82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include <linux/bitfield.h>
|
|
#include <linux/extable.h>
|
|
#include <linux/string.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/panic.h>
|
|
#include <asm/asm-extable.h>
|
|
#include <asm/extable.h>
|
|
|
|
const struct exception_table_entry *s390_search_extables(unsigned long addr)
|
|
{
|
|
const struct exception_table_entry *fixup;
|
|
size_t num;
|
|
|
|
fixup = search_exception_tables(addr);
|
|
if (fixup)
|
|
return fixup;
|
|
num = __stop_amode31_ex_table - __start_amode31_ex_table;
|
|
return search_extable(__start_amode31_ex_table, num, addr);
|
|
}
|
|
|
|
static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs)
|
|
{
|
|
regs->psw.addr = extable_fixup(ex);
|
|
return true;
|
|
}
|
|
|
|
static bool ex_handler_ua_store(const struct exception_table_entry *ex, struct pt_regs *regs)
|
|
{
|
|
unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
|
|
|
|
regs->gprs[reg_err] = -EFAULT;
|
|
regs->psw.addr = extable_fixup(ex);
|
|
return true;
|
|
}
|
|
|
|
static bool ex_handler_ua_load_mem(const struct exception_table_entry *ex, struct pt_regs *regs)
|
|
{
|
|
unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
|
|
unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
|
|
size_t len = FIELD_GET(EX_DATA_LEN, ex->data);
|
|
|
|
regs->gprs[reg_err] = -EFAULT;
|
|
memset((void *)regs->gprs[reg_addr], 0, len);
|
|
regs->psw.addr = extable_fixup(ex);
|
|
return true;
|
|
}
|
|
|
|
static bool ex_handler_ua_load_reg(const struct exception_table_entry *ex, struct pt_regs *regs)
|
|
{
|
|
unsigned int reg_zero = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
|
|
unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
|
|
|
|
regs->gprs[reg_err] = -EFAULT;
|
|
regs->gprs[reg_zero] = 0;
|
|
regs->psw.addr = extable_fixup(ex);
|
|
return true;
|
|
}
|
|
|
|
bool fixup_exception(struct pt_regs *regs)
|
|
{
|
|
const struct exception_table_entry *ex;
|
|
|
|
ex = s390_search_extables(instruction_pointer(regs));
|
|
if (!ex)
|
|
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_UA_STORE:
|
|
return ex_handler_ua_store(ex, regs);
|
|
case EX_TYPE_UA_LOAD_MEM:
|
|
return ex_handler_ua_load_mem(ex, regs);
|
|
case EX_TYPE_UA_LOAD_REG:
|
|
return ex_handler_ua_load_reg(ex, regs);
|
|
}
|
|
panic("invalid exception table entry");
|
|
}
|