162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0 262306a36Sopenharmony_ci 362306a36Sopenharmony_ci#include <linux/bitfield.h> 462306a36Sopenharmony_ci#include <linux/extable.h> 562306a36Sopenharmony_ci#include <linux/string.h> 662306a36Sopenharmony_ci#include <linux/errno.h> 762306a36Sopenharmony_ci#include <linux/panic.h> 862306a36Sopenharmony_ci#include <asm/asm-extable.h> 962306a36Sopenharmony_ci#include <asm/extable.h> 1062306a36Sopenharmony_ci 1162306a36Sopenharmony_ciconst struct exception_table_entry *s390_search_extables(unsigned long addr) 1262306a36Sopenharmony_ci{ 1362306a36Sopenharmony_ci const struct exception_table_entry *fixup; 1462306a36Sopenharmony_ci size_t num; 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci fixup = search_exception_tables(addr); 1762306a36Sopenharmony_ci if (fixup) 1862306a36Sopenharmony_ci return fixup; 1962306a36Sopenharmony_ci num = __stop_amode31_ex_table - __start_amode31_ex_table; 2062306a36Sopenharmony_ci return search_extable(__start_amode31_ex_table, num, addr); 2162306a36Sopenharmony_ci} 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_cistatic bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs) 2462306a36Sopenharmony_ci{ 2562306a36Sopenharmony_ci regs->psw.addr = extable_fixup(ex); 2662306a36Sopenharmony_ci return true; 2762306a36Sopenharmony_ci} 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_cistatic bool ex_handler_ua_store(const struct exception_table_entry *ex, struct pt_regs *regs) 3062306a36Sopenharmony_ci{ 3162306a36Sopenharmony_ci unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data); 3262306a36Sopenharmony_ci 3362306a36Sopenharmony_ci regs->gprs[reg_err] = -EFAULT; 3462306a36Sopenharmony_ci regs->psw.addr = extable_fixup(ex); 3562306a36Sopenharmony_ci return true; 3662306a36Sopenharmony_ci} 3762306a36Sopenharmony_ci 3862306a36Sopenharmony_cistatic bool ex_handler_ua_load_mem(const struct exception_table_entry *ex, struct pt_regs *regs) 3962306a36Sopenharmony_ci{ 4062306a36Sopenharmony_ci unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data); 4162306a36Sopenharmony_ci unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data); 4262306a36Sopenharmony_ci size_t len = FIELD_GET(EX_DATA_LEN, ex->data); 4362306a36Sopenharmony_ci 4462306a36Sopenharmony_ci regs->gprs[reg_err] = -EFAULT; 4562306a36Sopenharmony_ci memset((void *)regs->gprs[reg_addr], 0, len); 4662306a36Sopenharmony_ci regs->psw.addr = extable_fixup(ex); 4762306a36Sopenharmony_ci return true; 4862306a36Sopenharmony_ci} 4962306a36Sopenharmony_ci 5062306a36Sopenharmony_cistatic bool ex_handler_ua_load_reg(const struct exception_table_entry *ex, 5162306a36Sopenharmony_ci bool pair, struct pt_regs *regs) 5262306a36Sopenharmony_ci{ 5362306a36Sopenharmony_ci unsigned int reg_zero = FIELD_GET(EX_DATA_REG_ADDR, ex->data); 5462306a36Sopenharmony_ci unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data); 5562306a36Sopenharmony_ci 5662306a36Sopenharmony_ci regs->gprs[reg_err] = -EFAULT; 5762306a36Sopenharmony_ci regs->gprs[reg_zero] = 0; 5862306a36Sopenharmony_ci if (pair) 5962306a36Sopenharmony_ci regs->gprs[reg_zero + 1] = 0; 6062306a36Sopenharmony_ci regs->psw.addr = extable_fixup(ex); 6162306a36Sopenharmony_ci return true; 6262306a36Sopenharmony_ci} 6362306a36Sopenharmony_ci 6462306a36Sopenharmony_cibool fixup_exception(struct pt_regs *regs) 6562306a36Sopenharmony_ci{ 6662306a36Sopenharmony_ci const struct exception_table_entry *ex; 6762306a36Sopenharmony_ci 6862306a36Sopenharmony_ci ex = s390_search_extables(instruction_pointer(regs)); 6962306a36Sopenharmony_ci if (!ex) 7062306a36Sopenharmony_ci return false; 7162306a36Sopenharmony_ci switch (ex->type) { 7262306a36Sopenharmony_ci case EX_TYPE_FIXUP: 7362306a36Sopenharmony_ci return ex_handler_fixup(ex, regs); 7462306a36Sopenharmony_ci case EX_TYPE_BPF: 7562306a36Sopenharmony_ci return ex_handler_bpf(ex, regs); 7662306a36Sopenharmony_ci case EX_TYPE_UA_STORE: 7762306a36Sopenharmony_ci return ex_handler_ua_store(ex, regs); 7862306a36Sopenharmony_ci case EX_TYPE_UA_LOAD_MEM: 7962306a36Sopenharmony_ci return ex_handler_ua_load_mem(ex, regs); 8062306a36Sopenharmony_ci case EX_TYPE_UA_LOAD_REG: 8162306a36Sopenharmony_ci return ex_handler_ua_load_reg(ex, false, regs); 8262306a36Sopenharmony_ci case EX_TYPE_UA_LOAD_REGPAIR: 8362306a36Sopenharmony_ci return ex_handler_ua_load_reg(ex, true, regs); 8462306a36Sopenharmony_ci } 8562306a36Sopenharmony_ci panic("invalid exception table entry"); 8662306a36Sopenharmony_ci} 87