| Message ID | 20230307140522.2311461-3-ardb@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Add support for LPA2 at stage1 and WXN | expand |
On Tue, Mar 07, 2023 at 03:04:24PM +0100, Ard Biesheuvel wrote: > We enable CONFIG_RELOCATABLE even when CONFIG_RANDOMIZE_BASE is > disabled, and this permits the loader (i.e., EFI) to place the kernel > anywhere in physical memory as long as the base address is 64k aligned. > > This means that the 'KASLR' case described in the header that defines > the size of the statically allocated page tables could take effect even > when CONFIG_RANDMIZE_BASE=n. So check for CONFIG_RELOCATABLE instead. Could we pleqase update the comment to describe that? As of this commit it'll be left describing a KASLR-specific case, and it'd be good to have it mention the case described in this commit message. Thanks, Mark. > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > --- > arch/arm64/include/asm/kernel-pgtable.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h > index fcd14197756f0619..4d13c73171e1e360 100644 > --- a/arch/arm64/include/asm/kernel-pgtable.h > +++ b/arch/arm64/include/asm/kernel-pgtable.h > @@ -53,7 +53,7 @@ > * address is just pushed over a boundary and the start address isn't). > */ > > -#ifdef CONFIG_RANDOMIZE_BASE > +#ifdef CONFIG_RELOCATABLE > #define EARLY_KASLR (1) > #else > #define EARLY_KASLR (0) > -- > 2.39.2 > >
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index fcd14197756f0619..4d13c73171e1e360 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -53,7 +53,7 @@ * address is just pushed over a boundary and the start address isn't). */ -#ifdef CONFIG_RANDOMIZE_BASE +#ifdef CONFIG_RELOCATABLE #define EARLY_KASLR (1) #else #define EARLY_KASLR (0)
We enable CONFIG_RELOCATABLE even when CONFIG_RANDOMIZE_BASE is disabled, and this permits the loader (i.e., EFI) to place the kernel anywhere in physical memory as long as the base address is 64k aligned. This means that the 'KASLR' case described in the header that defines the size of the statically allocated page tables could take effect even when CONFIG_RANDMIZE_BASE=n. So check for CONFIG_RELOCATABLE instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm64/include/asm/kernel-pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)