[PATCH v3] x86_64/efi: Use all 64 bit of efi_memmap in setup_e820()

[PATCH v3] x86_64/efi: Use all 64 bit of efi_memmap in setup_e820()

[Dmitry Skorodumov]

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.

Signed-off-by: Dmitry Skorodumov <sdmitry-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
CC: Denis V. Lunev <den-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>

The issue is triggered on Parallles virtual machine and
fixed with this patch
---
 arch/x86/boot/compressed/eboot.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 2c82bd1..92ab209 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1192,6 +1192,9 @@ static efi_status_t setup_e820(struct boot_params *params,
 		efi_memory_desc_t *d;
 		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) {
-- 
1.7.9.1

Re: [PATCH v3] x86_64/efi: Use all 64 bit of efi_memmap in setup_e820()

[Matt Fleming]

On Tue, 28 Jul, at 06:38:32PM, Dmitry Skorodumov wrote:
> 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.
> 
> Signed-off-by: Dmitry Skorodumov <sdmitry-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> CC: Denis V. Lunev <den-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
> 
> The issue is triggered on Parallles virtual machine and
> fixed with this patch
> ---
>  arch/x86/boot/compressed/eboot.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)

Applied to the EFI urgent queue, thanks!

-- 
Matt Fleming, Intel Open Source Technology Center