[PATCH] makedumpfile: disable mmap

Dave Young dyoung at redhat.com
Thu Nov 14 02:52:48 UTC 2013



There's a  kernel bug for mapping mem ranges which end with
an address not aligned to page boundry. It's still not resolved
in upstream, so let's disable mmap read for now as a workaround.

Once upstream got a right fix we can revert this patch.

Signed-off-by: Dave Young <dyoung at redhat.com>
---
 kexec-tools-2.0.4-makedumpfile-disable-mmap.patch | 36 +++++++++++++++++++++++
 kexec-tools.spec                                  |  2 ++
 2 files changed, 38 insertions(+)
 create mode 100644 kexec-tools-2.0.4-makedumpfile-disable-mmap.patch

diff --git a/kexec-tools-2.0.4-makedumpfile-disable-mmap.patch b/kexec-tools-2.0.4-makedumpfile-disable-mmap.patch
new file mode 100644
index 0000000..125b62f
--- /dev/null
+++ b/kexec-tools-2.0.4-makedumpfile-disable-mmap.patch
@@ -0,0 +1,36 @@
+makedumpfile: disable mmap read
+
+There's a kernel bug for mapping mem ranges which end with
+an address not aligned to page boundry. It's still not resolved
+in upstream, so let's disable mmap read for now as a workaround.
+
+Once upstream got a right fix we can revert this patch.
+
+Signed-off-by: Dave Young <dyoung at redhat.com>
+---
+ makedumpfile.c |    7 +++++++
+ 1 file changed, 7 insertions(+)
+
+--- kexec-tools/makedumpfile-1.5.4/makedumpfile.c.orig
++++ kexec-tools/makedumpfile-1.5.4/makedumpfile.c
+@@ -3144,6 +3144,12 @@ out:
+ 	if (info->dump_level & DL_EXCLUDE_FREE)
+ 		setup_page_is_buddy();
+ 
++	/* There's a kernel bug for mapping mem ranges which end with
++	 * an address not aligned to page boundry. It's still not resolved
++	 * in upstream, so let's disable mmap read for now.
++	 */
++	info->flag_usemmap = FALSE;
++#if 0
+ 	if (!initialize_mmap()) {
+ 		/* this kernel does not support mmap of vmcore */
+ 		DEBUG_MSG("Kernel can't mmap vmcore, using reads.\n");
+@@ -3152,6 +3158,7 @@ out:
+ 		DEBUG_MSG("read %s with mmap()\n", info->name_memory);
+ 		info->flag_usemmap = TRUE;
+ 	}
++#endif
+ 
+ 	return TRUE;
+ }
diff --git a/kexec-tools.spec b/kexec-tools.spec
index 5845b21..4182906 100644
--- a/kexec-tools.spec
+++ b/kexec-tools.spec
@@ -88,6 +88,7 @@ Patch607: kexec-tools-2.0.4-makedumpfile-Update-pfn_cyclic-when-the-cyclic-buffe
 Patch608: kexec-tools-2.0.4-makedumpfile-Use-divideup-to-calculate-maximum-required-bit.patch
 Patch609: kexec-tools-2.0.4-makedumpfile-cache-Allocate-buffers-at-initialization-t.patch
 Patch610: kexec-tools-2.0.4-makedumpfile-cache-Reuse-entry-in-pending-list.patch
+Patch611: kexec-tools-2.0.4-makedumpfile-disable-mmap.patch
 
 %description
 kexec-tools provides /sbin/kexec binary that facilitates a new
@@ -126,6 +127,7 @@ tar -z -x -v -f %{SOURCE19}
 %patch608 -p1
 %patch609 -p1
 %patch610 -p1
+%patch611 -p1
 %patch001 -p1
 %patch002 -p1
 %patch003 -p1


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