Merge branch 'for-next/extable' into for-next/core

* for-next/extable:
  arm64: vmlinux.lds.S: remove `.fixup` section
  arm64: extable: add load_unaligned_zeropad() handler
  arm64: extable: add a dedicated uaccess handler
  arm64: extable: add `type` and `data` fields
  arm64: extable: use `ex` for `exception_table_entry`
  arm64: extable: make fixup_exception() return bool
  arm64: extable: consolidate definitions
  arm64: gpr-num: support W registers
  arm64: factor out GPR numbering helpers
  arm64: kvm: use kvm_exception_table_entry
  arm64: lib: __arch_copy_to_user(): fold fixups into body
  arm64: lib: __arch_copy_from_user(): fold fixups into body
  arm64: lib: __arch_clear_user(): fold fixups into body

10 files changed, 175 insertions, 109 deletions

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
new file mode 100644
index 000000000000..c39f2437e08e
--- /dev/null
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_ASM_EXTABLE_H
+#define __ASM_ASM_EXTABLE_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_LOAD_UNALIGNED_ZEROPAD	4
+
+#ifdef __ASSEMBLY__
+
+#define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\
+	.pushsection	__ex_table, "a";		\
+	.align		2;				\
+	.long		((insn) - .);			\
+	.long		((fixup) - .);			\
+	.short		(type);				\
+	.short		(data);				\
+	.popsection;
+
+/*
+ * 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)
+	.endm
+
+/*
+ * 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
+	.endif
+	.endm
+
+#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"				\
+	".long		((" insn ") - .)\n"		\
+	".long		((" fixup ") - .)\n"		\
+	".short		(" type ")\n"			\
+	".short		(" data ")\n"			\
+	".popsection\n"
+
+#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) ")"
+
+#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)		\
+	__DEFINE_ASM_GPR_NUMS						\
+	__ASM_EXTABLE_RAW(#insn, #fixup, 				\
+			  __stringify(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 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,					\
+			  __stringify(EX_TYPE_LOAD_UNALIGNED_ZEROPAD),		\
+			  "("							\
+			    EX_DATA_REG(DATA, data) " | "			\
+			    EX_DATA_REG(ADDR, addr)				\
+			  ")")
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_ASM_EXTABLE_H */
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index ccedf548dac9..0557af834e03 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -3,10 +3,11 @@
 #define __ASM_ASM_UACCESS_H
 
 #include <asm/alternative-macros.h>
+#include <asm/asm-extable.h>
+#include <asm/assembler.h>
 #include <asm/kernel-pgtable.h>
 #include <asm/mmu.h>
 #include <asm/sysreg.h>
-#include <asm/assembler.h>
 
 /*
  * User access enabling/disabling macros.
@@ -58,6 +59,10 @@ alternative_else_nop_endif
 	.endm
 #endif
 
+#define USER(l, x...)				\
+9999:	x;					\
+	_asm_extable	9999b, l
+
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
  * This is complicated as there is no post-increment or pair versions of the
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index bfa58409a4d4..ec67480d55fb 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -14,9 +14,10 @@
 
 #include <asm-generic/export.h>
 
-#include <asm/asm-offsets.h>
 #include <asm/alternative.h>
 #include <asm/asm-bug.h>
+#include <asm/asm-extable.h>
+#include <asm/asm-offsets.h>
 #include <asm/cpufeature.h>
 #include <asm/cputype.h>
 #include <asm/debug-monitors.h>
@@ -130,32 +131,6 @@ alternative_endif
 	.endm
 
 /*
- * Create an exception table entry for `insn`, which will branch to `fixup`
- * when an unhandled fault is taken.
- */
-	.macro		_asm_extable, insn, fixup
-	.pushsection	__ex_table, "a"
-	.align		3
-	.long		(\insn - .), (\fixup - .)
-	.popsection
-	.endm
-
-/*
- * 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
-	.endif
-	.endm
-
-
-#define USER(l, x...)				\
-9999:	x;					\
-	_asm_extable	9999b, l
-
-/*
  * Register aliases.
  */
 lr	.req	x30		// link register
diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/extable.h
index b15eb4a3e6b2..8b300dd28def 100644
--- a/arch/arm64/include/asm/extable.h
+++ b/arch/arm64/include/asm/extable.h
@@ -18,10 +18,21 @@
 struct exception_table_entry
 {
 	int insn, fixup;
+	short type, data;
 };
 
 #define ARCH_HAS_RELATIVE_EXTABLE
 
+#define swap_ex_entry_fixup(a, b, tmp, delta)		\
+do {							\
+	(a)->fixup = (b)->fixup + (delta);		\
+	(b)->fixup = (tmp).fixup - (delta);		\
+	(a)->type = (b)->type;				\
+	(b)->type = (tmp).type;				\
+	(a)->data = (b)->data;				\
+	(b)->data = (tmp).data;				\
+} while (0)
+
 static inline bool in_bpf_jit(struct pt_regs *regs)
 {
 	if (!IS_ENABLED(CONFIG_BPF_JIT))
@@ -32,16 +43,16 @@ static inline bool in_bpf_jit(struct pt_regs *regs)
 }
 
 #ifdef CONFIG_BPF_JIT
-int arm64_bpf_fixup_exception(const struct exception_table_entry *ex,
-			      struct pt_regs *regs);
+bool ex_handler_bpf(const struct exception_table_entry *ex,
+		    struct pt_regs *regs);
 #else /* !CONFIG_BPF_JIT */
 static inline
-int arm64_bpf_fixup_exception(const struct exception_table_entry *ex,
-			      struct pt_regs *regs)
+bool ex_handler_bpf(const struct exception_table_entry *ex,
+		    struct pt_regs *regs)
 {
-	return 0;
+	return false;
 }
 #endif /* !CONFIG_BPF_JIT */
 
-extern int fixup_exception(struct pt_regs *regs);
+bool fixup_exception(struct pt_regs *regs);
 #endif
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index 8e41faa37c69..bc06691d2062 100644
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -25,19 +25,14 @@ do {									\
 "	cbz	%w0, 3f\n"						\
 "	sub	%w4, %w4, %w0\n"					\
 "	cbnz	%w4, 1b\n"						\
-"	mov	%w0, %w7\n"						\
+"	mov	%w0, %w6\n"						\
 "3:\n"									\
 "	dmb	ish\n"							\
-"	.pushsection .fixup,\"ax\"\n"					\
-"	.align	2\n"							\
-"4:	mov	%w0, %w6\n"						\
-"	b	3b\n"							\
-"	.popsection\n"							\
-	_ASM_EXTABLE(1b, 4b)						\
-	_ASM_EXTABLE(2b, 4b)						\
+	_ASM_EXTABLE_UACCESS_ERR(1b, 3b, %w0)				\
+	_ASM_EXTABLE_UACCESS_ERR(2b, 3b, %w0)				\
 	: "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp),	\
 	  "+r" (loops)							\
-	: "r" (oparg), "Ir" (-EFAULT), "Ir" (-EAGAIN)			\
+	: "r" (oparg), "Ir" (-EAGAIN)					\
 	: "memory");							\
 	uaccess_disable_privileged();					\
 } while (0)
@@ -105,18 +100,14 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *_uaddr,
 "	cbz	%w3, 3f\n"
 "	sub	%w4, %w4, %w3\n"
 "	cbnz	%w4, 1b\n"
-"	mov	%w0, %w8\n"
+"	mov	%w0, %w7\n"
 "3:\n"
 "	dmb	ish\n"
 "4:\n"
-"	.pushsection .fixup,\"ax\"\n"
-"5:	mov	%w0, %w7\n"
-"	b	4b\n"
-"	.popsection\n"
-	_ASM_EXTABLE(1b, 5b)
-	_ASM_EXTABLE(2b, 5b)
+	_ASM_EXTABLE_UACCESS_ERR(1b, 4b, %w0)
+	_ASM_EXTABLE_UACCESS_ERR(2b, 4b, %w0)
 	: "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp), "+r" (loops)
-	: "r" (oldval), "r" (newval), "Ir" (-EFAULT), "Ir" (-EAGAIN)
+	: "r" (oldval), "r" (newval), "Ir" (-EAGAIN)
 	: "memory");
 	uaccess_disable_privileged();
 
diff --git a/arch/arm64/include/asm/gpr-num.h b/arch/arm64/include/asm/gpr-num.h
new file mode 100644
index 000000000000..05da4a7c5788
--- /dev/null
+++ b/arch/arm64/include/asm/gpr-num.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GPR_NUM_H
+#define __ASM_GPR_NUM_H
+
+#ifdef __ASSEMBLY__
+
+	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
+	.equ	.L__gpr_num_x\num, \num
+	.equ	.L__gpr_num_w\num, \num
+	.endr
+	.equ	.L__gpr_num_xzr, 31
+	.equ	.L__gpr_num_wzr, 31
+
+#else /* __ASSEMBLY__ */
+
+#define __DEFINE_ASM_GPR_NUMS					\
+"	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n" \
+"	.equ	.L__gpr_num_x\\num, \\num\n"			\
+"	.equ	.L__gpr_num_w\\num, \\num\n"			\
+"	.endr\n"						\
+"	.equ	.L__gpr_num_xzr, 31\n"				\
+"	.equ	.L__gpr_num_wzr, 31\n"
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_GPR_NUM_H */
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index e86045ac43ba..6486b1db268e 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -263,9 +263,10 @@ extern u64 __kvm_get_mdcr_el2(void);
 
 /*
  * KVM extable for unexpected exceptions.
- * In the same format _asm_extable, but output to a different section so that
- * it can be mapped to EL2. The KVM version is not sorted. The caller must
- * ensure:
+ * Create a struct kvm_exception_table_entry output to a section that can be
+ * mapped by EL2. The table is not sorted.
+ *
+ * The caller must ensure:
  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
  */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 5ce70c034d37..f649cd27c986 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -13,6 +13,8 @@
 #include <linux/stringify.h>
 #include <linux/kasan-tags.h>
 
+#include <asm/gpr-num.h>
+
 /*
  * ARMv8 ARM reserves the following encoding for system registers:
  * (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
@@ -1195,17 +1197,12 @@
 
 #ifdef __ASSEMBLY__
 
-	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
-	.equ	.L__reg_num_x\num, \num
-	.endr
-	.equ	.L__reg_num_xzr, 31
-
 	.macro	mrs_s, rt, sreg
-	 __emit_inst(0xd5200000|(\sreg)|(.L__reg_num_\rt))
+	 __emit_inst(0xd5200000|(\sreg)|(.L__gpr_num_\rt))
 	.endm
 
 	.macro	msr_s, sreg, rt
-	__emit_inst(0xd5000000|(\sreg)|(.L__reg_num_\rt))
+	__emit_inst(0xd5000000|(\sreg)|(.L__gpr_num_\rt))
 	.endm
 
 #else
@@ -1214,22 +1211,16 @@
 #include <linux/types.h>
 #include <asm/alternative.h>
 
-#define __DEFINE_MRS_MSR_S_REGNUM				\
-"	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n" \
-"	.equ	.L__reg_num_x\\num, \\num\n"			\
-"	.endr\n"						\
-"	.equ	.L__reg_num_xzr, 31\n"
-
 #define DEFINE_MRS_S						\
-	__DEFINE_MRS_MSR_S_REGNUM				\
+	__DEFINE_ASM_GPR_NUMS					\
 "	.macro	mrs_s, rt, sreg\n"				\
-	__emit_inst(0xd5200000|(\\sreg)|(.L__reg_num_\\rt))	\
+	__emit_inst(0xd5200000|(\\sreg)|(.L__gpr_num_\\rt))	\
 "	.endm\n"
 
 #define DEFINE_MSR_S						\
-	__DEFINE_MRS_MSR_S_REGNUM				\
+	__DEFINE_ASM_GPR_NUMS					\
 "	.macro	msr_s, sreg, rt\n"				\
-	__emit_inst(0xd5000000|(\\sreg)|(.L__reg_num_\\rt))	\
+	__emit_inst(0xd5000000|(\\sreg)|(.L__gpr_num_\\rt))	\
 "	.endm\n"
 
 #define UNDEFINE_MRS_S						\
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 190b494e22ab..9bc218991c5a 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -18,6 +18,7 @@
 #include <linux/kasan-checks.h>
 #include <linux/string.h>
 
+#include <asm/asm-extable.h>
 #include <asm/cpufeature.h>
 #include <asm/mmu.h>
 #include <asm/mte.h>
@@ -70,12 +71,6 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
 
 #define access_ok(addr, size)	__range_ok(addr, size)
 
-#define _ASM_EXTABLE(from, to)						\
-	"	.pushsection	__ex_table, \"a\"\n"			\
-	"	.align		3\n"					\
-	"	.long		(" #from " - .), (" #to " - .)\n"	\
-	"	.popsection\n"
-
 /*
  * User access enabling/disabling.
  */
@@ -260,15 +255,9 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
 	asm volatile(							\
 	"1:	" load "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	"	.section .fixup, \"ax\"\n"				\
-	"	.align	2\n"						\
-	"3:	mov	%w0, %3\n"					\
-	"	mov	%1, #0\n"					\
-	"	b	2b\n"						\
-	"	.previous\n"						\
-	_ASM_EXTABLE(1b, 3b)						\
+	_ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %w0, %w1)			\
 	: "+r" (err), "=&r" (x)						\
-	: "r" (addr), "i" (-EFAULT))
+	: "r" (addr))
 
 #define __raw_get_mem(ldr, x, ptr, err)					\
 do {									\
@@ -337,14 +326,9 @@ do {									\
 	asm volatile(							\
 	"1:	" store "	" reg "1, [%2]\n"			\
 	"2:\n"								\
-	"	.section .fixup,\"ax\"\n"				\
-	"	.align	2\n"						\
-	"3:	mov	%w0, %3\n"					\
-	"	b	2b\n"						\
-	"	.previous\n"						\
-	_ASM_EXTABLE(1b, 3b)						\
+	_ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0)				\
 	: "+r" (err)							\
-	: "r" (x), "r" (addr), "i" (-EFAULT))
+	: "r" (x), "r" (addr))
 
 #define __raw_put_mem(str, x, ptr, err)					\
 do {									\
diff --git a/arch/arm64/include/asm/word-at-a-time.h b/arch/arm64/include/asm/word-at-a-time.h
index 2dcb104c645b..1c8e4f2490bf 100644
--- a/arch/arm64/include/asm/word-at-a-time.h
+++ b/arch/arm64/include/asm/word-at-a-time.h
@@ -53,29 +53,16 @@ static inline unsigned long find_zero(unsigned long mask)
  */
 static inline unsigned long load_unaligned_zeropad(const void *addr)
 {
-	unsigned long ret, tmp;
+	unsigned long ret;
 
 	__uaccess_enable_tco_async();
 
 	/* Load word from unaligned pointer addr */
 	asm(
-	"1:	ldr	%0, %3\n"
+	"1:	ldr	%0, %2\n"
 	"2:\n"
-	"	.pushsection .fixup,\"ax\"\n"
-	"	.align 2\n"
-	"3:	bic	%1, %2, #0x7\n"
-	"	ldr	%0, [%1]\n"
-	"	and	%1, %2, #0x7\n"
-	"	lsl	%1, %1, #0x3\n"
-#ifndef __AARCH64EB__
-	"	lsr	%0, %0, %1\n"
-#else
-	"	lsl	%0, %0, %1\n"
-#endif
-	"	b	2b\n"
-	"	.popsection\n"
-	_ASM_EXTABLE(1b, 3b)
-	: "=&r" (ret), "=&r" (tmp)
+	_ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(1b, 2b, %0, %1)
+	: "=&r" (ret)
 	: "r" (addr), "Q" (*(unsigned long *)addr));
 
 	__uaccess_disable_tco_async();