Jason Yan <yanai...@huawei.com> writes: > This patch add support to boot kernel from places other than KERNELBASE. > Since CONFIG_RELOCATABLE has already supported, what we need to do is > map or copy kernel to a proper place and relocate. Freescale Book-E > parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1 > entries are not suitable to map the kernel directly in a randomized > region, so we chose to copy the kernel to a proper place and restart to > relocate.
So to be 100% clear you are randomising the location of the kernel in virtual and physical space, by the same amount, and retaining the 1:1 linear mapping. > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 77f6ebf97113..755378887912 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -548,6 +548,17 @@ config RELOCATABLE > setting can still be useful to bootwrappers that need to know the > load address of the kernel (eg. u-boot/mkimage). > > +config RANDOMIZE_BASE > + bool "Randomize the address of the kernel image" > + depends on (FSL_BOOKE && FLATMEM && PPC32) > + select RELOCATABLE I think this should depend on RELOCATABLE, rather than selecting it. > diff --git a/arch/powerpc/kernel/kaslr_booke.c > b/arch/powerpc/kernel/kaslr_booke.c > new file mode 100644 > index 000000000000..30f84c0321b2 > --- /dev/null > +++ b/arch/powerpc/kernel/kaslr_booke.c > @@ -0,0 +1,84 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2019 Jason Yan <yanai...@huawei.com> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. You don't need that paragraph now that you have the SPDX tag. Rather than using a '//' comment followed by a single line block comment you can format it as: // SPDX-License-Identifier: GPL-2.0-only // // Copyright (C) 2019 Jason Yan <yanai...@huawei.com> > +#include <linux/signal.h> > +#include <linux/sched.h> > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <linux/string.h> > +#include <linux/types.h> > +#include <linux/ptrace.h> > +#include <linux/mman.h> > +#include <linux/mm.h> > +#include <linux/swap.h> > +#include <linux/stddef.h> > +#include <linux/vmalloc.h> > +#include <linux/init.h> > +#include <linux/delay.h> > +#include <linux/highmem.h> > +#include <linux/memblock.h> > +#include <asm/pgalloc.h> > +#include <asm/prom.h> > +#include <asm/io.h> > +#include <asm/mmu_context.h> > +#include <asm/pgtable.h> > +#include <asm/mmu.h> > +#include <linux/uaccess.h> > +#include <asm/smp.h> > +#include <asm/machdep.h> > +#include <asm/setup.h> > +#include <asm/paca.h> > +#include <mm/mmu_decl.h> Do you really need all those headers? > +extern int is_second_reloc; That should be in a header. Any reason why it isn't a bool? cheers
