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Commit 162573937679ff36c9acd54268c047199dab564e

Authored by Mahesh Salgaonkar
Committed by Benjamin Herrenschmidt
1 parent d34c5f26cf
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

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>

Showing 1 changed file with 23 additions and 0 deletions Side-by-side Diff

... ... @@ -700,4 +700,27 @@
700 700 return 0;
701 701 }
702 702 module_init(vmcore_init)
  703 +
  704 +/* Cleanup function for vmcore module. */
  705 +void vmcore_cleanup(void)
  706 +{
  707 + struct list_head *pos, *next;
  708 +
  709 + if (proc_vmcore) {
  710 + remove_proc_entry(proc_vmcore->name, proc_vmcore->parent);
  711 + proc_vmcore = NULL;
  712 + }
  713 +
  714 + /* clear the vmcore list. */
  715 + list_for_each_safe(pos, next, &vmcore_list) {
  716 + struct vmcore *m;
  717 +
  718 + m = list_entry(pos, struct vmcore, list);
  719 + list_del(&m->list);
  720 + kfree(m);
  721 + }
  722 + kfree(elfcorebuf);
  723 + elfcorebuf = NULL;
  724 +}
  725 +EXPORT_SYMBOL_GPL(vmcore_cleanup);