| Message ID | 20190809100800.5426-5-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement KASLR for powerpc/fsl_booke/32 | expand |
On Fri, Aug 09, 2019 at 06:07:52PM +0800, Jason Yan wrote: > Add a new helper create_tlb_entry() to create a tlb entry by the virtual > and physical address. This is a preparation to support boot kernel at a > randomized address. > > 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> > Reviewed-by: Diana Craciun <diana.craciun@nxp.com> > Tested-by: Diana Craciun <diana.craciun@nxp.com> > --- > arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++ > arch/powerpc/mm/mmu_decl.h | 1 + > 2 files changed, 30 insertions(+) > > diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S > index adf0505dbe02..04d124fee17d 100644 > --- a/arch/powerpc/kernel/head_fsl_booke.S > +++ b/arch/powerpc/kernel/head_fsl_booke.S > @@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge: > .long -1 > #endif > > +/* > + * Create a 64M tlb by address and entry > + * r3/r4 - physical address > + * r5 - virtual address > + * r6 - entry > + */ > +_GLOBAL(create_tlb_entry) This function is broadly named but contains various assumptions about the entry being created. I'd just call it create_kaslr_tlb_entry. > + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ > + rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ > + mtspr SPRN_MAS0,r7 /* Write MAS0 */ > + > + lis r6,(MAS1_VALID|MAS1_IPROT)@h > + ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l > + mtspr SPRN_MAS1,r6 /* Write MAS1 */ > + > + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h > + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l > + and r6,r6,r5 > + ori r6,r6,MAS2_M@l > + mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */ > + > + ori r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX) > + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ > + > + tlbwe /* Write TLB */ > + isync > + sync > + blr Should set MAS7 under MMU_FTR_BIG_PHYS (or CONFIG_PHYS_64BIT if it's too early for features) -- even if relocatable kernels over 4GiB aren't supported (I don't remember if they work or not), MAS7 might be non-zero on entry. And the function claims to take a 64-bit phys addr as input... MAS2_M should be MAS2_M_IF_NEEDED to match other kmem tlb entries. -Scott
Hi Scott, Thanks for your reply. On 2019/8/28 6:07, Scott Wood wrote: > On Fri, Aug 09, 2019 at 06:07:52PM +0800, Jason Yan wrote: >> Add a new helper create_tlb_entry() to create a tlb entry by the virtual >> and physical address. This is a preparation to support boot kernel at a >> randomized address. >> >> 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> >> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> >> Tested-by: Diana Craciun <diana.craciun@nxp.com> >> --- >> arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++ >> arch/powerpc/mm/mmu_decl.h | 1 + >> 2 files changed, 30 insertions(+) >> >> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S >> index adf0505dbe02..04d124fee17d 100644 >> --- a/arch/powerpc/kernel/head_fsl_booke.S >> +++ b/arch/powerpc/kernel/head_fsl_booke.S >> @@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge: >> .long -1 >> #endif >> >> +/* >> + * Create a 64M tlb by address and entry >> + * r3/r4 - physical address >> + * r5 - virtual address >> + * r6 - entry >> + */ >> +_GLOBAL(create_tlb_entry) > > This function is broadly named but contains various assumptions about the > entry being created. I'd just call it create_kaslr_tlb_entry. > OK. >> + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ >> + rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ >> + mtspr SPRN_MAS0,r7 /* Write MAS0 */ >> + >> + lis r6,(MAS1_VALID|MAS1_IPROT)@h >> + ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l >> + mtspr SPRN_MAS1,r6 /* Write MAS1 */ >> + >> + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h >> + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l >> + and r6,r6,r5 >> + ori r6,r6,MAS2_M@l >> + mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */ >> + >> + ori r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX) >> + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ >> + >> + tlbwe /* Write TLB */ >> + isync >> + sync >> + blr > > Should set MAS7 under MMU_FTR_BIG_PHYS (or CONFIG_PHYS_64BIT if it's > too early for features) -- even if relocatable kernels over 4GiB aren't > supported (I don't remember if they work or not), MAS7 might be non-zero > on entry. And the function claims to take a 64-bit phys addr as input... > Good catch. And I should consider 32-bit phys addr as input too. I will fix this in next version. Thanks. > MAS2_M should be MAS2_M_IF_NEEDED to match other kmem tlb entries. > OK > -Scott > > . >
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index adf0505dbe02..04d124fee17d 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge: .long -1 #endif +/* + * Create a 64M tlb by address and entry + * r3/r4 - physical address + * r5 - virtual address + * r6 - entry + */ +_GLOBAL(create_tlb_entry) + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ + rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ + mtspr SPRN_MAS0,r7 /* Write MAS0 */ + + lis r6,(MAS1_VALID|MAS1_IPROT)@h + ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l + mtspr SPRN_MAS1,r6 /* Write MAS1 */ + + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l + and r6,r6,r5 + ori r6,r6,MAS2_M@l + mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */ + + ori r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX) + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ + + tlbwe /* Write TLB */ + isync + sync + blr + /* * 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 32c1a191c28a..a09f89d3aa0f 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -142,6 +142,7 @@ extern unsigned long calc_cam_sz(unsigned long ram, unsigned long virt, 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); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx);