[PATCH 04/11] kdb: Allow kernel loadable modules to add kdb shell functions

From: Jason Wessel
Date: Fri Oct 22 2010 - 16:58:25 EST


In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.

Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.

Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
---
include/linux/kdb.h | 43 ++++++++++++++++++++++++++++++++++++++++
kernel/debug/kdb/kdb_io.c | 2 +-
kernel/debug/kdb/kdb_main.c | 4 +++
kernel/debug/kdb/kdb_private.h | 39 ------------------------------------
4 files changed, 48 insertions(+), 40 deletions(-)

diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index ea6e524..deda197 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -28,6 +28,41 @@ extern int kdb_poll_idx;
extern int kdb_initial_cpu;
extern atomic_t kdb_event;

+/* Types and messages used for dynamically added kdb shell commands */
+
+#define KDB_MAXARGS 16 /* Maximum number of arguments to a function */
+
+typedef enum {
+ KDB_REPEAT_NONE = 0, /* Do not repeat this command */
+ KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
+ KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
+} kdb_repeat_t;
+
+typedef int (*kdb_func_t)(int, const char **);
+
+/* KDB return codes from a command or internal kdb function */
+#define KDB_NOTFOUND (-1)
+#define KDB_ARGCOUNT (-2)
+#define KDB_BADWIDTH (-3)
+#define KDB_BADRADIX (-4)
+#define KDB_NOTENV (-5)
+#define KDB_NOENVVALUE (-6)
+#define KDB_NOTIMP (-7)
+#define KDB_ENVFULL (-8)
+#define KDB_ENVBUFFULL (-9)
+#define KDB_TOOMANYBPT (-10)
+#define KDB_TOOMANYDBREGS (-11)
+#define KDB_DUPBPT (-12)
+#define KDB_BPTNOTFOUND (-13)
+#define KDB_BADMODE (-14)
+#define KDB_BADINT (-15)
+#define KDB_INVADDRFMT (-16)
+#define KDB_BADREG (-17)
+#define KDB_BADCPUNUM (-18)
+#define KDB_BADLENGTH (-19)
+#define KDB_NOBP (-20)
+#define KDB_BADADDR (-21)
+
/*
* kdb_diemsg
*
@@ -105,9 +140,17 @@ int kdb_process_cpu(const struct task_struct *p)
/* kdb access to register set for stack dumping */
extern struct pt_regs *kdb_current_regs;

+/* Dynamic kdb shell command registration */
+extern int kdb_register(char *, kdb_func_t, char *, char *, short);
+extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
+ short, kdb_repeat_t);
+extern int kdb_unregister(char *);
#else /* ! CONFIG_KGDB_KDB */
#define kdb_printf(...)
#define kdb_init(x)
+#define kdb_register(...)
+#define kdb_register_repeat(...)
+#define kdb_uregister(x)
#endif /* CONFIG_KGDB_KDB */
enum {
KDB_NOT_INITIALIZED,
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index c9b7f4f..96fdaac 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -823,4 +823,4 @@ int kdb_printf(const char *fmt, ...)

return r;
}
-
+EXPORT_SYMBOL_GPL(kdb_printf);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index caf057a..5448990 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2783,6 +2783,8 @@ int kdb_register_repeat(char *cmd,

return 0;
}
+EXPORT_SYMBOL_GPL(kdb_register_repeat);
+

/*
* kdb_register - Compatibility register function for commands that do
@@ -2805,6 +2807,7 @@ int kdb_register(char *cmd,
return kdb_register_repeat(cmd, func, usage, help, minlen,
KDB_REPEAT_NONE);
}
+EXPORT_SYMBOL_GPL(kdb_register);

/*
* kdb_unregister - This function is used to unregister a kernel
@@ -2833,6 +2836,7 @@ int kdb_unregister(char *cmd)
/* Couldn't find it. */
return 1;
}
+EXPORT_SYMBOL_GPL(kdb_unregister);

/* Initialize the kdb command table. */
static void __init kdb_inittab(void)
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index be775f7..1921e6e 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -15,29 +15,6 @@
#include <linux/kgdb.h>
#include "../debug_core.h"

-/* Kernel Debugger Error codes. Must not overlap with command codes. */
-#define KDB_NOTFOUND (-1)
-#define KDB_ARGCOUNT (-2)
-#define KDB_BADWIDTH (-3)
-#define KDB_BADRADIX (-4)
-#define KDB_NOTENV (-5)
-#define KDB_NOENVVALUE (-6)
-#define KDB_NOTIMP (-7)
-#define KDB_ENVFULL (-8)
-#define KDB_ENVBUFFULL (-9)
-#define KDB_TOOMANYBPT (-10)
-#define KDB_TOOMANYDBREGS (-11)
-#define KDB_DUPBPT (-12)
-#define KDB_BPTNOTFOUND (-13)
-#define KDB_BADMODE (-14)
-#define KDB_BADINT (-15)
-#define KDB_INVADDRFMT (-16)
-#define KDB_BADREG (-17)
-#define KDB_BADCPUNUM (-18)
-#define KDB_BADLENGTH (-19)
-#define KDB_NOBP (-20)
-#define KDB_BADADDR (-21)
-
/* Kernel Debugger Command codes. Must not overlap with error codes. */
#define KDB_CMD_GO (-1001)
#define KDB_CMD_CPU (-1002)
@@ -93,17 +70,6 @@
*/
#define KDB_MAXBPT 16

-/* Maximum number of arguments to a function */
-#define KDB_MAXARGS 16
-
-typedef enum {
- KDB_REPEAT_NONE = 0, /* Do not repeat this command */
- KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
- KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
-} kdb_repeat_t;
-
-typedef int (*kdb_func_t)(int, const char **);
-
/* Symbol table format returned by kallsyms. */
typedef struct __ksymtab {
unsigned long value; /* Address of symbol */
@@ -123,11 +89,6 @@ extern int kallsyms_symbol_next(char *prefix_name, int flag);
extern int kallsyms_symbol_complete(char *prefix_name, int max_len);

/* Exported Symbols for kernel loadable modules to use. */
-extern int kdb_register(char *, kdb_func_t, char *, char *, short);
-extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
- short, kdb_repeat_t);
-extern int kdb_unregister(char *);
-
extern int kdb_getarea_size(void *, unsigned long, size_t);
extern int kdb_putarea_size(unsigned long, void *, size_t);

--
1.6.3.3

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