| Message ID | 20190730074225.39544-6-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement KASLR for powerpc/fsl_booke/32 | expand |
Le 30/07/2019 à 09:42, Jason Yan a écrit : > Add a new helper reloc_kernel_entry() to jump back to the start of the > new kernel. After we put the new kernel in a randomized place we can use > this new helper to enter the kernel and begin to relocate again. > > Signed-off-by: Jason Yan <yanaijie@huawei.com> > Cc: Diana Craciun <diana.craciun@nxp.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Christophe Leroy <christophe.leroy@c-s.fr> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++ > arch/powerpc/mm/mmu_decl.h | 1 + > 2 files changed, 14 insertions(+) > > diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S > index 04d124fee17d..2083382dd662 100644 > --- a/arch/powerpc/kernel/head_fsl_booke.S > +++ b/arch/powerpc/kernel/head_fsl_booke.S > @@ -1143,6 +1143,19 @@ _GLOBAL(create_tlb_entry) > sync > blr > > +/* > + * Return to the start of the relocated kernel and run again > + * r3 - virtual address of fdt > + * r4 - entry of the kernel > + */ > +_GLOBAL(reloc_kernel_entry) > + mfmsr r7 > + rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) > + > + mtspr SPRN_SRR0,r4 > + mtspr SPRN_SRR1,r7 > + rfi > + > /* > * Create a tlb entry with the same effective and physical address as > * the tlb entry used by the current running code. But set the TS to 1. > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index a09f89d3aa0f..804da298beb3 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); > extern int switch_to_as1(void); > extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); > void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry); > +void reloc_kernel_entry(void *fdt, int addr); > #endif > extern void loadcam_entry(unsigned int index); > extern void loadcam_multi(int first_idx, int num, int tmp_idx); >
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 04d124fee17d..2083382dd662 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1143,6 +1143,19 @@ _GLOBAL(create_tlb_entry) sync blr +/* + * Return to the start of the relocated kernel and run again + * r3 - virtual address of fdt + * r4 - entry of the kernel + */ +_GLOBAL(reloc_kernel_entry) + mfmsr r7 + rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) + + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r7 + rfi + /* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1. diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index a09f89d3aa0f..804da298beb3 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); extern int switch_to_as1(void); extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry); +void reloc_kernel_entry(void *fdt, int addr); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx);
Add a new helper reloc_kernel_entry() to jump back to the start of the new kernel. After we put the new kernel in a randomized place we can use this new helper to enter the kernel and begin to relocate again. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: Diana Craciun <diana.craciun@nxp.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Kees Cook <keescook@chromium.org> --- arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++ arch/powerpc/mm/mmu_decl.h | 1 + 2 files changed, 14 insertions(+)