[PATCH] x86: Support large number of memory ranges

[Ramsay, Frank]

acking I tested this
Tested-by: Frank Ramsay <frank.ramsay at hpe.com>

________________________________________
From: Xunlei Pang <xlpang at redhat.com>
Sent: Thursday, March 23, 2017 7:16:59 AM
To: kexec at lists.infradead.org
Cc: Dave Young; Xunlei Pang; Ramsay, Frank
Subject: [PATCH] x86: Support large number of memory ranges

We got a problem on one SGI 64TB machine, the current kexec-tools
failed to work due to the insufficient ranges(MAX_MEMORY_RANGES)
allowed which is defined as 1024(less than the ranges on the machine).
The kcore header is insufficient due to the same reason as well.

To solve this, this patch simply doubles "MAX_MEMORY_RANGES" and
"KCORE_ELF_HEADERS_SIZE".

Cc: Frank Ramsay <frank.ramsay at hpe.com>
Signed-off-by: Xunlei Pang <xlpang at redhat.com>
---
 kexec/arch/i386/kexec-x86.h | 2 +-
 kexec/crashdump.h           | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kexec/arch/i386/kexec-x86.h b/kexec/arch/i386/kexec-x86.h
index 33df352..51855f8 100644
--- a/kexec/arch/i386/kexec-x86.h
+++ b/kexec/arch/i386/kexec-x86.h
@@ -1,7 +1,7 @@
 #ifndef KEXEC_X86_H
 #define KEXEC_X86_H

-#define MAX_MEMORY_RANGES 1024
+#define MAX_MEMORY_RANGES 2048

 enum coretype {
        CORE_TYPE_UNDEF = 0,
diff --git a/kexec/crashdump.h b/kexec/crashdump.h
index 86e1ef2..18bd691 100644
--- a/kexec/crashdump.h
+++ b/kexec/crashdump.h
@@ -7,8 +7,8 @@ extern int get_xen_vmcoreinfo(uint64_t *addr, uint64_t *len);

 /* Need to find a better way to determine per cpu notes section size. */
 #define MAX_NOTE_BYTES         1024
-/* Expecting ELF headers to fit in 32K. Increase it if you need more. */
-#define KCORE_ELF_HEADERS_SIZE  32768
+/* Expecting ELF headers to fit in 64K. Increase it if you need more. */
+#define KCORE_ELF_HEADERS_SIZE  65536
 /* The address of the ELF header is passed to the secondary kernel
  * using the kernel command line option memmap=nnn.
  * The smallest unit the kernel accepts is in kilobytes,
--
1.8.3.1