/* * Handle unaligned accesses by emulation. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1996, 1998, 1999, 2002 by Ralf Baechle * Copyright (C) 1999 Silicon Graphics, Inc. * * This file contains exception handler for address error exception with the * special capability to execute faulting instructions in software. The * handler does not try to handle the case when the program counter points * to an address not aligned to a word boundary. * * Putting data to unaligned addresses is a bad practice even on Intel where * only the performance is affected. Much worse is that such code is non- * portable. Due to several programs that die on MIPS due to alignment * problems I decided to implement this handler anyway though I originally * didn't intend to do this at all for user code. * * For now I enable fixing of address errors by default to make life easier. * I however intend to disable this somewhen in the future when the alignment * problems with user programs have been fixed. For programmers this is the * right way to go. * * Fixing address errors is a per process option. The option is inherited * across fork(2) and execve(2) calls. If you really want to use the * option in your user programs - I discourage the use of the software * emulation strongly - use the following code in your userland stuff: * * #include <sys/sysmips.h> * * ... * sysmips(MIPS_FIXADE, x); * ... * * The argument x is 0 for disabling software emulation, enabled otherwise. * * Below a little program to play around with this feature. * * #include <stdio.h> * #include <sys/sysmips.h> * * struct foo { * unsigned char bar[8]; * }; * * main(int argc, char *argv[]) * { * struct foo x = {0, 1, 2, 3, 4, 5, 6, 7}; * unsigned int *p = (unsigned int *) (x.bar + 3); * int i; * * if (argc > 1) * sysmips(MIPS_FIXADE, atoi(argv[1])); * * printf("*p = %08lx\n", *p); * * *p = 0xdeadface; * * for(i = 0; i <= 7; i++) * printf("%02x ", x.bar[i]); * printf("\n"); * } * * Coprocessor loads are not supported; I think this case is unimportant * in the practice. * * TODO: Handle ndc (attempted store to doubleword in uncached memory) * exception for the R6000. * A store crossing a page boundary might be executed only partially. * Undo the partial store in this case. */ #include <linux/mm.h> #include <linux/signal.h> #include <linux/smp.h> #include <linux/sched.h> #include <linux/debugfs.h> #include <linux/perf_event.h> #include <asm/asm.h> #include <asm/branch.h> #include <asm/byteorder.h> #include <asm/cop2.h> #include <asm/fpu.h> #include <asm/fpu_emulator.h> #include <asm/inst.h> #include <asm/uaccess.h> #include <asm/fpu.h> #include <asm/fpu_emulator.h> #define STR(x) __STR(x) #define __STR(x) #x enum { UNALIGNED_ACTION_QUIET, UNALIGNED_ACTION_SIGNAL, UNALIGNED_ACTION_SHOW, }; #ifdef CONFIG_DEBUG_FS static u32 unaligned_instructions; static u32 unaligned_action; #else #define unaligned_action UNALIGNED_ACTION_QUIET #endif extern void show_registers(struct pt_regs *regs); #ifdef __BIG_ENDIAN #define LoadHW(addr, value, res) \ __asm__ __volatile__ (".set\tnoat\n" \ "1:\tlb\t%0, 0(%2)\n" \ "2:\tlbu\t$1, 1(%2)\n\t" \ "sll\t%0, 0x8\n\t" \ "or\t%0, $1\n\t" \ "li\t%1, 0\n" \ "3:\t.set\tat\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tlwl\t%0, (%2)\n" \ "2:\tlwr\t%0, 3(%2)\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadHWU(addr, value, res) \ __asm__ __volatile__ ( \ ".set\tnoat\n" \ "1:\tlbu\t%0, 0(%2)\n" \ "2:\tlbu\t$1, 1(%2)\n\t" \ "sll\t%0, 0x8\n\t" \ "or\t%0, $1\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".set\tat\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadWU(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tlwl\t%0, (%2)\n" \ "2:\tlwr\t%0, 3(%2)\n\t" \ "dsll\t%0, %0, 32\n\t" \ "dsrl\t%0, %0, 32\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ "\t.section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadDW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tldl\t%0, (%2)\n" \ "2:\tldr\t%0, 7(%2)\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ "\t.section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define StoreHW(addr, value, res) \ __asm__ __volatile__ ( \ ".set\tnoat\n" \ "1:\tsb\t%1, 1(%2)\n\t" \ "srl\t$1, %1, 0x8\n" \ "2:\tsb\t$1, 0(%2)\n\t" \ ".set\tat\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #define StoreW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tswl\t%1,(%2)\n" \ "2:\tswr\t%1, 3(%2)\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #define StoreDW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tsdl\t%1,(%2)\n" \ "2:\tsdr\t%1, 7(%2)\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #endif #ifdef __LITTLE_ENDIAN #define LoadHW(addr, value, res) \ __asm__ __volatile__ (".set\tnoat\n" \ "1:\tlb\t%0, 1(%2)\n" \ "2:\tlbu\t$1, 0(%2)\n\t" \ "sll\t%0, 0x8\n\t" \ "or\t%0, $1\n\t" \ "li\t%1, 0\n" \ "3:\t.set\tat\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tlwl\t%0, 3(%2)\n" \ "2:\tlwr\t%0, (%2)\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadHWU(addr, value, res) \ __asm__ __volatile__ ( \ ".set\tnoat\n" \ "1:\tlbu\t%0, 1(%2)\n" \ "2:\tlbu\t$1, 0(%2)\n\t" \ "sll\t%0, 0x8\n\t" \ "or\t%0, $1\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".set\tat\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadWU(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tlwl\t%0, 3(%2)\n" \ "2:\tlwr\t%0, (%2)\n\t" \ "dsll\t%0, %0, 32\n\t" \ "dsrl\t%0, %0, 32\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ "\t.section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define LoadDW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tldl\t%0, 7(%2)\n" \ "2:\tldr\t%0, (%2)\n\t" \ "li\t%1, 0\n" \ "3:\n\t" \ ".insn\n\t" \ "\t.section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%1, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=&r" (value), "=r" (res) \ : "r" (addr), "i" (-EFAULT)); #define StoreHW(addr, value, res) \ __asm__ __volatile__ ( \ ".set\tnoat\n" \ "1:\tsb\t%1, 0(%2)\n\t" \ "srl\t$1,%1, 0x8\n" \ "2:\tsb\t$1, 1(%2)\n\t" \ ".set\tat\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #define StoreW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tswl\t%1, 3(%2)\n" \ "2:\tswr\t%1, (%2)\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #define StoreDW(addr, value, res) \ __asm__ __volatile__ ( \ "1:\tsdl\t%1, 7(%2)\n" \ "2:\tsdr\t%1, (%2)\n\t" \ "li\t%0, 0\n" \ "3:\n\t" \ ".insn\n\t" \ ".section\t.fixup,\"ax\"\n\t" \ "4:\tli\t%0, %3\n\t" \ "j\t3b\n\t" \ ".previous\n\t" \ ".section\t__ex_table,\"a\"\n\t" \ STR(PTR)"\t1b, 4b\n\t" \ STR(PTR)"\t2b, 4b\n\t" \ ".previous" \ : "=r" (res) \ : "r" (value), "r" (addr), "i" (-EFAULT)); #endif static void emulate_load_store_insn(struct pt_regs *regs, void __user *addr, unsigned int __user *pc) { union mips_instruction insn; unsigned long value; unsigned int res; unsigned long origpc; unsigned long orig31; void __user *fault_addr = NULL; origpc = (unsigned long)pc; orig31 = regs->regs[31]; perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); /* * This load never faults. */ __get_user(insn.word, pc); switch (insn.i_format.opcode) { /* * These are instructions that a compiler doesn't generate. We * can assume therefore that the code is MIPS-aware and * really buggy. Emulating these instructions would break the * semantics anyway. */ case ll_op: case lld_op: case sc_op: case scd_op: /* * For these instructions the only way to create an address * error is an attempted access to kernel/supervisor address * space. */ case ldl_op: case ldr_op: case lwl_op: case lwr_op: case sdl_op: case sdr_op: case swl_op: case swr_op: case lb_op: case lbu_op: case sb_op: goto sigbus; /* * The remaining opcodes are the ones that are really of * interest. */ case lh_op: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHW(addr, value, res); if (res) goto fault; compute_return_epc(regs); regs->regs[insn.i_format.rt] = value; break; case lw_op: if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadW(addr, value, res); if (res) goto fault; compute_return_epc(regs); regs->regs[insn.i_format.rt] = value; break; case lhu_op: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHWU(addr, value, res); if (res) goto fault; compute_return_epc(regs); regs->regs[insn.i_format.rt] = value; break; case lwu_op: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadWU(addr, value, res); if (res) goto fault; compute_return_epc(regs); regs->regs[insn.i_format.rt] = value; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; case ld_op: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 8)) goto sigbus; LoadDW(addr, value, res); if (res) goto fault; compute_return_epc(regs); regs->regs[insn.i_format.rt] = value; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; case sh_op: if (!access_ok(VERIFY_WRITE, addr, 2)) goto sigbus; compute_return_epc(regs); value = regs->regs[insn.i_format.rt]; StoreHW(addr, value, res); if (res) goto fault; break; case sw_op: if (!access_ok(VERIFY_WRITE, addr, 4)) goto sigbus; compute_return_epc(regs); value = regs->regs[insn.i_format.rt]; StoreW(addr, value, res); if (res) goto fault; break; case sd_op: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_WRITE, addr, 8)) goto sigbus; compute_return_epc(regs); value = regs->regs[insn.i_format.rt]; StoreDW(addr, value, res); if (res) goto fault; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; case lwc1_op: case ldc1_op: case swc1_op: case sdc1_op: die_if_kernel("Unaligned FP access in kernel code", regs); BUG_ON(!used_math()); BUG_ON(!is_fpu_owner()); lose_fpu(1); /* Save FPU state for the emulator. */ res = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, &fault_addr); own_fpu(1); /* Restore FPU state. */ /* Signal if something went wrong. */ process_fpemu_return(res, fault_addr); if (res == 0) break; return; /* * COP2 is available to implementor for application specific use. * It's up to applications to register a notifier chain and do * whatever they have to do, including possible sending of signals. */ case lwc2_op: cu2_notifier_call_chain(CU2_LWC2_OP, regs); break; case ldc2_op: cu2_notifier_call_chain(CU2_LDC2_OP, regs); break; case swc2_op: cu2_notifier_call_chain(CU2_SWC2_OP, regs); break; case sdc2_op: cu2_notifier_call_chain(CU2_SDC2_OP, regs); break; default: /* * Pheeee... We encountered an yet unknown instruction or * cache coherence problem. Die sucker, die ... */ goto sigill; } #ifdef CONFIG_DEBUG_FS unaligned_instructions++; #endif return; fault: /* roll back jump/branch */ regs->cp0_epc = origpc; regs->regs[31] = orig31; /* Did we have an exception handler installed? */ if (fixup_exception(regs)) return; die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGSEGV, current); return; sigbus: die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGBUS, current); return; sigill: die_if_kernel ("Unhandled kernel unaligned access or invalid instruction", regs); force_sig(SIGILL, current); } /* Recode table from 16-bit register notation to 32-bit GPR. */ const int reg16to32[] = { 16, 17, 2, 3, 4, 5, 6, 7 }; /* Recode table from 16-bit STORE register notation to 32-bit GPR. */ const int reg16to32st[] = { 0, 17, 2, 3, 4, 5, 6, 7 }; void emulate_load_store_microMIPS(struct pt_regs *regs, void __user * addr) { unsigned long value; unsigned int res; int i; unsigned int reg = 0, rvar; unsigned long orig31; u16 __user *pc16; u16 halfword; unsigned int word; unsigned long origpc, contpc; union mips_instruction insn; struct mm_decoded_insn mminsn; void __user *fault_addr = NULL; origpc = regs->cp0_epc; orig31 = regs->regs[31]; mminsn.micro_mips_mode = 1; /* * This load never faults. */ pc16 = (unsigned short __user *)msk_isa16_mode(regs->cp0_epc); __get_user(halfword, pc16); pc16++; contpc = regs->cp0_epc + 2; word = ((unsigned int)halfword << 16); mminsn.pc_inc = 2; if (!mm_insn_16bit(halfword)) { __get_user(halfword, pc16); pc16++; contpc = regs->cp0_epc + 4; mminsn.pc_inc = 4; word |= halfword; } mminsn.insn = word; if (get_user(halfword, pc16)) goto fault; mminsn.next_pc_inc = 2; word = ((unsigned int)halfword << 16); if (!mm_insn_16bit(halfword)) { pc16++; if (get_user(halfword, pc16)) goto fault; mminsn.next_pc_inc = 4; word |= halfword; } mminsn.next_insn = word; insn = (union mips_instruction)(mminsn.insn); if (mm_isBranchInstr(regs, mminsn, &contpc)) insn = (union mips_instruction)(mminsn.next_insn); /* Parse instruction to find what to do */ switch (insn.mm_i_format.opcode) { case mm_pool32a_op: switch (insn.mm_x_format.func) { case mm_lwxs_op: reg = insn.mm_x_format.rd; goto loadW; } goto sigbus; case mm_pool32b_op: switch (insn.mm_m_format.func) { case mm_lwp_func: reg = insn.mm_m_format.rd; if (reg == 31) goto sigbus; if (!access_ok(VERIFY_READ, addr, 8)) goto sigbus; LoadW(addr, value, res); if (res) goto fault; regs->regs[reg] = value; addr += 4; LoadW(addr, value, res); if (res) goto fault; regs->regs[reg + 1] = value; goto success; case mm_swp_func: reg = insn.mm_m_format.rd; if (reg == 31) goto sigbus; if (!access_ok(VERIFY_WRITE, addr, 8)) goto sigbus; value = regs->regs[reg]; StoreW(addr, value, res); if (res) goto fault; addr += 4; value = regs->regs[reg + 1]; StoreW(addr, value, res); if (res) goto fault; goto success; case mm_ldp_func: #ifdef CONFIG_64BIT reg = insn.mm_m_format.rd; if (reg == 31) goto sigbus; if (!access_ok(VERIFY_READ, addr, 16)) goto sigbus; LoadDW(addr, value, res); if (res) goto fault; regs->regs[reg] = value; addr += 8; LoadDW(addr, value, res); if (res) goto fault; regs->regs[reg + 1] = value; goto success; #endif /* CONFIG_64BIT */ goto sigill; case mm_sdp_func: #ifdef CONFIG_64BIT reg = insn.mm_m_format.rd; if (reg == 31) goto sigbus; if (!access_ok(VERIFY_WRITE, addr, 16)) goto sigbus; value = regs->regs[reg]; StoreDW(addr, value, res); if (res) goto fault; addr += 8; value = regs->regs[reg + 1]; StoreDW(addr, value, res); if (res) goto fault; goto success; #endif /* CONFIG_64BIT */ goto sigill; case mm_lwm32_func: reg = insn.mm_m_format.rd; rvar = reg & 0xf; if ((rvar > 9) || !reg) goto sigill; if (reg & 0x10) { if (!access_ok (VERIFY_READ, addr, 4 * (rvar + 1))) goto sigbus; } else { if (!access_ok(VERIFY_READ, addr, 4 * rvar)) goto sigbus; } if (rvar == 9) rvar = 8; for (i = 16; rvar; rvar--, i++) { LoadW(addr, value, res); if (res) goto fault; addr += 4; regs->regs[i] = value; } if ((reg & 0xf) == 9) { LoadW(addr, value, res); if (res) goto fault; addr += 4; regs->regs[30] = value; } if (reg & 0x10) { LoadW(addr, value, res); if (res) goto fault; regs->regs[31] = value; } goto success; case mm_swm32_func: reg = insn.mm_m_format.rd; rvar = reg & 0xf; if ((rvar > 9) || !reg) goto sigill; if (reg & 0x10) { if (!access_ok (VERIFY_WRITE, addr, 4 * (rvar + 1))) goto sigbus; } else { if (!access_ok(VERIFY_WRITE, addr, 4 * rvar)) goto sigbus; } if (rvar == 9) rvar = 8; for (i = 16; rvar; rvar--, i++) { value = regs->regs[i]; StoreW(addr, value, res); if (res) goto fault; addr += 4; } if ((reg & 0xf) == 9) { value = regs->regs[30]; StoreW(addr, value, res); if (res) goto fault; addr += 4; } if (reg & 0x10) { value = regs->regs[31]; StoreW(addr, value, res); if (res) goto fault; } goto success; case mm_ldm_func: #ifdef CONFIG_64BIT reg = insn.mm_m_format.rd; rvar = reg & 0xf; if ((rvar > 9) || !reg) goto sigill; if (reg & 0x10) { if (!access_ok (VERIFY_READ, addr, 8 * (rvar + 1))) goto sigbus; } else { if (!access_ok(VERIFY_READ, addr, 8 * rvar)) goto sigbus; } if (rvar == 9) rvar = 8; for (i = 16; rvar; rvar--, i++) { LoadDW(addr, value, res); if (res) goto fault; addr += 4; regs->regs[i] = value; } if ((reg & 0xf) == 9) { LoadDW(addr, value, res); if (res) goto fault; addr += 8; regs->regs[30] = value; } if (reg & 0x10) { LoadDW(addr, value, res); if (res) goto fault; regs->regs[31] = value; } goto success; #endif /* CONFIG_64BIT */ goto sigill; case mm_sdm_func: #ifdef CONFIG_64BIT reg = insn.mm_m_format.rd; rvar = reg & 0xf; if ((rvar > 9) || !reg) goto sigill; if (reg & 0x10) { if (!access_ok (VERIFY_WRITE, addr, 8 * (rvar + 1))) goto sigbus; } else { if (!access_ok(VERIFY_WRITE, addr, 8 * rvar)) goto sigbus; } if (rvar == 9) rvar = 8; for (i = 16; rvar; rvar--, i++) { value = regs->regs[i]; StoreDW(addr, value, res); if (res) goto fault; addr += 8; } if ((reg & 0xf) == 9) { value = regs->regs[30]; StoreDW(addr, value, res); if (res) goto fault; addr += 8; } if (reg & 0x10) { value = regs->regs[31]; StoreDW(addr, value, res); if (res) goto fault; } goto success; #endif /* CONFIG_64BIT */ goto sigill; /* LWC2, SWC2, LDC2, SDC2 are not serviced */ } goto sigbus; case mm_pool32c_op: switch (insn.mm_m_format.func) { case mm_lwu_func: reg = insn.mm_m_format.rd; goto loadWU; } /* LL,SC,LLD,SCD are not serviced */ goto sigbus; case mm_pool32f_op: switch (insn.mm_x_format.func) { case mm_lwxc1_func: case mm_swxc1_func: case mm_ldxc1_func: case mm_sdxc1_func: goto fpu_emul; } goto sigbus; case mm_ldc132_op: case mm_sdc132_op: case mm_lwc132_op: case mm_swc132_op: fpu_emul: /* roll back jump/branch */ regs->cp0_epc = origpc; regs->regs[31] = orig31; die_if_kernel("Unaligned FP access in kernel code", regs); BUG_ON(!used_math()); BUG_ON(!is_fpu_owner()); lose_fpu(1); /* save the FPU state for the emulator */ res = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, &fault_addr); own_fpu(1); /* restore FPU state */ /* If something went wrong, signal */ process_fpemu_return(res, fault_addr); if (res == 0) goto success; return; case mm_lh32_op: reg = insn.mm_i_format.rt; goto loadHW; case mm_lhu32_op: reg = insn.mm_i_format.rt; goto loadHWU; case mm_lw32_op: reg = insn.mm_i_format.rt; goto loadW; case mm_sh32_op: reg = insn.mm_i_format.rt; goto storeHW; case mm_sw32_op: reg = insn.mm_i_format.rt; goto storeW; case mm_ld32_op: reg = insn.mm_i_format.rt; goto loadDW; case mm_sd32_op: reg = insn.mm_i_format.rt; goto storeDW; case mm_pool16c_op: switch (insn.mm16_m_format.func) { case mm_lwm16_op: reg = insn.mm16_m_format.rlist; rvar = reg + 1; if (!access_ok(VERIFY_READ, addr, 4 * rvar)) goto sigbus; for (i = 16; rvar; rvar--, i++) { LoadW(addr, value, res); if (res) goto fault; addr += 4; regs->regs[i] = value; } LoadW(addr, value, res); if (res) goto fault; regs->regs[31] = value; goto success; case mm_swm16_op: reg = insn.mm16_m_format.rlist; rvar = reg + 1; if (!access_ok(VERIFY_WRITE, addr, 4 * rvar)) goto sigbus; for (i = 16; rvar; rvar--, i++) { value = regs->regs[i]; StoreW(addr, value, res); if (res) goto fault; addr += 4; } value = regs->regs[31]; StoreW(addr, value, res); if (res) goto fault; goto success; } goto sigbus; case mm_lhu16_op: reg = reg16to32[insn.mm16_rb_format.rt]; goto loadHWU; case mm_lw16_op: reg = reg16to32[insn.mm16_rb_format.rt]; goto loadW; case mm_sh16_op: reg = reg16to32st[insn.mm16_rb_format.rt]; goto storeHW; case mm_sw16_op: reg = reg16to32st[insn.mm16_rb_format.rt]; goto storeW; case mm_lwsp16_op: reg = insn.mm16_r5_format.rt; goto loadW; case mm_swsp16_op: reg = insn.mm16_r5_format.rt; goto storeW; case mm_lwgp16_op: reg = reg16to32[insn.mm16_r3_format.rt]; goto loadW; default: goto sigill; } loadHW: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHW(addr, value, res); if (res) goto fault; regs->regs[reg] = value; goto success; loadHWU: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHWU(addr, value, res); if (res) goto fault; regs->regs[reg] = value; goto success; loadW: if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadW(addr, value, res); if (res) goto fault; regs->regs[reg] = value; goto success; loadWU: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadWU(addr, value, res); if (res) goto fault; regs->regs[reg] = value; goto success; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; loadDW: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 8)) goto sigbus; LoadDW(addr, value, res); if (res) goto fault; regs->regs[reg] = value; goto success; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; storeHW: if (!access_ok(VERIFY_WRITE, addr, 2)) goto sigbus; value = regs->regs[reg]; StoreHW(addr, value, res); if (res) goto fault; goto success; storeW: if (!access_ok(VERIFY_WRITE, addr, 4)) goto sigbus; value = regs->regs[reg]; StoreW(addr, value, res); if (res) goto fault; goto success; storeDW: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_WRITE, addr, 8)) goto sigbus; value = regs->regs[reg]; StoreDW(addr, value, res); if (res) goto fault; goto success; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; success: regs->cp0_epc = contpc; /* advance or branch */ #ifdef CONFIG_DEBUG_FS unaligned_instructions++; #endif return; fault: /* roll back jump/branch */ regs->cp0_epc = origpc; regs->regs[31] = orig31; /* Did we have an exception handler installed? */ if (fixup_exception(regs)) return; die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGSEGV, current); return; sigbus: die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGBUS, current); return; sigill: die_if_kernel ("Unhandled kernel unaligned access or invalid instruction", regs); force_sig(SIGILL, current); } static void emulate_load_store_MIPS16e(struct pt_regs *regs, void __user * addr) { unsigned long value; unsigned int res; int reg; unsigned long orig31; u16 __user *pc16; unsigned long origpc; union mips16e_instruction mips16inst, oldinst; origpc = regs->cp0_epc; orig31 = regs->regs[31]; pc16 = (unsigned short __user *)msk_isa16_mode(origpc); /* * This load never faults. */ __get_user(mips16inst.full, pc16); oldinst = mips16inst; /* skip EXTEND instruction */ if (mips16inst.ri.opcode == MIPS16e_extend_op) { pc16++; __get_user(mips16inst.full, pc16); } else if (delay_slot(regs)) { /* skip jump instructions */ /* JAL/JALX are 32 bits but have OPCODE in first short int */ if (mips16inst.ri.opcode == MIPS16e_jal_op) pc16++; pc16++; if (get_user(mips16inst.full, pc16)) goto sigbus; } switch (mips16inst.ri.opcode) { case MIPS16e_i64_op: /* I64 or RI64 instruction */ switch (mips16inst.i64.func) { /* I64/RI64 func field check */ case MIPS16e_ldpc_func: case MIPS16e_ldsp_func: reg = reg16to32[mips16inst.ri64.ry]; goto loadDW; case MIPS16e_sdsp_func: reg = reg16to32[mips16inst.ri64.ry]; goto writeDW; case MIPS16e_sdrasp_func: reg = 29; /* GPRSP */ goto writeDW; } goto sigbus; case MIPS16e_swsp_op: case MIPS16e_lwpc_op: case MIPS16e_lwsp_op: reg = reg16to32[mips16inst.ri.rx]; break; case MIPS16e_i8_op: if (mips16inst.i8.func != MIPS16e_swrasp_func) goto sigbus; reg = 29; /* GPRSP */ break; default: reg = reg16to32[mips16inst.rri.ry]; break; } switch (mips16inst.ri.opcode) { case MIPS16e_lb_op: case MIPS16e_lbu_op: case MIPS16e_sb_op: goto sigbus; case MIPS16e_lh_op: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHW(addr, value, res); if (res) goto fault; MIPS16e_compute_return_epc(regs, &oldinst); regs->regs[reg] = value; break; case MIPS16e_lhu_op: if (!access_ok(VERIFY_READ, addr, 2)) goto sigbus; LoadHWU(addr, value, res); if (res) goto fault; MIPS16e_compute_return_epc(regs, &oldinst); regs->regs[reg] = value; break; case MIPS16e_lw_op: case MIPS16e_lwpc_op: case MIPS16e_lwsp_op: if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadW(addr, value, res); if (res) goto fault; MIPS16e_compute_return_epc(regs, &oldinst); regs->regs[reg] = value; break; case MIPS16e_lwu_op: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 4)) goto sigbus; LoadWU(addr, value, res); if (res) goto fault; MIPS16e_compute_return_epc(regs, &oldinst); regs->regs[reg] = value; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; case MIPS16e_ld_op: loadDW: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_READ, addr, 8)) goto sigbus; LoadDW(addr, value, res); if (res) goto fault; MIPS16e_compute_return_epc(regs, &oldinst); regs->regs[reg] = value; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; case MIPS16e_sh_op: if (!access_ok(VERIFY_WRITE, addr, 2)) goto sigbus; MIPS16e_compute_return_epc(regs, &oldinst); value = regs->regs[reg]; StoreHW(addr, value, res); if (res) goto fault; break; case MIPS16e_sw_op: case MIPS16e_swsp_op: case MIPS16e_i8_op: /* actually - MIPS16e_swrasp_func */ if (!access_ok(VERIFY_WRITE, addr, 4)) goto sigbus; MIPS16e_compute_return_epc(regs, &oldinst); value = regs->regs[reg]; StoreW(addr, value, res); if (res) goto fault; break; case MIPS16e_sd_op: writeDW: #ifdef CONFIG_64BIT /* * A 32-bit kernel might be running on a 64-bit processor. But * if we're on a 32-bit processor and an i-cache incoherency * or race makes us see a 64-bit instruction here the sdl/sdr * would blow up, so for now we don't handle unaligned 64-bit * instructions on 32-bit kernels. */ if (!access_ok(VERIFY_WRITE, addr, 8)) goto sigbus; MIPS16e_compute_return_epc(regs, &oldinst); value = regs->regs[reg]; StoreDW(addr, value, res); if (res) goto fault; break; #endif /* CONFIG_64BIT */ /* Cannot handle 64-bit instructions in 32-bit kernel */ goto sigill; default: /* * Pheeee... We encountered an yet unknown instruction or * cache coherence problem. Die sucker, die ... */ goto sigill; } #ifdef CONFIG_DEBUG_FS unaligned_instructions++; #endif return; fault: /* roll back jump/branch */ regs->cp0_epc = origpc; regs->regs[31] = orig31; /* Did we have an exception handler installed? */ if (fixup_exception(regs)) return; die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGSEGV, current); return; sigbus: die_if_kernel("Unhandled kernel unaligned access", regs); force_sig(SIGBUS, current); return; sigill: die_if_kernel ("Unhandled kernel unaligned access or invalid instruction", regs); force_sig(SIGILL, current); } asmlinkage void do_ade(struct pt_regs *regs) { unsigned int __user *pc; mm_segment_t seg; perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->cp0_badvaddr); /* * Did we catch a fault trying to load an instruction? */ if (regs->cp0_badvaddr == regs->cp0_epc) goto sigbus; if (user_mode(regs) && !test_thread_flag(TIF_FIXADE)) goto sigbus; if (unaligned_action == UNALIGNED_ACTION_SIGNAL) goto sigbus; /* * Do branch emulation only if we didn't forward the exception. * This is all so but ugly ... */ /* * Are we running in microMIPS mode? */ if (get_isa16_mode(regs->cp0_epc)) { /* * Did we catch a fault trying to load an instruction in * 16-bit mode? */ if (regs->cp0_badvaddr == msk_isa16_mode(regs->cp0_epc)) goto sigbus; if (unaligned_action == UNALIGNED_ACTION_SHOW) show_registers(regs); if (cpu_has_mmips) { seg = get_fs(); if (!user_mode(regs)) set_fs(KERNEL_DS); emulate_load_store_microMIPS(regs, (void __user *)regs->cp0_badvaddr); set_fs(seg); return; } if (cpu_has_mips16) { seg = get_fs(); if (!user_mode(regs)) set_fs(KERNEL_DS); emulate_load_store_MIPS16e(regs, (void __user *)regs->cp0_badvaddr); set_fs(seg); return; } goto sigbus; } if (unaligned_action == UNALIGNED_ACTION_SHOW) show_registers(regs); pc = (unsigned int __user *)exception_epc(regs); seg = get_fs(); if (!user_mode(regs)) set_fs(KERNEL_DS); emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc); set_fs(seg); return; sigbus: die_if_kernel("Kernel unaligned instruction access", regs); force_sig(SIGBUS, current); /* * XXX On return from the signal handler we should advance the epc */ } #ifdef CONFIG_DEBUG_FS extern struct dentry *mips_debugfs_dir; static int __init debugfs_unaligned(void) { struct dentry *d; if (!mips_debugfs_dir) return -ENODEV; d = debugfs_create_u32("unaligned_instructions", S_IRUGO, mips_debugfs_dir, &unaligned_instructions); if (!d) return -ENOMEM; d = debugfs_create_u32("unaligned_action", S_IRUGO | S_IWUSR, mips_debugfs_dir, &unaligned_action); if (!d) return -ENOMEM; return 0; } __initcall(debugfs_unaligned); #endif