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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2014-01-30 16:14:02 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-22 12:41:26 -0800
commit312cdf57ee8b7ef9ae1967e243a770dc5557af05 (patch)
treeebe4736e9b03bcd37af0db65497164d2b0b53e28 /arch
parent22c7a1899d2d59b1aed821e8d4946431911be28a (diff)
downloadlinaro-lsk-312cdf57ee8b7ef9ae1967e243a770dc5557af05.tar.gz
s390/dump: Fix dump memory detection
commit d7736ff5be31edaa4fe5ab62810c64529a24b149 upstream. Dumps created by kdump or zfcpdump can contain invalid memory holes when dumping z/VM systems that have memory pressure. For example: # zgetdump -i /proc/vmcore. Memory map: 0000000000000000 - 0000000000bfffff (12 MB) 0000000000e00000 - 00000000014fffff (7 MB) 000000000bd00000 - 00000000f3bfffff (3711 MB) The memory detection function find_memory_chunks() issues tprot to find valid memory chunks. In case of CMM it can happen that pages are marked as unstable via set_page_unstable() in arch_free_page(). If z/VM has released that pages, tprot returns -EFAULT and indicates a memory hole. So fix this and switch off CMM in case of kdump or zfcpdump. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/mm/page-states.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
index a90d45e9dfb..27c50f4d90c 100644
--- a/arch/s390/mm/page-states.c
+++ b/arch/s390/mm/page-states.c
@@ -12,6 +12,8 @@
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/init.h>
+#include <asm/setup.h>
+#include <asm/ipl.h>
#define ESSA_SET_STABLE 1
#define ESSA_SET_UNUSED 2
@@ -41,6 +43,14 @@ void __init cmma_init(void)
if (!cmma_flag)
return;
+ /*
+ * Disable CMM for dump, otherwise the tprot based memory
+ * detection can fail because of unstable pages.
+ */
+ if (OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP) {
+ cmma_flag = 0;
+ return;
+ }
asm volatile(
" .insn rrf,0xb9ab0000,%1,%1,0,0\n"
"0: la %0,0\n"