On Mon, Apr 30, 2007 at 10:12:44AM +0100, Christoph Hellwig wrote: > On Sun, Apr 29, 2007 at 09:02:32PM -0700, Roland McGrath wrote: > > > EXPORT_SYMBOL_GPL(utrace_attach); > > > > > > There is not modular user of this, so this and the other utrace_ > > > functions should not be exported. Nor do I think that exporting > > > such a low-level process control is nessecary a good idea, but > > > we'll have to evaluate that if patches to add users show up. > > > > If you remove the exports, just throw the whole thing away. > > The reason utrace exists is to be used by modules. > > used != used by modules. Even without things exported you can use > things in the kernel. Once we have a valid modular use case we can > add exports.
Christoph, it's at http://people.redhat.com/roland/utrace/crash-suspend.c The file crash-suspend.c is a simple example of a loadable kernel module using the new infrastructure. It implements the old GNU feature of doing a job suspend on crash, so you can attach a debugger right then instead of just looking at the core file afterwards. Try for example: $ sudo /sbin/insmod crash-suspend.ko pid=$$ to load the module and attach it to your shell. It then attaches to any children of your shell. Now run something that crashes and would ordinarily dump core--you can just run cat or sleep and hit ^\ to crash it with a SIGQUIT. See it suspend. Try "jobs -l" and see it stopped with a non-stop signal. If you resume it with "fg" it will go ahead and dump core. Or, you can attach a debugger like gdb first, and then debug it. Most certainly, it should be included into utrace patchset to pin some exports. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
