ void mte_free_tag_storage(char *storage);
 void mte_zero_clear_page_tags(void *addr);
 void mte_sync_tags(pte_t old_pte, pte_t pte);
 void mte_copy_page_tags(void *kto, const void *kfrom);
+void mte_copy_page_tags_mc(void *kto, const void *kfrom);
 void mte_thread_init_user(void);
 void mte_thread_switch(struct task_struct *next);
 void mte_suspend_enter(void);
@@ -63,6 +64,9 @@ static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
 {
 }
+static inline void mte_copy_page_tags_mc(void *kto, const void *kfrom)
+{
+}
 static inline void mte_thread_init_user(void)
 {
 }
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 993a27ea6f54..832571a7dddb 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -29,6 +29,16 @@ void copy_user_highpage(struct page *to, struct page *from,
 void copy_highpage(struct page *to, struct page *from);
 #define __HAVE_ARCH_COPY_HIGHPAGE
 
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void copy_page_mc(void *to, const void *from);
+void copy_highpage_mc(struct page *to, struct page *from);
+#define __HAVE_ARCH_COPY_HIGHPAGE_MC
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+		unsigned long vaddr, struct vm_area_struct *vma);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#endif
+
 struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
 						unsigned long vaddr);
 #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 29490be2546b..0d9f292ef68a 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -15,6 +15,8 @@ endif
 
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
 
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_page_mc.o
+
 obj-$(CONFIG_CRC32) += crc32.o
 
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/arm64/lib/copy_page_mc.S b/arch/arm64/lib/copy_page_mc.S
new file mode 100644
index 000000000000..65fcad1dd7c8
--- /dev/null
+++ b/arch/arm64/lib/copy_page_mc.S
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/linkage.h>
+#include <linux/const.h>
+#include <asm/assembler.h>
+#include <asm/page.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+#include <asm/asm-extable.h>
+
+/*
+ * Copy a page from src to dest (both are page aligned) with machine check
+ *
+ * Parameters:
+ *	x0 - dest
+ *	x1 - src
+ */
+SYM_FUNC_START(__pi_copy_page_mc)
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	// Prefetch three cache lines ahead.
+	prfm	pldl1strm, [x1, #128]
+	prfm	pldl1strm, [x1, #256]
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #256
+	add	x1, x1, #128
+1:
+	tst	x0, #(PAGE_SIZE - 1)
+
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #128
+	add	x1, x1, #128
+
+	b.ne	1b
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+
+9998:	ret
+
+SYM_FUNC_END(__pi_copy_page_mc)
+SYM_FUNC_ALIAS(copy_page_mc, __pi_copy_page_mc)
+EXPORT_SYMBOL(copy_page_mc)
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index eeb9e45bcce8..cf728a9f39b5 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -80,6 +80,25 @@ SYM_FUNC_START(mte_copy_page_tags)
 	ret
 SYM_FUNC_END(mte_copy_page_tags)
 
+/*
+ * Copy the tags from the source page to the destination one wiht machine check safe
+ *   x0 - address of the destination page
+ *   x1 - address of the source page
+ */
+SYM_FUNC_START(mte_copy_page_tags_mc)
+	mov	x2, x0
+	mov	x3, x1
+	multitag_transfer_size x5, x6
+1:
+CPY_MC(2f, ldgm	x4, [x3])
+	stgm	x4, [x2]
+	add	x2, x2, x5
+	add	x3, x3, x5
+	tst	x2, #(PAGE_SIZE - 1)
+	b.ne	1b
+2:	ret
+SYM_FUNC_END(mte_copy_page_tags_mc)
+
 /*
  * Read tags from a user buffer (one tag per byte) and set the corresponding
  * tags at the given kernel address. Used by PTRACE_POKEMTETAGS.
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 0dea80bf6de4..d68c5fc753a2 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -14,13 +14,8 @@
 #include <asm/cpufeature.h>
 #include <asm/mte.h>
 
-void copy_highpage(struct page *to, struct page *from)
+static void do_mte(struct page *to, struct page *from, void *kto, void *kfrom, bool mc)
 {
-	void *kto = page_address(to);
-	void *kfrom = page_address(from);
-
-	copy_page(kto, kfrom);
-
 	if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
 		set_bit(PG_mte_tagged, &to->flags);
 		page_kasan_tag_reset(to);
@@ -32,9 +27,21 @@ void copy_highpage(struct page *to, struct page *from)
 		 * the new page->flags are visible before the tags were updated.
 		 */
 		smp_wmb();
-		mte_copy_page_tags(kto, kfrom);
+		if (mc)
+			mte_copy_page_tags_mc(kto, kfrom);
+		else
+			mte_copy_page_tags(kto, kfrom);
 	}
 }
+
+void copy_highpage(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page(kto, kfrom);
+	do_mte(to, from, kto, kfrom, false);
+}
 EXPORT_SYMBOL(copy_highpage);
 
 void copy_user_highpage(struct page *to, struct page *from,
@@ -44,3 +51,23 @@ void copy_user_highpage(struct page *to, struct page *from,
 	flush_dcache_page(to);
 }
 EXPORT_SYMBOL_GPL(copy_user_highpage);
+
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+void copy_highpage_mc(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page_mc(kto, kfrom);
+	do_mte(to, from, kto, kfrom, true);
+}
+EXPORT_SYMBOL(copy_highpage_mc);
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	copy_highpage_mc(to, from);
+	flush_dcache_page(to);
+}
+EXPORT_SYMBOL_GPL(copy_user_highpage_mc);
+#endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 28ec35e3d210..b986333a3100 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,6 +16,13 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
+static bool ex_handler_fixup(const struct exception_table_entry *ex,
+			     struct pt_regs *regs)
+{
+	regs->pc = get_ex_fixup(ex);
+	return true;
+}
+
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -88,6 +95,8 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	switch (ex->type) {
 	case EX_TYPE_UACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
+	case EX_TYPE_COPY_PAGE_MC:
+		return ex_handler_fixup(ex, regs);
 	}
 
 	return false;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 22379a63e293..5ba234b89be5 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -318,6 +318,10 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#define copy_user_highpage_mc copy_user_highpage
+#endif
+
 #ifndef __HAVE_ARCH_COPY_HIGHPAGE
 
 static inline void copy_highpage(struct page *to, struct page *from)
@@ -333,6 +337,10 @@ static inline void copy_highpage(struct page *to, struct page *from)
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_HIGHPAGE_MC
+#define copy_highpage_mc copy_highpage
+#endif
+
 static inline void memcpy_page(struct page *dst_page, size_t dst_off,
 			       struct page *src_page, size_t src_off,
 			       size_t len)
diff --git a/mm/memory.c b/mm/memory.c
index fee2884481f2..7decc792a02d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2868,7 +2868,7 @@ static inline bool __wp_page_copy_user(struct page *dst, struct page *src,
 	unsigned long addr = vmf->address;
 
 	if (likely(src)) {
-		copy_user_highpage(dst, src, addr, vma);
+		copy_user_highpage_mc(dst, src, addr, vma);
 		return true;
 	}
 
-- 
2.25.1

[PATCH -next v6 10/10] arm64: add cow to machine check safe

[Tong Tiangen]

In the cow(copy on write) processing, the data of the user process is
copied, when hardware memory error is encountered during copy, only the
relevant processes are affected, so killing the user process and isolate
the user page with hardware memory errors is a more reasonable choice than
kernel panic.

Add new helper copy_page_mc() which provide a page copy implementation with
machine check safe. At present, only used in cow. In future, we can expand
more scenes. As long as the consequences of page copy failure are not
fatal(eg: only affect user process), we can use this helper.

The copy_page_mc() in copy_page_mc.S is largely borrows from copy_page()
in copy_page.S and the main difference is copy_page_mc() add extable entry
to every load/store insn to support machine check safe. largely to keep the
patch simple. If needed those optimizations can be folded in.

Add new extable type EX_TYPE_COPY_PAGE_MC which used in copy_page_mc().

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  5 ++
 arch/arm64/include/asm/assembler.h   |  4 ++
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 ++++
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 +++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++++---
 arch/arm64/mm/extable.c              |  9 +++
 include/linux/highmem.h              |  8 +++
 mm/memory.c                          |  2 +-
 11 files changed, 178 insertions(+), 8 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 980d1dd8e1a3..969e2848ca13 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -10,6 +10,7 @@
 #define EX_TYPE_UACCESS_ERR_ZERO	2
 #define EX_TYPE_KACCESS_ERR_ZERO	3
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_COPY_PAGE_MC		5
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -59,6 +60,10 @@
 	_ASM_EXTABLE_UACCESS(\insn, \fixup)
 	.endm
 
+	.macro          _asm_extable_copy_page_mc, insn, fixup
+	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_COPY_PAGE_MC, 0)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index dc422fa437c2..44927fa3a844 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -168,6 +168,10 @@ lr	.req	x30		// link register
 #define CPU_LE(code...) code
 #endif
 
+#define CPY_MC(l, x...)		\
+9999:   x;			\
+	_asm_extable_copy_page_mc    9999b, l
+
 /*
  * Define a macro that constructs a 64-bit value by concatenating two
  * 32-bit registers. Note that on big endian systems the order of the
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..b8129f64cfea 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -40,6 +40,7 @@ void mte_free_tag_storage(char *storage);
 void mte_zero_clear_page_tags(void *addr);
 void mte_sync_tags(pte_t old_pte, pte_t pte);
 void mte_copy_page_tags(void *kto, const void *kfrom);
+void mte_copy_page_tags_mc(void *kto, const void *kfrom);
 void mte_thread_init_user(void);
 void mte_thread_switch(struct task_struct *next);
 void mte_suspend_enter(void);
@@ -63,6 +64,9 @@ static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
 {
 }
+static inline void mte_copy_page_tags_mc(void *kto, const void *kfrom)
+{
+}
 static inline void mte_thread_init_user(void)
 {
 }
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 993a27ea6f54..832571a7dddb 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -29,6 +29,16 @@ void copy_user_highpage(struct page *to, struct page *from,
 void copy_highpage(struct page *to, struct page *from);
 #define __HAVE_ARCH_COPY_HIGHPAGE
 
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void copy_page_mc(void *to, const void *from);
+void copy_highpage_mc(struct page *to, struct page *from);
+#define __HAVE_ARCH_COPY_HIGHPAGE_MC
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+		unsigned long vaddr, struct vm_area_struct *vma);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#endif
+
 struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
 						unsigned long vaddr);
 #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 29490be2546b..0d9f292ef68a 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -15,6 +15,8 @@ endif
 
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
 
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_page_mc.o
+
 obj-$(CONFIG_CRC32) += crc32.o
 
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/arm64/lib/copy_page_mc.S b/arch/arm64/lib/copy_page_mc.S
new file mode 100644
index 000000000000..65fcad1dd7c8
--- /dev/null
+++ b/arch/arm64/lib/copy_page_mc.S
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/linkage.h>
+#include <linux/const.h>
+#include <asm/assembler.h>
+#include <asm/page.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+#include <asm/asm-extable.h>
+
+/*
+ * Copy a page from src to dest (both are page aligned) with machine check
+ *
+ * Parameters:
+ *	x0 - dest
+ *	x1 - src
+ */
+SYM_FUNC_START(__pi_copy_page_mc)
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	// Prefetch three cache lines ahead.
+	prfm	pldl1strm, [x1, #128]
+	prfm	pldl1strm, [x1, #256]
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #256
+	add	x1, x1, #128
+1:
+	tst	x0, #(PAGE_SIZE - 1)
+
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #128
+	add	x1, x1, #128
+
+	b.ne	1b
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+
+9998:	ret
+
+SYM_FUNC_END(__pi_copy_page_mc)
+SYM_FUNC_ALIAS(copy_page_mc, __pi_copy_page_mc)
+EXPORT_SYMBOL(copy_page_mc)
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index eeb9e45bcce8..cf728a9f39b5 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -80,6 +80,25 @@ SYM_FUNC_START(mte_copy_page_tags)
 	ret
 SYM_FUNC_END(mte_copy_page_tags)
 
+/*
+ * Copy the tags from the source page to the destination one wiht machine check safe
+ *   x0 - address of the destination page
+ *   x1 - address of the source page
+ */
+SYM_FUNC_START(mte_copy_page_tags_mc)
+	mov	x2, x0
+	mov	x3, x1
+	multitag_transfer_size x5, x6
+1:
+CPY_MC(2f, ldgm	x4, [x3])
+	stgm	x4, [x2]
+	add	x2, x2, x5
+	add	x3, x3, x5
+	tst	x2, #(PAGE_SIZE - 1)
+	b.ne	1b
+2:	ret
+SYM_FUNC_END(mte_copy_page_tags_mc)
+
 /*
  * Read tags from a user buffer (one tag per byte) and set the corresponding
  * tags at the given kernel address. Used by PTRACE_POKEMTETAGS.
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 0dea80bf6de4..d68c5fc753a2 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -14,13 +14,8 @@
 #include <asm/cpufeature.h>
 #include <asm/mte.h>
 
-void copy_highpage(struct page *to, struct page *from)
+static void do_mte(struct page *to, struct page *from, void *kto, void *kfrom, bool mc)
 {
-	void *kto = page_address(to);
-	void *kfrom = page_address(from);
-
-	copy_page(kto, kfrom);
-
 	if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
 		set_bit(PG_mte_tagged, &to->flags);
 		page_kasan_tag_reset(to);
@@ -32,9 +27,21 @@ void copy_highpage(struct page *to, struct page *from)
 		 * the new page->flags are visible before the tags were updated.
 		 */
 		smp_wmb();
-		mte_copy_page_tags(kto, kfrom);
+		if (mc)
+			mte_copy_page_tags_mc(kto, kfrom);
+		else
+			mte_copy_page_tags(kto, kfrom);
 	}
 }
+
+void copy_highpage(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page(kto, kfrom);
+	do_mte(to, from, kto, kfrom, false);
+}
 EXPORT_SYMBOL(copy_highpage);
 
 void copy_user_highpage(struct page *to, struct page *from,
@@ -44,3 +51,23 @@ void copy_user_highpage(struct page *to, struct page *from,
 	flush_dcache_page(to);
 }
 EXPORT_SYMBOL_GPL(copy_user_highpage);
+
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+void copy_highpage_mc(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page_mc(kto, kfrom);
+	do_mte(to, from, kto, kfrom, true);
+}
+EXPORT_SYMBOL(copy_highpage_mc);
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	copy_highpage_mc(to, from);
+	flush_dcache_page(to);
+}
+EXPORT_SYMBOL_GPL(copy_user_highpage_mc);
+#endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 28ec35e3d210..b986333a3100 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,6 +16,13 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
+static bool ex_handler_fixup(const struct exception_table_entry *ex,
+			     struct pt_regs *regs)
+{
+	regs->pc = get_ex_fixup(ex);
+	return true;
+}
+
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -88,6 +95,8 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	switch (ex->type) {
 	case EX_TYPE_UACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
+	case EX_TYPE_COPY_PAGE_MC:
+		return ex_handler_fixup(ex, regs);
 	}
 
 	return false;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 22379a63e293..5ba234b89be5 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -318,6 +318,10 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#define copy_user_highpage_mc copy_user_highpage
+#endif
+
 #ifndef __HAVE_ARCH_COPY_HIGHPAGE
 
 static inline void copy_highpage(struct page *to, struct page *from)
@@ -333,6 +337,10 @@ static inline void copy_highpage(struct page *to, struct page *from)
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_HIGHPAGE_MC
+#define copy_highpage_mc copy_highpage
+#endif
+
 static inline void memcpy_page(struct page *dst_page, size_t dst_off,
 			       struct page *src_page, size_t src_off,
 			       size_t len)
diff --git a/mm/memory.c b/mm/memory.c
index fee2884481f2..7decc792a02d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2868,7 +2868,7 @@ static inline bool __wp_page_copy_user(struct page *dst, struct page *src,
 	unsigned long addr = vmf->address;
 
 	if (likely(src)) {
-		copy_user_highpage(dst, src, addr, vma);
+		copy_user_highpage_mc(dst, src, addr, vma);
 		return true;
 	}
 
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH -next v6 10/10] arm64: add cow to machine check safe

[Tong Tiangen]

In the cow(copy on write) processing, the data of the user process is
copied, when hardware memory error is encountered during copy, only the
relevant processes are affected, so killing the user process and isolate
the user page with hardware memory errors is a more reasonable choice than
kernel panic.

Add new helper copy_page_mc() which provide a page copy implementation with
machine check safe. At present, only used in cow. In future, we can expand
more scenes. As long as the consequences of page copy failure are not
fatal(eg: only affect user process), we can use this helper.

The copy_page_mc() in copy_page_mc.S is largely borrows from copy_page()
in copy_page.S and the main difference is copy_page_mc() add extable entry
to every load/store insn to support machine check safe. largely to keep the
patch simple. If needed those optimizations can be folded in.

Add new extable type EX_TYPE_COPY_PAGE_MC which used in copy_page_mc().

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  5 ++
 arch/arm64/include/asm/assembler.h   |  4 ++
 arch/arm64/include/asm/mte.h         |  4 ++
 arch/arm64/include/asm/page.h        | 10 ++++
 arch/arm64/lib/Makefile              |  2 +
 arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++++++
 arch/arm64/lib/mte.S                 | 19 +++++++
 arch/arm64/mm/copypage.c             | 41 +++++++++++---
 arch/arm64/mm/extable.c              |  9 +++
 include/linux/highmem.h              |  8 +++
 mm/memory.c                          |  2 +-
 11 files changed, 178 insertions(+), 8 deletions(-)
 create mode 100644 arch/arm64/lib/copy_page_mc.S

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 980d1dd8e1a3..969e2848ca13 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -10,6 +10,7 @@
 #define EX_TYPE_UACCESS_ERR_ZERO	2
 #define EX_TYPE_KACCESS_ERR_ZERO	3
 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
+#define EX_TYPE_COPY_PAGE_MC		5
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -59,6 +60,10 @@
 	_ASM_EXTABLE_UACCESS(\insn, \fixup)
 	.endm
 
+	.macro          _asm_extable_copy_page_mc, insn, fixup
+	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_COPY_PAGE_MC, 0)
+	.endm
+
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index dc422fa437c2..44927fa3a844 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -168,6 +168,10 @@ lr	.req	x30		// link register
 #define CPU_LE(code...) code
 #endif
 
+#define CPY_MC(l, x...)		\
+9999:   x;			\
+	_asm_extable_copy_page_mc    9999b, l
+
 /*
  * Define a macro that constructs a 64-bit value by concatenating two
  * 32-bit registers. Note that on big endian systems the order of the
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..b8129f64cfea 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -40,6 +40,7 @@ void mte_free_tag_storage(char *storage);
 void mte_zero_clear_page_tags(void *addr);
 void mte_sync_tags(pte_t old_pte, pte_t pte);
 void mte_copy_page_tags(void *kto, const void *kfrom);
+void mte_copy_page_tags_mc(void *kto, const void *kfrom);
 void mte_thread_init_user(void);
 void mte_thread_switch(struct task_struct *next);
 void mte_suspend_enter(void);
@@ -63,6 +64,9 @@ static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
 {
 }
+static inline void mte_copy_page_tags_mc(void *kto, const void *kfrom)
+{
+}
 static inline void mte_thread_init_user(void)
 {
 }
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 993a27ea6f54..832571a7dddb 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -29,6 +29,16 @@ void copy_user_highpage(struct page *to, struct page *from,
 void copy_highpage(struct page *to, struct page *from);
 #define __HAVE_ARCH_COPY_HIGHPAGE
 
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern void copy_page_mc(void *to, const void *from);
+void copy_highpage_mc(struct page *to, struct page *from);
+#define __HAVE_ARCH_COPY_HIGHPAGE_MC
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+		unsigned long vaddr, struct vm_area_struct *vma);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#endif
+
 struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
 						unsigned long vaddr);
 #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 29490be2546b..0d9f292ef68a 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -15,6 +15,8 @@ endif
 
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
 
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_page_mc.o
+
 obj-$(CONFIG_CRC32) += crc32.o
 
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/arm64/lib/copy_page_mc.S b/arch/arm64/lib/copy_page_mc.S
new file mode 100644
index 000000000000..65fcad1dd7c8
--- /dev/null
+++ b/arch/arm64/lib/copy_page_mc.S
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/linkage.h>
+#include <linux/const.h>
+#include <asm/assembler.h>
+#include <asm/page.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+#include <asm/asm-extable.h>
+
+/*
+ * Copy a page from src to dest (both are page aligned) with machine check
+ *
+ * Parameters:
+ *	x0 - dest
+ *	x1 - src
+ */
+SYM_FUNC_START(__pi_copy_page_mc)
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	// Prefetch three cache lines ahead.
+	prfm	pldl1strm, [x1, #128]
+	prfm	pldl1strm, [x1, #256]
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #256
+	add	x1, x1, #128
+1:
+	tst	x0, #(PAGE_SIZE - 1)
+
+alternative_if ARM64_HAS_NO_HW_PREFETCH
+	prfm	pldl1strm, [x1, #384]
+alternative_else_nop_endif
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, ldp	x2, x3, [x1])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, ldp	x4, x5, [x1, #16])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, ldp	x6, x7, [x1, #32])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, ldp	x8, x9, [x1, #48])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, ldp	x10, x11, [x1, #64])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, ldp	x12, x13, [x1, #80])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, ldp	x14, x15, [x1, #96])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+CPY_MC(9998f, ldp	x16, x17, [x1, #112])
+
+	add	x0, x0, #128
+	add	x1, x1, #128
+
+	b.ne	1b
+
+CPY_MC(9998f, stnp	x2, x3, [x0, #-256])
+CPY_MC(9998f, stnp	x4, x5, [x0, #16 - 256])
+CPY_MC(9998f, stnp	x6, x7, [x0, #32 - 256])
+CPY_MC(9998f, stnp	x8, x9, [x0, #48 - 256])
+CPY_MC(9998f, stnp	x10, x11, [x0, #64 - 256])
+CPY_MC(9998f, stnp	x12, x13, [x0, #80 - 256])
+CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])
+CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])
+
+9998:	ret
+
+SYM_FUNC_END(__pi_copy_page_mc)
+SYM_FUNC_ALIAS(copy_page_mc, __pi_copy_page_mc)
+EXPORT_SYMBOL(copy_page_mc)
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index eeb9e45bcce8..cf728a9f39b5 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -80,6 +80,25 @@ SYM_FUNC_START(mte_copy_page_tags)
 	ret
 SYM_FUNC_END(mte_copy_page_tags)
 
+/*
+ * Copy the tags from the source page to the destination one wiht machine check safe
+ *   x0 - address of the destination page
+ *   x1 - address of the source page
+ */
+SYM_FUNC_START(mte_copy_page_tags_mc)
+	mov	x2, x0
+	mov	x3, x1
+	multitag_transfer_size x5, x6
+1:
+CPY_MC(2f, ldgm	x4, [x3])
+	stgm	x4, [x2]
+	add	x2, x2, x5
+	add	x3, x3, x5
+	tst	x2, #(PAGE_SIZE - 1)
+	b.ne	1b
+2:	ret
+SYM_FUNC_END(mte_copy_page_tags_mc)
+
 /*
  * Read tags from a user buffer (one tag per byte) and set the corresponding
  * tags at the given kernel address. Used by PTRACE_POKEMTETAGS.
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 0dea80bf6de4..d68c5fc753a2 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -14,13 +14,8 @@
 #include <asm/cpufeature.h>
 #include <asm/mte.h>
 
-void copy_highpage(struct page *to, struct page *from)
+static void do_mte(struct page *to, struct page *from, void *kto, void *kfrom, bool mc)
 {
-	void *kto = page_address(to);
-	void *kfrom = page_address(from);
-
-	copy_page(kto, kfrom);
-
 	if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
 		set_bit(PG_mte_tagged, &to->flags);
 		page_kasan_tag_reset(to);
@@ -32,9 +27,21 @@ void copy_highpage(struct page *to, struct page *from)
 		 * the new page->flags are visible before the tags were updated.
 		 */
 		smp_wmb();
-		mte_copy_page_tags(kto, kfrom);
+		if (mc)
+			mte_copy_page_tags_mc(kto, kfrom);
+		else
+			mte_copy_page_tags(kto, kfrom);
 	}
 }
+
+void copy_highpage(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page(kto, kfrom);
+	do_mte(to, from, kto, kfrom, false);
+}
 EXPORT_SYMBOL(copy_highpage);
 
 void copy_user_highpage(struct page *to, struct page *from,
@@ -44,3 +51,23 @@ void copy_user_highpage(struct page *to, struct page *from,
 	flush_dcache_page(to);
 }
 EXPORT_SYMBOL_GPL(copy_user_highpage);
+
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+void copy_highpage_mc(struct page *to, struct page *from)
+{
+	void *kto = page_address(to);
+	void *kfrom = page_address(from);
+
+	copy_page_mc(kto, kfrom);
+	do_mte(to, from, kto, kfrom, true);
+}
+EXPORT_SYMBOL(copy_highpage_mc);
+
+void copy_user_highpage_mc(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	copy_highpage_mc(to, from);
+	flush_dcache_page(to);
+}
+EXPORT_SYMBOL_GPL(copy_user_highpage_mc);
+#endif
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 28ec35e3d210..b986333a3100 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,6 +16,13 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
+static bool ex_handler_fixup(const struct exception_table_entry *ex,
+			     struct pt_regs *regs)
+{
+	regs->pc = get_ex_fixup(ex);
+	return true;
+}
+
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -88,6 +95,8 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	switch (ex->type) {
 	case EX_TYPE_UACCESS_ERR_ZERO:
 		return ex_handler_uaccess_err_zero(ex, regs);
+	case EX_TYPE_COPY_PAGE_MC:
+		return ex_handler_fixup(ex, regs);
 	}
 
 	return false;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 22379a63e293..5ba234b89be5 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -318,6 +318,10 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE_MC
+#define copy_user_highpage_mc copy_user_highpage
+#endif
+
 #ifndef __HAVE_ARCH_COPY_HIGHPAGE
 
 static inline void copy_highpage(struct page *to, struct page *from)
@@ -333,6 +337,10 @@ static inline void copy_highpage(struct page *to, struct page *from)
 
 #endif
 
+#ifndef __HAVE_ARCH_COPY_HIGHPAGE_MC
+#define copy_highpage_mc copy_highpage
+#endif
+
 static inline void memcpy_page(struct page *dst_page, size_t dst_off,
 			       struct page *src_page, size_t src_off,
 			       size_t len)
diff --git a/mm/memory.c b/mm/memory.c
index fee2884481f2..7decc792a02d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2868,7 +2868,7 @@ static inline bool __wp_page_copy_user(struct page *dst, struct page *src,
 	unsigned long addr = vmf->address;
 
 	if (likely(src)) {
-		copy_user_highpage(dst, src, addr, vma);
+		copy_user_highpage_mc(dst, src, addr, vma);
 		return true;
 	}
 
-- 
2.25.1

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Kefeng Wang]

On 2022/6/21 15:26, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
>
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
>
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
>
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
>
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.

It's a good to see more RAS feature on arm64, and we do meet some panic

during copy_from/to_user and CoW processing in our production, for series，

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>

>
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
>
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
>
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
>
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
>
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
>
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
>
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
>
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
>

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Kefeng Wang]

On 2022/6/21 15:26, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
>
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
>
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
>
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
>
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.

It's a good to see more RAS feature on arm64, and we do meet some panic

during copy_from/to_user and CoW processing in our production, for series，

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>

>
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
>
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
>
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
>
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
>
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
>
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
>
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
>
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Kefeng Wang]

On 2022/6/21 15:26, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
>
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
>
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
>
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
>
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.

It's a good to see more RAS feature on arm64, and we do meet some panic

during copy_from/to_user and CoW processing in our production, for series，

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>

>
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
>
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
>
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
>
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
>
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
>
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
>
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
>
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
>

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

Hi,Mark, kindly ping...

Thanks,
Tong.

在 2022/6/21 15:26, Tong Tiangen 写道:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
> 
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
> 
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.
> 
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
> 
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
> 
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
> 
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
> 
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
> 
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
> 
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
> 
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
> 

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

Hi,Mark, kindly ping...

Thanks,
Tong.

在 2022/6/21 15:26, Tong Tiangen 写道:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
> 
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
> 
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.
> 
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
> 
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
> 
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
> 
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
> 
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
> 
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
> 
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
> 
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Tong Tiangen]

Hi,Mark, kindly ping...

Thanks,
Tong.

在 2022/6/21 15:26, Tong Tiangen 写道:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> For arm64, the hardware memory error handling is do_sea() which divided
> into two cases:
>   1. The user state consumed the memory errors, the solution is kill the
>      user process and isolate the error page.
>   2. The kernel state consumed the memory errors, the solution is panic.
> 
> For case 2, Undifferentiated panic maybe not the optimal choice, it can be
> handled better, in some scenarios, we can avoid panic, such as uaccess, if the
> uaccess fails due to memory error, only the user process will be affected,
> kill the user process and isolate the user page with hardware memory errors
> is a better choice.
> 
> This patchset can be divided into two parts:
>   1. Patch 1~6    - do some restructuring to arm64 extable.
>   2. Patch 7~10   - arm64 add support for machine check safe framework,
>   then ,add two specific scenarios(uaccess/cow) to machine check safe.
> 
> Since V5:
>   1. Add patch2/3 to add uaccess assembly helpers.
>   2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8.
>   3. Remove kernel access fixup in patch9.
>   All suggestion are from Mark.
> 
> Since V4:
>   1. According Michael's suggestion, add patch5.
>   2. According Mark's suggestiog, do some restructuring to arm64
>   extable, then a new adaptation of machine check safe support is made based
>   on this.
>   3. According Mark's suggestion, support machine check safe in do_mte() in
>   cow scene.
>   4. In V4, two patches have been merged into -next, so V5 not send these
>   two patches.
> 
> Since V3:
>   1. According to Robin's suggestion, direct modify user_ldst and
>   user_ldp in asm-uaccess.h and modify mte.S.
>   2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S
>   and copy_to_user.S.
>   3. According to Robin's suggestion, using micro in copy_page_mc.S to
>   simplify code.
>   4. According to KeFeng's suggestion, modify powerpc code in patch1.
>   5. According to KeFeng's suggestion, modify mm/extable.c and some code
>   optimization.
> 
> Since V2:
>   1. According to Mark's suggestion, all uaccess can be recovered due to
>      memory error.
>   2. Scenario pagecache reading is also supported as part of uaccess
>      (copy_to_user()) and duplication code problem is also solved.
>      Thanks for Robin's suggestion.
>   3. According Mark's suggestion, update commit message of patch 2/5.
>   4. According Borisllav's suggestion, update commit message of patch 1/5.
> 
> Since V1:
>   1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of
>     ARM64_UCE_KERNEL_RECOVERY.
>   2.Add two new scenes, cow and pagecache reading.
>   3.Fix two small bug(the first two patch).
> 
> V1 in here:
> https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/
> 
> Tong Tiangen (10):
>    arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
>    arm64: asm-extable: move data fields
>    arm64: asm-extable: add asm uacess helpers
>    arm64: extable: make uaaccess helper use extable type
>      EX_TYPE_UACCESS_ERR_ZERO
>    arm64: extable: move _cond_extable to _cond_uaccess_extable
>    arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
>    Add generic fallback version of copy_mc_to_user()
>    arm64: add support for machine check error safe
>    arm64: add uaccess to machine check safe
>    arm64: add cow to machine check safe
> 
>   arch/arm64/Kconfig                   |  1 +
>   arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++-------
>   arch/arm64/include/asm/asm-uaccess.h | 12 ++--
>   arch/arm64/include/asm/assembler.h   |  8 ++-
>   arch/arm64/include/asm/extable.h     |  1 +
>   arch/arm64/include/asm/mte.h         |  4 ++
>   arch/arm64/include/asm/page.h        | 10 +++
>   arch/arm64/include/asm/uaccess.h     | 94 ++++++++++++++--------------
>   arch/arm64/lib/Makefile              |  2 +
>   arch/arm64/lib/copy_page_mc.S        | 82 ++++++++++++++++++++++++
>   arch/arm64/lib/mte.S                 | 19 ++++++
>   arch/arm64/mm/copypage.c             | 41 +++++++++---
>   arch/arm64/mm/extable.c              | 21 ++++++-
>   arch/arm64/mm/fault.c                | 29 ++++++++-
>   arch/powerpc/include/asm/uaccess.h   |  1 +
>   arch/x86/include/asm/uaccess.h       |  1 +
>   include/linux/highmem.h              |  8 +++
>   include/linux/uaccess.h              |  9 +++
>   mm/memory.c                          |  2 +-
>   19 files changed, 339 insertions(+), 90 deletions(-)
>   create mode 100644 arch/arm64/lib/copy_page_mc.S
> 

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Will Deacon]

On Tue, 21 Jun 2022 07:26:28 +0000, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> [...]

Applied first six patches to arm64 (for-next/extable), thanks!

[01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
        https://git.kernel.org/arm64/c/4953fc3d3270
[02/10] arm64: asm-extable: move data fields
        https://git.kernel.org/arm64/c/5519d7de2f8e
[03/10] arm64: asm-extable: add asm uacess helpers
        https://git.kernel.org/arm64/c/59e8a1ce8f7b
[04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO
        https://git.kernel.org/arm64/c/c4ed0d73ede9
[05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable
        https://git.kernel.org/arm64/c/e4208e80a353
[06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
        https://git.kernel.org/arm64/c/bacac637025c

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Will Deacon]

On Tue, 21 Jun 2022 07:26:28 +0000, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> [...]

Applied first six patches to arm64 (for-next/extable), thanks!

[01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
        https://git.kernel.org/arm64/c/4953fc3d3270
[02/10] arm64: asm-extable: move data fields
        https://git.kernel.org/arm64/c/5519d7de2f8e
[03/10] arm64: asm-extable: add asm uacess helpers
        https://git.kernel.org/arm64/c/59e8a1ce8f7b
[04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO
        https://git.kernel.org/arm64/c/c4ed0d73ede9
[05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable
        https://git.kernel.org/arm64/c/e4208e80a353
[06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
        https://git.kernel.org/arm64/c/bacac637025c

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH -next v6 00/10]arm64: add machine check safe support

[Will Deacon]

On Tue, 21 Jun 2022 07:26:28 +0000, Tong Tiangen wrote:
> With the increase of memory capacity and density, the probability of
> memory error increases. The increasing size and density of server RAM
> in the data center and cloud have shown increased uncorrectable memory
> errors.
> 
> Currently, the kernel has a mechanism to recover from hardware memory
> errors. This patchset provides an new recovery mechanism.
> 
> [...]

Applied first six patches to arm64 (for-next/extable), thanks!

[01/10] arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
        https://git.kernel.org/arm64/c/4953fc3d3270
[02/10] arm64: asm-extable: move data fields
        https://git.kernel.org/arm64/c/5519d7de2f8e
[03/10] arm64: asm-extable: add asm uacess helpers
        https://git.kernel.org/arm64/c/59e8a1ce8f7b
[04/10] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO
        https://git.kernel.org/arm64/c/c4ed0d73ede9
[05/10] arm64: extable: move _cond_extable to _cond_uaccess_extable
        https://git.kernel.org/arm64/c/e4208e80a353
[06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP
        https://git.kernel.org/arm64/c/bacac637025c

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev