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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 <linux/kernel.h>
- #include <linux/kgdb.h>
- #include <linux/kdb.h>
- #include <linux/serial_core.h>
- #include <linux/reboot.h>
- #include <linux/uaccess.h>
- #include <asm/cacheflush.h>
- #include <asm/unaligned.h>
- #include "debug_core.h"
- #define KGDB_MAX_THREAD_QUERY 17
- /* Our I/O buffers. */
- static char remcom_in_buffer[BUFMAX];
- static char remcom_out_buffer[BUFMAX];
- static int gdbstub_use_prev_in_buf;
- static int gdbstub_prev_in_buf_pos;
- /* Storage for the registers, in GDB format. */
- static unsigned long gdb_regs[(NUMREGBYTES +
- sizeof(unsigned long) - 1) /
- sizeof(unsigned long)];
- /*
- * GDB remote protocol parser:
- */
- #ifdef CONFIG_KGDB_KDB
- static int gdbstub_read_wait(void)
- {
- int ret = -1;
- int i;
- if (unlikely(gdbstub_use_prev_in_buf)) {
- if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf)
- return remcom_in_buffer[gdbstub_prev_in_buf_pos++];
- else
- gdbstub_use_prev_in_buf = 0;
- }
- /* poll any additional I/O interfaces that are defined */
- while (ret < 0)
- for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
- ret = kdb_poll_funcs[i]();
- if (ret > 0)
- break;
- }
- return ret;
- }
- #else
- static int gdbstub_read_wait(void)
- {
- int ret = dbg_io_ops->read_char();
- while (ret == NO_POLL_CHAR)
- ret = dbg_io_ops->read_char();
- return ret;
- }
- #endif
- /* 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 */;
- kgdb_connected = 1;
- 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)
- /* failed checksum */
- dbg_io_ops->write_char('-');
- else
- /* successful transfer */
- dbg_io_ops->write_char('+');
- if (dbg_io_ops->flush)
- dbg_io_ops->flush();
- }
- buffer[count] = 0;
- } while (checksum != xmitcsum);
- }
- /*
- * 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;
- /*
- * $<packet info>#<checksum>.
- */
- while (1) {
- dbg_io_ops->write_char('$');
- checksum = 0;
- count = 0;
- while ((ch = buffer[count])) {
- dbg_io_ops->write_char(ch);
- checksum += ch;
- count++;
- }
- dbg_io_ops->write_char('#');
- dbg_io_ops->write_char(hex_asc_hi(checksum));
- dbg_io_ops->write_char(hex_asc_lo(checksum));
- if (dbg_io_ops->flush)
- dbg_io_ops->flush();
- /* 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 == '$') {
- dbg_io_ops->write_char('-');
- if (dbg_io_ops->flush)
- dbg_io_ops->flush();
- 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 *kgdb_mem2hex(char *mem, char *buf, int count)
- {
- char *tmp;
- int err;
- /*
- * We use the upper half of buf as an intermediate buffer for the
- * raw memory copy. Hex conversion will work against this one.
- */
- tmp = buf + count;
- err = probe_kernel_read(tmp, mem, count);
- if (err)
- return NULL;
- while (count > 0) {
- buf = hex_byte_pack(buf, *tmp);
- tmp++;
- count--;
- }
- *buf = 0;
- return buf;
- }
- /*
- * 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.
- */
- int kgdb_hex2mem(char *buf, 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 probe_kernel_write(mem, tmp_raw, count);
- }
- /*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
- int kgdb_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 buf into mem. Fix $, #, and
- * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
- * The input buf is overwitten with the result to write to mem.
- */
- static int kgdb_ebin2mem(char *buf, char *mem, int count)
- {
- int size = 0;
- char *c = buf;
- while (count-- > 0) {
- c[size] = *buf++;
- if (c[size] == 0x7d)
- c[size] = *buf++ ^ 0x20;
- size++;
- }
- return probe_kernel_write(mem, c, size);
- }
- #if DBG_MAX_REG_NUM > 0
- void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
- {
- int i;
- int idx = 0;
- char *ptr = (char *)gdb_regs;
- for (i = 0; i < DBG_MAX_REG_NUM; i++) {
- dbg_get_reg(i, ptr + idx, regs);
- idx += dbg_reg_def[i].size;
- }
- }
- void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
- {
- int i;
- int idx = 0;
- char *ptr = (char *)gdb_regs;
- for (i = 0; i < DBG_MAX_REG_NUM; i++) {
- dbg_set_reg(i, ptr + idx, regs);
- idx += dbg_reg_def[i].size;
- }
- }
- #endif /* DBG_MAX_REG_NUM > 0 */
- /* Write memory due to an 'M' or 'X' packet. */
- static int write_mem_msg(int binary)
- {
- char *ptr = &remcom_in_buffer[1];
- unsigned long addr;
- unsigned long length;
- int err;
- if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
- kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
- if (binary)
- err = kgdb_ebin2mem(ptr, (char *)addr, length);
- else
- err = kgdb_hex2mem(ptr, (char *)addr, length);
- if (err)
- return err;
- if (CACHE_FLUSH_IS_SAFE)
- flush_icache_range(addr, addr + length);
- return 0;
- }
- return -EINVAL;
- }
- static void error_packet(char *pkt, int error)
- {
- error = -error;
- pkt[0] = 'E';
- pkt[1] = hex_asc[(error / 10)];
- pkt[2] = hex_asc[(error % 10)];
- pkt[3] = '\0';
- }
- /*
- * Thread ID accessors. We represent a flat TID space to GDB, where
- * the per CPU idle threads (which under Linux all have PID 0) are
- * remapped to negative TIDs.
- */
- #define BUF_THREAD_ID_SIZE 8
- 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)
- {
- put_unaligned_be32(value, id);
- }
- static struct task_struct *getthread(struct pt_regs *regs, int tid)
- {
- /*
- * Non-positive TIDs are remapped to the cpu shadow information
- */
- if (tid == 0 || tid == -1)
- tid = -atomic_read(&kgdb_active) - 2;
- if (tid < -1 && tid > -NR_CPUS - 2) {
- if (kgdb_info[-tid - 2].task)
- return kgdb_info[-tid - 2].task;
- else
- return idle_task(-tid - 2);
- }
- if (tid <= 0) {
- printk(KERN_ERR "KGDB: Internal thread select error\n");
- dump_stack();
- return NULL;
- }
- /*
- * find_task_by_pid_ns() does not take the tasklist lock anymore
- * but is nicely RCU locked - hence is a pretty resilient
- * thing to use:
- */
- return find_task_by_pid_ns(tid, &init_pid_ns);
- }
- /*
- * Remap normal tasks to their real PID,
- * CPU shadow threads are mapped to -CPU - 2
- */
- static inline int shadow_pid(int realpid)
- {
- if (realpid)
- return realpid;
- return -raw_smp_processor_id() - 2;
- }
- /*
- * 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 kgdb_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();
- remcom_out_buffer[0] = 'S';
- hex_byte_pack(&remcom_out_buffer[1], ks->signo);
- }
- static void gdb_get_regs_helper(struct kgdb_state *ks)
- {
- struct task_struct *thread;
- void *local_debuggerinfo;
- int i;
- thread = kgdb_usethread;
- if (!thread) {
- thread = kgdb_info[ks->cpu].task;
- local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
- } else {
- local_debuggerinfo = NULL;
- for_each_online_cpu(i) {
- /*
- * Try to find the task on some other
- * or possibly this node if we do not
- * find the matching task then we try
- * to approximate the results.
- */
- if (thread == kgdb_info[i].task)
- local_debuggerinfo = kgdb_info[i].debuggerinfo;
- }
- }
- /*
- * All threads that don't have debuggerinfo should be
- * in schedule() sleeping, since all other CPUs
- * are in kgdb_wait, and thus have debuggerinfo.
- */
- if (local_debuggerinfo) {
- pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
- } else {
- /*
- * Pull stuff saved during switch_to; nothing
- * else is accessible (or even particularly
- * relevant).
- *
- * This should be enough for a stack trace.
- */
- sleeping_thread_to_gdb_regs(gdb_regs, thread);
- }
- }
- /* Handle the 'g' get registers request */
- static void gdb_cmd_getregs(struct kgdb_state *ks)
- {
- gdb_get_regs_helper(ks);
- kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
- }
- /* Handle the 'G' set registers request */
- static void gdb_cmd_setregs(struct kgdb_state *ks)
- {
- kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
- if (kgdb_usethread && kgdb_usethread != current) {
- error_packet(remcom_out_buffer, -EINVAL);
- } else {
- 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 kgdb_state *ks)
- {
- char *ptr = &remcom_in_buffer[1];
- unsigned long length;
- unsigned long addr;
- char *err;
- if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
- kgdb_hex2long(&ptr, &length) > 0) {
- err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
- if (!err)
- error_packet(remcom_out_buffer, -EINVAL);
- } else {
- error_packet(remcom_out_buffer, -EINVAL);
- }
- }
- /* Handle the 'M' memory write bytes */
- static void gdb_cmd_memwrite(struct kgdb_state *ks)
- {
- int err = write_mem_msg(0);
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy(remcom_out_buffer, "OK");
- }
- #if DBG_MAX_REG_NUM > 0
- static char *gdb_hex_reg_helper(int regnum, char *out)
- {
- int i;
- int offset = 0;
- for (i = 0; i < regnum; i++)
- offset += dbg_reg_def[i].size;
- return kgdb_mem2hex((char *)gdb_regs + offset, out,
- dbg_reg_def[i].size);
- }
- /* Handle the 'p' individual regster get */
- static void gdb_cmd_reg_get(struct kgdb_state *ks)
- {
- unsigned long regnum;
- char *ptr = &remcom_in_buffer[1];
- kgdb_hex2long(&ptr, ®num);
- if (regnum >= DBG_MAX_REG_NUM) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- gdb_get_regs_helper(ks);
- gdb_hex_reg_helper(regnum, remcom_out_buffer);
- }
- /* Handle the 'P' individual regster set */
- static void gdb_cmd_reg_set(struct kgdb_state *ks)
- {
- unsigned long regnum;
- char *ptr = &remcom_in_buffer[1];
- int i = 0;
- kgdb_hex2long(&ptr, ®num);
- if (*ptr++ != '=' ||
- !(!kgdb_usethread || kgdb_usethread == current) ||
- !dbg_get_reg(regnum, gdb_regs, ks->linux_regs)) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- memset(gdb_regs, 0, sizeof(gdb_regs));
- while (i < sizeof(gdb_regs) * 2)
- if (hex_to_bin(ptr[i]) >= 0)
- i++;
- else
- break;
- i = i / 2;
- kgdb_hex2mem(ptr, (char *)gdb_regs, i);
- dbg_set_reg(regnum, gdb_regs, ks->linux_regs);
- strcpy(remcom_out_buffer, "OK");
- }
- #endif /* DBG_MAX_REG_NUM > 0 */
- /* Handle the 'X' memory binary write bytes */
- static void gdb_cmd_binwrite(struct kgdb_state *ks)
- {
- int err = write_mem_msg(1);
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy(remcom_out_buffer, "OK");
- }
- /* Handle the 'D' or 'k', detach or kill packets */
- static void gdb_cmd_detachkill(struct kgdb_state *ks)
- {
- int error;
- /* The detach case */
- if (remcom_in_buffer[0] == 'D') {
- error = dbg_remove_all_break();
- if (error < 0) {
- error_packet(remcom_out_buffer, error);
- } else {
- strcpy(remcom_out_buffer, "OK");
- kgdb_connected = 0;
- }
- put_packet(remcom_out_buffer);
- } else {
- /*
- * Assume the kill case, with no exit code checking,
- * trying to force detach the debugger:
- */
- dbg_remove_all_break();
- kgdb_connected = 0;
- }
- }
- /* Handle the 'R' reboot packets */
- static int gdb_cmd_reboot(struct kgdb_state *ks)
- {
- /* For now, only honor R0 */
- if (strcmp(remcom_in_buffer, "R0") == 0) {
- printk(KERN_CRIT "Executing emergency reboot\n");
- strcpy(remcom_out_buffer, "OK");
- put_packet(remcom_out_buffer);
- /*
- * Execution should not return from
- * machine_emergency_restart()
- */
- machine_emergency_restart();
- kgdb_connected = 0;
- return 1;
- }
- return 0;
- }
- /* Handle the 'q' query packets */
- static void gdb_cmd_query(struct kgdb_state *ks)
- {
- struct task_struct *g;
- struct task_struct *p;
- unsigned char thref[BUF_THREAD_ID_SIZE];
- char *ptr;
- int i;
- int cpu;
- int finished = 0;
- switch (remcom_in_buffer[1]) {
- case 's':
- case 'f':
- if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
- break;
- i = 0;
- remcom_out_buffer[0] = 'm';
- ptr = remcom_out_buffer + 1;
- if (remcom_in_buffer[1] == 'f') {
- /* Each cpu is a shadow thread */
- for_each_online_cpu(cpu) {
- ks->thr_query = 0;
- int_to_threadref(thref, -cpu - 2);
- ptr = pack_threadid(ptr, thref);
- *(ptr++) = ',';
- i++;
- }
- }
- do_each_thread(g, p) {
- if (i >= ks->thr_query && !finished) {
- int_to_threadref(thref, p->pid);
- ptr = pack_threadid(ptr, thref);
- *(ptr++) = ',';
- ks->thr_query++;
- if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
- finished = 1;
- }
- i++;
- } while_each_thread(g, p);
- *(--ptr) = '\0';
- break;
- case 'C':
- /* Current thread id */
- strcpy(remcom_out_buffer, "QC");
- ks->threadid = shadow_pid(current->pid);
- int_to_threadref(thref, ks->threadid);
- pack_threadid(remcom_out_buffer + 2, thref);
- break;
- case 'T':
- if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
- break;
- ks->threadid = 0;
- ptr = remcom_in_buffer + 17;
- kgdb_hex2long(&ptr, &ks->threadid);
- if (!getthread(ks->linux_regs, ks->threadid)) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- if ((int)ks->threadid > 0) {
- kgdb_mem2hex(getthread(ks->linux_regs,
- ks->threadid)->comm,
- remcom_out_buffer, 16);
- } else {
- static char tmpstr[23 + BUF_THREAD_ID_SIZE];
- sprintf(tmpstr, "shadowCPU%d",
- (int)(-ks->threadid - 2));
- kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
- }
- break;
- #ifdef CONFIG_KGDB_KDB
- case 'R':
- if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
- int len = strlen(remcom_in_buffer + 6);
- if ((len % 2) != 0) {
- strcpy(remcom_out_buffer, "E01");
- break;
- }
- kgdb_hex2mem(remcom_in_buffer + 6,
- remcom_out_buffer, len);
- len = len / 2;
- remcom_out_buffer[len++] = 0;
- kdb_common_init_state(ks);
- kdb_parse(remcom_out_buffer);
- kdb_common_deinit_state();
- strcpy(remcom_out_buffer, "OK");
- }
- break;
- #endif
- }
- }
- /* Handle the 'H' task query packets */
- static void gdb_cmd_task(struct kgdb_state *ks)
- {
- struct task_struct *thread;
- char *ptr;
- switch (remcom_in_buffer[1]) {
- case 'g':
- ptr = &remcom_in_buffer[2];
- kgdb_hex2long(&ptr, &ks->threadid);
- thread = getthread(ks->linux_regs, ks->threadid);
- if (!thread && ks->threadid > 0) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- kgdb_usethread = thread;
- ks->kgdb_usethreadid = ks->threadid;
- strcpy(remcom_out_buffer, "OK");
- break;
- case 'c':
- ptr = &remcom_in_buffer[2];
- kgdb_hex2long(&ptr, &ks->threadid);
- if (!ks->threadid) {
- kgdb_contthread = NULL;
- } else {
- thread = getthread(ks->linux_regs, ks->threadid);
- if (!thread && ks->threadid > 0) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- kgdb_contthread = thread;
- }
- strcpy(remcom_out_buffer, "OK");
- break;
- }
- }
- /* Handle the 'T' thread query packets */
- static void gdb_cmd_thread(struct kgdb_state *ks)
- {
- char *ptr = &remcom_in_buffer[1];
- struct task_struct *thread;
- kgdb_hex2long(&ptr, &ks->threadid);
- thread = getthread(ks->linux_regs, ks->threadid);
- if (thread)
- strcpy(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 kgdb_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 = &remcom_in_buffer[1];
- char *ptr = &remcom_in_buffer[2];
- unsigned long addr;
- unsigned long length;
- int error = 0;
- if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
- /* Unsupported */
- if (*bpt_type > '4')
- return;
- } else {
- if (*bpt_type != '0' && *bpt_type != '1')
- /* Unsupported. */
- return;
- }
- /*
- * Test if this is a hardware breakpoint, and
- * if we support it:
- */
- if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
- /* Unsupported. */
- return;
- if (*(ptr++) != ',') {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- if (!kgdb_hex2long(&ptr, &addr)) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- if (*(ptr++) != ',' ||
- !kgdb_hex2long(&ptr, &length)) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
- error = dbg_set_sw_break(addr);
- else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
- error = dbg_remove_sw_break(addr);
- else if (remcom_in_buffer[0] == 'Z')
- error = arch_kgdb_ops.set_hw_breakpoint(addr,
- (int)length, *bpt_type - '0');
- else if (remcom_in_buffer[0] == 'z')
- error = arch_kgdb_ops.remove_hw_breakpoint(addr,
- (int) length, *bpt_type - '0');
- if (error == 0)
- strcpy(remcom_out_buffer, "OK");
- else
- error_packet(remcom_out_buffer, error);
- }
- /* Handle the 'C' signal / exception passing packets */
- static int gdb_cmd_exception_pass(struct kgdb_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();
- kgdb_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;
- }
- /*
- * This function performs all gdbserial command procesing
- */
- int gdb_serial_stub(struct kgdb_state *ks)
- {
- int error = 0;
- int tmp;
- /* Initialize comm buffer and globals. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
- kgdb_usethread = kgdb_info[ks->cpu].task;
- ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
- ks->pass_exception = 0;
- if (kgdb_connected) {
- unsigned char thref[BUF_THREAD_ID_SIZE];
- char *ptr;
- /* Reply to host that an exception has occurred */
- ptr = remcom_out_buffer;
- *ptr++ = 'T';
- ptr = hex_byte_pack(ptr, ks->signo);
- ptr += strlen(strcpy(ptr, "thread:"));
- int_to_threadref(thref, shadow_pid(current->pid));
- 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);
- 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;
- #if DBG_MAX_REG_NUM > 0
- 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;
- #endif /* DBG_MAX_REG_NUM > 0 */
- 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 */
- case 'k': /* Debugger detach via kill */
- gdb_cmd_detachkill(ks);
- goto default_handle;
- 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;
- #ifdef CONFIG_KGDB_KDB
- case '3': /* Escape into back into kdb */
- if (remcom_in_buffer[1] == '\0') {
- gdb_cmd_detachkill(ks);
- return DBG_PASS_EVENT;
- }
- #endif
- 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 */
- case 's': /* Single step packet */
- if (kgdb_contthread && kgdb_contthread != current) {
- /* Can't switch threads in kgdb */
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- dbg_activate_sw_breakpoints();
- /* Fall through to default processing */
- default:
- default_handle:
- error = kgdb_arch_handle_exception(ks->ex_vector,
- ks->signo,
- ks->err_code,
- remcom_in_buffer,
- remcom_out_buffer,
- ks->linux_regs);
- /*
- * Leave cmd processing on error, detach,
- * kill, continue, or single step.
- */
- if (error >= 0 || remcom_in_buffer[0] == 'D' ||
- remcom_in_buffer[0] == 'k') {
- error = 0;
- goto kgdb_exit;
- }
- }
- /* reply to the request */
- put_packet(remcom_out_buffer);
- }
- kgdb_exit:
- if (ks->pass_exception)
- error = 1;
- return error;
- }
- int gdbstub_state(struct kgdb_state *ks, char *cmd)
- {
- int error;
- switch (cmd[0]) {
- case 'e':
- error = kgdb_arch_handle_exception(ks->ex_vector,
- ks->signo,
- ks->err_code,
- remcom_in_buffer,
- remcom_out_buffer,
- ks->linux_regs);
- return error;
- case 's':
- case 'c':
- strcpy(remcom_in_buffer, cmd);
- return 0;
- case '$':
- strcpy(remcom_in_buffer, cmd);
- gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
- gdbstub_prev_in_buf_pos = 0;
- return 0;
- }
- dbg_io_ops->write_char('+');
- put_packet(remcom_out_buffer);
- return 0;
- }
- /**
- * 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 (!kgdb_connected)
- return;
- kgdb_connected = 0;
- if (!dbg_io_ops || dbg_kdb_mode)
- return;
- buffer[0] = 'W';
- buffer[1] = hex_asc_hi(status);
- buffer[2] = hex_asc_lo(status);
- dbg_io_ops->write_char('$');
- checksum = 0;
- for (loop = 0; loop < 3; loop++) {
- ch = buffer[loop];
- checksum += ch;
- dbg_io_ops->write_char(ch);
- }
- dbg_io_ops->write_char('#');
- dbg_io_ops->write_char(hex_asc_hi(checksum));
- dbg_io_ops->write_char(hex_asc_lo(checksum));
- /* make sure the output is flushed, lest the bootloader clobber it */
- if (dbg_io_ops->flush)
- dbg_io_ops->flush();
- }
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