--- qemu/linux-user/vm86.c 2018/04/24 16:41:13 1.1.1.2 +++ qemu/linux-user/vm86.c 2018/04/24 16:51:56 1.1.1.4 @@ -1,6 +1,6 @@ /* * vm86 linux syscall support - * + * * Copyright (c) 2003 Fabrice Bellard * * This program is free software; you can redistribute it and/or modify @@ -15,7 +15,8 @@ * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, + * MA 02110-1301, USA. */ #include #include @@ -28,6 +29,13 @@ //#define DEBUG_VM86 +#ifdef DEBUG_VM86 +# define LOG_VM86(...) qemu_log(__VA_ARGS__); +#else +# define LOG_VM86(...) do { } while (0) +#endif + + #define set_flags(X,new,mask) \ ((X) = ((X) & ~(mask)) | ((new) & (mask))) @@ -39,22 +47,27 @@ static inline int is_revectored(int nr, return (((uint8_t *)bitmap)[nr >> 3] >> (nr & 7)) & 1; } -static inline void vm_putw(uint8_t *segptr, unsigned int reg16, unsigned int val) +static inline void vm_putw(uint32_t segptr, unsigned int reg16, unsigned int val) { stw(segptr + (reg16 & 0xffff), val); } -static inline void vm_putl(uint8_t *segptr, unsigned int reg16, unsigned int val) +static inline void vm_putl(uint32_t segptr, unsigned int reg16, unsigned int val) { stl(segptr + (reg16 & 0xffff), val); } -static inline unsigned int vm_getw(uint8_t *segptr, unsigned int reg16) +static inline unsigned int vm_getb(uint32_t segptr, unsigned int reg16) +{ + return ldub(segptr + (reg16 & 0xffff)); +} + +static inline unsigned int vm_getw(uint32_t segptr, unsigned int reg16) { return lduw(segptr + (reg16 & 0xffff)); } -static inline unsigned int vm_getl(uint8_t *segptr, unsigned int reg16) +static inline unsigned int vm_getl(uint32_t segptr, unsigned int reg16) { return ldl(segptr + (reg16 & 0xffff)); } @@ -64,7 +77,9 @@ void save_v86_state(CPUX86State *env) TaskState *ts = env->opaque; struct target_vm86plus_struct * target_v86; - lock_user_struct(target_v86, ts->target_v86, 0); + if (!lock_user_struct(VERIFY_WRITE, target_v86, ts->target_v86, 0)) + /* FIXME - should return an error */ + return; /* put the VM86 registers in the userspace register structure */ target_v86->regs.eax = tswap32(env->regs[R_EAX]); target_v86->regs.ebx = tswap32(env->regs[R_EBX]); @@ -84,10 +99,8 @@ void save_v86_state(CPUX86State *env) set_flags(env->eflags, ts->v86flags, VIF_MASK | ts->v86mask); target_v86->regs.eflags = tswap32(env->eflags); unlock_user_struct(target_v86, ts->target_v86, 1); -#ifdef DEBUG_VM86 - fprintf(logfile, "save_v86_state: eflags=%08x cs:ip=%04x:%04x\n", - env->eflags, env->segs[R_CS].selector, env->eip); -#endif + LOG_VM86("save_v86_state: eflags=%08x cs:ip=%04x:%04x\n", + env->eflags, env->segs[R_CS].selector, env->eip); /* restore 32 bit registers */ env->regs[R_EAX] = ts->vm86_saved_regs.eax; @@ -113,9 +126,7 @@ void save_v86_state(CPUX86State *env) 'retval' */ static inline void return_to_32bit(CPUX86State *env, int retval) { -#ifdef DEBUG_VM86 - fprintf(logfile, "return_to_32bit: ret=0x%x\n", retval); -#endif + LOG_VM86("return_to_32bit: ret=0x%x\n", retval); save_v86_state(env); env->regs[R_EAX] = retval; } @@ -123,7 +134,7 @@ static inline void return_to_32bit(CPUX8 static inline int set_IF(CPUX86State *env) { TaskState *ts = env->opaque; - + ts->v86flags |= VIF_MASK; if (ts->v86flags & VIP_MASK) { return_to_32bit(env, TARGET_VM86_STI); @@ -194,27 +205,24 @@ static inline unsigned int get_vflags(CP static void do_int(CPUX86State *env, int intno) { TaskState *ts = env->opaque; - uint32_t *int_ptr, segoffs; - uint8_t *ssp; + uint32_t int_addr, segoffs, ssp; unsigned int sp; if (env->segs[R_CS].selector == TARGET_BIOSSEG) goto cannot_handle; if (is_revectored(intno, &ts->vm86plus.int_revectored)) goto cannot_handle; - if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff, + if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff, &ts->vm86plus.int21_revectored)) goto cannot_handle; - int_ptr = (uint32_t *)(intno << 2); - segoffs = tswap32(*int_ptr); + int_addr = (intno << 2); + segoffs = ldl(int_addr); if ((segoffs >> 16) == TARGET_BIOSSEG) goto cannot_handle; -#if defined(DEBUG_VM86) - fprintf(logfile, "VM86: emulating int 0x%x. CS:IP=%04x:%04x\n", - intno, segoffs >> 16, segoffs & 0xffff); -#endif + LOG_VM86("VM86: emulating int 0x%x. CS:IP=%04x:%04x\n", + intno, segoffs >> 16, segoffs & 0xffff); /* save old state */ - ssp = (uint8_t *)(env->segs[R_SS].selector << 4); + ssp = env->segs[R_SS].selector << 4; sp = env->regs[R_ESP] & 0xffff; vm_putw(ssp, sp - 2, get_vflags(env)); vm_putw(ssp, sp - 4, env->segs[R_CS].selector); @@ -228,9 +236,7 @@ static void do_int(CPUX86State *env, int clear_AC(env); return; cannot_handle: -#if defined(DEBUG_VM86) - fprintf(logfile, "VM86: return to 32 bits int 0x%x\n", intno); -#endif + LOG_VM86("VM86: return to 32 bits int 0x%x\n", intno); return_to_32bit(env, TARGET_VM86_INTx | (intno << 8)); } @@ -257,26 +263,23 @@ void handle_vm86_trap(CPUX86State *env, void handle_vm86_fault(CPUX86State *env) { TaskState *ts = env->opaque; - uint8_t *csp, *pc, *ssp; + uint32_t csp, ssp; unsigned int ip, sp, newflags, newip, newcs, opcode, intno; int data32, pref_done; - csp = (uint8_t *)(env->segs[R_CS].selector << 4); + csp = env->segs[R_CS].selector << 4; ip = env->eip & 0xffff; - pc = csp + ip; - - ssp = (uint8_t *)(env->segs[R_SS].selector << 4); + + ssp = env->segs[R_SS].selector << 4; sp = env->regs[R_ESP] & 0xffff; -#if defined(DEBUG_VM86) - fprintf(logfile, "VM86 exception %04x:%08x %02x %02x\n", - env->segs[R_CS].selector, env->eip, pc[0], pc[1]); -#endif + LOG_VM86("VM86 exception %04x:%08x\n", + env->segs[R_CS].selector, env->eip); data32 = 0; pref_done = 0; do { - opcode = csp[ip]; + opcode = vm_getb(csp, ip); ADD16(ip, 1); switch (opcode) { case 0x66: /* 32-bit data */ data32=1; break; @@ -326,11 +329,11 @@ void handle_vm86_fault(CPUX86State *env) VM86_FAULT_RETURN; case 0xcd: /* int */ - intno = csp[ip]; + intno = vm_getb(csp, ip); ADD16(ip, 1); env->eip = ip; if (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) { - if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >> + if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >> (intno &7)) & 1) { return_to_32bit(env, TARGET_VM86_INTx + (intno << 8)); return; @@ -362,12 +365,12 @@ void handle_vm86_fault(CPUX86State *env) return; } VM86_FAULT_RETURN; - + case 0xfa: /* cli */ env->eip = ip; clear_IF(env); VM86_FAULT_RETURN; - + case 0xfb: /* sti */ env->eip = ip; if (set_IF(env)) @@ -381,19 +384,19 @@ void handle_vm86_fault(CPUX86State *env) } } -int do_vm86(CPUX86State *env, long subfunction, target_ulong vm86_addr) +int do_vm86(CPUX86State *env, long subfunction, abi_ulong vm86_addr) { TaskState *ts = env->opaque; struct target_vm86plus_struct * target_v86; int ret; - + switch (subfunction) { case TARGET_VM86_REQUEST_IRQ: case TARGET_VM86_FREE_IRQ: case TARGET_VM86_GET_IRQ_BITS: case TARGET_VM86_GET_AND_RESET_IRQ: gemu_log("qemu: unsupported vm86 subfunction (%ld)\n", subfunction); - ret = -EINVAL; + ret = -TARGET_EINVAL; goto out; case TARGET_VM86_PLUS_INSTALL_CHECK: /* NOTE: on old vm86 stuff this will return the error @@ -424,10 +427,11 @@ int do_vm86(CPUX86State *env, long subfu ts->vm86_saved_regs.gs = env->segs[R_GS].selector; ts->target_v86 = vm86_addr; - lock_user_struct(target_v86, vm86_addr, 1); + if (!lock_user_struct(VERIFY_READ, target_v86, vm86_addr, 1)) + return -TARGET_EFAULT; /* build vm86 CPU state */ ts->v86flags = tswap32(target_v86->regs.eflags); - env->eflags = (env->eflags & ~SAFE_MASK) | + env->eflags = (env->eflags & ~SAFE_MASK) | (tswap32(target_v86->regs.eflags) & SAFE_MASK) | VM_MASK; ts->vm86plus.cpu_type = tswapl(target_v86->cpu_type); @@ -462,21 +466,18 @@ int do_vm86(CPUX86State *env, long subfu cpu_x86_load_seg(env, R_GS, tswap16(target_v86->regs.gs)); ret = tswap32(target_v86->regs.eax); /* eax will be restored at the end of the syscall */ - memcpy(&ts->vm86plus.int_revectored, + memcpy(&ts->vm86plus.int_revectored, &target_v86->int_revectored, 32); - memcpy(&ts->vm86plus.int21_revectored, + memcpy(&ts->vm86plus.int21_revectored, &target_v86->int21_revectored, 32); ts->vm86plus.vm86plus.flags = tswapl(target_v86->vm86plus.flags); - memcpy(&ts->vm86plus.vm86plus.vm86dbg_intxxtab, + memcpy(&ts->vm86plus.vm86plus.vm86dbg_intxxtab, target_v86->vm86plus.vm86dbg_intxxtab, 32); unlock_user_struct(target_v86, vm86_addr, 0); - -#ifdef DEBUG_VM86 - fprintf(logfile, "do_vm86: cs:ip=%04x:%04x\n", - env->segs[R_CS].selector, env->eip); -#endif + + LOG_VM86("do_vm86: cs:ip=%04x:%04x\n", + env->segs[R_CS].selector, env->eip); /* now the virtual CPU is ready for vm86 execution ! */ out: return ret; } -