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1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/bitfield.h>
4#include <linux/extable.h>
5#include <linux/string.h>
6#include <linux/errno.h>
7#include <linux/panic.h>
8#include <asm/asm-extable.h>
9#include <asm/extable.h>
10
11const struct exception_table_entry *s390_search_extables(unsigned long addr)
12{
13 const struct exception_table_entry *fixup;
14 size_t num;
15
16 fixup = search_exception_tables(addr);
17 if (fixup)
18 return fixup;
19 num = __stop_amode31_ex_table - __start_amode31_ex_table;
20 return search_extable(__start_amode31_ex_table, num, addr);
21}
22
23static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs)
24{
25 regs->psw.addr = extable_fixup(ex);
26 return true;
27}
28
29static bool ex_handler_ua_store(const struct exception_table_entry *ex, struct pt_regs *regs)
30{
31 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
32
33 regs->gprs[reg_err] = -EFAULT;
34 regs->psw.addr = extable_fixup(ex);
35 return true;
36}
37
38static bool ex_handler_ua_load_mem(const struct exception_table_entry *ex, struct pt_regs *regs)
39{
40 unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
41 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
42 size_t len = FIELD_GET(EX_DATA_LEN, ex->data);
43
44 regs->gprs[reg_err] = -EFAULT;
45 memset((void *)regs->gprs[reg_addr], 0, len);
46 regs->psw.addr = extable_fixup(ex);
47 return true;
48}
49
50static bool ex_handler_ua_load_reg(const struct exception_table_entry *ex, struct pt_regs *regs)
51{
52 unsigned int reg_zero = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
53 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
54
55 regs->gprs[reg_err] = -EFAULT;
56 regs->gprs[reg_zero] = 0;
57 regs->psw.addr = extable_fixup(ex);
58 return true;
59}
60
61bool fixup_exception(struct pt_regs *regs)
62{
63 const struct exception_table_entry *ex;
64
65 ex = s390_search_extables(instruction_pointer(regs));
66 if (!ex)
67 return false;
68 switch (ex->type) {
69 case EX_TYPE_FIXUP:
70 return ex_handler_fixup(ex, regs);
71 case EX_TYPE_BPF:
72 return ex_handler_bpf(ex, regs);
73 case EX_TYPE_UA_STORE:
74 return ex_handler_ua_store(ex, regs);
75 case EX_TYPE_UA_LOAD_MEM:
76 return ex_handler_ua_load_mem(ex, regs);
77 case EX_TYPE_UA_LOAD_REG:
78 return ex_handler_ua_load_reg(ex, regs);
79 }
80 panic("invalid exception table entry");
81}
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/bitfield.h>
4#include <linux/extable.h>
5#include <linux/string.h>
6#include <linux/errno.h>
7#include <linux/panic.h>
8#include <asm/asm-extable.h>
9#include <asm/extable.h>
10
11const struct exception_table_entry *s390_search_extables(unsigned long addr)
12{
13 const struct exception_table_entry *fixup;
14 size_t num;
15
16 fixup = search_exception_tables(addr);
17 if (fixup)
18 return fixup;
19 num = __stop_amode31_ex_table - __start_amode31_ex_table;
20 return search_extable(__start_amode31_ex_table, num, addr);
21}
22
23static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs)
24{
25 regs->psw.addr = extable_fixup(ex);
26 return true;
27}
28
29static bool ex_handler_ua_store(const struct exception_table_entry *ex, struct pt_regs *regs)
30{
31 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
32
33 regs->gprs[reg_err] = -EFAULT;
34 regs->psw.addr = extable_fixup(ex);
35 return true;
36}
37
38static bool ex_handler_ua_load_mem(const struct exception_table_entry *ex, struct pt_regs *regs)
39{
40 unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
41 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
42 size_t len = FIELD_GET(EX_DATA_LEN, ex->data);
43
44 regs->gprs[reg_err] = -EFAULT;
45 memset((void *)regs->gprs[reg_addr], 0, len);
46 regs->psw.addr = extable_fixup(ex);
47 return true;
48}
49
50static bool ex_handler_ua_load_reg(const struct exception_table_entry *ex,
51 bool pair, struct pt_regs *regs)
52{
53 unsigned int reg_zero = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
54 unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
55
56 regs->gprs[reg_err] = -EFAULT;
57 regs->gprs[reg_zero] = 0;
58 if (pair)
59 regs->gprs[reg_zero + 1] = 0;
60 regs->psw.addr = extable_fixup(ex);
61 return true;
62}
63
64static bool ex_handler_zeropad(const struct exception_table_entry *ex, struct pt_regs *regs)
65{
66 unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
67 unsigned int reg_data = FIELD_GET(EX_DATA_REG_ERR, ex->data);
68 unsigned long data, addr, offset;
69
70 addr = regs->gprs[reg_addr];
71 offset = addr & (sizeof(unsigned long) - 1);
72 addr &= ~(sizeof(unsigned long) - 1);
73 data = *(unsigned long *)addr;
74 data <<= BITS_PER_BYTE * offset;
75 regs->gprs[reg_data] = data;
76 regs->psw.addr = extable_fixup(ex);
77 return true;
78}
79
80bool fixup_exception(struct pt_regs *regs)
81{
82 const struct exception_table_entry *ex;
83
84 ex = s390_search_extables(instruction_pointer(regs));
85 if (!ex)
86 return false;
87 switch (ex->type) {
88 case EX_TYPE_FIXUP:
89 return ex_handler_fixup(ex, regs);
90 case EX_TYPE_BPF:
91 return ex_handler_bpf(ex, regs);
92 case EX_TYPE_UA_STORE:
93 return ex_handler_ua_store(ex, regs);
94 case EX_TYPE_UA_LOAD_MEM:
95 return ex_handler_ua_load_mem(ex, regs);
96 case EX_TYPE_UA_LOAD_REG:
97 return ex_handler_ua_load_reg(ex, false, regs);
98 case EX_TYPE_UA_LOAD_REGPAIR:
99 return ex_handler_ua_load_reg(ex, true, regs);
100 case EX_TYPE_ZEROPAD:
101 return ex_handler_zeropad(ex, regs);
102 }
103 panic("invalid exception table entry");
104}