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Subject[PATCH 2/8] Separate the gdbstub from the debug core
Date
Split the former kernel/kgdb.c into debug_core.c which contains the
kernel debugger exception logic and to the gdbstub.c which contains
the logic for allowing gdb to talk to the debug core.

This also created a private include file called debug_core.h which
contains all the definitions to glue the debug_core to any other
debugger connections.

CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
include/linux/kgdb.h | 1 +
kernel/debug/Makefile | 2 +-
kernel/debug/debug_core.c | 992 ++-------------------------------------------
kernel/debug/debug_core.h | 48 +++
kernel/debug/gdbstub.c | 939 ++++++++++++++++++++++++++++++++++++++++++
5 files changed, 1028 insertions(+), 954 deletions(-)
create mode 100644 kernel/debug/debug_core.h
create mode 100644 kernel/debug/gdbstub.c
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 19ec41a..4830142 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -264,6 +264,7 @@ extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);

extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
+extern struct kgdb_io *dbg_io_ops;

extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
extern int kgdb_mem2hex(char *mem, char *buf, int count);
diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile
index 5287fc8..3657c64 100644
--- a/kernel/debug/Makefile
+++ b/kernel/debug/Makefile
@@ -2,4 +2,4 @@
# Makefile for the linux kernel debugger
#

-obj-$(CONFIG_KGDB) += debug_core.o
\ No newline at end of file
+obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o
\ No newline at end of file
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 761fdd2..ad3caaa 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -1,5 +1,5 @@
/*
- * KGDB stub.
+ * Kernel Debug Core
*
* Maintainer: Jason Wessel <jason.wessel@windriver.com>
*
@@ -9,7 +9,7 @@
* Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
* Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
* Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
- * Copyright (C) 2005-2008 Wind River Systems, Inc.
+ * 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>
*
@@ -37,7 +37,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ptrace.h>
-#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/sched.h>
@@ -52,27 +51,12 @@
#include <asm/byteorder.h>
#include <asm/atomic.h>
#include <asm/system.h>
-#include <asm/unaligned.h>

-static int kgdb_break_asap;
+#include "debug_core.h"

-#define KGDB_MAX_THREAD_QUERY 17
-struct kgdb_state {
- int ex_vector;
- int signo;
- int err_code;
- int cpu;
- int pass_exception;
- unsigned long thr_query;
- unsigned long threadid;
- long kgdb_usethreadid;
- struct pt_regs *linux_regs;
-};
+static int kgdb_break_asap;

-static struct debuggerinfo_struct {
- void *debuggerinfo;
- struct task_struct *task;
-} kgdb_info[NR_CPUS];
+struct debuggerinfo_struct kgdb_info[NR_CPUS];

/**
* kgdb_connected - Is a host GDB connected to us?
@@ -86,7 +70,7 @@ static int kgdb_io_module_registered;
/* Guard for recursive entry */
static int exception_level;

-static struct kgdb_io *kgdb_io_ops;
+struct kgdb_io *dbg_io_ops;
static DEFINE_SPINLOCK(kgdb_registration_lock);

/* kgdb console driver is loaded */
@@ -129,16 +113,7 @@ struct task_struct *kgdb_usethread;
struct task_struct *kgdb_contthread;

int kgdb_single_step;
-pid_t kgdb_sstep_pid;
-
-/* Our I/O buffers. */
-static char remcom_in_buffer[BUFMAX];
-static char remcom_out_buffer[BUFMAX];
-
-/* Storage for the registers, in GDB format. */
-static unsigned long gdb_regs[(NUMREGBYTES +
- sizeof(unsigned long) - 1) /
- sizeof(unsigned long)];
+static pid_t kgdb_sstep_pid;

/* to keep track of the CPU which is doing the single stepping*/
atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1);
@@ -240,329 +215,6 @@ void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
}

/*
- * GDB remote protocol parser:
- */
-
-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;
-}
-
-/* scan for the sequence $<data>#<checksum> */
-static void get_packet(char *buffer)
-{
- unsigned char checksum;
- unsigned char xmitcsum;
- int count;
- char ch;
-
- do {
- /*
- * Spin and wait around for the start character, ignore all
- * other characters:
- */
- while ((ch = (kgdb_io_ops->read_char())) != '$')
- /* 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 = kgdb_io_ops->read_char();
- if (ch == '#')
- break;
- checksum = checksum + ch;
- buffer[count] = ch;
- count = count + 1;
- }
- buffer[count] = 0;
-
- if (ch == '#') {
- xmitcsum = hex(kgdb_io_ops->read_char()) << 4;
- xmitcsum += hex(kgdb_io_ops->read_char());
-
- if (checksum != xmitcsum)
- /* failed checksum */
- kgdb_io_ops->write_char('-');
- else
- /* successful transfer */
- kgdb_io_ops->write_char('+');
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
- }
- } 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;
-
- /*
- * $<packet info>#<checksum>.
- */
- while (1) {
- kgdb_io_ops->write_char('$');
- checksum = 0;
- count = 0;
-
- while ((ch = buffer[count])) {
- kgdb_io_ops->write_char(ch);
- checksum += ch;
- count++;
- }
-
- kgdb_io_ops->write_char('#');
- kgdb_io_ops->write_char(hex_asc_hi(checksum));
- kgdb_io_ops->write_char(hex_asc_lo(checksum));
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
-
- /* Now see what we get in reply. */
- ch = kgdb_io_ops->read_char();
-
- if (ch == 3)
- ch = kgdb_io_ops->read_char();
-
- /* 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 == '$') {
- kgdb_io_ops->write_char('-');
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
- return;
- }
- }
-}
-
-/*
- * 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.
- */
-int 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) {
- while (count > 0) {
- buf = pack_hex_byte(buf, *tmp);
- tmp++;
- count--;
- }
-
- *buf = 0;
- }
-
- return err;
-}
-
-/*
- * Copy the binary array pointed to by buf into mem. Fix $, #, and
- * 0x7d escaped with 0x7d. Return a pointer to the character after
- * the last byte written.
- */
-static int kgdb_ebin2mem(char *buf, char *mem, int count)
-{
- int err = 0;
- char c;
-
- while (count-- > 0) {
- c = *buf++;
- if (c == 0x7d)
- c = *buf++ ^ 0x20;
-
- err = probe_kernel_write(mem, &c, 1);
- if (err)
- break;
-
- mem++;
- }
-
- return err;
-}
-
-/*
- * 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(*tmp_hex--);
- *tmp_raw |= hex(*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(**ptr);
- if (hex_val < 0)
- break;
-
- *long_val = (*long_val << 4) | hex_val;
- num++;
- (*ptr)++;
- }
-
- if (negate)
- *long_val = -*long_val;
-
- return num;
-}
-
-/* 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 16
-
-static char *pack_threadid(char *pkt, unsigned char *id)
-{
- char *limit;
-
- limit = pkt + BUF_THREAD_ID_SIZE;
- while (pkt < limit)
- pkt = pack_hex_byte(pkt, *id++);
-
- return pkt;
-}
-
-static void int_to_threadref(unsigned char *id, int value)
-{
- unsigned char *scan;
- int i = 4;
-
- scan = (unsigned char *)id;
- while (i--)
- *scan++ = 0;
- put_unaligned_be32(value, scan);
-}
-
-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);
-}
-
-/*
* CPU debug state control:
*/

@@ -625,7 +277,7 @@ static void kgdb_flush_swbreak_addr(unsigned long addr)
/*
* SW breakpoint management:
*/
-static int kgdb_activate_sw_breakpoints(void)
+int dbg_activate_sw_breakpoints(void)
{
unsigned long addr;
int error;
@@ -651,7 +303,7 @@ static int kgdb_activate_sw_breakpoints(void)
return ret;
}

-static int kgdb_set_sw_break(unsigned long addr)
+int dbg_set_sw_break(unsigned long addr)
{
int err = kgdb_validate_break_address(addr);
int breakno = -1;
@@ -716,7 +368,7 @@ static int kgdb_deactivate_sw_breakpoints(void)
return ret;
}

-static int kgdb_remove_sw_break(unsigned long addr)
+int dbg_remove_sw_break(unsigned long addr)
{
int i;

@@ -742,7 +394,7 @@ int kgdb_isremovedbreak(unsigned long addr)
return 0;
}

-static int remove_all_break(void)
+int dbg_remove_all_break(void)
{
unsigned long addr;
int error;
@@ -770,53 +422,6 @@ setundefined:
}

/*
- * 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;
-}
-
-static char gdbmsgbuf[BUFMAX + 1];
-
-static void kgdb_msg_write(const char *s, int len)
-{
- char *bufptr;
- int wcount;
- int i;
-
- /* '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 = pack_hex_byte(bufptr, s[i]);
- *bufptr = '\0';
-
- /* Move up */
- s += wcount;
- len -= wcount;
-
- /* Write packet */
- put_packet(gdbmsgbuf);
- }
-}
-
-/*
* Return true if there is a valid kgdb I/O module. Also if no
* debugger is attached a message can be printed to the console about
* waiting for the debugger to attach.
@@ -827,7 +432,7 @@ static void kgdb_msg_write(const char *s, int len)
*/
static int kgdb_io_ready(int print_wait)
{
- if (!kgdb_io_ops)
+ if (!dbg_io_ops)
return 0;
if (kgdb_connected)
return 1;
@@ -838,525 +443,6 @@ static int kgdb_io_ready(int print_wait)
return 1;
}

-/*
- * 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.
- */
- remove_all_break();
-
- remcom_out_buffer[0] = 'S';
- pack_hex_byte(&remcom_out_buffer[1], ks->signo);
-}
-
-/* Handle the 'g' get registers request */
-static void gdb_cmd_getregs(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);
- }
- 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;
- int 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, err);
- } 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");
-}
-
-/* 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 = 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:
- */
- 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[8];
- 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)) {
- error_packet(remcom_out_buffer, -EINVAL);
- 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);
- pack_threadid(ptr, thref);
- ptr += BUF_THREAD_ID_SIZE;
- *(ptr++) = ',';
- i++;
- }
- }
-
- do_each_thread(g, p) {
- if (i >= ks->thr_query && !finished) {
- int_to_threadref(thref, p->pid);
- pack_threadid(ptr, thref);
- ptr += BUF_THREAD_ID_SIZE;
- *(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)) {
- error_packet(remcom_out_buffer, -EINVAL);
- 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;
- }
-}
-
-/* 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 = kgdb_set_sw_break(addr);
- else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
- error = kgdb_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';
- remove_all_break();
- kgdb_connected = 0;
- return 1;
-
- } else {
- kgdb_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
- */
-static int gdb_serial_stub(struct kgdb_state *ks)
-{
- int error = 0;
- int tmp;
-
- /* Clear the out buffer. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
-
- if (kgdb_connected) {
- unsigned char thref[8];
- char *ptr;
-
- /* Reply to host that an exception has occurred */
- ptr = remcom_out_buffer;
- *ptr++ = 'T';
- ptr = pack_hex_byte(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);
- }
-
- kgdb_usethread = kgdb_info[ks->cpu].task;
- ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
- ks->pass_exception = 0;
-
- 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;
- 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;
- 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;
- }
- kgdb_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;
-}
-
static int kgdb_reenter_check(struct kgdb_state *ks)
{
unsigned long addr;
@@ -1375,17 +461,17 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
* user because the user planted a breakpoint in a place that
* KGDB needs in order to function.
*/
- if (kgdb_remove_sw_break(addr) == 0) {
+ if (dbg_remove_sw_break(addr) == 0) {
exception_level = 0;
kgdb_skipexception(ks->ex_vector, ks->linux_regs);
- kgdb_activate_sw_breakpoints();
+ dbg_activate_sw_breakpoints();
printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
addr);
WARN_ON_ONCE(1);

return 1;
}
- remove_all_break();
+ dbg_remove_all_break();
kgdb_skipexception(ks->ex_vector, ks->linux_regs);

if (exception_level > 1) {
@@ -1462,7 +548,7 @@ acquirelock:

if (!kgdb_io_ready(1)) {
error = 1;
- goto kgdb_restore; /* No I/O connection, so resume the system */
+ goto kgdb_restore; /* No I/O connection, resume the system */
}

/*
@@ -1472,8 +558,8 @@ acquirelock:
goto kgdb_restore;

/* Call the I/O driver's pre_exception routine */
- if (kgdb_io_ops->pre_exception)
- kgdb_io_ops->pre_exception();
+ if (dbg_io_ops->pre_exception)
+ dbg_io_ops->pre_exception();

kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
kgdb_info[ks->cpu].task = current;
@@ -1523,8 +609,8 @@ acquirelock:
error = gdb_serial_stub(ks);

/* Call the I/O driver's post_exception routine */
- if (kgdb_io_ops->post_exception)
- kgdb_io_ops->post_exception();
+ if (dbg_io_ops->post_exception)
+ dbg_io_ops->post_exception();

kgdb_info[ks->cpu].debuggerinfo = NULL;
kgdb_info[ks->cpu].task = NULL;
@@ -1584,7 +670,7 @@ static void kgdb_console_write(struct console *co, const char *s,
return;

local_irq_save(flags);
- kgdb_msg_write(s, count);
+ gdbstub_msg_write(s, count);
local_irq_restore(flags);
}

@@ -1596,9 +682,9 @@ static struct console kgdbcons = {
};

#ifdef CONFIG_MAGIC_SYSRQ
-static void sysrq_handle_gdb(int key, struct tty_struct *tty)
+static void sysrq_handle_dbg(int key, struct tty_struct *tty)
{
- if (!kgdb_io_ops) {
+ if (!dbg_io_ops) {
printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
return;
}
@@ -1608,8 +694,8 @@ static void sysrq_handle_gdb(int key, struct tty_struct *tty)
kgdb_breakpoint();
}

-static struct sysrq_key_op sysrq_gdb_op = {
- .handler = sysrq_handle_gdb,
+static struct sysrq_key_op sysrq_dbg_op = {
+ .handler = sysrq_handle_dbg,
.help_msg = "debug(G)",
.action_msg = "DEBUG",
};
@@ -1621,7 +707,7 @@ static void kgdb_register_callbacks(void)
kgdb_io_module_registered = 1;
kgdb_arch_init();
#ifdef CONFIG_MAGIC_SYSRQ
- register_sysrq_key('g', &sysrq_gdb_op);
+ register_sysrq_key('g', &sysrq_dbg_op);
#endif
if (kgdb_use_con && !kgdb_con_registered) {
register_console(&kgdbcons);
@@ -1641,7 +727,7 @@ static void kgdb_unregister_callbacks(void)
kgdb_io_module_registered = 0;
kgdb_arch_exit();
#ifdef CONFIG_MAGIC_SYSRQ
- unregister_sysrq_key('g', &sysrq_gdb_op);
+ unregister_sysrq_key('g', &sysrq_dbg_op);
#endif
if (kgdb_con_registered) {
unregister_console(&kgdbcons);
@@ -1660,17 +746,17 @@ static void kgdb_initial_breakpoint(void)

/**
* kgdb_register_io_module - register KGDB IO module
- * @new_kgdb_io_ops: the io ops vector
+ * @new_dbg_io_ops: the io ops vector
*
* Register it with the KGDB core.
*/
-int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
+int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
{
int err;

spin_lock(&kgdb_registration_lock);

- if (kgdb_io_ops) {
+ if (dbg_io_ops) {
spin_unlock(&kgdb_registration_lock);

printk(KERN_ERR "kgdb: Another I/O driver is already "
@@ -1678,20 +764,20 @@ int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
return -EBUSY;
}

- if (new_kgdb_io_ops->init) {
- err = new_kgdb_io_ops->init();
+ if (new_dbg_io_ops->init) {
+ err = new_dbg_io_ops->init();
if (err) {
spin_unlock(&kgdb_registration_lock);
return err;
}
}

- kgdb_io_ops = new_kgdb_io_ops;
+ dbg_io_ops = new_dbg_io_ops;

spin_unlock(&kgdb_registration_lock);

printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
- new_kgdb_io_ops->name);
+ new_dbg_io_ops->name);

/* Arm KGDB now. */
kgdb_register_callbacks();
@@ -1705,11 +791,11 @@ EXPORT_SYMBOL_GPL(kgdb_register_io_module);

/**
* kkgdb_unregister_io_module - unregister KGDB IO module
- * @old_kgdb_io_ops: the io ops vector
+ * @old_dbg_io_ops: the io ops vector
*
* Unregister it with the KGDB core.
*/
-void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)
+void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops)
{
BUG_ON(kgdb_connected);

@@ -1721,14 +807,14 @@ void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)

spin_lock(&kgdb_registration_lock);

- WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops);
- kgdb_io_ops = NULL;
+ WARN_ON_ONCE(dbg_io_ops != old_dbg_io_ops);
+ dbg_io_ops = NULL;

spin_unlock(&kgdb_registration_lock);

printk(KERN_INFO
"kgdb: Unregistered I/O driver %s, debugger disabled.\n",
- old_kgdb_io_ops->name);
+ old_dbg_io_ops->name);
}
EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);

diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
new file mode 100644
index 0000000..4b9d512
--- /dev/null
+++ b/kernel/debug/debug_core.h
@@ -0,0 +1,48 @@
+/*
+ * Created by: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+
+#ifndef _DEBUG_CORE_H_
+#define _DEBUG_CORE_H_
+/*
+ * These are the private implementation headers between the kernel
+ * debugger core and the debugger front end code.
+ */
+
+/* kernel debug core data structures */
+struct kgdb_state {
+ int ex_vector;
+ int signo;
+ int err_code;
+ int cpu;
+ int pass_exception;
+ unsigned long thr_query;
+ unsigned long threadid;
+ long kgdb_usethreadid;
+ struct pt_regs *linux_regs;
+};
+
+struct debuggerinfo_struct {
+ void *debuggerinfo;
+ struct task_struct *task;
+};
+
+extern struct debuggerinfo_struct kgdb_info[];
+
+/* kernel debug core break point routines */
+extern int dbg_remove_all_break(void);
+extern int dbg_set_sw_break(unsigned long addr);
+extern int dbg_remove_sw_break(unsigned long addr);
+extern int dbg_activate_sw_breakpoints(void);
+
+/* gdbstub interface functions */
+extern int gdb_serial_stub(struct kgdb_state *ks);
+extern void gdbstub_msg_write(const char *s, int len);
+
+#endif /* _DEBUG_CORE_H_ */
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
new file mode 100644
index 0000000..ab29bce
--- /dev/null
+++ b/kernel/debug/gdbstub.c
@@ -0,0 +1,939 @@
+/*
+ * 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@suse.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/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];
+
+/* Storage for the registers, in GDB format. */
+static unsigned long gdb_regs[(NUMREGBYTES +
+ sizeof(unsigned long) - 1) /
+ sizeof(unsigned long)];
+
+/*
+ * GDB remote protocol parser:
+ */
+
+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;
+}
+
+/* scan for the sequence $<data>#<checksum> */
+static void get_packet(char *buffer)
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int count;
+ char ch;
+
+ do {
+ /*
+ * Spin and wait around for the start character, ignore all
+ * other characters:
+ */
+ while ((ch = (dbg_io_ops->read_char())) != '$')
+ /* 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 = dbg_io_ops->read_char();
+ if (ch == '#')
+ break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+ buffer[count] = 0;
+
+ if (ch == '#') {
+ xmitcsum = hex(dbg_io_ops->read_char()) << 4;
+ xmitcsum += hex(dbg_io_ops->read_char());
+
+ 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();
+ }
+ } 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 = dbg_io_ops->read_char();
+
+ if (ch == 3)
+ ch = dbg_io_ops->read_char();
+
+ /* 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;
+
+ /* '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 = pack_hex_byte(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.
+ */
+int 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) {
+ while (count > 0) {
+ buf = pack_hex_byte(buf, *tmp);
+ tmp++;
+ count--;
+ }
+
+ *buf = 0;
+ }
+
+ return err;
+}
+
+/*
+ * 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(*tmp_hex--);
+ *tmp_raw |= hex(*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(**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 a pointer to the character after
+ * the last byte written.
+ */
+static int kgdb_ebin2mem(char *buf, char *mem, int count)
+{
+ int err = 0;
+ char c;
+
+ while (count-- > 0) {
+ c = *buf++;
+ if (c == 0x7d)
+ c = *buf++ ^ 0x20;
+
+ err = probe_kernel_write(mem, &c, 1);
+ if (err)
+ break;
+
+ mem++;
+ }
+
+ return err;
+}
+
+/* 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 16
+
+static char *pack_threadid(char *pkt, unsigned char *id)
+{
+ char *limit;
+
+ limit = pkt + BUF_THREAD_ID_SIZE;
+ while (pkt < limit)
+ pkt = pack_hex_byte(pkt, *id++);
+
+ return pkt;
+}
+
+static void int_to_threadref(unsigned char *id, int value)
+{
+ unsigned char *scan;
+ int i = 4;
+
+ scan = (unsigned char *)id;
+ while (i--)
+ *scan++ = 0;
+ put_unaligned_be32(value, scan);
+}
+
+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';
+ pack_hex_byte(&remcom_out_buffer[1], ks->signo);
+}
+
+/* Handle the 'g' get registers request */
+static void gdb_cmd_getregs(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);
+ }
+ 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;
+ int 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, err);
+ } 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");
+}
+
+/* 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[8];
+ 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)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ 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);
+ pack_threadid(ptr, thref);
+ ptr += BUF_THREAD_ID_SIZE;
+ *(ptr++) = ',';
+ i++;
+ }
+ }
+
+ do_each_thread(g, p) {
+ if (i >= ks->thr_query && !finished) {
+ int_to_threadref(thref, p->pid);
+ pack_threadid(ptr, thref);
+ ptr += BUF_THREAD_ID_SIZE;
+ *(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)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ 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;
+ }
+}
+
+/* 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;
+
+ /* Clear the out buffer. */
+ memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
+
+ if (kgdb_connected) {
+ unsigned char thref[8];
+ char *ptr;
+
+ /* Reply to host that an exception has occurred */
+ ptr = remcom_out_buffer;
+ *ptr++ = 'T';
+ ptr = pack_hex_byte(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);
+ }
+
+ kgdb_usethread = kgdb_info[ks->cpu].task;
+ ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
+ ks->pass_exception = 0;
+
+ 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;
+ 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;
+ 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;
+}
--
1.6.4.rc1


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