[PATCH 4.1 093/123] x86/efi: Use all 64 bit of efi_memmap in setup_e820()

From: Greg Kroah-Hartman
Date: Sat Aug 08 2015 - 18:18:25 EST

4.1-stable review patch. If anyone has any objections, please let me know.


From: Dmitry Skorodumov <sdmitry@xxxxxxxxxxxxx>

commit 7cc03e48965453b5df1cce5062c826189b04b960 upstream.

The efi_info structure stores low 32 bits of memory map
in efi_memmap and high 32 bits in efi_memmap_hi.

While constructing pointer in the setup_e820(), need
to take into account all 64 bit of the pointer.

It is because on 64bit machine the function
efi_get_memory_map() may return full 64bit pointer and before
the patch that pointer was truncated.

The issue is triggered on Parallles virtual machine and
fixed with this patch.

Signed-off-by: Dmitry Skorodumov <sdmitry@xxxxxxxxxxxxx>
Cc: Denis V. Lunev <den@xxxxxxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/x86/boot/compressed/eboot.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1193,6 +1193,10 @@ static efi_status_t setup_e820(struct bo
unsigned int e820_type = 0;
unsigned long m = efi->efi_memmap;

+#ifdef CONFIG_X86_64
+ m |= (u64)efi->efi_memmap_hi << 32;
d = (efi_memory_desc_t *)(m + (i * efi->efi_memdesc_size));
switch (d->type) {

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