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>
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1 changed files with 6 additions and 2 deletions
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@ -681,6 +681,10 @@ static int kdb_defcmd(int argc, const char **argv)
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}
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if (argc != 3)
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return KDB_ARGCOUNT;
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if (in_dbg_master()) {
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kdb_printf("Command only available during kdb_init()\n");
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return KDB_NOTIMP;
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}
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defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
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GFP_KDB);
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if (!defcmd_set)
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@ -2796,8 +2800,8 @@ static void __init kdb_inittab(void)
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"Stack traceback", 1, KDB_REPEAT_NONE);
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kdb_register_repeat("btp", kdb_bt, "<pid>",
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"Display stack for process <pid>", 0, KDB_REPEAT_NONE);
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kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]",
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"Display stack all processes", 0, KDB_REPEAT_NONE);
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kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
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"Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE);
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kdb_register_repeat("btc", kdb_bt, "",
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"Backtrace current process on each cpu", 0, KDB_REPEAT_NONE);
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kdb_register_repeat("btt", kdb_bt, "<vaddr>",
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