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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/kernel.h>#include <linux/sched/signal.h>#include <linux/hex.h>#include <linux/kgdb.h>#include <linux/kdb.h>#include <linux/serial_core.h>#include <linux/string.h>#include <linux/reboot.h>#include <linux/uaccess.h>#include <asm/cacheflush.h>#include <linux/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_KDBstatic 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;}#elsestatic 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 = copy_from_kernel_nofault(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 copy_to_kernel_nofault(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 overwritten 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 copy_to_kernel_nofault(mem, c, size);}
#if DBG_MAX_REG_NUM > 0void 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_cpu_enter(), 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); strscpy(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 strscpy(remcom_out_buffer, "OK");}
#if DBG_MAX_REG_NUM > 0static 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 register 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 register 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); strscpy(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 strscpy(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 { strscpy(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"); strscpy(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++; } }
for_each_process_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++; }
*(--ptr) = '\0'; break;
case 'C': /* Current thread id */ strscpy(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) { strscpy(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();
strscpy(remcom_out_buffer, "OK"); } break;#endif#ifdef CONFIG_HAVE_ARCH_KGDB_QXFER_PKT case 'S': if (!strncmp(remcom_in_buffer, "qSupported:", 11)) strscpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature); break; case 'X': if (!strncmp(remcom_in_buffer, "qXfer:", 6)) kgdb_arch_handle_qxfer_pkt(remcom_in_buffer, remcom_out_buffer); break;#endif default: break; }}
/* 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; strscpy(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; } strscpy(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) strscpy(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) strscpy(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 processing */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; } fallthrough;#endif case 'C': /* Exception passing */ tmp = gdb_cmd_exception_pass(ks); if (tmp > 0) goto default_handle; if (tmp == 0) break; fallthrough; /* 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; } fallthrough; /* 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': strscpy(remcom_in_buffer, cmd, sizeof(remcom_in_buffer)); return 0; case '$': strscpy(remcom_in_buffer, cmd, sizeof(remcom_in_buffer)); 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();}