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

[PATCH] 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>

tested in Parallles virtual machine, kernel 3.10.0
---
 arch/x86/boot/compressed/eboot.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 2c82bd1..908a81f 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1184,6 +1184,12 @@ static efi_status_t setup_e820(struct boot_params *params,
 	u32 nr_entries;
 	u32 nr_desc;
 	int i;
+	unsigned long m
+
+	m = efi->efi_memmap;
+#ifdef CONFIG_X86_64
+	m |= (u64)efi->efi_memmap_hi << 32;
+#endif
 
 	nr_entries = 0;
 	nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
@@ -1191,7 +1197,6 @@ static efi_status_t setup_e820(struct boot_params *params,
 	for (i = 0; i < nr_desc; i++) {
 		efi_memory_desc_t *d;
 		unsigned int e820_type = 0;
-		unsigned long m = efi->efi_memmap;
 
 		d = (efi_memory_desc_t *)(m + (i * efi->efi_memdesc_size));
 		switch (d->type) {
-- 
1.7.9.1

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

[Borislav Petkov]

On Wed, Jul 22, 2015 at 07:06:10PM +0400, 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>
> 
> tested in Parallles virtual machine, kernel 3.10.0
> ---
>  arch/x86/boot/compressed/eboot.c |   10 +++++++++-
>  1 files changed, 9 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
> index 2c82bd1..908a81f 100644
> --- a/arch/x86/boot/compressed/eboot.c
> +++ b/arch/x86/boot/compressed/eboot.c
> @@ -1184,6 +1184,12 @@ static efi_status_t setup_e820(struct boot_params *params,
>  	u32 nr_entries;
>  	u32 nr_desc;
>  	int i;
> +	unsigned long m

Did you even build-test it before sending?

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

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

[Dmitry Skorodumov]

Borislav Petkov <bp@...> writes:
> > +	unsigned long m
> 
> Did you even build-test it before sending?

Sorry for inaccuracy, somehow lost the semicolon during final editing..