2019-07-17 07:51:16

by Jason Yan

Subject: [RFC PATCH 03/10] powerpc: introduce kimage_vaddr to store the kernel base

Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
need a variable to store the kernel base.

Signed-off-by: Jason Yan <[email protected]>
Cc: Diana Craciun <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Kees Cook <[email protected]>
---
arch/powerpc/include/asm/page.h | 2 ++
arch/powerpc/mm/init-common.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 0d52f57fca04..60a68d3a54b1 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -315,6 +315,8 @@ void arch_free_page(struct page *page, int order);

struct vm_area_struct;

+extern unsigned long kimage_vaddr;
+
#include <asm-generic/memory_model.h>
#endif /* __ASSEMBLY__ */
#include <asm/slice.h>
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 9273c38009cb..c7a98c73e5c1 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -25,6 +25,8 @@ phys_addr_t memstart_addr = (phys_addr_t)~0ull;
EXPORT_SYMBOL(memstart_addr);
phys_addr_t kernstart_addr;
EXPORT_SYMBOL(kernstart_addr);
+unsigned long kimage_vaddr = KERNELBASE;
+EXPORT_SYMBOL(kimage_vaddr);

static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
--
2.17.2

2019-07-29 11:02:18

by Christophe Leroy

Subject: Re: [RFC PATCH 03/10] powerpc: introduce kimage_vaddr to store the kernel base

Le 17/07/2019 à 10:06, Jason Yan a écrit :
> Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
> need a variable to store the kernel base.
>
> Signed-off-by: Jason Yan <[email protected]>
> Cc: Diana Craciun <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Christophe Leroy <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> Cc: Nicholas Piggin <[email protected]>
> Cc: Kees Cook <[email protected]>

Reviewed-by: Christophe Leroy <[email protected]>


> ---
> arch/powerpc/include/asm/page.h | 2 ++
> arch/powerpc/mm/init-common.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index 0d52f57fca04..60a68d3a54b1 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -315,6 +315,8 @@ void arch_free_page(struct page *page, int order);
>
> struct vm_area_struct;
>
> +extern unsigned long kimage_vaddr;
> +
> #include <asm-generic/memory_model.h>
> #endif /* __ASSEMBLY__ */
> #include <asm/slice.h>
> diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
> index 9273c38009cb..c7a98c73e5c1 100644
> --- a/arch/powerpc/mm/init-common.c
> +++ b/arch/powerpc/mm/init-common.c
> @@ -25,6 +25,8 @@ phys_addr_t memstart_addr = (phys_addr_t)~0ull;
> EXPORT_SYMBOL(memstart_addr);
> phys_addr_t kernstart_addr;
> EXPORT_SYMBOL(kernstart_addr);
> +unsigned long kimage_vaddr = KERNELBASE;
> +EXPORT_SYMBOL(kimage_vaddr);
>
> static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
> static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
>

2019-07-29 14:35:21

by Christoph Hellwig

Subject: Re: [RFC PATCH 03/10] powerpc: introduce kimage_vaddr to store the kernel base

On Wed, Jul 17, 2019 at 04:06:14PM +0800, Jason Yan wrote:
> Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
> need a variable to store the kernel base.

This should probably merged into the patch actually using it.