Commit 16257393 authored Feb 16, 2012 by Mahesh Salgaonkar Committed by Benjamin Herrenschmidt Feb 23, 2012

fadump: Introduce cleanup routine to invalidate /proc/vmcore.



With the firmware-assisted dump support we don't require a reboot when we
are in second kernel after crash. The second kernel after crash is a normal
kernel boot and has knowledge about entire system RAM with the page tables
initialized for entire system RAM. Hence once the dump is saved to disk, we
can just release the reserved memory area for general use and continue
with second kernel as production kernel.

Hence when we release the reserved memory that contains dump data, the
'/proc/vmcore' will not be valid anymore. Hence this patch introduces
a cleanup routine that invalidates and removes the /proc/vmcore file. This
routine will be invoked before we release the reserved dump memory area.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

parent d34c5f26

fs/proc/vmcore.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -700,3 +700,26 @@ static int __init vmcore_init(void)
		return 0;
		}
		module_init(vmcore_init)

		/* Cleanup function for vmcore module. */
		void vmcore_cleanup(void)
		{
		struct list_head pos, next;

		if (proc_vmcore) {
		remove_proc_entry(proc_vmcore->name, proc_vmcore->parent);
		proc_vmcore = NULL;
		}

		/* clear the vmcore list. */
		list_for_each_safe(pos, next, &vmcore_list) {
		struct vmcore *m;

		m = list_entry(pos, struct vmcore, list);
		list_del(&m->list);
		kfree(m);
		}
		kfree(elfcorebuf);
		elfcorebuf = NULL;
		}
		EXPORT_SYMBOL_GPL(vmcore_cleanup);

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