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-rw-r--r--arch/mips/kernel/unaligned.c1610
1 files changed, 1610 insertions, 0 deletions
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
new file mode 100644
index 000000000..126a5f3f4
--- /dev/null
+++ b/arch/mips/kernel/unaligned.c
@@ -0,0 +1,1610 @@
+/*
+ * 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.
+ * Copyright (C) 2014 Imagination Technologies Ltd.
+ *
+ * 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/context_tracking.h>
+#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/debug.h>
+#include <asm/fpu.h>
+#include <asm/fpu_emulator.h>
+#include <asm/inst.h>
+#include <asm/unaligned-emul.h>
+#include <asm/mmu_context.h>
+#include <linux/uaccess.h>
+
+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);
+
+static void emulate_load_store_insn(struct pt_regs *regs,
+ void __user *addr, unsigned int __user *pc)
+{
+ unsigned long origpc, orig31, value;
+ union mips_instruction insn;
+ unsigned int res;
+#ifdef CONFIG_EVA
+ mm_segment_t seg;
+#endif
+ 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 spec3_op:
+ if (insn.dsp_format.func == lx_op) {
+ switch (insn.dsp_format.op) {
+ case lwx_op:
+ if (!access_ok(addr, 4))
+ goto sigbus;
+ LoadW(addr, value, res);
+ if (res)
+ goto fault;
+ compute_return_epc(regs);
+ regs->regs[insn.dsp_format.rd] = value;
+ break;
+ case lhx_op:
+ if (!access_ok(addr, 2))
+ goto sigbus;
+ LoadHW(addr, value, res);
+ if (res)
+ goto fault;
+ compute_return_epc(regs);
+ regs->regs[insn.dsp_format.rd] = value;
+ break;
+ default:
+ goto sigill;
+ }
+ }
+#ifdef CONFIG_EVA
+ else {
+ /*
+ * we can land here only from kernel accessing user
+ * memory, so we need to "switch" the address limit to
+ * user space, so that address check can work properly.
+ */
+ seg = force_uaccess_begin();
+ switch (insn.spec3_format.func) {
+ case lhe_op:
+ if (!access_ok(addr, 2)) {
+ force_uaccess_end(seg);
+ goto sigbus;
+ }
+ LoadHWE(addr, value, res);
+ if (res) {
+ force_uaccess_end(seg);
+ goto fault;
+ }
+ compute_return_epc(regs);
+ regs->regs[insn.spec3_format.rt] = value;
+ break;
+ case lwe_op:
+ if (!access_ok(addr, 4)) {
+ force_uaccess_end(seg);
+ goto sigbus;
+ }
+ LoadWE(addr, value, res);
+ if (res) {
+ force_uaccess_end(seg);
+ goto fault;
+ }
+ compute_return_epc(regs);
+ regs->regs[insn.spec3_format.rt] = value;
+ break;
+ case lhue_op:
+ if (!access_ok(addr, 2)) {
+ force_uaccess_end(seg);
+ goto sigbus;
+ }
+ LoadHWUE(addr, value, res);
+ if (res) {
+ force_uaccess_end(seg);
+ goto fault;
+ }
+ compute_return_epc(regs);
+ regs->regs[insn.spec3_format.rt] = value;
+ break;
+ case she_op:
+ if (!access_ok(addr, 2)) {
+ force_uaccess_end(seg);
+ goto sigbus;
+ }
+ compute_return_epc(regs);
+ value = regs->regs[insn.spec3_format.rt];
+ StoreHWE(addr, value, res);
+ if (res) {
+ force_uaccess_end(seg);
+ goto fault;
+ }
+ break;
+ case swe_op:
+ if (!access_ok(addr, 4)) {
+ force_uaccess_end(seg);
+ goto sigbus;
+ }
+ compute_return_epc(regs);
+ value = regs->regs[insn.spec3_format.rt];
+ StoreWE(addr, value, res);
+ if (res) {
+ force_uaccess_end(seg);
+ goto fault;
+ }
+ break;
+ default:
+ force_uaccess_end(seg);
+ goto sigill;
+ }
+ force_uaccess_end(seg);
+ }
+#endif
+ break;
+ case lh_op:
+ if (!access_ok(addr, 2))
+ goto sigbus;
+
+ if (IS_ENABLED(CONFIG_EVA)) {
+ if (uaccess_kernel())
+ LoadHW(addr, value, res);
+ else
+ LoadHWE(addr, value, res);
+ } else {
+ 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(addr, 4))
+ goto sigbus;
+
+ if (IS_ENABLED(CONFIG_EVA)) {
+ if (uaccess_kernel())
+ LoadW(addr, value, res);
+ else
+ LoadWE(addr, value, res);
+ } else {
+ 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(addr, 2))
+ goto sigbus;
+
+ if (IS_ENABLED(CONFIG_EVA)) {
+ if (uaccess_kernel())
+ LoadHWU(addr, value, res);
+ else
+ LoadHWUE(addr, value, res);
+ } else {
+ 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(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(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(addr, 2))
+ goto sigbus;
+
+ compute_return_epc(regs);
+ value = regs->regs[insn.i_format.rt];
+
+ if (IS_ENABLED(CONFIG_EVA)) {
+ if (uaccess_kernel())
+ StoreHW(addr, value, res);
+ else
+ StoreHWE(addr, value, res);
+ } else {
+ StoreHW(addr, value, res);
+ }
+
+ if (res)
+ goto fault;
+ break;
+
+ case sw_op:
+ if (!access_ok(addr, 4))
+ goto sigbus;
+
+ compute_return_epc(regs);
+ value = regs->regs[insn.i_format.rt];
+
+ if (IS_ENABLED(CONFIG_EVA)) {
+ if (uaccess_kernel())
+ StoreW(addr, value, res);
+ else
+ StoreWE(addr, value, res);
+ } else {
+ 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(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;
+
+#ifdef CONFIG_MIPS_FP_SUPPORT
+
+ case lwc1_op:
+ case ldc1_op:
+ case swc1_op:
+ case sdc1_op:
+ case cop1x_op: {
+ void __user *fault_addr = NULL;
+
+ die_if_kernel("Unaligned FP access in kernel code", regs);
+ BUG_ON(!used_math());
+
+ res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
+ &fault_addr);
+ own_fpu(1); /* Restore FPU state. */
+
+ /* Signal if something went wrong. */
+ process_fpemu_return(res, fault_addr, 0);
+
+ if (res == 0)
+ break;
+ return;
+ }
+#endif /* CONFIG_MIPS_FP_SUPPORT */
+
+#ifdef CONFIG_CPU_HAS_MSA
+
+ case msa_op: {
+ unsigned int wd, preempted;
+ enum msa_2b_fmt df;
+ union fpureg *fpr;
+
+ if (!cpu_has_msa)
+ goto sigill;
+
+ /*
+ * If we've reached this point then userland should have taken
+ * the MSA disabled exception & initialised vector context at
+ * some point in the past.
+ */
+ BUG_ON(!thread_msa_context_live());
+
+ df = insn.msa_mi10_format.df;
+ wd = insn.msa_mi10_format.wd;
+ fpr = &current->thread.fpu.fpr[wd];
+
+ switch (insn.msa_mi10_format.func) {
+ case msa_ld_op:
+ if (!access_ok(addr, sizeof(*fpr)))
+ goto sigbus;
+
+ do {
+ /*
+ * If we have live MSA context keep track of
+ * whether we get preempted in order to avoid
+ * the register context we load being clobbered
+ * by the live context as it's saved during
+ * preemption. If we don't have live context
+ * then it can't be saved to clobber the value
+ * we load.
+ */
+ preempted = test_thread_flag(TIF_USEDMSA);
+
+ res = __copy_from_user_inatomic(fpr, addr,
+ sizeof(*fpr));
+ if (res)
+ goto fault;
+
+ /*
+ * Update the hardware register if it is in use
+ * by the task in this quantum, in order to
+ * avoid having to save & restore the whole
+ * vector context.
+ */
+ preempt_disable();
+ if (test_thread_flag(TIF_USEDMSA)) {
+ write_msa_wr(wd, fpr, df);
+ preempted = 0;
+ }
+ preempt_enable();
+ } while (preempted);
+ break;
+
+ case msa_st_op:
+ if (!access_ok(addr, sizeof(*fpr)))
+ goto sigbus;
+
+ /*
+ * Update from the hardware register if it is in use by
+ * the task in this quantum, in order to avoid having to
+ * save & restore the whole vector context.
+ */
+ preempt_disable();
+ if (test_thread_flag(TIF_USEDMSA))
+ read_msa_wr(wd, fpr, df);
+ preempt_enable();
+
+ res = __copy_to_user_inatomic(addr, fpr, sizeof(*fpr));
+ if (res)
+ goto fault;
+ break;
+
+ default:
+ goto sigbus;
+ }
+
+ compute_return_epc(regs);
+ break;
+ }
+#endif /* CONFIG_CPU_HAS_MSA */
+
+#ifndef CONFIG_CPU_MIPSR6
+ /*
+ * 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.
+ *
+ * This instruction has been reallocated in Release 6
+ */
+ 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;
+#endif
+ 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);
+
+ return;
+
+sigbus:
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGBUS);
+
+ return;
+
+sigill:
+ die_if_kernel
+ ("Unhandled kernel unaligned access or invalid instruction", regs);
+ force_sig(SIGILL);
+}
+
+/* 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. */
+static const int reg16to32st[] = { 0, 17, 2, 3, 4, 5, 6, 7 };
+
+static 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;
+
+ 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(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(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(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(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(addr, 4 * (rvar + 1)))
+ goto sigbus;
+ } else {
+ if (!access_ok(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(addr, 4 * (rvar + 1)))
+ goto sigbus;
+ } else {
+ if (!access_ok(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(addr, 8 * (rvar + 1)))
+ goto sigbus;
+ } else {
+ if (!access_ok(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(addr, 8 * (rvar + 1)))
+ goto sigbus;
+ } else {
+ if (!access_ok(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;
+
+#ifdef CONFIG_MIPS_FP_SUPPORT
+ 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: {
+ void __user *fault_addr = NULL;
+
+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());
+
+ res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
+ &fault_addr);
+ own_fpu(1); /* restore FPU state */
+
+ /* If something went wrong, signal */
+ process_fpemu_return(res, fault_addr, 0);
+
+ if (res == 0)
+ goto success;
+ return;
+ }
+#endif /* CONFIG_MIPS_FP_SUPPORT */
+
+ 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(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(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(addr, 2))
+ goto sigbus;
+
+ LoadHW(addr, value, res);
+ if (res)
+ goto fault;
+ regs->regs[reg] = value;
+ goto success;
+
+loadHWU:
+ if (!access_ok(addr, 2))
+ goto sigbus;
+
+ LoadHWU(addr, value, res);
+ if (res)
+ goto fault;
+ regs->regs[reg] = value;
+ goto success;
+
+loadW:
+ if (!access_ok(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(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(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(addr, 2))
+ goto sigbus;
+
+ value = regs->regs[reg];
+ StoreHW(addr, value, res);
+ if (res)
+ goto fault;
+ goto success;
+
+storeW:
+ if (!access_ok(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(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);
+
+ return;
+
+sigbus:
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGBUS);
+
+ return;
+
+sigill:
+ die_if_kernel
+ ("Unhandled kernel unaligned access or invalid instruction", regs);
+ force_sig(SIGILL);
+}
+
+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;
+ unsigned int opcode;
+ int extended = 0;
+
+ 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) {
+ extended = 1;
+ 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;
+ }
+
+ opcode = mips16inst.ri.opcode;
+ switch (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:
+ reg = reg16to32[mips16inst.ri.rx];
+ if (extended && cpu_has_mips16e2)
+ switch (mips16inst.ri.imm >> 5) {
+ case 0: /* SWSP */
+ case 1: /* SWGP */
+ break;
+ case 2: /* SHGP */
+ opcode = MIPS16e_sh_op;
+ break;
+ default:
+ goto sigbus;
+ }
+ break;
+
+ case MIPS16e_lwpc_op:
+ reg = reg16to32[mips16inst.ri.rx];
+ break;
+
+ case MIPS16e_lwsp_op:
+ reg = reg16to32[mips16inst.ri.rx];
+ if (extended && cpu_has_mips16e2)
+ switch (mips16inst.ri.imm >> 5) {
+ case 0: /* LWSP */
+ case 1: /* LWGP */
+ break;
+ case 2: /* LHGP */
+ opcode = MIPS16e_lh_op;
+ break;
+ case 4: /* LHUGP */
+ opcode = MIPS16e_lhu_op;
+ break;
+ default:
+ goto sigbus;
+ }
+ 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 (opcode) {
+
+ case MIPS16e_lb_op:
+ case MIPS16e_lbu_op:
+ case MIPS16e_sb_op:
+ goto sigbus;
+
+ case MIPS16e_lh_op:
+ if (!access_ok(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(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(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(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(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(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(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(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);
+
+ return;
+
+sigbus:
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGBUS);
+
+ return;
+
+sigill:
+ die_if_kernel
+ ("Unhandled kernel unaligned access or invalid instruction", regs);
+ force_sig(SIGILL);
+}
+
+asmlinkage void do_ade(struct pt_regs *regs)
+{
+ enum ctx_state prev_state;
+ unsigned int __user *pc;
+ mm_segment_t seg;
+
+ prev_state = exception_enter();
+ 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);
+
+ /*
+ * XXX On return from the signal handler we should advance the epc
+ */
+ exception_exit(prev_state);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int __init debugfs_unaligned(void)
+{
+ debugfs_create_u32("unaligned_instructions", S_IRUGO, mips_debugfs_dir,
+ &unaligned_instructions);
+ debugfs_create_u32("unaligned_action", S_IRUGO | S_IWUSR,
+ mips_debugfs_dir, &unaligned_action);
+ return 0;
+}
+arch_initcall(debugfs_unaligned);
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 11:35:30 +0000