From a37372f6c3c03dc7613eaae8bb3458c8068f5fff Mon Sep 17 00:00:00 2001
From: Jason Wessel <jason.wessel@windriver.com>
Date: Mon, 4 Feb 2013 10:35:33 -0600
Subject: [PATCH] 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>
---
kernel/debug/kdb/kdb_main.c | 8 ++++++--
1 file 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>",
--
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