[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>

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 971dc11..f1f977a 100644 (file)
--- 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);