[PATCH 3.16.y-ckt 019/130] x86/efi: Use all 64 bit of efi_memmap in setup_e820()

[Luis Henriques]

3.16.7-ckt17 -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: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 arch/x86/boot/compressed/eboot.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index bfb3908493f8..c4784a052461 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1159,6 +1159,10 @@ static efi_status_t setup_e820(struct boot_params *params,
 		unsigned int e820_type = 0;
 		unsigned long m = efi->efi_memmap;
 
+#ifdef CONFIG_X86_64
+		m |= (u64)efi->efi_memmap_hi << 32;
+#endif
+
 		d = (efi_memory_desc_t *)(m + (i * efi->efi_memdesc_size));
 		switch (d->type) {
 		case EFI_RESERVED_TYPE:
--
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