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- /*
- * Kernel Debug Core
- *
- * Maintainer: Jason Wessel <jason.wessel@windriver.com>
- *
- * Copyright (C) 2000-2001 VERITAS Software Corporation.
- * Copyright (C) 2002-2004 Timesys Corporation
- * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
- * Copyright (C) 2004 Pavel Machek <pavel@ucw.cz>
- * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
- * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
- * Copyright (C) 2005-2009 Wind River Systems, Inc.
- * Copyright (C) 2007 MontaVista Software, Inc.
- * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- *
- * Contributors at various stages not listed above:
- * Jason Wessel ( jason.wessel@windriver.com )
- * George Anzinger <george@mvista.com>
- * Anurekh Saxena (anurekh.saxena@timesys.com)
- * Lake Stevens Instrument Division (Glenn Engel)
- * Jim Kingdon, Cygnus Support.
- *
- * Original KGDB stub: David Grothe <dave@gcom.com>,
- * Tigran Aivazian <tigran@sco.com>
- *
- * This file is licensed under the terms of the GNU General Public License
- * version 2. This program is licensed "as is" without any warranty of any
- * kind, whether express or implied.
- */
- #include <u.h>
- #include <libc.h>
- #include <ureg.h>
- #include <ctype.h>
- #include <bio.h>
- #include <mach.h>
- #include "debug_core.h"
- #include "gdb.h"
- #define MAX_THREAD_QUERY 17
- #define BUFMAX 1024
- #define BUF_THREAD_ID_SIZE 8
- // Everything always does EINVAL.
- #define EINVAL 22
- /* Our I/O buffers. */
- char remcom_in_buffer[BUFMAX];
- char remcom_out_buffer[BUFMAX];
- static int gdbstub_use_prev_in_buf;
- static int gdbstub_prev_in_buf_pos;
- int remotefd;
- int notefid;
- int debug = 0;
- int attached_to_existing_pid = 0;
- Map* cormap;
- static struct state ks;
- /* support crap */
- /*
- * GDB remote protocol parser:
- */
- static char *hex_asc = "0123456789abcdef";
- char* regstrs[] = {
- [GDB_AX] = "AX",
- [GDB_BX] = "BX",
- [GDB_CX] = "CX",
- [GDB_DX] = "DX",
- [GDB_SI] = "SI",
- [GDB_DI] = "DI",
- [GDB_BP] = "BP",
- [GDB_SP] = "SP",
- [GDB_R8] = "R8",
- [GDB_R9] = "R9",
- [GDB_R10] = "R10",
- [GDB_R11] = "R11",
- [GDB_R12] = "R12",
- [GDB_R13] = "R13",
- [GDB_R14] = "R14",
- [GDB_R15] = "R15",
- [GDB_PC] = "PC",
- [GDB_PS] = "PS",
- [GDB_CS] = "CS",
- [GDB_SS] = "SS",
- [GDB_DS] = "DS",
- [GDB_ES] = "ES",
- [GDB_FS] = "FS",
- [GDB_GS] = "GS",
- };
- // not reentrant, bla bla bla
- char *
- errstring(char *prefix)
- {
- static char error[ERRMAX];
- snprint(error, sizeof(error), "%s%r", prefix);
- return error;
- }
- static uint8_t
- hex_asc_lo(int x)
- {
- return hex_asc[x & 0xf];
- }
- static uint8_t
- hex_asc_hi(int x)
- {
- return hex_asc_lo(x >> 4);
- }
- static void *
- hex_byte_pack(char *dest, int val)
- {
- *dest++ = hex_asc_hi(val);
- *dest++ = hex_asc_lo(val);
- return dest;
- }
- static int
- hex_to_bin(int c)
- {
- if ((c >= '0') && (c <= '9'))
- return c - '0';
- if ((c >= 'a') && (c <= 'f'))
- return c + 10 - 'a';
- if ((c >= 'A') && (c <= 'F'))
- return c + 10 - 'A';
- return -1;
- }
- char *
- p8(char *dest, int c)
- {
- *dest++ = hex_to_bin(c);
- *dest++ = hex_to_bin(c >> 4);
- return dest;
- }
- char *
- p16(char *dest, int c)
- {
- dest = p8(dest, c);
- dest = p8(dest, c >> 4);
- return dest;
- }
- char *
- p32(char *dest, uint32_t c)
- {
- dest = p16(dest, c);
- dest = p16(dest, c >> 16);
- return dest;
- }
- char *
- p64(char *dest, uint64_t c)
- {
- dest = p32(dest, c);
- dest = p32(dest, c >> 32);
- return dest;
- }
- void
- attach_to_process(int pid)
- {
- char buf[100];
- sprint(buf, "/proc/%d/text", pid);
- int textfid = open(buf, OREAD);
- if (textfid < 0){
- syslog(0, "gdbserver", "couldn't open %s: %r", buf);
- return;
- }
- Fhdr fhdr;
- if (!crackhdr(textfid, &fhdr)) {
- syslog(0, "gdbserver", "couldn't decode file header: %r");
- return;
- }
- // machdata will be valid after this
- machbytype(fhdr.type);
- Map* symmap = loadmap(0, textfid, &fhdr);
- if (symmap == nil) {
- syslog(0, "gdbserver", "loadmap failed: %r");
- return;
- }
- snprint(buf, sizeof(buf), "/proc/%d/mem", pid);
- int memfid = open(buf, ORDWR);
- if (memfid < 0) {
- syslog(0, "gdbserver", "couldn't open %s: %r", buf);
- return;
- }
- cormap = attachproc(pid, 0, memfid, &fhdr);
- if (cormap == 0) {
- syslog(0, "gdbserver", "couldn't attachproc: %r");
- return;
- }
- int i = findseg(cormap, "text");
- if (i > 0) {
- cormap->seg[i].name = "*text";
- }
- i = findseg(cormap, "data");
- if (i > 0) {
- cormap->seg[i].name = "*data";
- }
- snprint(buf, sizeof(buf), "/proc/%d/note", pid);
- notefid = open(buf, OREAD);
- if (notefid < 0) {
- syslog(0, "gdbserver", "couldn't open %s: %r", buf);
- return;
- }
- syslog(0, "gdbserver", "attach_to_process completed");
- }
- void
- sendctl(int pid, char* message)
- {
- char buf[100];
- int ctlfd;
- sprint(buf, "/proc/%d/ctl", pid);
- ctlfd = open(buf, OWRITE);
- if (ctlfd >= 0) {
- write(ctlfd, message, strlen(message));
- close(ctlfd);
- syslog(0, "gdbserver", "sent '%s' to %s", message, buf);
- }
- }
- static char *
- getstatus(int pid)
- {
- int fd, n;
- char *argv[16], buf[64];
- static char status[128];
- snprint(buf, sizeof(buf), "/proc/%d/status", pid);
- fd = open(buf, OREAD);
- if(fd < 0) {
- syslog(0, "gdbserver", "Failed to open %s: %r", buf);
- return nil;
- }
- n = read(fd, status, sizeof(status)-1);
- close(fd);
- if(n <= 0) {
- syslog(0, "gdbserver", "Failed to read %s: %r", buf);
- return nil;
- }
- status[n] = '\0';
- if(tokenize(status, argv, nelem(argv)-1) < 3) {
- syslog(0, "gdbserver", "Failed to tokenize %s: %r", buf);
- return nil;
- }
- return argv[2];
- }
- // Remove any pending breakpoint notes
- static void
- remove_note(void)
- {
- char buf[ERRMAX];
- switch (read(notefid, buf, sizeof buf)) {
- case -1:
- syslog(0, "gdbserver", "Error reading note: %r");
- return;
- case 0:
- syslog(0, "gdbserver", "No note to remove");
- return;
- }
- buf[ERRMAX-1] = '\0';
- if(strncmp(buf, "sys: breakpoint", 15) == 0)
- syslog(0, "gdbserver", "Removed breakpoint note");
- else
- syslog(0, "gdbserver", "Found unexpected note: %s", buf);
- }
- static void
- write_char(uint8_t c)
- {
- write(remotefd, &c, 1);
- }
- static int
- read_char()
- {
- uint8_t c;
- if (read(remotefd, &c, 1) < 0)
- return -1;
- return c;
- }
- static int
- gdbstub_read_wait(void)
- {
- int ret;
- ret = read_char();
- if (ret < 0) {
- print("Session ended\n");
- exits("die");
- }
- return ret;
- }
- /* scan for the sequence $<data>#<checksum> */
- static void
- get_packet(char *buffer)
- {
- unsigned char checksum;
- unsigned char xmitcsum;
- int count;
- char ch;
- do {
- /*
- * Spin and wait around for the start character, ignore all
- * other characters:
- */
- while ((ch = (gdbstub_read_wait())) != '$')
- /* nothing */ ;
- checksum = 0;
- xmitcsum = -1;
- count = 0;
- /*
- * now, read until a # or end of buffer is found:
- */
- while (count < (BUFMAX - 1)) {
- ch = gdbstub_read_wait();
- if (ch == '#')
- break;
- checksum = checksum + ch;
- buffer[count] = ch;
- count = count + 1;
- }
- if (ch == '#') {
- xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
- xmitcsum += hex_to_bin(gdbstub_read_wait());
- if (checksum != xmitcsum) syslog(0, "gdbserver", "BAD CSUM Computed 0x%x want 0x%x", xmitcsum, checksum);
- if (checksum != xmitcsum)
- /* failed checksum */
- write_char('-');
- else
- /* successful transfer */
- write_char('+');
- }
- buffer[count] = 0;
- } while (checksum != xmitcsum);
- if (debug)
- print("<-%s\n", buffer);
- }
- /*
- * Send the packet in buffer.
- * Check for gdb connection if asked for.
- */
- static void
- put_packet(char *buffer)
- {
- unsigned char checksum;
- int count;
- char ch;
- /*
- * $<packet info>#<checksum>.
- */
- if (debug)
- print("->%s\n", buffer);
- while (1) {
- write_char('$');
- checksum = 0;
- count = 0;
- while ((ch = buffer[count])) {
- write_char(ch);
- checksum += ch;
- count++;
- }
- write_char('#');
- write_char(hex_asc_hi(checksum));
- write_char(hex_asc_lo(checksum));
- /* Now see what we get in reply. */
- ch = gdbstub_read_wait();
- if (ch == 3)
- ch = gdbstub_read_wait();
- /* If we get an ACK, we are done. */
- if (ch == '+')
- return;
- /*
- * If we get the start of another packet, this means
- * that GDB is attempting to reconnect. We will NAK
- * the packet being sent, and stop trying to send this
- * packet.
- */
- if (ch == '$') {
- write_char('-');
- return;
- }
- }
- }
- static char gdbmsgbuf[BUFMAX + 1];
- void
- gdbstub_msg_write(const char *s, int len)
- {
- char *bufptr;
- int wcount;
- int i;
- if (len == 0)
- len = strlen(s);
- /* 'O'utput */
- gdbmsgbuf[0] = 'O';
- /* Fill and send buffers... */
- while (len > 0) {
- bufptr = gdbmsgbuf + 1;
- /* Calculate how many this time */
- if ((len << 1) > (BUFMAX - 2))
- wcount = (BUFMAX - 2) >> 1;
- else
- wcount = len;
- /* Pack in hex chars */
- for (i = 0; i < wcount; i++)
- bufptr = hex_byte_pack(bufptr, s[i]);
- *bufptr = '\0';
- /* Move up */
- s += wcount;
- len -= wcount;
- /* Write packet */
- put_packet(gdbmsgbuf);
- }
- }
- /*
- * Convert the memory pointed to by mem into hex, placing result in
- * buf. Return a pointer to the last char put in buf (null). May
- * return an error.
- */
- char *
- mem2hex(unsigned char *mem, char *buf, int count)
- {
- char *tmp;
- for(tmp = buf; count; tmp += 2, count--, mem++){
- sprint(tmp, "%02x", *mem);
- }
- *tmp = 0;
- return tmp;
- }
- /*
- * Convert the hex array pointed to by buf into binary to be placed in
- * mem. Return a pointer to the character AFTER the last byte
- * written. May return an error.
- */
- char *
- hex2mem(char *buf, unsigned char *mem, int count)
- {
- char *tmp_raw;
- char *tmp_hex;
- /*
- * We use the upper half of buf as an intermediate buffer for the
- * raw memory that is converted from hex.
- */
- tmp_raw = buf + count * 2;
- tmp_hex = tmp_raw - 1;
- while (tmp_hex >= buf) {
- tmp_raw--;
- *tmp_raw = hex_to_bin(*tmp_hex--);
- *tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
- }
- return nil; // Check for valid stuff some day?
- }
- /*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
- int
- hex2long(char **ptr, unsigned long *long_val)
- {
- int hex_val;
- int num = 0;
- int negate = 0;
- *long_val = 0;
- if (**ptr == '-') {
- negate = 1;
- (*ptr)++;
- }
- while (**ptr) {
- hex_val = hex_to_bin(**ptr);
- if (hex_val < 0)
- break;
- *long_val = (*long_val << 4) | hex_val;
- num++;
- (*ptr)++;
- }
- if (negate)
- *long_val = -*long_val;
- return num;
- }
- /*
- * Copy the binary array pointed to by src into dest. Fix $, #, and
- * 0x7d escaped with 0x7d.
- */
- static void
- ebin2mem(unsigned char *src, unsigned char *dest, int count)
- {
- int size = 0;
- unsigned char *c = dest;
- while (count-- > 0) {
- c[size] = *src++;
- if (c[size] == 0x7d)
- c[size] = *src++ ^ 0x20;
- size++;
- }
- }
- /* Write memory due to an 'M' or 'X' packet. */
- static char *
- write_mem_msg(struct state *ks, int binary)
- {
- char *cp = (char *)&remcom_in_buffer[1];
- unsigned long addr;
- unsigned long length;
- char *err;
- if (hex2long(&cp, &addr) > 0 && *(cp++) == ',' &&
- hex2long(&cp, &length) > 0 && *(cp++) == ':') {
- // When gdb wants to set a variable, we seem to get a zero length write
- // packet immediately before the real write packet. Not sure why,
- // but let's not try to write it at least.
- if (length == 0) {
- return nil;
- }
- unsigned char *data = malloc(length);
- if (binary)
- ebin2mem((unsigned char *)cp, data, length);
- else
- hex2mem(cp, data, length);
- err = wmem(addr, ks->threadid, data, length);
- free(data);
- return err;
- }
- return Einval;
- }
- // Yep, the protocol really is this shitty: errors are numbers. Assholes.
- void
- error_packet(char *pkt, char *error)
- {
- pkt[0] = 'E';
- pkt[1] = error[0];
- pkt[2] = error[1];
- pkt[3] = '\0';
- }
- static char *
- pack_threadid(char *pkt, unsigned char *id)
- {
- unsigned char *limit;
- int lzero = 1;
- limit = id + (BUF_THREAD_ID_SIZE / 2);
- while (id < limit) {
- if (!lzero || *id != 0) {
- pkt = hex_byte_pack(pkt, *id);
- lzero = 0;
- }
- id++;
- }
- if (lzero)
- pkt = hex_byte_pack(pkt, 0);
- return pkt;
- }
- static void
- int_to_threadref(unsigned char *id, int value)
- {
- print("%s: panic\n", __func__);
- exits("fuck");
- // put_unaligned_be32(value, id);
- }
- uint64_t
- get_reg(Map *map, char *reg)
- {
- (void)map;
- int reg_idx = -1;
- for (int i = 0; i < DBG_MAX_REG_NUM; i++) {
- if (!strcmp(reg, regstrs[i])) {
- reg_idx = i;
- break;
- }
- }
- if (reg_idx == -1) {
- syslog(0, "gdbserver", "get_reg: Unrecognised register %s.", reg);
- return 0;
- }
- uint64_t value = arch_get_reg(&ks, reg_idx);
- return value;
- }
- /*
- * All the functions that start with gdb_cmd are the various
- * operations to implement the handlers for the gdbserial protocol
- * where KGDB is communicating with an external debugger
- */
- /* Handle the '?' status packets */
- static void
- gdb_cmd_status(struct state *ks)
- {
- /*
- * We know that this packet is only sent
- * during initial connect. So to be safe,
- * we clear out our breakpoints now in case
- * GDB is reconnecting.
- */
- dbg_remove_all_break(ks);
- remcom_out_buffer[0] = 'S';
- hex_byte_pack((char *)&remcom_out_buffer[1], ks->signo);
- }
- /* Handle the 'g' get registers request */
- static void
- gdb_cmd_getregs(struct state *ks)
- {
- if (ks->threadid <= 0) {
- syslog(0, "gdbserver", "%s: id <= 0, fuck it, make it 1", __func__);
- }
- gpr(ks, ks->threadid);
- mem2hex(ks->gdbregs, (char *)remcom_out_buffer, NUMREGBYTES);
- }
- /* Handle the 'G' set registers request */
- static void
- gdb_cmd_setregs(struct state *ks)
- {
- hex2mem((char *)&remcom_in_buffer[1], ks->gdbregs, NUMREGBYTES);
- error_packet(remcom_out_buffer, Einval);
- //gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
- // strcpy(remcom_out_buffer, "OK");
- }
- /* Handle the 'm' memory read bytes */
- static void
- gdb_cmd_memread(struct state *ks)
- {
- char *ptr = (char *)&remcom_in_buffer[1];
- unsigned long length;
- unsigned long addr;
- char *err;
- if (hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
- hex2long(&ptr, &length) > 0) {
- char *data = malloc(length);
- if ((err = rmem(data, ks->threadid, addr, length)) != 0) {
- if (debug)
- print("%s: %r", __func__);
- syslog(0, "gdbserver", "%s: %r", __func__);
- error_packet(remcom_out_buffer, err);
- free(data);
- return;
- }
- mem2hex((unsigned char *)data, (char *)remcom_out_buffer, length);
- free(data);
- } else {
- syslog(0, "gdbserver", "%s failed: %s : no good", __func__, remcom_in_buffer);
- error_packet(remcom_out_buffer, Einval);
- }
- }
- /* Handle the 'M' memory write bytes */
- static void
- gdb_cmd_memwrite(struct state *ks)
- {
- char *err = write_mem_msg(ks, 0);
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy((char *)remcom_out_buffer, "OK");
- }
- /* Handle the 'X' memory binary write bytes */
- static void
- gdb_cmd_binwrite(struct state *ks)
- {
- char *err = write_mem_msg(ks, 1);
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy((char *)remcom_out_buffer, "OK");
- }
- /* Handle the 'D', detach packet */
- static void
- gdb_cmd_detach(struct state *ks)
- {
- char *error;
- error = dbg_remove_all_break(ks);
- if (error < 0) {
- error_packet(remcom_out_buffer, error);
- } else {
- strcpy((char *)remcom_out_buffer, "OK");
- connected = 0;
- sendctl(ks->threadid, "start");
- }
- put_packet(remcom_out_buffer);
- }
- /* Handle the 'k' kill packet */
- static void
- gdb_cmd_kill(struct state *ks)
- {
- sendctl(ks->threadid, "kill");
- connected = 0;
- print("Process %d killed by gdb\n", ks->threadid);
- }
- /* Handle the 'R' reboot packets */
- static int
- gdb_cmd_reboot(struct state *ks)
- {
- /* For now, only honor R0 */
- if (strcmp((char *)remcom_in_buffer, "R0") == 0) {
- print(" NOT Executing emergency reboot\n");
- strcpy((char *)remcom_out_buffer, "OK");
- put_packet(remcom_out_buffer);
- /*
- * Execution should not return from
- * machine_emergency_restart()
- */
- connected = 0;
- return 1;
- }
- return 0;
- }
- /* Handle the 'q' query packets */
- static void
- gdb_cmd_query(struct state *ks)
- {
- if (strcmp(&remcom_in_buffer[1], "Symbol::") == 0) {
- strcpy((char *)remcom_out_buffer, "OK");
- return;
- }
- switch (remcom_in_buffer[1]) {
- case 'S':
- if (memcmp(remcom_in_buffer + 2, "upported", 8))
- break;
- // this code sucks.
- // We don't really have procs and threads for now. Just use the
- // thread id as the pid. i.e. no multiprocess.
- strcpy((char *)remcom_out_buffer, ""); // "multiprocess+");
- break;
- case 'f':
- if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
- break;
- // Just pass the main pid for now
- remcom_out_buffer[0] = 'm';
- pack_threadid((char *)remcom_out_buffer + 1, (uint8_t *)&ks->threadid);
- break;
- case 'C':
- /* Current thread id */
- strcpy((char *)remcom_out_buffer, "QC");
- pack_threadid((char *)remcom_out_buffer + 2, (uint8_t *) & ks->threadid);
- break;
- case 'T':
- if (memcmp(remcom_in_buffer+2, "Status", 6) == 0) {
- // TODO: proper status
- strcpy(remcom_out_buffer, "Tnotrun:0");
- break;
- }
- strcpy((char *)remcom_out_buffer, "");
- break;
- case 'A':
- if (memcmp(remcom_in_buffer + 2, "ttached", 7))
- break;
- strcpy((char *)remcom_out_buffer, attached_to_existing_pid ? "1" : "0");
- break;
- }
- }
- /* Handle the 'H' task query packets */
- static void
- gdb_cmd_task(struct state *ks)
- {
- char *ptr;
- char *err;
- unsigned long id;
- switch (remcom_in_buffer[1]) {
- case 'g':
- ptr = (char *)&remcom_in_buffer[2];
- //hex2long(&ptr, &ks->threadid);
- if (ks->threadid <= 0) {
- syslog(0, "gdbserver", "Warning: using 1 instead of 0");
- }
- err = gpr(ks, ks->threadid);
- syslog(0, "gdbserver", "Try to use thread %d: %s", ks->threadid, err);
- if (err){
- error_packet(remcom_out_buffer, err);
- } else {
- strcpy((char *)remcom_out_buffer, "OK");
- }
- break;
- case 'c':
- ptr = (char *)&remcom_in_buffer[2];
- hex2long(&ptr, &id);
- strcpy((char *)remcom_out_buffer, "OK");
- break;
- }
- }
- /* Handle the 'T' thread query packets */
- static void
- gdb_cmd_thread(struct state *ks)
- {
- //char *ptr = (char *)&remcom_in_buffer[1];
- char *err;
- //hex2long(&ptr, &ks->threadid);
- if (ks->threadid <= 0) {
- syslog(0, "gdbserver", "%s: id <= 0, fuck it, make it 1", __func__);
- }
- err = gpr(ks, ks->threadid);
- if (!err)
- strcpy((char *)remcom_out_buffer, "OK");
- else
- error_packet(remcom_out_buffer, Einval);
- }
- /* Handle the 'z' or 'Z' breakpoint remove or set packets */
- static void
- gdb_cmd_break(struct state *ks)
- {
- /*
- * Since GDB-5.3, it's been drafted that '0' is a software
- * breakpoint, '1' is a hardware breakpoint, so let's do that.
- */
- char *bpt_type = (char *)&remcom_in_buffer[1];
- char *ptr = (char *)&remcom_in_buffer[2];
- unsigned long addr;
- unsigned long length;
- char *error = nil;
- // We only support software breakpoints
- if (*bpt_type >= '1') {
- return;
- }
- if (*(ptr++) != ',') {
- error_packet(remcom_out_buffer, Einval);
- return;
- }
- if (!hex2long(&ptr, &addr)) {
- error_packet(remcom_out_buffer, Einval);
- return;
- }
- if (*(ptr++) != ',' || !hex2long(&ptr, &length)) {
- error_packet(remcom_out_buffer, Einval);
- return;
- }
- if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
- error = dbg_set_sw_break(ks, addr);
- else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
- error = dbg_remove_sw_break(ks, addr);
- if (error == 0) {
- strcpy((char *)remcom_out_buffer, "OK");
- } else {
- syslog(0, "gdbserver", "gdb_cmd_break: error: %s", error);
- error_packet(remcom_out_buffer, Einval);
- }
- }
- /* Handle the 'C' signal / exception passing packets */
- static int
- gdb_cmd_exception_pass(struct state *ks)
- {
- /* C09 == pass exception
- * C15 == detach kgdb, pass exception
- */
- if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
- ks->pass_exception = 1;
- remcom_in_buffer[0] = 'c';
- } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
- ks->pass_exception = 1;
- remcom_in_buffer[0] = 'D';
- dbg_remove_all_break(ks);
- connected = 0;
- return 1;
- } else {
- gdbstub_msg_write("KGDB only knows signal 9 (pass)"
- " and 15 (pass and disconnect)\n"
- "Executing a continue without signal passing\n", 0);
- remcom_in_buffer[0] = 'c';
- }
- /* Indicate fall through */
- return -1;
- }
- static void
- gdb_cmd_continue(struct state *ks)
- {
- if (strcmp("Stopped", getstatus(ks->threadid)) != 0) {
- syslog(0, "gdbserver", "Process not stopped - can't activate breakpoints");
- // Not really sure what to reply with here
- return;
- }
- syslog(0, "gdbserver", "activating breakpoints");
- dbg_activate_sw_breakpoints(ks);
- // Block for the process to stop or receive a note
- sendctl(ks->threadid, "startstop");
- // Remove the breakpoint note so the process
- // doesn't suicide
- remove_note();
- // Send code indicating we've hit a breakpoint
- strcpy((char *)remcom_out_buffer, "S05");
- }
- static void
- gdb_cmd_single_step(struct state *ks)
- {
- if (machdata == nil) {
- syslog(0, "gdbserver", "machdata not set");
- return;
- }
- if (machdata->foll == nil) {
- syslog(0, "gdbserver", "machdata->foll not set");
- return;
- }
- uint64_t foll[] = {0, 0, 0};
- uint64_t pc = arch_get_pc(ks);
- int nfoll = machdata->foll(cormap, pc, get_reg, foll);
- if (nfoll < 0)
- syslog(0, "gdbserver", "machdata->foll failed: %r");
- else
- syslog(0, "gdbserver", "machdata->foll succeeded, nfoll: %d", nfoll);
- for (int i = 0; i < nfoll; i++) {
- syslog(0, "gdbserver", "Setting single-step breakpoint at: %p", foll[i]);
- dbg_set_sw_break(ks, foll[i]);
- }
- gdb_cmd_continue(ks);
- for (int i = 0; i < nfoll; i++) {
- syslog(0, "gdbserver", "Removing single-step breakpoint at: %p", foll[i]);
- dbg_remove_sw_break(ks, foll[i]);
- }
- }
- /*
- * This function performs all gdbserial command procesing
- */
- int
- gdb_serial_stub(struct state *ks, int port)
- {
- int error = 0;
- int tmp;
- char adir[40], ldir[40], buff[256];
- int acfd, lcfd;
- sprint(buff, "tcp!*!%d", port);
- acfd = announce(buff, adir);
- if (acfd < 0) {
- fprint(2, "Unable to connect %r\n");
- exits("announce");
- }
- lcfd = listen(adir, ldir);
- if (lcfd < 0) {
- fprint(2, "listen failed %r\n");
- exits("listen");
- }
- print("Waiting for connection on %d...\n", port);
- remotefd = accept(lcfd, ldir);
- if (remotefd < 0) {
- fprint(2, "Accept failed %r\n");
- exits("accept");
- }
- print("Connected\n");
- /* Initialize comm buffer and globals. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
- if (connected) {
- unsigned char thref[BUF_THREAD_ID_SIZE];
- char *ptr;
- /* Reply to host that an exception has occurred */
- ptr = (char *)remcom_out_buffer;
- *ptr++ = 'T';
- ptr = hex_byte_pack(ptr, ks->signo);
- ptr += strlen(strcpy(ptr, "thread:"));
- int_to_threadref(thref, 1);
- ptr = pack_threadid(ptr, thref);
- *ptr++ = ';';
- put_packet(remcom_out_buffer);
- }
- while (1) {
- error = 0;
- /* Clear the out buffer. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
- get_packet(remcom_in_buffer);
- syslog(0, "gdbserver", "packet :%s:", remcom_in_buffer);
- switch (remcom_in_buffer[0]) {
- case '?': /* gdbserial status */
- gdb_cmd_status(ks);
- break;
- case 'g': /* return the value of the CPU registers */
- gdb_cmd_getregs(ks);
- break;
- case 'G': /* set the value of the CPU registers - return OK */
- gdb_cmd_setregs(ks);
- break;
- case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
- gdb_cmd_memread(ks);
- break;
- case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
- gdb_cmd_memwrite(ks);
- break;
- case 'p': /* pXX Return gdb register XX (in hex) */
- gdb_cmd_reg_get(ks);
- break;
- case 'P': /* PXX=aaaa Set gdb register XX to aaaa (in hex) */
- gdb_cmd_reg_set(ks);
- break;
- case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
- gdb_cmd_binwrite(ks);
- break;
- /* kill or detach. KGDB should treat this like a
- * continue.
- */
- case 'D': /* Debugger detach */
- gdb_cmd_detach(ks);
- break;
- case 'k': /* Debugger detach via kill */
- gdb_cmd_kill(ks);
- goto exit;
- case 'R': /* Reboot */
- if (gdb_cmd_reboot(ks))
- goto default_handle;
- break;
- case 'q': /* query command */
- gdb_cmd_query(ks);
- break;
- case 'H': /* task related */
- gdb_cmd_task(ks);
- break;
- case 'T': /* Query thread status */
- gdb_cmd_thread(ks);
- break;
- case 'z': /* Break point remove */
- case 'Z': /* Break point set */
- gdb_cmd_break(ks);
- break;
- case 'C': /* Exception passing */
- tmp = gdb_cmd_exception_pass(ks);
- if (tmp > 0)
- goto default_handle;
- if (tmp == 0)
- break;
- /* Fall through on tmp < 0 */
- case 'c': /* Continue packet */
- gdb_cmd_continue(ks);
- break;
- case 's': /* Single step packet */
- gdb_cmd_single_step(ks);
- break;
- default:
- default_handle:
- if (remcom_in_buffer[0] == 'v') {
- // Specifically indicate we don't handle
- // v packets.
- strcpy((char *)remcom_out_buffer, "");
- }
- else if (error > 0 || remcom_in_buffer[0] == 'D' ||
- remcom_in_buffer[0] == 'k') {
- /*
- * I have no idea what to do.
- * Leave cmd processing on error, detach,
- * kill, continue, or single step.
- */
- error = 0;
- goto exit;
- }
- }
- syslog(0, "gdbserver", "RETURN :%s:", remcom_out_buffer);
- /* reply to the request */
- put_packet(remcom_out_buffer);
- }
- exit:
- if (ks->pass_exception)
- error = 1;
- return error;
- }
- char *
- gdbstub_state(struct state *ks, char *cmd)
- {
- char *error;
- switch (cmd[0]) {
- case 'e':
- error = Einval;
- #if 0
- error = arch_handle_exception(ks->ex_vector,
- ks->signo,
- ks->err_code,
- remcom_in_buffer,
- remcom_out_buffer, ks->linux_regs);
- #endif
- return error;
- case 's':
- case 'c':
- strcpy(remcom_in_buffer, cmd);
- return nil;
- case '$':
- strcpy(remcom_in_buffer, cmd);
- gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
- gdbstub_prev_in_buf_pos = 0;
- return nil;
- }
- write_char('+');
- put_packet(remcom_out_buffer);
- return nil;
- }
- /**
- * gdbstub_exit - Send an exit message to GDB
- * @status: The exit code to report.
- */
- void
- gdbstub_exit(int status)
- {
- unsigned char checksum, ch, buffer[3];
- int loop;
- if (!connected)
- return;
- connected = 0;
- buffer[0] = 'W';
- buffer[1] = hex_asc_hi(status);
- buffer[2] = hex_asc_lo(status);
- write_char('$');
- checksum = 0;
- for (loop = 0; loop < 3; loop++) {
- ch = buffer[loop];
- checksum += ch;
- write_char(ch);
- }
- write_char('#');
- write_char(hex_asc_hi(checksum));
- write_char(hex_asc_lo(checksum));
- }
- char *
- rmem(void *dest, int pid, uint64_t addr, int size)
- {
- syslog(0, "gdbserver", "rmem(%p, %d, %p, %d)", dest, pid, addr, size);
- if (get1(cormap, addr, dest, size) < 0) {
- syslog(0, "gdbserver", "get1 failed: %r");
- return errstring(Eio);
- }
- syslog(0, "gdbserver", "rmem read %d bytes", size);
- return nil;
- }
- char *
- wmem(uint64_t dest, int pid, void *addr, int size)
- {
- syslog(0, "gdbserver", "wmem(%p, %d, %p, %d)", dest, pid, addr, size);
- if (put1(cormap, dest, addr, size) < 0) {
- syslog(0, "gdbserver", "put1 failed: %r");
- return errstring(Eio);
- }
- syslog(0, "gdbserver", "wmem wrote %d bytes", size);
- return nil;
- }
- void
- main(int argc, char **argv)
- {
- char* pid = nil;
- char* port = "1666";
- ARGBEGIN {
- case 'l':
- port = ARGF();
- if (port == nil) {
- fprint(2, "Please specify a listening port\n");
- exits("listen");
- }
- break;
- case 'p':
- pid = ARGF();
- if (pid == nil) {
- fprint(2, "Please specify a pid\n");
- exits("pid");
- }
- break;
- case 'd':
- debug = 1;
- break;
- default:
- fprint(2, " badflag('%c')", ARGC());
- } ARGEND
- if (pid == nil) {
- fprint(2, "Please specify a pid\n");
- exits("pid");
- }
- ks.threadid = atoi(pid);
- // Set to 0 if we eventually support creating a new process
- attached_to_existing_pid = 1;
- print("Stopping process...\n", ks.threadid);
- sendctl(ks.threadid, "stop");
- print("Process stopped. Waiting for remote gdb connection...\n");
- attach_to_process(ks.threadid);
- gdb_serial_stub(&ks, atoi(port));
- }
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