1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology
4 */
5 #include <linux/bitfield.h>
6 #include <linux/extable.h>
7 #include <linux/uaccess.h>
8 #include <asm/asm-extable.h>
9 #include <asm/branch.h>
10
11 static inline unsigned long
12 get_ex_fixup(const struct exception_table_entr
13 {
14 return ((unsigned long)&ex->fixup + ex
15 }
16
17 static inline void regs_set_gpr(struct pt_regs
18 unsigned int o
19 {
20 if (offset && offset <= MAX_REG_OFFSET
21 *(unsigned long *)((unsigned l
22 }
23
24 static bool ex_handler_fixup(const struct exce
25 struct pt_regs *r
26 {
27 regs->csr_era = get_ex_fixup(ex);
28
29 return true;
30 }
31
32 static bool ex_handler_uaccess_err_zero(const
33 struct
34 {
35 int reg_err = FIELD_GET(EX_DATA_REG_ER
36 int reg_zero = FIELD_GET(EX_DATA_REG_Z
37
38 regs_set_gpr(regs, reg_err * sizeof(un
39 regs_set_gpr(regs, reg_zero * sizeof(u
40 regs->csr_era = get_ex_fixup(ex);
41
42 return true;
43 }
44
45 bool fixup_exception(struct pt_regs *regs)
46 {
47 const struct exception_table_entry *ex
48
49 ex = search_exception_tables(exception
50 if (!ex)
51 return false;
52
53 switch (ex->type) {
54 case EX_TYPE_FIXUP:
55 return ex_handler_fixup(ex, re
56 case EX_TYPE_UACCESS_ERR_ZERO:
57 return ex_handler_uaccess_err_
58 case EX_TYPE_BPF:
59 return ex_handler_bpf(ex, regs
60 }
61
62 BUG();
63 }
64
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