[PATCH] x86-64: Handle reserve_bootmem_generic beyond end_pfn

This can happen on kexec kernels with some configurations, in particularly
on Unisys ES7000 systems.

Analysis by Amul Shah

Cc: Amul Shah <amul.shah@unisys.com>

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 14 insertions, 1 deletions

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 971dc1181e69..f1f977aafae1 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -655,9 +655,22 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 
 void __init reserve_bootmem_generic(unsigned long phys, unsigned len) 
 { 
-        /* Should check here against the e820 map to avoid double free */ 
 #ifdef CONFIG_NUMA
         int nid = phys_to_nid(phys);
+#endif
+        unsigned long pfn = phys >> PAGE_SHIFT;
+        if (pfn >= end_pfn) {
+                /* This can happen with kdump kernels when accessing firmware
+                   tables. */
+                if (pfn < end_pfn_map)
+                        return;
+                printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
+                                phys, len);
+                return;
+        }
+
+        /* Should check here against the e820 map to avoid double free */
+#ifdef CONFIG_NUMA
         reserve_bootmem_node(NODE_DATA(nid), phys, len);
 #else                   
         reserve_bootmem(phys, len);