From d027fdc4fa30a409e7425219d0d089e4e4ebdc4d Mon Sep 17 00:00:00 2001
From: Sumit Garg <sumit.garg@linaro.org>
Date: Wed, 24 Feb 2021 12:46:53 +0530
Subject: [PATCH 1/4] kdb: Remove redundant function definitions/prototypes

Cleanup kdb code to get rid of unused function definitions/prototypes.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/20210224071653.409150-1-sumit.garg@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
 kernel/debug/kdb/kdb_private.h |  2 --
 kernel/debug/kdb/kdb_support.c | 18 ------------------
 2 files changed, 20 deletions(-)

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 6cb92f7bbbd0c..135a706c2e783 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -207,9 +207,7 @@ extern unsigned long kdb_task_state(const struct task_struct *p,
 				    unsigned long mask);
 extern void kdb_ps_suppressed(void);
 extern void kdb_ps1(const struct task_struct *p);
-extern void kdb_print_nameval(const char *name, unsigned long val);
 extern void kdb_send_sig(struct task_struct *p, int sig);
-extern void kdb_meminfo_proc_show(void);
 extern char kdb_getchar(void);
 extern char *kdb_getstr(char *, size_t, const char *);
 extern void kdb_gdb_state_pass(char *buf);
diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index f7c1885abeb69..91bb666d7c039 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -654,24 +654,6 @@ unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask)
 	return (mask & kdb_task_state_string(state)) != 0;
 }
 
-/*
- * kdb_print_nameval - Print a name and its value, converting the
- *	value to a symbol lookup if possible.
- * Inputs:
- *	name	field name to print
- *	val	value of field
- */
-void kdb_print_nameval(const char *name, unsigned long val)
-{
-	kdb_symtab_t symtab;
-	kdb_printf("  %-11.11s ", name);
-	if (kdbnearsym(val, &symtab))
-		kdb_symbol_print(val, &symtab,
-				 KDB_SP_VALUE|KDB_SP_SYMSIZE|KDB_SP_NEWLINE);
-	else
-		kdb_printf("0x%lx\n", val);
-}
-
 /* Last ditch allocator for debugging, so we can still debug even when
  * the GFP_ATOMIC pool has been exhausted.  The algorithms are tuned
  * for space usage, not for speed.  One smallish memory pool, the free

From e4f291b3f7bb1855318e1009de65585a72d595ad Mon Sep 17 00:00:00 2001
From: Sumit Garg <sumit.garg@linaro.org>
Date: Wed, 24 Feb 2021 12:38:27 +0530
Subject: [PATCH 2/4] kdb: Simplify kdb commands registration

Simplify kdb commands registration via using linked list instead of
static array for commands storage.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/20210224070827.408771-1-sumit.garg@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
[daniel.thompson@linaro.org: Removed a bunch of .cmd_minline = 0
initializers]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
 kernel/debug/kdb/kdb_bp.c      |  75 ++++--
 kernel/debug/kdb/kdb_main.c    | 446 +++++++++++++++++++--------------
 kernel/debug/kdb/kdb_private.h |   3 +
 3 files changed, 311 insertions(+), 213 deletions(-)

diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index ec49401466123..2168f8dacb994 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -522,6 +522,54 @@ static int kdb_ss(int argc, const char **argv)
 	return KDB_CMD_SS;
 }
 
+static kdbtab_t bptab[] = {
+	{	.cmd_name = "bp",
+		.cmd_func = kdb_bp,
+		.cmd_usage = "[<vaddr>]",
+		.cmd_help = "Set/Display breakpoints",
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "bl",
+		.cmd_func = kdb_bp,
+		.cmd_usage = "[<vaddr>]",
+		.cmd_help = "Display breakpoints",
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "bc",
+		.cmd_func = kdb_bc,
+		.cmd_usage = "<bpnum>",
+		.cmd_help = "Clear Breakpoint",
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL,
+	},
+	{	.cmd_name = "be",
+		.cmd_func = kdb_bc,
+		.cmd_usage = "<bpnum>",
+		.cmd_help = "Enable Breakpoint",
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL,
+	},
+	{	.cmd_name = "bd",
+		.cmd_func = kdb_bc,
+		.cmd_usage = "<bpnum>",
+		.cmd_help = "Disable Breakpoint",
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL,
+	},
+	{	.cmd_name = "ss",
+		.cmd_func = kdb_ss,
+		.cmd_usage = "",
+		.cmd_help = "Single Step",
+		.cmd_minlen = 1,
+		.cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS,
+	},
+};
+
+static kdbtab_t bphcmd = {
+	.cmd_name = "bph",
+	.cmd_func = kdb_bp,
+	.cmd_usage = "[<vaddr>]",
+	.cmd_help = "[datar [length]|dataw [length]]   Set hw brk",
+	.cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS,
+};
+
 /* Initialize the breakpoint table and register	breakpoint commands. */
 
 void __init kdb_initbptab(void)
@@ -537,30 +585,7 @@ void __init kdb_initbptab(void)
 	for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
 		bp->bp_free = 1;
 
-	kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
-		"Set/Display breakpoints", 0,
-		KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
-		"Display breakpoints", 0,
-		KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+	kdb_register_table(bptab, ARRAY_SIZE(bptab));
 	if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
-		kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
-		"[datar [length]|dataw [length]]   Set hw brk", 0,
-		KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("bc", kdb_bc, "<bpnum>",
-		"Clear Breakpoint", 0,
-		KDB_ENABLE_FLOW_CTRL);
-	kdb_register_flags("be", kdb_bc, "<bpnum>",
-		"Enable Breakpoint", 0,
-		KDB_ENABLE_FLOW_CTRL);
-	kdb_register_flags("bd", kdb_bc, "<bpnum>",
-		"Disable Breakpoint", 0,
-		KDB_ENABLE_FLOW_CTRL);
-
-	kdb_register_flags("ss", kdb_ss, "",
-		"Single Step", 1,
-		KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
-	/*
-	 * Architecture dependent initialization.
-	 */
+		kdb_register_table(&bphcmd, 1);
 }
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 930ac1b25ec7c..95a1b1f543269 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -33,6 +33,7 @@
 #include <linux/kallsyms.h>
 #include <linux/kgdb.h>
 #include <linux/kdb.h>
+#include <linux/list.h>
 #include <linux/notifier.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
@@ -84,15 +85,8 @@ static unsigned int kdb_continue_catastrophic =
 static unsigned int kdb_continue_catastrophic;
 #endif
 
-/* kdb_commands describes the available commands. */
-static kdbtab_t *kdb_commands;
-#define KDB_BASE_CMD_MAX 50
-static int kdb_max_commands = KDB_BASE_CMD_MAX;
-static kdbtab_t kdb_base_commands[KDB_BASE_CMD_MAX];
-#define for_each_kdbcmd(cmd, num)					\
-	for ((cmd) = kdb_base_commands, (num) = 0;			\
-	     num < kdb_max_commands;					\
-	     num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
+/* kdb_cmds_head describes the available commands. */
+static LIST_HEAD(kdb_cmds_head);
 
 typedef struct _kdbmsg {
 	int	km_diag;	/* kdb diagnostic */
@@ -921,7 +915,7 @@ int kdb_parse(const char *cmdstr)
 	char *cp;
 	char *cpp, quoted;
 	kdbtab_t *tp;
-	int i, escaped, ignore_errors = 0, check_grep = 0;
+	int escaped, ignore_errors = 0, check_grep = 0;
 
 	/*
 	 * First tokenize the command string.
@@ -1011,25 +1005,17 @@ int kdb_parse(const char *cmdstr)
 		++argv[0];
 	}
 
-	for_each_kdbcmd(tp, i) {
-		if (tp->cmd_name) {
-			/*
-			 * If this command is allowed to be abbreviated,
-			 * check to see if this is it.
-			 */
-
-			if (tp->cmd_minlen
-			 && (strlen(argv[0]) <= tp->cmd_minlen)) {
-				if (strncmp(argv[0],
-					    tp->cmd_name,
-					    tp->cmd_minlen) == 0) {
-					break;
-				}
-			}
+	list_for_each_entry(tp, &kdb_cmds_head, list_node) {
+		/*
+		 * If this command is allowed to be abbreviated,
+		 * check to see if this is it.
+		 */
+		if (tp->cmd_minlen && (strlen(argv[0]) <= tp->cmd_minlen) &&
+		    (strncmp(argv[0], tp->cmd_name, tp->cmd_minlen) == 0))
+			break;
 
-			if (strcmp(argv[0], tp->cmd_name) == 0)
-				break;
-		}
+		if (strcmp(argv[0], tp->cmd_name) == 0)
+			break;
 	}
 
 	/*
@@ -1037,19 +1023,15 @@ int kdb_parse(const char *cmdstr)
 	 * few characters of this match any of the known commands.
 	 * e.g., md1c20 should match md.
 	 */
-	if (i == kdb_max_commands) {
-		for_each_kdbcmd(tp, i) {
-			if (tp->cmd_name) {
-				if (strncmp(argv[0],
-					    tp->cmd_name,
-					    strlen(tp->cmd_name)) == 0) {
-					break;
-				}
-			}
+	if (list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
+		list_for_each_entry(tp, &kdb_cmds_head, list_node) {
+			if (strncmp(argv[0], tp->cmd_name,
+				    strlen(tp->cmd_name)) == 0)
+				break;
 		}
 	}
 
-	if (i < kdb_max_commands) {
+	if (!list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
 		int result;
 
 		if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
@@ -2428,17 +2410,14 @@ static int kdb_kgdb(int argc, const char **argv)
 static int kdb_help(int argc, const char **argv)
 {
 	kdbtab_t *kt;
-	int i;
 
 	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
 	kdb_printf("-----------------------------"
 		   "-----------------------------\n");
-	for_each_kdbcmd(kt, i) {
+	list_for_each_entry(kt, &kdb_cmds_head, list_node) {
 		char *space = "";
 		if (KDB_FLAG(CMD_INTERRUPT))
 			return 0;
-		if (!kt->cmd_name)
-			continue;
 		if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
 			continue;
 		if (strlen(kt->cmd_usage) > 20)
@@ -2659,7 +2638,6 @@ static int kdb_grep_help(int argc, const char **argv)
  * Returns:
  *	zero for success, one if a duplicate command.
  */
-#define kdb_command_extend 50	/* arbitrary */
 int kdb_register_flags(char *cmd,
 		       kdb_func_t func,
 		       char *usage,
@@ -2667,49 +2645,20 @@ int kdb_register_flags(char *cmd,
 		       short minlen,
 		       kdb_cmdflags_t flags)
 {
-	int i;
 	kdbtab_t *kp;
 
-	/*
-	 *  Brute force method to determine duplicates
-	 */
-	for_each_kdbcmd(kp, i) {
-		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
+	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
+		if (strcmp(kp->cmd_name, cmd) == 0) {
 			kdb_printf("Duplicate kdb command registered: "
 				"%s, func %px help %s\n", cmd, func, help);
 			return 1;
 		}
 	}
 
-	/*
-	 * Insert command into first available location in table
-	 */
-	for_each_kdbcmd(kp, i) {
-		if (kp->cmd_name == NULL)
-			break;
-	}
-
-	if (i >= kdb_max_commands) {
-		kdbtab_t *new = kmalloc_array(kdb_max_commands -
-						KDB_BASE_CMD_MAX +
-						kdb_command_extend,
-					      sizeof(*new),
-					      GFP_KDB);
-		if (!new) {
-			kdb_printf("Could not allocate new kdb_command "
-				   "table\n");
-			return 1;
-		}
-		if (kdb_commands) {
-			memcpy(new, kdb_commands,
-			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
-			kfree(kdb_commands);
-		}
-		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
-		       kdb_command_extend * sizeof(*new));
-		kdb_commands = new;
-		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
-		kdb_max_commands += kdb_command_extend;
+	kp = kmalloc(sizeof(*kp), GFP_KDB);
+	if (!kp) {
+		kdb_printf("Could not allocate new kdb_command table\n");
+		return 1;
 	}
 
 	kp->cmd_name   = cmd;
@@ -2718,11 +2667,27 @@ int kdb_register_flags(char *cmd,
 	kp->cmd_help   = help;
 	kp->cmd_minlen = minlen;
 	kp->cmd_flags  = flags;
+	kp->is_dynamic = true;
+
+	list_add_tail(&kp->list_node, &kdb_cmds_head);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(kdb_register_flags);
 
+/*
+ * kdb_register_table() - This function is used to register a kdb command
+ *                        table.
+ * @kp: pointer to kdb command table
+ * @len: length of kdb command table
+ */
+void kdb_register_table(kdbtab_t *kp, size_t len)
+{
+	while (len--) {
+		list_add_tail(&kp->list_node, &kdb_cmds_head);
+		kp++;
+	}
+}
 
 /*
  * kdb_register - Compatibility register function for commands that do
@@ -2757,15 +2722,16 @@ EXPORT_SYMBOL_GPL(kdb_register);
  */
 int kdb_unregister(char *cmd)
 {
-	int i;
 	kdbtab_t *kp;
 
 	/*
 	 *  find the command.
 	 */
-	for_each_kdbcmd(kp, i) {
-		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
-			kp->cmd_name = NULL;
+	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
+		if (strcmp(kp->cmd_name, cmd) == 0) {
+			list_del(&kp->list_node);
+			if (kp->is_dynamic)
+				kfree(kp);
 			return 0;
 		}
 	}
@@ -2775,118 +2741,222 @@ int kdb_unregister(char *cmd)
 }
 EXPORT_SYMBOL_GPL(kdb_unregister);
 
-/* Initialize the kdb command table. */
-static void __init kdb_inittab(void)
-{
-	int i;
-	kdbtab_t *kp;
-
-	for_each_kdbcmd(kp, i)
-		kp->cmd_name = NULL;
-
-	kdb_register_flags("md", kdb_md, "<vaddr>",
-	  "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
-	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
-	  "Display Raw Memory", 0,
-	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
-	  "Display Physical Memory", 0,
-	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("mds", kdb_md, "<vaddr>",
-	  "Display Memory Symbolically", 0,
-	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
-	  "Modify Memory Contents", 0,
-	  KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
-	kdb_register_flags("go", kdb_go, "[<vaddr>]",
-	  "Continue Execution", 1,
-	  KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
-	kdb_register_flags("rd", kdb_rd, "",
-	  "Display Registers", 0,
-	  KDB_ENABLE_REG_READ);
-	kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
-	  "Modify Registers", 0,
-	  KDB_ENABLE_REG_WRITE);
-	kdb_register_flags("ef", kdb_ef, "<vaddr>",
-	  "Display exception frame", 0,
-	  KDB_ENABLE_MEM_READ);
-	kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
-	  "Stack traceback", 1,
-	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
-	kdb_register_flags("btp", kdb_bt, "<pid>",
-	  "Display stack for process <pid>", 0,
-	  KDB_ENABLE_INSPECT);
-	kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
-	  "Backtrace all processes matching state flag", 0,
-	  KDB_ENABLE_INSPECT);
-	kdb_register_flags("btc", kdb_bt, "",
-	  "Backtrace current process on each cpu", 0,
-	  KDB_ENABLE_INSPECT);
-	kdb_register_flags("btt", kdb_bt, "<vaddr>",
-	  "Backtrace process given its struct task address", 0,
-	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
-	kdb_register_flags("env", kdb_env, "",
-	  "Show environment variables", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("set", kdb_set, "",
-	  "Set environment variables", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("help", kdb_help, "",
-	  "Display Help Message", 1,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("?", kdb_help, "",
-	  "Display Help Message", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
-	  "Switch to new cpu", 0,
-	  KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
-	kdb_register_flags("kgdb", kdb_kgdb, "",
-	  "Enter kgdb mode", 0, 0);
-	kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
-	  "Display active task list", 0,
-	  KDB_ENABLE_INSPECT);
-	kdb_register_flags("pid", kdb_pid, "<pidnum>",
-	  "Switch to another task", 0,
-	  KDB_ENABLE_INSPECT);
-	kdb_register_flags("reboot", kdb_reboot, "",
-	  "Reboot the machine immediately", 0,
-	  KDB_ENABLE_REBOOT);
+static kdbtab_t maintab[] = {
+	{	.cmd_name = "md",
+		.cmd_func = kdb_md,
+		.cmd_usage = "<vaddr>",
+		.cmd_help = "Display Memory Contents, also mdWcN, e.g. md8c1",
+		.cmd_minlen = 1,
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "mdr",
+		.cmd_func = kdb_md,
+		.cmd_usage = "<vaddr> <bytes>",
+		.cmd_help = "Display Raw Memory",
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "mdp",
+		.cmd_func = kdb_md,
+		.cmd_usage = "<paddr> <bytes>",
+		.cmd_help = "Display Physical Memory",
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "mds",
+		.cmd_func = kdb_md,
+		.cmd_usage = "<vaddr>",
+		.cmd_help = "Display Memory Symbolically",
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "mm",
+		.cmd_func = kdb_mm,
+		.cmd_usage = "<vaddr> <contents>",
+		.cmd_help = "Modify Memory Contents",
+		.cmd_flags = KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS,
+	},
+	{	.cmd_name = "go",
+		.cmd_func = kdb_go,
+		.cmd_usage = "[<vaddr>]",
+		.cmd_help = "Continue Execution",
+		.cmd_minlen = 1,
+		.cmd_flags = KDB_ENABLE_REG_WRITE |
+			     KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
+	},
+	{	.cmd_name = "rd",
+		.cmd_func = kdb_rd,
+		.cmd_usage = "",
+		.cmd_help = "Display Registers",
+		.cmd_flags = KDB_ENABLE_REG_READ,
+	},
+	{	.cmd_name = "rm",
+		.cmd_func = kdb_rm,
+		.cmd_usage = "<reg> <contents>",
+		.cmd_help = "Modify Registers",
+		.cmd_flags = KDB_ENABLE_REG_WRITE,
+	},
+	{	.cmd_name = "ef",
+		.cmd_func = kdb_ef,
+		.cmd_usage = "<vaddr>",
+		.cmd_help = "Display exception frame",
+		.cmd_flags = KDB_ENABLE_MEM_READ,
+	},
+	{	.cmd_name = "bt",
+		.cmd_func = kdb_bt,
+		.cmd_usage = "[<vaddr>]",
+		.cmd_help = "Stack traceback",
+		.cmd_minlen = 1,
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
+	},
+	{	.cmd_name = "btp",
+		.cmd_func = kdb_bt,
+		.cmd_usage = "<pid>",
+		.cmd_help = "Display stack for process <pid>",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
+	{	.cmd_name = "bta",
+		.cmd_func = kdb_bt,
+		.cmd_usage = "[D|R|S|T|C|Z|E|U|I|M|A]",
+		.cmd_help = "Backtrace all processes matching state flag",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
+	{	.cmd_name = "btc",
+		.cmd_func = kdb_bt,
+		.cmd_usage = "",
+		.cmd_help = "Backtrace current process on each cpu",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
+	{	.cmd_name = "btt",
+		.cmd_func = kdb_bt,
+		.cmd_usage = "<vaddr>",
+		.cmd_help = "Backtrace process given its struct task address",
+		.cmd_flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
+	},
+	{	.cmd_name = "env",
+		.cmd_func = kdb_env,
+		.cmd_usage = "",
+		.cmd_help = "Show environment variables",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "set",
+		.cmd_func = kdb_set,
+		.cmd_usage = "",
+		.cmd_help = "Set environment variables",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "help",
+		.cmd_func = kdb_help,
+		.cmd_usage = "",
+		.cmd_help = "Display Help Message",
+		.cmd_minlen = 1,
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "?",
+		.cmd_func = kdb_help,
+		.cmd_usage = "",
+		.cmd_help = "Display Help Message",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "cpu",
+		.cmd_func = kdb_cpu,
+		.cmd_usage = "<cpunum>",
+		.cmd_help = "Switch to new cpu",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
+	},
+	{	.cmd_name = "kgdb",
+		.cmd_func = kdb_kgdb,
+		.cmd_usage = "",
+		.cmd_help = "Enter kgdb mode",
+		.cmd_flags = 0,
+	},
+	{	.cmd_name = "ps",
+		.cmd_func = kdb_ps,
+		.cmd_usage = "[<flags>|A]",
+		.cmd_help = "Display active task list",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
+	{	.cmd_name = "pid",
+		.cmd_func = kdb_pid,
+		.cmd_usage = "<pidnum>",
+		.cmd_help = "Switch to another task",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
+	{	.cmd_name = "reboot",
+		.cmd_func = kdb_reboot,
+		.cmd_usage = "",
+		.cmd_help = "Reboot the machine immediately",
+		.cmd_flags = KDB_ENABLE_REBOOT,
+	},
 #if defined(CONFIG_MODULES)
-	kdb_register_flags("lsmod", kdb_lsmod, "",
-	  "List loaded kernel modules", 0,
-	  KDB_ENABLE_INSPECT);
+	{	.cmd_name = "lsmod",
+		.cmd_func = kdb_lsmod,
+		.cmd_usage = "",
+		.cmd_help = "List loaded kernel modules",
+		.cmd_flags = KDB_ENABLE_INSPECT,
+	},
 #endif
 #if defined(CONFIG_MAGIC_SYSRQ)
-	kdb_register_flags("sr", kdb_sr, "<key>",
-	  "Magic SysRq key", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
+	{	.cmd_name = "sr",
+		.cmd_func = kdb_sr,
+		.cmd_usage = "<key>",
+		.cmd_help = "Magic SysRq key",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
 #endif
 #if defined(CONFIG_PRINTK)
-	kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
-	  "Display syslog buffer", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
+	{	.cmd_name = "dmesg",
+		.cmd_func = kdb_dmesg,
+		.cmd_usage = "[lines]",
+		.cmd_help = "Display syslog buffer",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
 #endif
-	if (arch_kgdb_ops.enable_nmi) {
-		kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
-		  "Disable NMI entry to KDB", 0,
-		  KDB_ENABLE_ALWAYS_SAFE);
-	}
-	kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
-	  "Define a set of commands, down to endefcmd", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
-	  "Send a signal to a process", 0,
-	  KDB_ENABLE_SIGNAL);
-	kdb_register_flags("summary", kdb_summary, "",
-	  "Summarize the system", 4,
-	  KDB_ENABLE_ALWAYS_SAFE);
-	kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
-	  "Display per_cpu variables", 3,
-	  KDB_ENABLE_MEM_READ);
-	kdb_register_flags("grephelp", kdb_grep_help, "",
-	  "Display help on | grep", 0,
-	  KDB_ENABLE_ALWAYS_SAFE);
+	{	.cmd_name = "defcmd",
+		.cmd_func = kdb_defcmd,
+		.cmd_usage = "name \"usage\" \"help\"",
+		.cmd_help = "Define a set of commands, down to endefcmd",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "kill",
+		.cmd_func = kdb_kill,
+		.cmd_usage = "<-signal> <pid>",
+		.cmd_help = "Send a signal to a process",
+		.cmd_flags = KDB_ENABLE_SIGNAL,
+	},
+	{	.cmd_name = "summary",
+		.cmd_func = kdb_summary,
+		.cmd_usage = "",
+		.cmd_help = "Summarize the system",
+		.cmd_minlen = 4,
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+	{	.cmd_name = "per_cpu",
+		.cmd_func = kdb_per_cpu,
+		.cmd_usage = "<sym> [<bytes>] [<cpu>]",
+		.cmd_help = "Display per_cpu variables",
+		.cmd_minlen = 3,
+		.cmd_flags = KDB_ENABLE_MEM_READ,
+	},
+	{	.cmd_name = "grephelp",
+		.cmd_func = kdb_grep_help,
+		.cmd_usage = "",
+		.cmd_help = "Display help on | grep",
+		.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+	},
+};
+
+static kdbtab_t nmicmd = {
+	.cmd_name = "disable_nmi",
+	.cmd_func = kdb_disable_nmi,
+	.cmd_usage = "",
+	.cmd_help = "Disable NMI entry to KDB",
+	.cmd_flags = KDB_ENABLE_ALWAYS_SAFE,
+};
+
+/* Initialize the kdb command table. */
+static void __init kdb_inittab(void)
+{
+	kdb_register_table(maintab, ARRAY_SIZE(maintab));
+	if (arch_kgdb_ops.enable_nmi)
+		kdb_register_table(&nmicmd, 1);
 }
 
 /* Execute any commands defined in kdb_cmds.  */
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 135a706c2e783..ccbed90898082 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -174,8 +174,11 @@ typedef struct _kdbtab {
 	short    cmd_minlen;		/* Minimum legal # command
 					 * chars required */
 	kdb_cmdflags_t cmd_flags;	/* Command behaviour flags */
+	struct list_head list_node;	/* Command list */
+	bool    is_dynamic;		/* Command table allocation type */
 } kdbtab_t;
 
+extern void kdb_register_table(kdbtab_t *kp, size_t len);
 extern int kdb_bt(int, const char **);	/* KDB display back trace */
 
 /* KDB breakpoint management functions */

From 2bbd9b0f2b4ec0afa80b52b1a68bd3bc80618275 Mon Sep 17 00:00:00 2001
From: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Date: Wed, 17 Mar 2021 16:16:58 +0530
Subject: [PATCH 3/4] kernel: debug: Ordinary typo fixes in the file gdbstub.c

s/overwitten/overwritten/
s/procesing/processing/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20210317104658.4053473-1-unixbhaskar@gmail.com
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
 kernel/debug/gdbstub.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index e149a0ac9e9e7..8372897402f4a 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -321,7 +321,7 @@ 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 -EFAULT on failure or 0 on success.
- * The input buf is overwitten with the result to write to mem.
+ * The input buf is overwritten with the result to write to mem.
  */
 static int kgdb_ebin2mem(char *buf, char *mem, int count)
 {
@@ -952,7 +952,7 @@ static int gdb_cmd_exception_pass(struct kgdb_state *ks)
 }
 
 /*
- * This function performs all gdbserial command procesing
+ * This function performs all gdbserial command processing
  */
 int gdb_serial_stub(struct kgdb_state *ks)
 {

From 83fa2d13d628be901a21cdfb3553963cd8858052 Mon Sep 17 00:00:00 2001
From: Sumit Garg <sumit.garg@linaro.org>
Date: Mon, 8 Feb 2021 13:32:22 +0530
Subject: [PATCH 4/4] kdb: Refactor env variables get/set code

Add two new kdb environment access methods as kdb_setenv() and
kdb_printenv() in order to abstract out environment access code
from kdb command functions.

Also, replace (char *)0 with NULL as an initializer for environment
variables array.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/1612771342-16883-1-git-send-email-sumit.garg@linaro.org
[daniel.thompson@linaro.org: Replaced (char *)0/NULL initializers with
an array size]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
 kernel/debug/kdb/kdb_main.c | 142 +++++++++++++++++-------------------
 1 file changed, 68 insertions(+), 74 deletions(-)

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 95a1b1f543269..405d24aa51561 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -140,42 +140,18 @@ static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
  * KDB_ENVBUFSIZE if required).
  */
 
-static char *__env[] = {
+static char *__env[31] = {
 #if defined(CONFIG_SMP)
- "PROMPT=[%d]kdb> ",
+	"PROMPT=[%d]kdb> ",
 #else
- "PROMPT=kdb> ",
+	"PROMPT=kdb> ",
 #endif
- "MOREPROMPT=more> ",
- "RADIX=16",
- "MDCOUNT=8",			/* lines of md output */
- KDB_PLATFORM_ENV,
- "DTABCOUNT=30",
- "NOSECT=1",
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
- (char *)0,
+	"MOREPROMPT=more> ",
+	"RADIX=16",
+	"MDCOUNT=8",		/* lines of md output */
+	KDB_PLATFORM_ENV,
+	"DTABCOUNT=30",
+	"NOSECT=1",
 };
 
 static const int __nenv = ARRAY_SIZE(__env);
@@ -317,6 +293,63 @@ int kdbgetintenv(const char *match, int *value)
 	return diag;
 }
 
+/*
+ * kdb_setenv() - Alter an existing environment variable or create a new one.
+ * @var: Name of the variable
+ * @val: Value of the variable
+ *
+ * Return: Zero on success, a kdb diagnostic on failure.
+ */
+static int kdb_setenv(const char *var, const char *val)
+{
+	int i;
+	char *ep;
+	size_t varlen, vallen;
+
+	varlen = strlen(var);
+	vallen = strlen(val);
+	ep = kdballocenv(varlen + vallen + 2);
+	if (ep == (char *)0)
+		return KDB_ENVBUFFULL;
+
+	sprintf(ep, "%s=%s", var, val);
+
+	for (i = 0; i < __nenv; i++) {
+		if (__env[i]
+		 && ((strncmp(__env[i], var, varlen) == 0)
+		   && ((__env[i][varlen] == '\0')
+		    || (__env[i][varlen] == '=')))) {
+			__env[i] = ep;
+			return 0;
+		}
+	}
+
+	/*
+	 * Wasn't existing variable.  Fit into slot.
+	 */
+	for (i = 0; i < __nenv-1; i++) {
+		if (__env[i] == (char *)0) {
+			__env[i] = ep;
+			return 0;
+		}
+	}
+
+	return KDB_ENVFULL;
+}
+
+/*
+ * kdb_printenv() - Display the current environment variables.
+ */
+static void kdb_printenv(void)
+{
+	int i;
+
+	for (i = 0; i < __nenv; i++) {
+		if (__env[i])
+			kdb_printf("%s\n", __env[i]);
+	}
+}
+
 /*
  * kdbgetularg - This function will convert a numeric string into an
  *	unsigned long value.
@@ -374,10 +407,6 @@ int kdbgetu64arg(const char *arg, u64 *value)
  */
 int kdb_set(int argc, const char **argv)
 {
-	int i;
-	char *ep;
-	size_t varlen, vallen;
-
 	/*
 	 * we can be invoked two ways:
 	 *   set var=value    argv[1]="var", argv[2]="value"
@@ -422,37 +451,7 @@ int kdb_set(int argc, const char **argv)
 	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 	 * name, argv[2] = value.
 	 */
-	varlen = strlen(argv[1]);
-	vallen = strlen(argv[2]);
-	ep = kdballocenv(varlen + vallen + 2);
-	if (ep == (char *)0)
-		return KDB_ENVBUFFULL;
-
-	sprintf(ep, "%s=%s", argv[1], argv[2]);
-
-	ep[varlen+vallen+1] = '\0';
-
-	for (i = 0; i < __nenv; i++) {
-		if (__env[i]
-		 && ((strncmp(__env[i], argv[1], varlen) == 0)
-		   && ((__env[i][varlen] == '\0')
-		    || (__env[i][varlen] == '=')))) {
-			__env[i] = ep;
-			return 0;
-		}
-	}
-
-	/*
-	 * Wasn't existing variable.  Fit into slot.
-	 */
-	for (i = 0; i < __nenv-1; i++) {
-		if (__env[i] == (char *)0) {
-			__env[i] = ep;
-			return 0;
-		}
-	}
-
-	return KDB_ENVFULL;
+	return kdb_setenv(argv[1], argv[2]);
 }
 
 static int kdb_check_regs(void)
@@ -2055,12 +2054,7 @@ static int kdb_lsmod(int argc, const char **argv)
 
 static int kdb_env(int argc, const char **argv)
 {
-	int i;
-
-	for (i = 0; i < __nenv; i++) {
-		if (__env[i])
-			kdb_printf("%s\n", __env[i]);
-	}
+	kdb_printenv();
 
 	if (KDB_DEBUG(MASK))
 		kdb_printf("KDBDEBUG=0x%x\n",