diff options
Diffstat (limited to 'linux-user/arm/cpu_loop.c')
| -rw-r--r-- | linux-user/arm/cpu_loop.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index b7700a5561..d911929bf6 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -19,8 +19,438 @@ #include "qemu/osdep.h" #include "qemu.h" +#include "elf.h" #include "cpu_loop-common.h" +#define get_user_code_u32(x, gaddr, env) \ + ({ abi_long __r = get_user_u32((x), (gaddr)); \ + if (!__r && bswap_code(arm_sctlr_b(env))) { \ + (x) = bswap32(x); \ + } \ + __r; \ + }) + +#define get_user_code_u16(x, gaddr, env) \ + ({ abi_long __r = get_user_u16((x), (gaddr)); \ + if (!__r && bswap_code(arm_sctlr_b(env))) { \ + (x) = bswap16(x); \ + } \ + __r; \ + }) + +#define get_user_data_u32(x, gaddr, env) \ + ({ abi_long __r = get_user_u32((x), (gaddr)); \ + if (!__r && arm_cpu_bswap_data(env)) { \ + (x) = bswap32(x); \ + } \ + __r; \ + }) + +#define get_user_data_u16(x, gaddr, env) \ + ({ abi_long __r = get_user_u16((x), (gaddr)); \ + if (!__r && arm_cpu_bswap_data(env)) { \ + (x) = bswap16(x); \ + } \ + __r; \ + }) + +#define put_user_data_u32(x, gaddr, env) \ + ({ typeof(x) __x = (x); \ + if (arm_cpu_bswap_data(env)) { \ + __x = bswap32(__x); \ + } \ + put_user_u32(__x, (gaddr)); \ + }) + +#define put_user_data_u16(x, gaddr, env) \ + ({ typeof(x) __x = (x); \ + if (arm_cpu_bswap_data(env)) { \ + __x = bswap16(__x); \ + } \ + put_user_u16(__x, (gaddr)); \ + }) + +/* Commpage handling -- there is no commpage for AArch64 */ + +/* + * See the Linux kernel's Documentation/arm/kernel_user_helpers.txt + * Input: + * r0 = pointer to oldval + * r1 = pointer to newval + * r2 = pointer to target value + * + * Output: + * r0 = 0 if *ptr was changed, non-0 if no exchange happened + * C set if *ptr was changed, clear if no exchange happened + * + * Note segv's in kernel helpers are a bit tricky, we can set the + * data address sensibly but the PC address is just the entry point. + */ +static void arm_kernel_cmpxchg64_helper(CPUARMState *env) +{ + uint64_t oldval, newval, val; + uint32_t addr, cpsr; + target_siginfo_t info; + + /* Based on the 32 bit code in do_kernel_trap */ + + /* XXX: This only works between threads, not between processes. + It's probably possible to implement this with native host + operations. However things like ldrex/strex are much harder so + there's not much point trying. */ + start_exclusive(); + cpsr = cpsr_read(env); + addr = env->regs[2]; + + if (get_user_u64(oldval, env->regs[0])) { + env->exception.vaddress = env->regs[0]; + goto segv; + }; + + if (get_user_u64(newval, env->regs[1])) { + env->exception.vaddress = env->regs[1]; + goto segv; + }; + + if (get_user_u64(val, addr)) { + env->exception.vaddress = addr; + goto segv; + } + + if (val == oldval) { + val = newval; + + if (put_user_u64(val, addr)) { + env->exception.vaddress = addr; + goto segv; + }; + + env->regs[0] = 0; + cpsr |= CPSR_C; + } else { + env->regs[0] = -1; + cpsr &= ~CPSR_C; + } + cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr); + end_exclusive(); + return; + +segv: + end_exclusive(); + /* We get the PC of the entry address - which is as good as anything, + on a real kernel what you get depends on which mode it uses. */ + info.si_signo = TARGET_SIGSEGV; + info.si_errno = 0; + /* XXX: check env->error_code */ + info.si_code = TARGET_SEGV_MAPERR; + info._sifields._sigfault._addr = env->exception.vaddress; + queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); +} + +/* Handle a jump to the kernel code page. */ +static int +do_kernel_trap(CPUARMState *env) +{ + uint32_t addr; + uint32_t cpsr; + uint32_t val; + + switch (env->regs[15]) { + case 0xffff0fa0: /* __kernel_memory_barrier */ + /* ??? No-op. Will need to do better for SMP. */ + break; + case 0xffff0fc0: /* __kernel_cmpxchg */ + /* XXX: This only works between threads, not between processes. + It's probably possible to implement this with native host + operations. However things like ldrex/strex are much harder so + there's not much point trying. */ + start_exclusive(); + cpsr = cpsr_read(env); + addr = env->regs[2]; + /* FIXME: This should SEGV if the access fails. */ + if (get_user_u32(val, addr)) + val = ~env->regs[0]; + if (val == env->regs[0]) { + val = env->regs[1]; + /* FIXME: Check for segfaults. */ + put_user_u32(val, addr); + env->regs[0] = 0; + cpsr |= CPSR_C; + } else { + env->regs[0] = -1; + cpsr &= ~CPSR_C; + } + cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr); + end_exclusive(); + break; + case 0xffff0fe0: /* __kernel_get_tls */ + env->regs[0] = cpu_get_tls(env); + break; + case 0xffff0f60: /* __kernel_cmpxchg64 */ + arm_kernel_cmpxchg64_helper(env); + break; + + default: + return 1; + } + /* Jump back to the caller. */ + addr = env->regs[14]; + if (addr & 1) { + env->thumb = 1; + addr &= ~1; + } + env->regs[15] = addr; + + return 0; +} + +void cpu_loop(CPUARMState *env) +{ + CPUState *cs = CPU(arm_env_get_cpu(env)); + int trapnr; + unsigned int n, insn; + target_siginfo_t info; + uint32_t addr; + abi_ulong ret; + + for(;;) { + cpu_exec_start(cs); + trapnr = cpu_exec(cs); + cpu_exec_end(cs); + process_queued_cpu_work(cs); + + switch(trapnr) { + case EXCP_UDEF: + case EXCP_NOCP: + case EXCP_INVSTATE: + { + TaskState *ts = cs->opaque; + uint32_t opcode; + int rc; + + /* we handle the FPU emulation here, as Linux */ + /* we get the opcode */ + /* FIXME - what to do if get_user() fails? */ + get_user_code_u32(opcode, env->regs[15], env); + + rc = EmulateAll(opcode, &ts->fpa, env); + if (rc == 0) { /* illegal instruction */ + info.si_signo = TARGET_SIGILL; + info.si_errno = 0; + info.si_code = TARGET_ILL_ILLOPN; + info._sifields._sigfault._addr = env->regs[15]; + queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + } else if (rc < 0) { /* FP exception */ + int arm_fpe=0; + + /* translate softfloat flags to FPSR flags */ + if (-rc & float_flag_invalid) + arm_fpe |= BIT_IOC; + if (-rc & float_flag_divbyzero) + arm_fpe |= BIT_DZC; + if (-rc & float_flag_overflow) + arm_fpe |= BIT_OFC; + if (-rc & float_flag_underflow) + arm_fpe |= BIT_UFC; + if (-rc & float_flag_inexact) + arm_fpe |= BIT_IXC; + + FPSR fpsr = ts->fpa.fpsr; + //printf("fpsr 0x%x, arm_fpe 0x%x\n",fpsr,arm_fpe); + + if (fpsr & (arm_fpe << 16)) { /* exception enabled? */ + info.si_signo = TARGET_SIGFPE; + info.si_errno = 0; + + /* ordered by priority, least first */ + if (arm_fpe & BIT_IXC) info.si_code = TARGET_FPE_FLTRES; + if (arm_fpe & BIT_UFC) info.si_code = TARGET_FPE_FLTUND; + if (arm_fpe & BIT_OFC) info.si_code = TARGET_FPE_FLTOVF; + if (arm_fpe & BIT_DZC) info.si_code = TARGET_FPE_FLTDIV; + if (arm_fpe & BIT_IOC) info.si_code = TARGET_FPE_FLTINV; + + info._sifields._sigfault._addr = env->regs[15]; + queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + } else { + env->regs[15] += 4; + } + + /* accumulate unenabled exceptions */ + if ((!(fpsr & BIT_IXE)) && (arm_fpe & BIT_IXC)) + fpsr |= BIT_IXC; + if ((!(fpsr & BIT_UFE)) && (arm_fpe & BIT_UFC)) + fpsr |= BIT_UFC; + if ((!(fpsr & BIT_OFE)) && (arm_fpe & BIT_OFC)) + fpsr |= BIT_OFC; + if ((!(fpsr & BIT_DZE)) && (arm_fpe & BIT_DZC)) + fpsr |= BIT_DZC; + if ((!(fpsr & BIT_IOE)) && (arm_fpe & BIT_IOC)) + fpsr |= BIT_IOC; + ts->fpa.fpsr=fpsr; + } else { /* everything OK */ + /* increment PC */ + env->regs[15] += 4; + } + } + break; + case EXCP_SWI: + case EXCP_BKPT: + { + env->eabi = 1; + /* system call */ + if (trapnr == EXCP_BKPT) { + if (env->thumb) { + /* FIXME - what to do if get_user() fails? */ + get_user_code_u16(insn, env->regs[15], env); + n = insn & 0xff; + env->regs[15] += 2; + } else { + /* FIXME - what to do if get_user() fails? */ + get_user_code_u32(insn, env->regs[15], env); + n = (insn & 0xf) | ((insn >> 4) & 0xff0); + env->regs[15] += 4; + } + } else { + if (env->thumb) { + /* FIXME - what to do if get_user() fails? */ + get_user_code_u16(insn, env->regs[15] - 2, env); + n = insn & 0xff; + } else { + /* FIXME - what to do if get_user() fails? */ + get_user_code_u32(insn, env->regs[15] - 4, env); + n = insn & 0xffffff; + } + } + + if (n == ARM_NR_cacheflush) { + /* nop */ + } else if (n == ARM_NR_semihosting + || n == ARM_NR_thumb_semihosting) { + env->regs[0] = do_arm_semihosting (env); + } else if (n == 0 || n >= ARM_SYSCALL_BASE || env->thumb) { + /* linux syscall */ + if (env->thumb || n == 0) { + n = env->regs[7]; + } else { + n -= ARM_SYSCALL_BASE; + env->eabi = 0; + } + if ( n > ARM_NR_BASE) { + switch (n) { + case ARM_NR_cacheflush: + /* nop */ + break; + case ARM_NR_set_tls: + cpu_set_tls(env, env->regs[0]); + env->regs[0] = 0; + break; + case ARM_NR_breakpoint: + env->regs[15] -= env->thumb ? 2 : 4; + goto excp_debug; + default: + gemu_log("qemu: Unsupported ARM syscall: 0x%x\n", + n); + env->regs[0] = -TARGET_ENOSYS; + break; + } + } else { + ret = do_syscall(env, + n, + env->regs[0], + env->regs[1], + env->regs[2], + env->regs[3], + env->regs[4], + env->regs[5], + 0, 0); + if (ret == -TARGET_ERESTARTSYS) { + env->regs[15] -= env->thumb ? 2 : 4; + } else if (ret != -TARGET_QEMU_ESIGRETURN) { + env->regs[0] = ret; + } + } + } else { + goto error; + } + } + break; + case EXCP_SEMIHOST: + env->regs[0] = do_arm_semihosting(env); + break; + case EXCP_INTERRUPT: + /* just indicate that signals should be handled asap */ + break; + case EXCP_PREFETCH_ABORT: + case EXCP_DATA_ABORT: + addr = env->exception.vaddress; + { + info.si_signo = TARGET_SIGSEGV; + info.si_errno = 0; + /* XXX: check env->error_code */ + info.si_code = TARGET_SEGV_MAPERR; + info._sifields._sigfault._addr = addr; + queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + } + break; + case EXCP_DEBUG: + excp_debug: + { + int sig; + + sig = gdb_handlesig(cs, TARGET_SIGTRAP); + if (sig) + { + info.si_signo = sig; + info.si_errno = 0; + info.si_code = TARGET_TRAP_BRKPT; + queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + } + } + break; + case EXCP_KERNEL_TRAP: + if (do_kernel_trap(env)) + goto error; + break; + case EXCP_YIELD: + /* nothing to do here for user-mode, just resume guest code */ + break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; + default: + error: + EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr); + abort(); + } + process_pending_signals(env); + } +} + void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs) { + CPUState *cpu = ENV_GET_CPU(env); + TaskState *ts = cpu->opaque; + struct image_info *info = ts->info; + int i; + + cpsr_write(env, regs->uregs[16], CPSR_USER | CPSR_EXEC, + CPSRWriteByInstr); + for(i = 0; i < 16; i++) { + env->regs[i] = regs->uregs[i]; + } +#ifdef TARGET_WORDS_BIGENDIAN + /* Enable BE8. */ + if (EF_ARM_EABI_VERSION(info->elf_flags) >= EF_ARM_EABI_VER4 + && (info->elf_flags & EF_ARM_BE8)) { + env->uncached_cpsr |= CPSR_E; + env->cp15.sctlr_el[1] |= SCTLR_E0E; + } else { + env->cp15.sctlr_el[1] |= SCTLR_B; + } +#endif + + ts->stack_base = info->start_stack; + ts->heap_base = info->brk; + /* This will be filled in on the first SYS_HEAPINFO call. */ + ts->heap_limit = 0; } |