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authorJason Wessel <jason.wessel@windriver.com>2013-02-04 10:35:33 -0600
committerJason Wessel <jason.wessel@windriver.com>2013-03-02 08:52:19 -0600
commita37372f6c3c03dc7613eaae8bb3458c8068f5fff (patch)
treecf64786123ce7c2d47002d1d6b122967abca0eb5 /kernel/debug
parent1b2caa2dcb8f18d2be9c5c3c992cb6da03f1a70a (diff)
downloadlinux-a37372f6c3c03dc7613eaae8bb3458c8068f5fff.tar.gz
kdb: Prevent kernel oops with kdb_defcmd
The kdb_defcmd can only be used to display the available command aliases
while using the kernel debug shell.  If you try to define a new macro
while the kernel debugger is active it will oops.  The debug shell
macros must use pre-allocated memory set aside at the time kdb_init()
is run, and the kdb_defcmd is restricted to only working at the time
that the kdb_init sequence is being run, which only occurs if you
actually activate the kernel debugger.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/debug')
-rw-r--r--kernel/debug/kdb/kdb_main.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index cdfc0a7e583e..496f596aa807 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -681,6 +681,10 @@ static int kdb_defcmd(int argc, const char **argv)
 	}
 	if (argc != 3)
 		return KDB_ARGCOUNT;
+	if (in_dbg_master()) {
+		kdb_printf("Command only available during kdb_init()\n");
+		return KDB_NOTIMP;
+	}
 	defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
 			     GFP_KDB);
 	if (!defcmd_set)
@@ -2796,8 +2800,8 @@ static void __init kdb_inittab(void)
 	  "Stack traceback", 1, KDB_REPEAT_NONE);
 	kdb_register_repeat("btp", kdb_bt, "<pid>",
 	  "Display stack for process <pid>", 0, KDB_REPEAT_NONE);
-	kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]",
-	  "Display stack all processes", 0, KDB_REPEAT_NONE);
+	kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
+	  "Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("btc", kdb_bt, "",
 	  "Backtrace current process on each cpu", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("btt", kdb_bt, "<vaddr>",