x86: limit E820 map when a user-defined memory map is specified

This patch brings back limiting of the E820 map when a user-defined
E820 map is specified. While the behaviour of i386 (32 bit) was to limit
the E820 map (and /proc/iomem), the behaviour of x86-64 (64 bit) was not to
limit.

That patch limits the E820 map again for both x86 architectures.

Code was tested for compilation and booting on a 32 bit and 64 bit system.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: kexec@lists.infradead.org
Cc: vgoyal@redhat.com
Cc: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 1dcb66533dfc..7b7685b78852 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1117,6 +1117,9 @@ static int __init parse_memopt(char *p)
 
         mem_size = memparse(p, &p);
         end_user_pfn = mem_size>>PAGE_SHIFT;
+        e820_update_range(mem_size, ULLONG_MAX - mem_size,
+                E820_RAM, E820_RESERVED);
+
         return 0;
 }
 early_param("mem", parse_memopt);
@@ -1161,6 +1164,8 @@ static int __init parse_memmap_opt(char *p)
                 e820_add_region(start_at, mem_size, E820_RESERVED);
         } else {
                 end_user_pfn = (mem_size >> PAGE_SHIFT);
+                e820_update_range(mem_size, ULLONG_MAX - mem_size,
+                        E820_RAM, E820_RESERVED);
         }
         return *p == '\0' ? 0 : -EINVAL;
 }