/* * User emulator execution * * Copyright (c) 2003-2005 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. */ #include "qemu/osdep.h" #include "cpu.h" #include "disas/disas.h" #include "exec/exec-all.h" #include "tcg.h" #include "qemu/bitops.h" #include "exec/cpu_ldst.h" #include "translate-all.h" #undef EAX #undef ECX #undef EDX #undef EBX #undef ESP #undef EBP #undef ESI #undef EDI #undef EIP #ifdef __linux__ #include <sys/ucontext.h> #endif //#define DEBUG_SIGNAL /* exit the current TB from a signal handler. The host registers are restored in a state compatible with the CPU emulator */ static void cpu_exit_tb_from_sighandler(CPUState *cpu, sigset_t *old_set) { /* XXX: use siglongjmp ? */ sigprocmask(SIG_SETMASK, old_set, NULL); cpu_loop_exit_noexc(cpu); } /* 'pc' is the host PC at which the exception was raised. 'address' is the effective address of the memory exception. 'is_write' is 1 if a write caused the exception and otherwise 0'. 'old_set' is the signal set which should be restored */ static inline int handle_cpu_signal(uintptr_t pc, unsigned long address, int is_write, sigset_t *old_set) { CPUState *cpu = current_cpu; CPUClass *cc; int ret; /* For synchronous signals we expect to be coming from the vCPU * thread (so current_cpu should be valid) and either from running * code or during translation which can fault as we cross pages. * * If neither is true then something has gone wrong and we should * abort rather than try and restart the vCPU execution. */ if (!cpu || !cpu->running) { printf("qemu:%s received signal outside vCPU context @ pc=0x%" PRIxPTR "\n", __func__, pc); abort(); } #if defined(DEBUG_SIGNAL) printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n", pc, address, is_write, *(unsigned long *)old_set); #endif /* XXX: locking issue */ if (is_write && h2g_valid(address)) { switch (page_unprotect(h2g(address), pc)) { case 0: /* Fault not caused by a page marked unwritable to protect * cached translations, must be the guest binary's problem */ break; case 1: /* Fault caused by protection of cached translation; TBs * invalidated, so resume execution */ return 1; case 2: /* Fault caused by protection of cached translation, and the * currently executing TB was modified and must be exited * immediately. */ cpu_exit_tb_from_sighandler(cpu, old_set); g_assert_not_reached(); default: g_assert_not_reached(); } } /* Convert forcefully to guest address space, invalid addresses are still valid segv ones */ address = h2g_nocheck(address); cc = CPU_GET_CLASS(cpu); /* see if it is an MMU fault */ g_assert(cc->handle_mmu_fault); ret = cc->handle_mmu_fault(cpu, address, is_write, MMU_USER_IDX); if (ret < 0) { return 0; /* not an MMU fault */ } if (ret == 0) { return 1; /* the MMU fault was handled without causing real CPU fault */ } /* Now we have a real cpu fault. Since this is the exact location of * the exception, we must undo the adjustment done by cpu_restore_state * for handling call return addresses. */ cpu_restore_state(cpu, pc + GETPC_ADJ); sigprocmask(SIG_SETMASK, old_set, NULL); cpu_loop_exit(cpu); /* never comes here */ return 1; } #if defined(__i386__) #if defined(__NetBSD__) #include <ucontext.h> #define EIP_sig(context) ((context)->uc_mcontext.__gregs[_REG_EIP]) #define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO]) #define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR]) #define MASK_sig(context) ((context)->uc_sigmask) #elif defined(__FreeBSD__) || defined(__DragonFly__) #include <ucontext.h> #define EIP_sig(context) (*((unsigned long *)&(context)->uc_mcontext.mc_eip)) #define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno) #define ERROR_sig(context) ((context)->uc_mcontext.mc_err) #define MASK_sig(context) ((context)->uc_sigmask) #elif defined(__OpenBSD__) #define EIP_sig(context) ((context)->sc_eip) #define TRAP_sig(context) ((context)->sc_trapno) #define ERROR_sig(context) ((context)->sc_err) #define MASK_sig(context) ((context)->sc_mask) #else #define EIP_sig(context) ((context)->uc_mcontext.gregs[REG_EIP]) #define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO]) #define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR]) #define MASK_sig(context) ((context)->uc_sigmask) #endif int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) ucontext_t *uc = puc; #elif defined(__OpenBSD__) struct sigcontext *uc = puc; #else ucontext_t *uc = puc; #endif unsigned long pc; int trapno; #ifndef REG_EIP /* for glibc 2.1 */ #define REG_EIP EIP #define REG_ERR ERR #define REG_TRAPNO TRAPNO #endif pc = EIP_sig(uc); trapno = TRAP_sig(uc); return handle_cpu_signal(pc, (unsigned long)info->si_addr, trapno == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0, &MASK_sig(uc)); } #elif defined(__x86_64__) #ifdef __NetBSD__ #define PC_sig(context) _UC_MACHINE_PC(context) #define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO]) #define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR]) #define MASK_sig(context) ((context)->uc_sigmask) #elif defined(__OpenBSD__) #define PC_sig(context) ((context)->sc_rip) #define TRAP_sig(context) ((context)->sc_trapno) #define ERROR_sig(context) ((context)->sc_err) #define MASK_sig(context) ((context)->sc_mask) #elif defined(__FreeBSD__) || defined(__DragonFly__) #include <ucontext.h> #define PC_sig(context) (*((unsigned long *)&(context)->uc_mcontext.mc_rip)) #define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno) #define ERROR_sig(context) ((context)->uc_mcontext.mc_err) #define MASK_sig(context) ((context)->uc_sigmask) #else #define PC_sig(context) ((context)->uc_mcontext.gregs[REG_RIP]) #define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO]) #define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR]) #define MASK_sig(context) ((context)->uc_sigmask) #endif int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; unsigned long pc; #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) ucontext_t *uc = puc; #elif defined(__OpenBSD__) struct sigcontext *uc = puc; #else ucontext_t *uc = puc; #endif pc = PC_sig(uc); return handle_cpu_signal(pc, (unsigned long)info->si_addr, TRAP_sig(uc) == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0, &MASK_sig(uc)); } #elif defined(_ARCH_PPC) /*********************************************************************** * signal context platform-specific definitions * From Wine */ #ifdef linux /* All Registers access - only for local access */ #define REG_sig(reg_name, context) \ ((context)->uc_mcontext.regs->reg_name) /* Gpr Registers access */ #define GPR_sig(reg_num, context) REG_sig(gpr[reg_num], context) /* Program counter */ #define IAR_sig(context) REG_sig(nip, context) /* Machine State Register (Supervisor) */ #define MSR_sig(context) REG_sig(msr, context) /* Count register */ #define CTR_sig(context) REG_sig(ctr, context) /* User's integer exception register */ #define XER_sig(context) REG_sig(xer, context) /* Link register */ #define LR_sig(context) REG_sig(link, context) /* Condition register */ #define CR_sig(context) REG_sig(ccr, context) /* Float Registers access */ #define FLOAT_sig(reg_num, context) \ (((double *)((char *)((context)->uc_mcontext.regs + 48 * 4)))[reg_num]) #define FPSCR_sig(context) \ (*(int *)((char *)((context)->uc_mcontext.regs + (48 + 32 * 2) * 4))) /* Exception Registers access */ #define DAR_sig(context) REG_sig(dar, context) #define DSISR_sig(context) REG_sig(dsisr, context) #define TRAP_sig(context) REG_sig(trap, context) #endif /* linux */ #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) #include <ucontext.h> #define IAR_sig(context) ((context)->uc_mcontext.mc_srr0) #define MSR_sig(context) ((context)->uc_mcontext.mc_srr1) #define CTR_sig(context) ((context)->uc_mcontext.mc_ctr) #define XER_sig(context) ((context)->uc_mcontext.mc_xer) #define LR_sig(context) ((context)->uc_mcontext.mc_lr) #define CR_sig(context) ((context)->uc_mcontext.mc_cr) /* Exception Registers access */ #define DAR_sig(context) ((context)->uc_mcontext.mc_dar) #define DSISR_sig(context) ((context)->uc_mcontext.mc_dsisr) #define TRAP_sig(context) ((context)->uc_mcontext.mc_exc) #endif /* __FreeBSD__|| __FreeBSD_kernel__ */ int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) ucontext_t *uc = puc; #else ucontext_t *uc = puc; #endif unsigned long pc; int is_write; pc = IAR_sig(uc); is_write = 0; #if 0 /* ppc 4xx case */ if (DSISR_sig(uc) & 0x00800000) { is_write = 1; } #else if (TRAP_sig(uc) != 0x400 && (DSISR_sig(uc) & 0x02000000)) { is_write = 1; } #endif return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, &uc->uc_sigmask); } #elif defined(__alpha__) int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; uint32_t *pc = uc->uc_mcontext.sc_pc; uint32_t insn = *pc; int is_write = 0; /* XXX: need kernel patch to get write flag faster */ switch (insn >> 26) { case 0x0d: /* stw */ case 0x0e: /* stb */ case 0x0f: /* stq_u */ case 0x24: /* stf */ case 0x25: /* stg */ case 0x26: /* sts */ case 0x27: /* stt */ case 0x2c: /* stl */ case 0x2d: /* stq */ case 0x2e: /* stl_c */ case 0x2f: /* stq_c */ is_write = 1; } return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, &uc->uc_sigmask); } #elif defined(__sparc__) int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; int is_write; uint32_t insn; #if !defined(__arch64__) || defined(CONFIG_SOLARIS) uint32_t *regs = (uint32_t *)(info + 1); void *sigmask = (regs + 20); /* XXX: is there a standard glibc define ? */ unsigned long pc = regs[1]; #else #ifdef __linux__ struct sigcontext *sc = puc; unsigned long pc = sc->sigc_regs.tpc; void *sigmask = (void *)sc->sigc_mask; #elif defined(__OpenBSD__) struct sigcontext *uc = puc; unsigned long pc = uc->sc_pc; void *sigmask = (void *)(long)uc->sc_mask; #elif defined(__NetBSD__) ucontext_t *uc = puc; unsigned long pc = _UC_MACHINE_PC(uc); void *sigmask = (void *)&uc->uc_sigmask; #endif #endif /* XXX: need kernel patch to get write flag faster */ is_write = 0; insn = *(uint32_t *)pc; if ((insn >> 30) == 3) { switch ((insn >> 19) & 0x3f) { case 0x05: /* stb */ case 0x15: /* stba */ case 0x06: /* sth */ case 0x16: /* stha */ case 0x04: /* st */ case 0x14: /* sta */ case 0x07: /* std */ case 0x17: /* stda */ case 0x0e: /* stx */ case 0x1e: /* stxa */ case 0x24: /* stf */ case 0x34: /* stfa */ case 0x27: /* stdf */ case 0x37: /* stdfa */ case 0x26: /* stqf */ case 0x36: /* stqfa */ case 0x25: /* stfsr */ case 0x3c: /* casa */ case 0x3e: /* casxa */ is_write = 1; break; } } return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, sigmask); } #elif defined(__arm__) #if defined(__NetBSD__) #include <ucontext.h> #endif int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; #if defined(__NetBSD__) ucontext_t *uc = puc; #else ucontext_t *uc = puc; #endif unsigned long pc; int is_write; #if defined(__NetBSD__) pc = uc->uc_mcontext.__gregs[_REG_R15]; #elif defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3)) pc = uc->uc_mcontext.gregs[R15]; #else pc = uc->uc_mcontext.arm_pc; #endif /* error_code is the FSR value, in which bit 11 is WnR (assuming a v6 or * later processor; on v5 we will always report this as a read). */ is_write = extract32(uc->uc_mcontext.error_code, 11, 1); return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, &uc->uc_sigmask); } #elif defined(__aarch64__) int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; uintptr_t pc = uc->uc_mcontext.pc; uint32_t insn = *(uint32_t *)pc; bool is_write; /* XXX: need kernel patch to get write flag faster. */ is_write = ( (insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */ || (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */ || (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */ || (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */ || (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */ || (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */ || (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */ /* Ingore bits 10, 11 & 21, controlling indexing. */ || (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */ || (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */ /* Ignore bits 23 & 24, controlling indexing. */ || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */ return handle_cpu_signal(pc, (uintptr_t)info->si_addr, is_write, &uc->uc_sigmask); } #elif defined(__ia64) #ifndef __ISR_VALID /* This ought to be in <bits/siginfo.h>... */ # define __ISR_VALID 1 #endif int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; unsigned long ip; int is_write = 0; ip = uc->uc_mcontext.sc_ip; switch (host_signum) { case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGTRAP: if (info->si_code && (info->si_segvflags & __ISR_VALID)) { /* ISR.W (write-access) is bit 33: */ is_write = (info->si_isr >> 33) & 1; } break; default: break; } return handle_cpu_signal(ip, (unsigned long)info->si_addr, is_write, (sigset_t *)&uc->uc_sigmask); } #elif defined(__s390__) int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; unsigned long pc; uint16_t *pinsn; int is_write = 0; pc = uc->uc_mcontext.psw.addr; /* ??? On linux, the non-rt signal handler has 4 (!) arguments instead of the normal 2 arguments. The 3rd argument contains the "int_code" from the hardware which does in fact contain the is_write value. The rt signal handler, as far as I can tell, does not give this value at all. Not that we could get to it from here even if it were. */ /* ??? This is not even close to complete, since it ignores all of the read-modify-write instructions. */ pinsn = (uint16_t *)pc; switch (pinsn[0] >> 8) { case 0x50: /* ST */ case 0x42: /* STC */ case 0x40: /* STH */ is_write = 1; break; case 0xc4: /* RIL format insns */ switch (pinsn[0] & 0xf) { case 0xf: /* STRL */ case 0xb: /* STGRL */ case 0x7: /* STHRL */ is_write = 1; } break; case 0xe3: /* RXY format insns */ switch (pinsn[2] & 0xff) { case 0x50: /* STY */ case 0x24: /* STG */ case 0x72: /* STCY */ case 0x70: /* STHY */ case 0x8e: /* STPQ */ case 0x3f: /* STRVH */ case 0x3e: /* STRV */ case 0x2f: /* STRVG */ is_write = 1; } break; } return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, &uc->uc_sigmask); } #elif defined(__mips__) int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; greg_t pc = uc->uc_mcontext.pc; int is_write; /* XXX: compute is_write */ is_write = 0; return handle_cpu_signal(pc, (unsigned long)info->si_addr, is_write, &uc->uc_sigmask); } #else #error host CPU specific signal handler needed #endif