[PATCH] x86: Limit E820 map when a user-defined memory map is specified

[Bernhard Walle]

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 at suse.de>
---
 arch/x86/kernel/e820.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index a1b0548..3771386 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -988,6 +988,9 @@ 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);
@@ -1032,6 +1035,8 @@ 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;
 }
-- 
1.5.4.5