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authorWill Deacon <will@kernel.org>2021-10-29 12:24:37 +0100
committerWill Deacon <will@kernel.org>2021-10-29 12:24:37 +0100
commit99fe09c857c69be504ae43d6a417d21eafcc6cfb (patch)
tree7d23269411a16c91e6f7344acd28ddd80729534e /arch
parenta69483eeeffff016c8548c4388e23679be20f17f (diff)
parentbf6e667f47384585f737216ea1e928d987c3e6e2 (diff)
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
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/asm-extable.h95
-rw-r--r--arch/arm64/include/asm/asm-uaccess.h7
-rw-r--r--arch/arm64/include/asm/assembler.h29
-rw-r--r--arch/arm64/include/asm/extable.h23
-rw-r--r--arch/arm64/include/asm/futex.h25
-rw-r--r--arch/arm64/include/asm/gpr-num.h26
-rw-r--r--arch/arm64/include/asm/kvm_asm.h7
-rw-r--r--arch/arm64/include/asm/sysreg.h25
-rw-r--r--arch/arm64/include/asm/uaccess.h26
-rw-r--r--arch/arm64/include/asm/word-at-a-time.h21
-rw-r--r--arch/arm64/kernel/armv8_deprecated.c12
-rw-r--r--arch/arm64/kernel/traps.c9
-rw-r--r--arch/arm64/kernel/vmlinux.lds.S3
-rw-r--r--arch/arm64/kvm/hyp/include/hyp/switch.h10
-rw-r--r--arch/arm64/lib/clear_user.S10
-rw-r--r--arch/arm64/lib/copy_from_user.S8
-rw-r--r--arch/arm64/lib/copy_to_user.S8
-rw-r--r--arch/arm64/mm/extable.c85
-rw-r--r--arch/arm64/net/bpf_jit_comp.c9
19 files changed, 280 insertions, 158 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();
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 0e86e8b9cedd..6875a16b09d2 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -279,7 +279,7 @@ static void __init register_insn_emulation_sysctl(void)
do { \
uaccess_enable_privileged(); \
__asm__ __volatile__( \
- " mov %w3, %w7\n" \
+ " mov %w3, %w6\n" \
"0: ldxr"B" %w2, [%4]\n" \
"1: stxr"B" %w0, %w1, [%4]\n" \
" cbz %w0, 2f\n" \
@@ -290,16 +290,10 @@ do { \
"2:\n" \
" mov %w1, %w2\n" \
"3:\n" \
- " .pushsection .fixup,\"ax\"\n" \
- " .align 2\n" \
- "4: mov %w0, %w6\n" \
- " b 3b\n" \
- " .popsection" \
- _ASM_EXTABLE(0b, 4b) \
- _ASM_EXTABLE(1b, 4b) \
+ _ASM_EXTABLE_UACCESS_ERR(0b, 3b, %w0) \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %w0) \
: "=&r" (res), "+r" (data), "=&r" (temp), "=&r" (temp2) \
: "r" ((unsigned long)addr), "i" (-EAGAIN), \
- "i" (-EFAULT), \
"i" (__SWP_LL_SC_LOOPS) \
: "memory"); \
uaccess_disable_privileged(); \
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 16710ca55fbb..5e410d17d9e3 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -527,14 +527,9 @@ NOKPROBE_SYMBOL(do_ptrauth_fault);
"1: " insn ", %1\n" \
" mov %w0, #0\n" \
"2:\n" \
- " .pushsection .fixup,\"ax\"\n" \
- " .align 2\n" \
- "3: mov %w0, %w2\n" \
- " b 2b\n" \
- " .popsection\n" \
- _ASM_EXTABLE(1b, 3b) \
+ _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %w0) \
: "=r" (res) \
- : "r" (address), "i" (-EFAULT)); \
+ : "r" (address)); \
uaccess_ttbr0_disable(); \
}
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index f6b1a88245db..443f03453036 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -57,7 +57,7 @@
#define SBSS_ALIGN 0
#endif
-#define RO_EXCEPTION_TABLE_ALIGN 8
+#define RO_EXCEPTION_TABLE_ALIGN 4
#define RUNTIME_DISCARD_EXIT
#include <asm-generic/vmlinux.lds.h>
@@ -161,7 +161,6 @@ SECTIONS
IDMAP_TEXT
HIBERNATE_TEXT
TRAMP_TEXT
- *(.fixup)
*(.gnu.warning)
. = ALIGN(16);
*(.got) /* Global offset table */
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index a0e78a6027be..d5a47b93ef9b 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -30,8 +30,12 @@
#include <asm/processor.h>
#include <asm/thread_info.h>
-extern struct exception_table_entry __start___kvm_ex_table;
-extern struct exception_table_entry __stop___kvm_ex_table;
+struct kvm_exception_table_entry {
+ int insn, fixup;
+};
+
+extern struct kvm_exception_table_entry __start___kvm_ex_table;
+extern struct kvm_exception_table_entry __stop___kvm_ex_table;
/* Check whether the FP regs were dirtied while in the host-side run loop: */
static inline bool update_fp_enabled(struct kvm_vcpu *vcpu)
@@ -510,7 +514,7 @@ static inline void __kvm_unexpected_el2_exception(void)
{
extern char __guest_exit_panic[];
unsigned long addr, fixup;
- struct exception_table_entry *entry, *end;
+ struct kvm_exception_table_entry *entry, *end;
unsigned long elr_el2 = read_sysreg(elr_el2);
entry = &__start___kvm_ex_table;
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index a7efb2ad2a1c..a5a5f5b97b17 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -4,7 +4,7 @@
*/
#include <linux/linkage.h>
-#include <asm/assembler.h>
+#include <asm/asm-uaccess.h>
.text
@@ -45,13 +45,11 @@ USER(9f, sttrh wzr, [x0])
USER(7f, sttrb wzr, [x2, #-1])
5: mov x0, #0
ret
-SYM_FUNC_END(__arch_clear_user)
-EXPORT_SYMBOL(__arch_clear_user)
- .section .fixup,"ax"
- .align 2
+ // Exception fixups
7: sub x0, x2, #5 // Adjust for faulting on the final byte...
8: add x0, x0, #4 // ...or the second word of the 4-7 byte case
9: sub x0, x2, x0
ret
- .previous
+SYM_FUNC_END(__arch_clear_user)
+EXPORT_SYMBOL(__arch_clear_user)
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 2cf999e41d30..34e317907524 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -60,11 +60,8 @@ SYM_FUNC_START(__arch_copy_from_user)
#include "copy_template.S"
mov x0, #0 // Nothing to copy
ret
-SYM_FUNC_END(__arch_copy_from_user)
-EXPORT_SYMBOL(__arch_copy_from_user)
- .section .fixup,"ax"
- .align 2
+ // Exception fixups
9997: cmp dst, dstin
b.ne 9998f
// Before being absolutely sure we couldn't copy anything, try harder
@@ -72,4 +69,5 @@ USER(9998f, ldtrb tmp1w, [srcin])
strb tmp1w, [dst], #1
9998: sub x0, end, dst // bytes not copied
ret
- .previous
+SYM_FUNC_END(__arch_copy_from_user)
+EXPORT_SYMBOL(__arch_copy_from_user)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 9f380eecf653..802231772608 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -59,11 +59,8 @@ SYM_FUNC_START(__arch_copy_to_user)
#include "copy_template.S"
mov x0, #0
ret
-SYM_FUNC_END(__arch_copy_to_user)
-EXPORT_SYMBOL(__arch_copy_to_user)
- .section .fixup,"ax"
- .align 2
+ // Exception fixups
9997: cmp dst, dstin
b.ne 9998f
// Before being absolutely sure we couldn't copy anything, try harder
@@ -72,4 +69,5 @@ USER(9998f, sttrb tmp1w, [dst])
add dst, dst, #1
9998: sub x0, end, dst // bytes not copied
ret
- .previous
+SYM_FUNC_END(__arch_copy_to_user)
+EXPORT_SYMBOL(__arch_copy_to_user)
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index aa0060178343..c3d53811a15e 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -3,20 +3,87 @@
* Based on arch/arm/mm/extable.c
*/
+#include <linux/bitfield.h>
#include <linux/extable.h>
#include <linux/uaccess.h>
-int fixup_exception(struct pt_regs *regs)
+#include <asm/asm-extable.h>
+#include <asm/ptrace.h>
+
+typedef bool (*ex_handler_t)(const struct exception_table_entry *,
+ struct pt_regs *);
+
+static inline unsigned long
+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)
+{
+ int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+ int reg_zero = FIELD_GET(EX_DATA_REG_ZERO, ex->data);
+
+ pt_regs_write_reg(regs, reg_err, -EFAULT);
+ pt_regs_write_reg(regs, reg_zero, 0);
+
+ regs->pc = get_ex_fixup(ex);
+ return true;
+}
+
+static bool
+ex_handler_load_unaligned_zeropad(const struct exception_table_entry *ex,
+ struct pt_regs *regs)
+{
+ int reg_data = FIELD_GET(EX_DATA_REG_DATA, ex->type);
+ int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->type);
+ unsigned long data, addr, offset;
+
+ addr = pt_regs_read_reg(regs, reg_addr);
+
+ offset = addr & 0x7UL;
+ addr &= ~0x7UL;
+
+ data = *(unsigned long*)addr;
+
+#ifndef __AARCH64EB__
+ data >>= 8 * offset;
+#else
+ data <<= 8 * offset;
+#endif
+
+ pt_regs_write_reg(regs, reg_data, data);
+
+ regs->pc = get_ex_fixup(ex);
+ return true;
+}
+
+bool fixup_exception(struct pt_regs *regs)
{
- const struct exception_table_entry *fixup;
+ const struct exception_table_entry *ex;
- fixup = search_exception_tables(instruction_pointer(regs));
- if (!fixup)
- return 0;
+ ex = search_exception_tables(instruction_pointer(regs));
+ if (!ex)
+ return false;
- if (in_bpf_jit(regs))
- return arm64_bpf_fixup_exception(fixup, regs);
+ 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:
+ return ex_handler_uaccess_err_zero(ex, regs);
+ case EX_TYPE_LOAD_UNALIGNED_ZEROPAD:
+ return ex_handler_load_unaligned_zeropad(ex, regs);
+ }
- regs->pc = (unsigned long)&fixup->fixup + fixup->fixup;
- return 1;
+ BUG();
}
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 41c23f474ea6..7df7345e60d8 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -13,6 +13,7 @@
#include <linux/printk.h>
#include <linux/slab.h>
+#include <asm/asm-extable.h>
#include <asm/byteorder.h>
#include <asm/cacheflush.h>
#include <asm/debug-monitors.h>
@@ -358,15 +359,15 @@ static void build_epilogue(struct jit_ctx *ctx)
#define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0)
#define BPF_FIXUP_REG_MASK GENMASK(31, 27)
-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)
{
off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);
int dst_reg = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup);
regs->regs[dst_reg] = 0;
regs->pc = (unsigned long)&ex->fixup - offset;
- return 1;
+ return true;
}
/* For accesses to BTF pointers, add an entry to the exception table */
@@ -412,6 +413,8 @@ static int add_exception_handler(const struct bpf_insn *insn,
ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) |
FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);
+ ex->type = EX_TYPE_BPF;
+
ctx->exentry_idx++;
return 0;
}