///////////////////////////////////////////////////////////////////////// // $Id: gdbstub.cc,v 1.40 2009-12-28 20:07:41 sshwarts Exp $ ///////////////////////////////////////////////////////////////////////// // // Copyright (C) 2002-2006 The Bochs Project Team // // 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, write to the Free Software // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA // ///////////////////////////////////////////////////////////////////////// #include #include #include #ifdef __MINGW32__ #include #define SIGTRAP 5 #else #include #include #include #include #include #include #endif #define NEED_CPU_REG_SHORTCUTS 1 #include "bochs.h" #include "cpu/cpu.h" #include "iodev/iodev.h" #define LOG_THIS gdbstublog-> #define IFDBG(x) x static int last_stop_reason = GDBSTUB_STOP_NO_REASON; #define GDBSTUB_EXECUTION_BREAKPOINT (0xac1) #define GDBSTUB_TRACE (0xac2) #define GDBSTUB_USER_BREAK (0xac3) static bx_list_c *gdbstub_list; static int listen_socket_fd; static int socket_fd; static logfunctions *gdbstublog; static int hex(char ch) { if ((ch >= 'a') && (ch <= 'f')) return(ch - 'a' + 10); if ((ch >= '0') && (ch <= '9')) return(ch - '0'); if ((ch >= 'A') && (ch <= 'F')) return(ch - 'A' + 10); return(-1); } static char buf[4096], *bufptr = buf; static void flush_debug_buffer() { char *p = buf; while (p != bufptr) { int n = send(socket_fd, p, bufptr-p, 0); if (n == -1) { BX_ERROR(("error on debug socket: %m")); break; } p += n; } bufptr = buf; } static void put_debug_char(char ch) { if (bufptr == buf + sizeof buf) flush_debug_buffer(); *bufptr++ = ch; } static char get_debug_char(void) { char ch; recv(socket_fd, &ch, 1, 0); return(ch); } static const char hexchars[]="0123456789abcdef"; static void put_reply(const char* buffer) { unsigned char csum; int i; BX_DEBUG(("put_buffer '%s'", buffer)); do { put_debug_char('$'); csum = 0; i = 0; while (buffer[i] != 0) { put_debug_char(buffer[i]); csum = csum + buffer[i]; i++; } put_debug_char('#'); put_debug_char(hexchars[csum >> 4]); put_debug_char(hexchars[csum % 16]); flush_debug_buffer(); } while (get_debug_char() != '+'); } static void get_command(char* buffer) { unsigned char checksum; unsigned char xmitcsum; char ch; unsigned int count; unsigned int i; do { while ((ch = get_debug_char()) != '$'); checksum = 0; xmitcsum = 0; count = 0; while (1) { ch = get_debug_char(); if (ch == '#') break; checksum = checksum + ch; buffer[count] = ch; count++; } buffer[count] = 0; if (ch == '#') { xmitcsum = hex(get_debug_char()) << 4; xmitcsum += hex(get_debug_char()); if (checksum != xmitcsum) { BX_INFO(("Bad checksum")); } } if (checksum != xmitcsum) { put_debug_char('-'); flush_debug_buffer(); } else { put_debug_char('+'); if (buffer[2] == ':') { put_debug_char(buffer[0]); put_debug_char(buffer[1]); count = strlen(buffer); for (i = 3; i <= count; i++) { buffer[i - 3] = buffer[i]; } } flush_debug_buffer(); } } while (checksum != xmitcsum); } void hex2mem(char* buf, unsigned char* mem, int count) { unsigned char ch; for (int i = 0; i> 4]; *buf++ = hexchars[ch % 16]; } *buf = 0; return(buf); } int hexdigit(char c) { if (isdigit(c)) return c - '0'; else if (isupper(c)) return c - 'A' + 10; else return c - 'a' + 10; } Bit64u read_little_endian_hex(char *&buf) { int byte; Bit64u ret = 0; int n = 0; while (isxdigit(*buf)) { byte = hexdigit(*buf++); if (isxdigit(*buf)) byte = (byte << 4) | hexdigit(*buf++); ret |= (Bit64u)byte << (n*8); ++n; } return ret; } static int continue_thread = -1; static int other_thread = 0; #if !BX_SUPPORT_X86_64 #define NUMREGS (16) #define NUMREGSBYTES (NUMREGS * 4) static Bit32u registers[NUMREGS]; #endif #define MAX_BREAKPOINTS (255) static unsigned breakpoints[MAX_BREAKPOINTS] = {0,}; static unsigned nr_breakpoints = 0; static int stub_trace_flag = 0; static int instr_count = 0; static int saved_eip = 0; static int bx_enter_gdbstub = 0; void bx_gdbstub_break(void) { bx_enter_gdbstub = 1; } int bx_gdbstub_check(unsigned int eip) { unsigned int i; unsigned char ch; long arg; int r; #if defined(__CYGWIN__) || defined(__MINGW32__) fd_set fds; struct timeval tv = {0, 0}; #endif if (bx_enter_gdbstub) { bx_enter_gdbstub = 0; last_stop_reason = GDBSTUB_EXECUTION_BREAKPOINT; return GDBSTUB_EXECUTION_BREAKPOINT; } instr_count++; if ((instr_count % 500) == 0) { #if !defined(__CYGWIN__) && !defined(__MINGW32__) arg = fcntl(socket_fd, F_GETFL); fcntl(socket_fd, F_SETFL, arg | O_NONBLOCK); r = recv(socket_fd, &ch, 1, 0); fcntl(socket_fd, F_SETFL, arg); #else FD_ZERO(&fds); FD_SET(socket_fd, &fds); r = select(socket_fd + 1, &fds, NULL, NULL, &tv); if (r == 1) { r = recv(socket_fd, (char *)&ch, 1, 0); } #endif if (r == 1) { BX_INFO(("Got byte %x", (unsigned int)ch)); last_stop_reason = GDBSTUB_USER_BREAK; return GDBSTUB_USER_BREAK; } } for (i = 0; i < nr_breakpoints; i++) { if (eip == breakpoints[i]) { BX_INFO(("found breakpoint at %x", eip)); last_stop_reason = GDBSTUB_EXECUTION_BREAKPOINT; return GDBSTUB_EXECUTION_BREAKPOINT; } } if (stub_trace_flag == 1) { last_stop_reason = GDBSTUB_TRACE; return GDBSTUB_TRACE; } last_stop_reason = GDBSTUB_STOP_NO_REASON; return GDBSTUB_STOP_NO_REASON; } static int remove_breakpoint(unsigned addr, int len) { if (len != 1) { return(0); } for (unsigned i = 0; i < MAX_BREAKPOINTS; i++) { if (breakpoints[i] == addr) { BX_INFO(("Removing breakpoint at %x", addr)); breakpoints[i] = 0; return(1); } } return(0); } static void insert_breakpoint(unsigned addr) { unsigned int i; BX_INFO(("setting breakpoint at %x", addr)); for (i = 0; i < (unsigned)MAX_BREAKPOINTS; i++) { if (breakpoints[i] == 0) { breakpoints[i] = addr; if (i >= nr_breakpoints) { nr_breakpoints = i + 1; } return; } } BX_INFO(("No slot for breakpoint")); } static void do_pc_breakpoint(int insert, Bit64u addr, int len) { for (int i = 0; i < len; ++i) if (insert) insert_breakpoint(addr+i); else remove_breakpoint(addr+i, 1); } static void do_breakpoint(int insert, char* buffer) { char* ebuf; unsigned long type = strtoul(buffer, &ebuf, 16); Bit64u addr = strtoull(ebuf+1, &ebuf, 16); unsigned long len = strtoul(ebuf+1, &ebuf, 16); switch (type) { case 0: case 1: do_pc_breakpoint(insert, addr, len); put_reply("OK"); break; default: put_reply(""); break; } } static void write_signal(char* buf, int signal) { buf[0] = hexchars[signal >> 4]; buf[1] = hexchars[signal % 16]; buf[2] = 0; } static int access_linear(Bit64u laddress, unsigned len, unsigned int rw, Bit8u* data) { bx_phy_address phys; bx_bool valid; if (((laddress & 0xfff) + len) > 4096) { valid = access_linear(laddress, 4096 - (laddress & 0xfff), rw, data); if (!valid) return(0); valid = access_linear(laddress, len + (laddress & 0xfff) - 4096, rw, (Bit8u *)(data + (4096 - (laddress & 0xfff)))); return(valid); } valid = BX_CPU(0)->dbg_xlate_linear2phy(laddress, (bx_phy_address*)&phys); if (!valid) return(0); if (rw & 1) { valid = BX_MEM(0)->dbg_set_mem(phys, len, data); } else { valid = BX_MEM(0)->dbg_fetch_mem(BX_CPU(0), phys, len, data); } return(valid); } static void debug_loop(void) { char buffer[255]; char obuf[1024]; int ne = 0; Bit8u mem[255]; while (ne == 0) { get_command(buffer); BX_DEBUG(("get_buffer '%s'", buffer)); switch (buffer[0]) { case 'c': { char buf[255]; Bit32u new_eip; if (buffer[1] != 0) { new_eip = (Bit32u) atoi(buffer + 1); BX_INFO(("continuing at %x", new_eip)); for (int i=0; iinvalidate_prefetch_q(); } saved_eip = EIP; BX_CPU_THIS_PTR gen_reg[BX_32BIT_REG_EIP].dword.erx = new_eip; } stub_trace_flag = 0; bx_cpu.cpu_loop(0); DEV_vga_refresh(); if (buffer[1] != 0) { bx_cpu.invalidate_prefetch_q(); BX_CPU_THIS_PTR gen_reg[BX_32BIT_REG_EIP].dword.erx = saved_eip; } BX_INFO(("stopped with %x", last_stop_reason)); buf[0] = 'S'; if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT || last_stop_reason == GDBSTUB_TRACE) { write_signal(&buf[1], SIGTRAP); } else { write_signal(&buf[1], 0); } put_reply(buf); break; } case 's': { char buf[255]; BX_INFO(("stepping")); stub_trace_flag = 1; bx_cpu.cpu_loop(0); DEV_vga_refresh(); stub_trace_flag = 0; BX_INFO(("stopped with %x", last_stop_reason)); buf[0] = 'S'; if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT || last_stop_reason == GDBSTUB_TRACE) { write_signal(&buf[1], SIGTRAP); } else { write_signal(&buf[1], SIGTRAP); } put_reply(buf); break; } case 'M': { unsigned char mem[255]; char* ebuf; Bit64u addr = strtoull(&buffer[1], &ebuf, 16); int len = strtoul(ebuf + 1, &ebuf, 16); hex2mem(ebuf + 1, mem, len); if (len == 1 && mem[0] == 0xcc) { insert_breakpoint(addr); put_reply("OK"); } else if (remove_breakpoint(addr, len)) { put_reply("OK"); } else { if (access_linear(addr, len, BX_WRITE, mem)) { put_reply("OK"); } else { put_reply("Eff"); } } break; } case 'm': { Bit64u addr; int len; char* ebuf; addr = strtoull(&buffer[1], &ebuf, 16); len = strtoul(ebuf + 1, NULL, 16); BX_INFO(("addr %Lx len %x", addr, len)); access_linear(addr, len, BX_READ, mem); mem2hex(mem, obuf, len); put_reply(obuf); break; } case 'P': { int reg; Bit64u value; char* ebuf; reg = strtoul(&buffer[1], &ebuf, 16); ++ebuf; value = read_little_endian_hex(ebuf); BX_INFO(("reg %d set to %Lx", reg, value)); #if BX_SUPPORT_X86_64 == 0 switch (reg) { case 0: EAX = value; break; case 1: ECX = value; break; case 2: EBX = value; break; case 3: EDX = value; break; case 4: ESP = value; break; case 5: EBP = value; break; case 6: ESI = value; break; case 7: EDI = value; break; case 8: EIP = value; BX_CPU_THIS_PTR invalidate_prefetch_q(); break; default: break; } #else switch (reg) { case 0: RAX = value; break; case 1: RBX = value; break; case 2: RCX = value; break; case 3: RDX = value; break; case 4: RSP = value; break; case 5: RBP = value; break; case 6: RSI = value; break; case 7: RDI = value; break; case 8: R8 = value; break; case 9: R9 = value; break; case 10: R10 = value; break; case 11: R11 = value; break; case 12: R12 = value; break; case 13: R13 = value; break; case 14: R15 = value; break; case 15: R15 = value; break; case 16: RIP = value; BX_CPU_THIS_PTR invalidate_prefetch_q(); break; default: break; } #endif put_reply("OK"); break; } case 'g': #if BX_SUPPORT_X86_64 == 0 WriteHostDWordToLittleEndian(registers + 0, EAX); WriteHostDWordToLittleEndian(registers + 1, ECX); WriteHostDWordToLittleEndian(registers + 2, EDX); WriteHostDWordToLittleEndian(registers + 3, EBX); WriteHostDWordToLittleEndian(registers + 4, ESP); WriteHostDWordToLittleEndian(registers + 5, EBP); WriteHostDWordToLittleEndian(registers + 6, ESI); WriteHostDWordToLittleEndian(registers + 7, EDI); if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT) { WriteHostDWordToLittleEndian(registers + 8, EIP + 1); } else { WriteHostDWordToLittleEndian(registers + 8, EIP); } WriteHostDWordToLittleEndian(registers + 9, BX_CPU_THIS_PTR read_eflags()); WriteHostDWordToLittleEndian(registers + 10, BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); WriteHostDWordToLittleEndian(registers + 11, BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value); WriteHostDWordToLittleEndian(registers + 12, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value); WriteHostDWordToLittleEndian(registers + 13, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value); WriteHostDWordToLittleEndian(registers + 14, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value); WriteHostDWordToLittleEndian(registers + 15, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value); mem2hex((const Bit8u*) registers, obuf, NUMREGSBYTES); #else #define PUTREG(buf, val, len) do { \ Bit64u u = (val); \ (buf) = mem2hex((const Bit8u*)&u, (buf), (len)); \ } while (0) char* buf = obuf; PUTREG(buf, RAX, 8); PUTREG(buf, RBX, 8); PUTREG(buf, RCX, 8); PUTREG(buf, RDX, 8); PUTREG(buf, RSI, 8); PUTREG(buf, RDI, 8); PUTREG(buf, RBP, 8); PUTREG(buf, RSP, 8); PUTREG(buf, R8, 8); PUTREG(buf, R9, 8); PUTREG(buf, R10, 8); PUTREG(buf, R11, 8); PUTREG(buf, R12, 8); PUTREG(buf, R13, 8); PUTREG(buf, R14, 8); PUTREG(buf, R15, 8); Bit64u rip; rip = RIP; if (last_stop_reason == GDBSTUB_EXECUTION_BREAKPOINT) { ++rip; } PUTREG(buf, rip, 8); PUTREG(buf, BX_CPU_THIS_PTR read_eflags(), 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value, 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value, 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value, 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value, 4); PUTREG(buf, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value, 4); #endif put_reply(obuf); break; case '?': sprintf(obuf, "S%02x", SIGTRAP); put_reply(obuf); break; case 'H': if (buffer[1] == 'c') { continue_thread = strtol(&buffer[2], NULL, 16); put_reply("OK"); } else if (buffer[1] == 'g') { other_thread = strtol(&buffer[2], NULL, 16); put_reply("OK"); } else { put_reply("Eff"); } break; case 'q': if (buffer[1] == 'C') { sprintf(obuf,"%Lx", (Bit64u)1); put_reply(obuf); } else if (strncmp(&buffer[1], "Offsets", strlen("Offsets")) == 0) { sprintf(obuf, "Text=%x;Data=%x;Bss=%x", SIM->get_param_num("text_base", gdbstub_list)->get(), SIM->get_param_num("data_base", gdbstub_list)->get(), SIM->get_param_num("bss_base", gdbstub_list)->get()); put_reply(obuf); } else if (strncmp(&buffer[1], "Supported", strlen("Supported")) == 0) { put_reply(""); } else { put_reply("Eff"); } break; case 'Z': do_breakpoint(1, buffer+1); break; case 'z': do_breakpoint(0, buffer+1); break; case 'k': BX_PANIC(("Debugger asked us to quit")); break; case 'D': BX_INFO(("Debugger detached")); put_reply("OK"); return; break; default: put_reply(""); break; } } } static void wait_for_connect(int portn) { struct sockaddr_in sockaddr; socklen_t sockaddr_len; struct protoent *protoent; int r; int opt; listen_socket_fd = socket(PF_INET, SOCK_STREAM, 0); if (listen_socket_fd == -1) { BX_PANIC(("Failed to create socket")); exit(1); } /* Allow rapid reuse of this port */ opt = 1; #if __MINGW32__ r = setsockopt(listen_socket_fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&opt, sizeof(opt)); #else r = setsockopt(listen_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); #endif if (r == -1) { BX_INFO(("setsockopt(SO_REUSEADDR) failed")); } memset (&sockaddr, '\000', sizeof sockaddr); #if BX_HAVE_SOCKADDR_IN_SIN_LEN // if you don't have sin_len change that to #if 0. This is the subject of // bug [ 626840 ] no 'sin_len' in 'struct sockaddr_in'. sockaddr.sin_len = sizeof sockaddr; #endif sockaddr.sin_family = AF_INET; sockaddr.sin_port = htons(portn); sockaddr.sin_addr.s_addr = htonl(INADDR_ANY); r = bind(listen_socket_fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); if (r == -1) { BX_PANIC(("Failed to bind socket")); } r = listen(listen_socket_fd, 0); if (r == -1) { BX_PANIC(("Failed to listen on socket")); } sockaddr_len = sizeof sockaddr; socket_fd = accept(listen_socket_fd, (struct sockaddr *)&sockaddr, &sockaddr_len); if (socket_fd == -1) { BX_PANIC(("Failed to accept on socket")); } close(listen_socket_fd); protoent = getprotobyname ("tcp"); if (!protoent) { BX_INFO(("getprotobyname (\"tcp\") failed")); return; } /* Disable Nagle - allow small packets to be sent without delay. */ opt = 1; #ifdef __MINGW32__ r = setsockopt (socket_fd, protoent->p_proto, TCP_NODELAY, (const char *)&opt, sizeof(opt)); #else r = setsockopt (socket_fd, protoent->p_proto, TCP_NODELAY, &opt, sizeof(opt)); #endif if (r == -1) { BX_INFO(("setsockopt(TCP_NODELAY) failed")); } Bit32u ip = sockaddr.sin_addr.s_addr; printf("Connected to %d.%d.%d.%d\n", ip & 0xff, (ip >> 8) & 0xff, (ip >> 16) & 0xff, (ip >> 24) & 0xff); } void bx_gdbstub_init(void) { gdbstublog = new logfunctions(); gdbstublog->put("GDBST"); gdbstublog->setonoff(LOGLEV_PANIC, ACT_FATAL); gdbstub_list = (bx_list_c*) SIM->get_param(BXPN_GDBSTUB); int portn = SIM->get_param_num("port", gdbstub_list)->get(); #ifdef __MINGW32__ WSADATA wsaData; WSAStartup(2, &wsaData); #endif /* Wait for connect */ printf("Waiting for gdb connection on port %d\n", portn); wait_for_connect(portn); /* Do debugger command loop */ debug_loop(); /* CPU loop */ bx_cpu.cpu_loop(0); }