Re: [PULL}: latest tip/cpus4096 changes

From: Ingo Molnar
Date: Fri Jan 16 2009 - 04:29:37 EST



* Mike Travis <travis@xxxxxxx> wrote:

> diff --git a/kernel/kgdb.c b/kernel/kgdb.c
> index e4dcfb2..21fde60 100644
> --- a/kernel/kgdb.c
> +++ b/kernel/kgdb.c
> @@ -72,7 +72,7 @@ struct kgdb_state {
> static struct debuggerinfo_struct {
> void *debuggerinfo;
> struct task_struct *task;
> -} kgdb_info[NR_CPUS];
> +} *kgdb_info;
>
> /**
> * kgdb_connected - Is a host GDB connected to us?
> @@ -1651,6 +1651,13 @@ int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
> return -EBUSY;
> }
>
> + kgdb_info = kmalloc(nr_cpu_ids * sizeof(*kgdb_info), GFP_KERNEL);
> + if (unlikely(!kgdb_info)) {
> + spin_unlock(&kgdb_registration_lock);
> + printk(KERN_ERR "kgdb: No memory for kgdb_info\n");
> + return -ENOMEM;
> + }
> +
> if (new_kgdb_io_ops->init) {
> err = new_kgdb_io_ops->init();
> if (err) {

Look how it continues:

spin_unlock(&kgdb_registration_lock);
return err;
}
}

See the memory leak? This is _trivially_ broken. When you add dynamic
allocation to any codepath you _need_ to be careul and you need to check
all interim paths of return.

Also, please submit kgdb patches via the KGDB maintainer:

KGDB
P: Jason Wessel
M: jason.wessel@xxxxxxxxxxxxx
L: kgdb-bugreport@xxxxxxxxxxxxxxxxxxxxx
S: Maintained

Ingo
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