kdb: core for kgdb back end (1 of 2)

This patch contains only the kdb core.  Because the change set was
large, it was split.  The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.

This work is directly derived from kdb v4.4 found at:

ftp://oss.sgi.com/projects/kdb/download/v4.4/

The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).

The original version of kdb was 58,000 lines worth of changes to
support x86.  From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.

This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin.  More archictectures can be added by implementing the
architecture specific kgdb functions.

[mort@sgi.com: Compile fix with hugepages enabled]
[mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_]
[mort@sgi.com: fix new line after printing registers]
[mort@sgi.com: Remove the concept of global vs. local breakpoints]
[mort@sgi.com: Rework kdb_si_swapinfo to use more generic name]
[mort@sgi.com: fix the information dump macros, remove 'arch' from the names]
[sfr@canb.auug.org.au: include fixup to include linux/slab.h]

CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>

11 files changed, 5854 insertions, 0 deletions

diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile
index fd4dc6e7782c..a85edc339985 100644
--- a/kernel/debug/Makefile
+++ b/kernel/debug/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o
+obj-$(CONFIG_KGDB_KDB) += kdb/
diff --git a/kernel/debug/kdb/.gitignore b/kernel/debug/kdb/.gitignore
new file mode 100644
index 000000000000..396d12eda9e8
--- /dev/null
+++ b/kernel/debug/kdb/.gitignore
@@ -0,0 +1 @@
+gen-kdb_cmds.c
diff --git a/kernel/debug/kdb/Makefile b/kernel/debug/kdb/Makefile
new file mode 100644
index 000000000000..d1e925eddbcd
--- /dev/null
+++ b/kernel/debug/kdb/Makefile
@@ -0,0 +1,24 @@
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (c) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
+# Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
+#
+
+CCVERSION       := $(shell $(CC) -v 2>&1 | sed -ne '$$p')
+obj-y := kdb_io.o kdb_main.o kdb_support.o kdb_bt.o gen-kdb_cmds.o kdb_bp.o kdb_debugger.o
+
+clean-files := gen-kdb_cmds.c
+
+quiet_cmd_gen-kdb = GENKDB  $@
+      cmd_gen-kdb = $(AWK) 'BEGIN {print "\#include <linux/stddef.h>"; print "\#include <linux/init.h>"} \
+                /^\#/{next} \
+                /^[ \t]*$$/{next} \
+                {gsub(/"/, "\\\"", $$0); \
+                  print "static __initdata char kdb_cmd" cmds++ "[] = \"" $$0 "\\n\";"} \
+                END {print "extern char *kdb_cmds[]; char __initdata *kdb_cmds[] = {"; for (i = 0; i < cmds; ++i) {print "  kdb_cmd" i ","}; print("  NULL\n};");}' \
+                $(filter-out %/Makefile,$^) > $@#
+
+$(obj)/gen-kdb_cmds.c:  $(src)/kdb_cmds $(src)/Makefile
+        $(call cmd,gen-kdb)
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
new file mode 100644
index 000000000000..75bd9b3ebbb7
--- /dev/null
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -0,0 +1,564 @@
+/*
+ * Kernel Debugger Architecture Independent Breakpoint Handler
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
+ * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved.
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/kdb.h>
+#include <linux/kgdb.h>
+#include <linux/smp.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include "kdb_private.h"
+
+/*
+ * Table of kdb_breakpoints
+ */
+kdb_bp_t kdb_breakpoints[KDB_MAXBPT];
+
+static void kdb_setsinglestep(struct pt_regs *regs)
+{
+        KDB_STATE_SET(DOING_SS);
+}
+
+static char *kdb_rwtypes[] = {
+        "Instruction(i)",
+        "Instruction(Register)",
+        "Data Write",
+        "I/O",
+        "Data Access"
+};
+
+static char *kdb_bptype(kdb_bp_t *bp)
+{
+        if (bp->bp_type < 0 || bp->bp_type > 4)
+                return "";
+
+        return kdb_rwtypes[bp->bp_type];
+}
+
+static int kdb_parsebp(int argc, const char **argv, int *nextargp, kdb_bp_t *bp)
+{
+        int nextarg = *nextargp;
+        int diag;
+
+        bp->bph_length = 1;
+        if ((argc + 1) != nextarg) {
+                if (strnicmp(argv[nextarg], "datar", sizeof("datar")) == 0)
+                        bp->bp_type = BP_ACCESS_WATCHPOINT;
+                else if (strnicmp(argv[nextarg], "dataw", sizeof("dataw")) == 0)
+                        bp->bp_type = BP_WRITE_WATCHPOINT;
+                else if (strnicmp(argv[nextarg], "inst", sizeof("inst")) == 0)
+                        bp->bp_type = BP_HARDWARE_BREAKPOINT;
+                else
+                        return KDB_ARGCOUNT;
+
+                bp->bph_length = 1;
+
+                nextarg++;
+
+                if ((argc + 1) != nextarg) {
+                        unsigned long len;
+
+                        diag = kdbgetularg((char *)argv[nextarg],
+                                           &len);
+                        if (diag)
+                                return diag;
+
+
+                        if (len > 8)
+                                return KDB_BADLENGTH;
+
+                        bp->bph_length = len;
+                        nextarg++;
+                }
+
+                if ((argc + 1) != nextarg)
+                        return KDB_ARGCOUNT;
+        }
+
+        *nextargp = nextarg;
+        return 0;
+}
+
+static int _kdb_bp_remove(kdb_bp_t *bp)
+{
+        int ret = 1;
+        if (!bp->bp_installed)
+                return ret;
+        if (!bp->bp_type)
+                ret = dbg_remove_sw_break(bp->bp_addr);
+        else
+                ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr,
+                         bp->bph_length,
+                         bp->bp_type);
+        if (ret == 0)
+                bp->bp_installed = 0;
+        return ret;
+}
+
+static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp)
+{
+        if (KDB_DEBUG(BP))
+                kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs));
+
+        /*
+         * Setup single step
+         */
+        kdb_setsinglestep(regs);
+
+        /*
+         * Reset delay attribute
+         */
+        bp->bp_delay = 0;
+        bp->bp_delayed = 1;
+}
+
+static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
+{
+        int ret;
+        /*
+         * Install the breakpoint, if it is not already installed.
+         */
+
+        if (KDB_DEBUG(BP))
+                kdb_printf("%s: bp_installed %d\n",
+                           __func__, bp->bp_installed);
+        if (!KDB_STATE(SSBPT))
+                bp->bp_delay = 0;
+        if (bp->bp_installed)
+                return 1;
+        if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) {
+                if (KDB_DEBUG(BP))
+                        kdb_printf("%s: delayed bp\n", __func__);
+                kdb_handle_bp(regs, bp);