[GIT PULL] kgdb fixes for 2.6.34-rc2

[GIT PULL] kgdb fixes for 2.6.34-rc2

[Jason Wessel]

Linus, please pull the kgdb-fixes for 2.6.34.  

git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb.git kgdb-fixes

Summary:
  * The first 2 patches are the gdbstub and debug core split from the kdb tree
  * The rest are the fixes cherry picked from the kdb pull request

The previous kdb pull will require a rebase if you accept the kgdb
fixes because there were patch splits that occurred to make this patch
set.

Thanks,
Jason.

---
The following changes since commit 220bf991b0366cc50a94feede3d7341fa5710ee4:
  Linus Torvalds (1):
        Linux 2.6.34-rc2

are available in the git repository at:

Jason Wessel (8):
      Move kernel/kgdb.c to kernel/debug/debug_core.c
      Separate the gdbstub from the debug core
      kgdb: eliminate kgdb_wait(), all cpus enter the same way
      kgdb: have ebin2mem call probe_kernel_write once
      kgdb,debug_core: Use atomic operators which use barriers
      kgdbts,sh: Add in breakpoint pc offset for superh
      debug_core: Turn off tracing while in the debugger
      MAINTAINERS: update kgdb, and debug_core info

 MAINTAINERS               |    5 +-
 drivers/misc/kgdbts.c     |    6 +
 include/linux/kgdb.h      |    1 +
 kernel/Makefile           |    2 +-
 kernel/debug/Makefile     |    5 +
 kernel/debug/debug_core.c |  848 ++++++++++++++++++++++
 kernel/debug/debug_core.h |   55 ++
 kernel/debug/gdbstub.c    |  934 ++++++++++++++++++++++++
 kernel/kgdb.c             | 1763 ---------------------------------------------
 9 files changed, 1853 insertions(+), 1766 deletions(-)
 create mode 100644 kernel/debug/Makefile
 create mode 100644 kernel/debug/debug_core.c
 create mode 100644 kernel/debug/debug_core.h
 create mode 100644 kernel/debug/gdbstub.c
 delete mode 100644 kernel/kgdb.c

[PATCH 1/8] Move kernel/kgdb.c to kernel/debug/debug_core.c

[Jason Wessel]

Move kgdb.c in preparation to separate the gdbstub from the debug
core and exception handling.

CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 kernel/Makefile                       |    2 +-
 kernel/debug/Makefile                 |    5 +++++
 kernel/{kgdb.c => debug/debug_core.c} |    0
 3 files changed, 6 insertions(+), 1 deletions(-)
 create mode 100644 kernel/debug/Makefile
 rename kernel/{kgdb.c => debug/debug_core.c} (100%)

diff --git a/kernel/Makefile b/kernel/Makefile
index a987aa1..80b17ce 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -75,7 +75,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
 obj-$(CONFIG_GCOV_KERNEL) += gcov/
 obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
 obj-$(CONFIG_KPROBES) += kprobes.o
-obj-$(CONFIG_KGDB) += kgdb.o
+obj-$(CONFIG_KGDB) += debug/
 obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
 obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
 obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile
new file mode 100644
index 0000000..5287fc8
--- /dev/null
+++ b/kernel/debug/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the linux kernel debugger
+#
+
+obj-$(CONFIG_KGDB) += debug_core.o
\ No newline at end of file
diff --git a/kernel/kgdb.c b/kernel/debug/debug_core.c
similarity index 100%
rename from kernel/kgdb.c
rename to kernel/debug/debug_core.c
-- 
1.6.4.rc1

[PATCH 2/8] Separate the gdbstub from the debug core

[Jason Wessel]

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

[PATCH 3/8] kgdb: eliminate kgdb_wait(), all cpus enter the same way

[Jason Wessel]

This is a kgdb architectural change to have all the cpus (master or
slave) enter the same function.

A cpu that hits an exception (wants to be the master cpu) will call
kgdb_handle_exception() from the trap handler and then invoke a
kgdb_roundup_cpu() to synchronize the other cpus and bring them into
the kgdb_handle_exception() as well.

A slave cpu will enter kgdb_handle_exception() from the
kgdb_nmicallback() and set the exception state to note that the
processor is a slave.

Previously the salve cpu would have called kgdb_wait().  This change
allows the debug core to change cpus without resuming the system in
order to inspect arch specific cpu information.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 kernel/debug/debug_core.c |  158 +++++++++++++++++++++-----------------------
 kernel/debug/debug_core.h |    7 ++
 2 files changed, 82 insertions(+), 83 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index ad3caaa..91286e8 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -215,49 +215,6 @@ void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
 }
 
 /*
- * CPU debug state control:
- */
-
-#ifdef CONFIG_SMP
-static void kgdb_wait(struct pt_regs *regs)
-{
-	unsigned long flags;
-	int cpu;
-
-	local_irq_save(flags);
-	cpu = raw_smp_processor_id();
-	kgdb_info[cpu].debuggerinfo = regs;
-	kgdb_info[cpu].task = current;
-	/*
-	 * Make sure the above info reaches the primary CPU before
-	 * our cpu_in_kgdb[] flag setting does:
-	 */
-	smp_wmb();
-	atomic_set(&cpu_in_kgdb[cpu], 1);
-
-	/* Disable any cpu specific hw breakpoints */
-	kgdb_disable_hw_debug(regs);
-
-	/* Wait till primary CPU is done with debugging */
-	while (atomic_read(&passive_cpu_wait[cpu]))
-		cpu_relax();
-
-	kgdb_info[cpu].debuggerinfo = NULL;
-	kgdb_info[cpu].task = NULL;
-
-	/* fix up hardware debug registers on local cpu */
-	if (arch_kgdb_ops.correct_hw_break)
-		arch_kgdb_ops.correct_hw_break();
-
-	/* Signal the primary CPU that we are done: */
-	atomic_set(&cpu_in_kgdb[cpu], 0);
-	touch_softlockup_watchdog_sync();
-	clocksource_touch_watchdog();
-	local_irq_restore(flags);
-}
-#endif
-
-/*
  * Some architectures need cache flushes when we set/clear a
  * breakpoint:
  */
@@ -486,34 +443,12 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
 	return 1;
 }
 
-/*
- * kgdb_handle_exception() - main entry point from a kernel exception
- *
- * Locking hierarchy:
- *	interface locks, if any (begin_session)
- *	kgdb lock (kgdb_active)
- */
-int
-kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
 {
-	struct kgdb_state kgdb_var;
-	struct kgdb_state *ks = &kgdb_var;
 	unsigned long flags;
 	int sstep_tries = 100;
 	int error = 0;
 	int i, cpu;
-
-	ks->cpu			= raw_smp_processor_id();
-	ks->ex_vector		= evector;
-	ks->signo		= signo;
-	ks->ex_vector		= evector;
-	ks->err_code		= ecode;
-	ks->kgdb_usethreadid	= 0;
-	ks->linux_regs		= regs;
-
-	if (kgdb_reenter_check(ks))
-		return 0; /* Ouch, double exception ! */
-
 acquirelock:
 	/*
 	 * Interrupts will be restored by the 'trap return' code, except when
@@ -521,13 +456,42 @@ acquirelock:
 	 */
 	local_irq_save(flags);
 
-	cpu = raw_smp_processor_id();
+	cpu = ks->cpu;
+	kgdb_info[cpu].debuggerinfo = regs;
+	kgdb_info[cpu].task = current;
+	/*
+	 * Make sure the above info reaches the primary CPU before
+	 * our cpu_in_kgdb[] flag setting does:
+	 */
+	smp_wmb();
+	atomic_set(&cpu_in_kgdb[cpu], 1);
 
 	/*
-	 * Acquire the kgdb_active lock:
+	 * CPU will loop if it is a slave or request to become a kgdb
+	 * master cpu and acquire the kgdb_active lock:
 	 */
-	while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
+	while (1) {
+		if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
+			if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
+				break;
+		} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
+			if (!atomic_read(&passive_cpu_wait[cpu]))
+				goto return_normal;
+		} else {
+return_normal:
+			/* Return to normal operation by executing any
+			 * hw breakpoint fixup.
+			 */
+			if (arch_kgdb_ops.correct_hw_break)
+				arch_kgdb_ops.correct_hw_break();
+			atomic_set(&cpu_in_kgdb[cpu], 0);
+			touch_softlockup_watchdog_sync();
+			clocksource_touch_watchdog();
+			local_irq_restore(flags);
+			return 0;
+		}
 		cpu_relax();
+	}
 
 	/*
 	 * For single stepping, try to only enter on the processor
@@ -561,9 +525,6 @@ acquirelock:
 	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;
-
 	kgdb_disable_hw_debug(ks->linux_regs);
 
 	/*
@@ -575,12 +536,6 @@ acquirelock:
 			atomic_set(&passive_cpu_wait[i], 1);
 	}
 
-	/*
-	 * spin_lock code is good enough as a barrier so we don't
-	 * need one here:
-	 */
-	atomic_set(&cpu_in_kgdb[ks->cpu], 1);
-
 #ifdef CONFIG_SMP
 	/* Signal the other CPUs to enter kgdb_wait() */
 	if ((!kgdb_single_step) && kgdb_do_roundup)
@@ -612,8 +567,6 @@ acquirelock:
 	if (dbg_io_ops->post_exception)
 		dbg_io_ops->post_exception();
 
-	kgdb_info[ks->cpu].debuggerinfo = NULL;
-	kgdb_info[ks->cpu].task = NULL;
 	atomic_set(&cpu_in_kgdb[ks->cpu], 0);
 
 	if (!kgdb_single_step) {
@@ -646,13 +599,52 @@ kgdb_restore:
 	return error;
 }
 
+/*
+ * kgdb_handle_exception() - main entry point from a kernel exception
+ *
+ * Locking hierarchy:
+ *	interface locks, if any (begin_session)
+ *	kgdb lock (kgdb_active)
+ */
+int
+kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+{
+	struct kgdb_state kgdb_var;
+	struct kgdb_state *ks = &kgdb_var;
+	int ret;
+
+	ks->cpu			= raw_smp_processor_id();
+	ks->ex_vector		= evector;
+	ks->signo		= signo;
+	ks->ex_vector		= evector;
+	ks->err_code		= ecode;
+	ks->kgdb_usethreadid	= 0;
+	ks->linux_regs		= regs;
+
+	if (kgdb_reenter_check(ks))
+		return 0; /* Ouch, double exception ! */
+	kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER;
+	ret = kgdb_cpu_enter(ks, regs);
+	kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER;
+	return ret;
+}
+
 int kgdb_nmicallback(int cpu, void *regs)
 {
 #ifdef CONFIG_SMP
+	struct kgdb_state kgdb_var;
+	struct kgdb_state *ks = &kgdb_var;
+
+	memset(ks, 0, sizeof(struct kgdb_state));
+	ks->cpu			= cpu;
+	ks->linux_regs		= regs;
+
 	if (!atomic_read(&cpu_in_kgdb[cpu]) &&
-			atomic_read(&kgdb_active) != cpu &&
-			atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
-		kgdb_wait((struct pt_regs *)regs);
+	    atomic_read(&kgdb_active) != -1 &&
+	    atomic_read(&kgdb_active) != cpu) {
+		kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
+		kgdb_cpu_enter(ks, regs);
+		kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
 		return 0;
 	}
 #endif
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 4b9d512..9825c5e 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -28,9 +28,16 @@ struct kgdb_state {
 	struct pt_regs		*linux_regs;
 };
 
+/* Exception state values */
+#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
+#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
+#define DCPU_IS_SLAVE    0x4 /* Slave cpu enter exception */
+#define DCPU_SSTEP       0x8 /* CPU is single stepping */
+
 struct debuggerinfo_struct {
 	void			*debuggerinfo;
 	struct task_struct	*task;
+	int exception_state;
 };
 
 extern struct debuggerinfo_struct kgdb_info[];
-- 
1.6.4.rc1

[PATCH 4/8] kgdb: have ebin2mem call probe_kernel_write once

[Jason Wessel]

Rather than call probe_kernel_write() one byte at a time, process the
whole buffer locally and pass the entire result in one go.  This way,
architectures that need to do special handling based on the length can
do so, or we only end up calling memcpy() once.

[sonic.zhang@analog.com: Reported original problem and preliminary patch]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 kernel/debug/gdbstub.c |   23 +++++++++--------------
 1 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index ab29bce..ccdf092 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -293,27 +293,22 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val)
 
 /*
  * 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.
+ * 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 err = 0;
-	char c;
+	int size = 0;
+	char *c = buf;
 
 	while (count-- > 0) {
-		c = *buf++;
-		if (c == 0x7d)
-			c = *buf++ ^ 0x20;
-
-		err = probe_kernel_write(mem, &c, 1);
-		if (err)
-			break;
-
-		mem++;
+		c[size] = *buf++;
+		if (c[size] == 0x7d)
+			c[size] = *buf++ ^ 0x20;
+		size++;
 	}
 
-	return err;
+	return probe_kernel_write(mem, c, size);
 }
 
 /* Write memory due to an 'M' or 'X' packet. */
-- 
1.6.4.rc1

[PATCH 5/8] kgdb,debug_core: Use atomic operators which use barriers

[Jason Wessel]

A cpu_relax() does not mandate that there is an smp memory barrier.
As a result on the arm smp architecture the kernel debugger can hang
on entry from time to time, as shown by the kgdb regression tests.

The solution is simply to use the atomic operators which include a
proper smp memory barrier, instead of using atomic_set() and
atomic_read().

Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 kernel/debug/debug_core.c |   21 ++++++++++-----------
 1 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 91286e8..f471268 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -463,8 +463,7 @@ acquirelock:
 	 * Make sure the above info reaches the primary CPU before
 	 * our cpu_in_kgdb[] flag setting does:
 	 */
-	smp_wmb();
-	atomic_set(&cpu_in_kgdb[cpu], 1);
+	atomic_inc(&cpu_in_kgdb[cpu]);
 
 	/*
 	 * CPU will loop if it is a slave or request to become a kgdb
@@ -475,7 +474,7 @@ acquirelock:
 			if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
 				break;
 		} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
-			if (!atomic_read(&passive_cpu_wait[cpu]))
+			if (!atomic_add_return(0, &passive_cpu_wait[cpu]))
 				goto return_normal;
 		} else {
 return_normal:
@@ -484,7 +483,7 @@ return_normal:
 			 */
 			if (arch_kgdb_ops.correct_hw_break)
 				arch_kgdb_ops.correct_hw_break();
-			atomic_set(&cpu_in_kgdb[cpu], 0);
+			atomic_dec(&cpu_in_kgdb[cpu]);
 			touch_softlockup_watchdog_sync();
 			clocksource_touch_watchdog();
 			local_irq_restore(flags);
@@ -533,7 +532,7 @@ return_normal:
 	 */
 	if (!kgdb_single_step) {
 		for (i = 0; i < NR_CPUS; i++)
-			atomic_set(&passive_cpu_wait[i], 1);
+			atomic_inc(&passive_cpu_wait[i]);
 	}
 
 #ifdef CONFIG_SMP
@@ -546,7 +545,7 @@ return_normal:
 	 * Wait for the other CPUs to be notified and be waiting for us:
 	 */
 	for_each_online_cpu(i) {
-		while (!atomic_read(&cpu_in_kgdb[i]))
+		while (!atomic_add_return(0, &cpu_in_kgdb[i]))
 			cpu_relax();
 	}
 
@@ -567,17 +566,17 @@ return_normal:
 	if (dbg_io_ops->post_exception)
 		dbg_io_ops->post_exception();
 
-	atomic_set(&cpu_in_kgdb[ks->cpu], 0);
+	atomic_dec(&cpu_in_kgdb[ks->cpu]);
 
 	if (!kgdb_single_step) {
 		for (i = NR_CPUS-1; i >= 0; i--)
-			atomic_set(&passive_cpu_wait[i], 0);
+			atomic_dec(&passive_cpu_wait[i]);
 		/*
 		 * Wait till all the CPUs have quit
 		 * from the debugger.
 		 */
 		for_each_online_cpu(i) {
-			while (atomic_read(&cpu_in_kgdb[i]))
+			while (atomic_add_return(0, &cpu_in_kgdb[i]))
 				cpu_relax();
 		}
 	}
@@ -820,11 +819,11 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
  */
 void kgdb_breakpoint(void)
 {
-	atomic_set(&kgdb_setting_breakpoint, 1);
+	atomic_inc(&kgdb_setting_breakpoint);
 	wmb(); /* Sync point before breakpoint */
 	arch_kgdb_breakpoint();
 	wmb(); /* Sync point after breakpoint */
-	atomic_set(&kgdb_setting_breakpoint, 0);
+	atomic_dec(&kgdb_setting_breakpoint);
 }
 EXPORT_SYMBOL_GPL(kgdb_breakpoint);
 
-- 
1.6.4.rc1

[PATCH 6/8] kgdbts,sh: Add in breakpoint pc offset for superh

[Jason Wessel]

The kgdb test suite mimics the behavior of gdb.  For the sh
architecture the pc must be decremented by 2 for software breakpoint.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
---
 drivers/misc/kgdbts.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index fcb6ec1..7245023 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -295,6 +295,10 @@ static int check_and_rewind_pc(char *put_str, char *arg)
 	/* On x86 a breakpoint stop requires it to be decremented */
 	if (addr + 1 == kgdbts_regs.ip)
 		offset = -1;
+#elif defined(CONFIG_SUPERH)
+	/* On SUPERH a breakpoint stop requires it to be decremented */
+	if (addr + 2 == kgdbts_regs.pc)
+		offset = -2;
 #endif
 	if (strcmp(arg, "silent") &&
 		instruction_pointer(&kgdbts_regs) + offset != addr) {
@@ -305,6 +309,8 @@ static int check_and_rewind_pc(char *put_str, char *arg)
 #ifdef CONFIG_X86
 	/* On x86 adjust the instruction pointer if needed */
 	kgdbts_regs.ip += offset;
+#elif defined(CONFIG_SUPERH)
+	kgdbts_regs.pc += offset;
 #endif
 	return 0;
 }
-- 
1.6.4.rc1

[PATCH 7/8] debug_core: Turn off tracing while in the debugger

[Jason Wessel]

The kernel debugger should turn off kernel tracing any time the
debugger is active and restore it on resume.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/debug/debug_core.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index f471268..ab2a43f 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -449,6 +449,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
 	int sstep_tries = 100;
 	int error = 0;
 	int i, cpu;
+	int trace_on = 0;
 acquirelock:
 	/*
 	 * Interrupts will be restored by the 'trap return' code, except when
@@ -483,6 +484,8 @@ return_normal:
 			 */
 			if (arch_kgdb_ops.correct_hw_break)
 				arch_kgdb_ops.correct_hw_break();
+			if (trace_on)
+				tracing_on();
 			atomic_dec(&cpu_in_kgdb[cpu]);
 			touch_softlockup_watchdog_sync();
 			clocksource_touch_watchdog();
@@ -558,6 +561,9 @@ return_normal:
 	kgdb_single_step = 0;
 	kgdb_contthread = current;
 	exception_level = 0;
+	trace_on = tracing_is_on();
+	if (trace_on)
+		tracing_off();
 
 	/* Talk to debugger with gdbserial protocol */
 	error = gdb_serial_stub(ks);
@@ -589,6 +595,8 @@ kgdb_restore:
 		else
 			kgdb_sstep_pid = 0;
 	}
+	if (trace_on)
+		tracing_on();
 	/* Free kgdb_active */
 	atomic_set(&kgdb_active, -1);
 	touch_softlockup_watchdog_sync();
-- 
1.6.4.rc1

[PATCH 8/8] MAINTAINERS: update kgdb, and debug_core info

[Jason Wessel]

Update the kgdb section.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 MAINTAINERS |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 449d444..2468613 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3269,15 +3269,16 @@ S:	Maintained
 F:	include/linux/kexec.h
 F:	kernel/kexec.c
 
-KGDB
+KGDB / debug_core
 M:	Jason Wessel <jason.wessel@windriver.com>
+W:	http://kgdb.wiki.kernel.org/
 L:	kgdb-bugreport@lists.sourceforge.net
 S:	Maintained
 F:	Documentation/DocBook/kgdb.tmpl
 F:	drivers/misc/kgdbts.c
 F:	drivers/serial/kgdboc.c
 F:	include/linux/kgdb.h
-F:	kernel/kgdb.c
+F:	kernel/debug/
 
 KMEMCHECK
 M:	Vegard Nossum <vegardno@ifi.uio.no>
-- 
1.6.4.rc1

Re: [GIT PULL] kgdb fixes for 2.6.34-rc2

[Jason Wessel]

On 03/22/2010 02:17 PM, Jason Wessel wrote:
> Linus, please pull the kgdb-fixes for 2.6.34.  
>
> git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb.git kgdb-fixes
>
> Summary:
>   * The first 2 patches are the gdbstub and debug core split from the kdb tree
>   * The rest are the fixes cherry picked from the kdb pull request
>
> The previous kdb pull will require a rebase if you accept the kgdb
> fixes because there were patch splits that occurred to make this patch
> set.
>
>   

Ping.

Linus, please help me understand how we can continue to move forward on
the kernel debugger pull requests.  There have been numerous requests
that have not been pulled and have no response as to what needs to be
acted on to resolve any outstanding issues.

Thanks,
Jason.

Re: [GIT PULL] kgdb fixes for 2.6.34-rc2

[Linus Torvalds]

On Mon, 29 Mar 2010, Jason Wessel wrote:
>
> Ping.
> 
> Linus, please help me understand how we can continue to move forward on
> the kernel debugger pull requests.  There have been numerous requests
> that have not been pulled and have no response as to what needs to be
> acted on to resolve any outstanding issues.

I've been swamped and bad, and since I wrote another email to explain why 
I'm always so grumpy (unrelated thread, nothing to do with kgdb), I'll 
cut-and-paste some of the relevant explanation for my pulling (or not 
pulling, as in this case) here too..

--> begin cut-and-pastee <--
  
  Even on the merging side, what ends up happening is that some trees I 
  decide I can't afford to merge, simply because the potential pain of 
  merging without knowing the code is too high. So I can merge a new 
  filesystem without any issues - if it's buggy, all I need to know is "new 
  filesystem craps out". But when it comes to core generic code that anybody 
  can hit, I have to _rely_ on submaintainers doing the right thing.
  
  And when that doesn't work out, and stuff falls through the cracks, I'm 
  kind of screwed. And this looked like a "fall through the cracks" thing.
  
  [ I skipped the kdb merge this window, for example, and I feel bad about 
    that, and will have to walk over the pull request with a comb once the 
    merge window fallout calms down, so that I can do it the next merge 
    window. Not because I need to understand each line, but because I 
    need to understand what the potential bigger-picture impacts are when 
    something that looks odd pops up ]
  
--> end cut-and-paste <--

and obviously one of the issues is that I end up always prioritizing my 
pulls etc, and because I'm not a huge fan of debuggers (understatement of 
the year), that pull request was always at the bottom of the pile. And 
this merge window I ended up having some Intel event things that took up a 
good chunk of the window, so I never did get to that bottom.

Usually things calm down for me at around -rc4, when it turns into a 
waiting game instead of fighting fires. So I'm expecting to do that "look 
things over" this weekend or next week. 

			Linus

Re: [GIT PULL] kgdb fixes for 2.6.34-rc2

[Jason Wessel]

On 04/01/2010 11:04 AM, Linus Torvalds wrote:
>
> Usually things calm down for me at around -rc4, when it turns into a 
> waiting game instead of fighting fires. So I'm expecting to do that "look 
> things over" this weekend or next week. 
>
>   

Thanks for the response.   Please do let me know if you have any
questions about the kdb patches.

I can repost the series with the minor changes and base it off the
pending kgdb-fixes pull request.

Thanks,
Jason.