| Message ID | 20200206025825.22934-4-yanaijie@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement KASLR for powerpc/fsl_booke/64 | expand |
Le 06/02/2020 à 03:58, Jason Yan a écrit : > The implementation for Freescale BookE64 is similar as BookE32. One > difference is that Freescale BookE64 set up a TLB mapping of 1G during > booting. Another difference is that ppc64 needs the kernel to be > 64K-aligned. So we can randomize the kernel in this 1G mapping and make > it 64K-aligned. This can save some code to creat another TLB map at > early boot. The disadvantage is that we only have about 1G/64K = 16384 > slots to put the kernel in. > > To support secondary cpu boot up, a variable __kaslr_offset was added in > first_256B section. This can help secondary cpu get the kaslr offset > before the 1:1 mapping has been setup. > > Signed-off-by: Jason Yan <yanaijie@huawei.com> > Cc: Scott Wood <oss@buserror.net> > 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/Kconfig | 2 +- > arch/powerpc/kernel/exceptions-64e.S | 10 +++++++++ > arch/powerpc/kernel/head_64.S | 7 ++++++ > arch/powerpc/kernel/setup_64.c | 4 +++- > arch/powerpc/mm/mmu_decl.h | 16 +++++++------- > arch/powerpc/mm/nohash/kaslr_booke.c | 33 +++++++++++++++++++++++++--- > 6 files changed, 59 insertions(+), 13 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index c150a9d49343..754aeb96bb1c 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -568,7 +568,7 @@ config RELOCATABLE > > config RANDOMIZE_BASE > bool "Randomize the address of the kernel image" > - depends on (FSL_BOOKE && FLATMEM && PPC32) > + depends on (PPC_FSL_BOOK3E && FLATMEM) > depends on RELOCATABLE > help > Randomizes the virtual address at which the kernel image is > diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S > index 1b9b174bee86..c1c05b8684ca 100644 > --- a/arch/powerpc/kernel/exceptions-64e.S > +++ b/arch/powerpc/kernel/exceptions-64e.S > @@ -1378,6 +1378,7 @@ skpinv: addi r6,r6,1 /* Increment */ > 1: mflr r6 > addi r6,r6,(2f - 1b) > tovirt(r6,r6) > + add r6,r6,r19 > lis r7,MSR_KERNEL@h > ori r7,r7,MSR_KERNEL@l > mtspr SPRN_SRR0,r6 > @@ -1400,6 +1401,7 @@ skpinv: addi r6,r6,1 /* Increment */ > > /* We translate LR and return */ > tovirt(r8,r8) > + add r8,r8,r19 > mtlr r8 > blr > > @@ -1528,6 +1530,7 @@ a2_tlbinit_code_end: > */ > _GLOBAL(start_initialization_book3e) > mflr r28 > + li r19, 0 > > /* First, we need to setup some initial TLBs to map the kernel > * text, data and bss at PAGE_OFFSET. We don't have a real mode > @@ -1570,6 +1573,12 @@ _GLOBAL(book3e_secondary_core_init) > cmplwi r4,0 > bne 2f > > + li r19, 0 > +#ifdef CONFIG_RANDOMIZE_BASE > + LOAD_REG_ADDR_PIC(r19, __kaslr_offset) > + lwz r19,0(r19) > + rlwinm r19,r19,0,0,5 > +#endif > /* Setup TLB for this core */ > bl initial_tlb_book3e > > @@ -1602,6 +1611,7 @@ _GLOBAL(book3e_secondary_core_init) > lis r3,PAGE_OFFSET@highest > sldi r3,r3,32 > or r28,r28,r3 > + add r28,r28,r19 > 1: mtlr r28 > blr > > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S > index ad79fddb974d..744624140fb8 100644 > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: > .8byte 0x0 > > #ifdef CONFIG_RELOCATABLE > +#ifdef CONFIG_RANDOMIZE_BASE > + . = 0x58 > + .globl __kaslr_offset > +__kaslr_offset: > +DEFINE_FIXED_SYMBOL(__kaslr_offset) > + .long 0 > +#endif > /* This flag is set to 1 by a loader if the kernel should run > * at the loaded address instead of the linked address. This > * is used by kexec-tools to keep the the kdump kernel in the > diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c > index 6104917a282d..a16b970a8d1a 100644 > --- a/arch/powerpc/kernel/setup_64.c > +++ b/arch/powerpc/kernel/setup_64.c > @@ -66,7 +66,7 @@ > #include <asm/feature-fixups.h> > #include <asm/kup.h> > #include <asm/early_ioremap.h> > - Why remove this new line which clearly separates things in asm/ and things in local dir ? > +#include <mm/mmu_decl.h> > #include "setup.h" > > int spinning_secondaries; > @@ -300,6 +300,8 @@ void __init early_setup(unsigned long dt_ptr) > /* Enable early debugging if any specified (see udbg.h) */ > udbg_early_init(); > > + kaslr_early_init(__va(dt_ptr), 0); > + > udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); > > /* > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index 3e1c85c7d10b..bbd721d1e3d7 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -147,14 +147,6 @@ void reloc_kernel_entry(void *fdt, long addr); > extern void loadcam_entry(unsigned int index); > extern void loadcam_multi(int first_idx, int num, int tmp_idx); > > -#ifdef CONFIG_RANDOMIZE_BASE > -void kaslr_early_init(void *dt_ptr, phys_addr_t size); > -void kaslr_late_init(void); > -#else > -static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} > -static inline void kaslr_late_init(void) {} > -#endif > - > struct tlbcam { > u32 MAS0; > u32 MAS1; > @@ -164,6 +156,14 @@ struct tlbcam { > }; > #endif > > +#ifdef CONFIG_RANDOMIZE_BASE > +void kaslr_early_init(void *dt_ptr, phys_addr_t size); > +void kaslr_late_init(void); > +#else > +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} > +static inline void kaslr_late_init(void) {} > +#endif > + > #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_FSL_BOOKE) || defined(CONFIG_PPC_8xx) > /* 6xx have BATS */ > /* FSL_BOOKE have TLBCAM */ > diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c > index 07b036e98353..c6f5c1db1394 100644 > --- a/arch/powerpc/mm/nohash/kaslr_booke.c > +++ b/arch/powerpc/mm/nohash/kaslr_booke.c > @@ -231,7 +231,7 @@ static __init unsigned long get_usable_address(const void *fdt, > unsigned long pa; > unsigned long pa_end; > > - for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { > + for (pa = offset; (long)pa > (long)start; pa -= SZ_64K) { Doesn't this modify the behaviour for PPC32 too ? > pa_end = pa + regions.kernel_size; > if (overlaps_region(fdt, pa, pa_end)) > continue; > @@ -265,14 +265,14 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando > { > unsigned long koffset = 0; > unsigned long start; > - unsigned long index; > unsigned long offset; > > +#ifdef CONFIG_PPC32 Can we use if (IS_ENABLED(CONFIG_PPC32)) { /* 32 bits stuff */ } else { /* 64 bits stuff */ } > /* > * Decide which 64M we want to start > * Only use the low 8 bits of the random seed > */ > - index = random & 0xFF; > + unsigned long index = random & 0xFF; That's not good in terms of readability, index declaration should remain at the top of the function, should be possible if using IS_ENABLED() instead > index %= regions.linear_sz / SZ_64M; > > /* Decide offset inside 64M */ > @@ -287,6 +287,15 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando > break; > index--; > } > +#else > + /* Decide kernel offset inside 1G */ > + offset = random % (SZ_1G - regions.kernel_size); > + offset = round_down(offset, SZ_64K); > + > + start = memstart_addr; > + offset = memstart_addr + offset; > + koffset = get_usable_address(dt_ptr, start, offset); > +#endif > > if (koffset != 0) > koffset -= memstart_addr; > @@ -325,6 +334,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size > else > pr_warn("KASLR: No safe seed for randomizing the kernel base.\n"); > > +#ifdef CONFIG_PPC32 > ram = min_t(phys_addr_t, __max_low_memory, size); > ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); > linear_sz = min_t(unsigned long, ram, SZ_512M); > @@ -332,6 +342,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size > /* If the linear size is smaller than 64M, do not randmize */ > if (linear_sz < SZ_64M) > return 0; > +#endif > > /* check for a reserved-memory node and record its cell sizes */ > regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); > @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > unsigned long offset; > unsigned long kernel_sz; > > +#ifdef CONFIG_PPC64 Same, can we use a standard C if/else sequence with IS_ENABLED(CONFIG_PPC64) ? > + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); > + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); > + > + if (*__run_at_load == 1) > + return; > + > + /* Setup flat device-tree pointer */ > + initial_boot_params = dt_ptr; > +#endif > + > kernel_sz = (unsigned long)_end - (unsigned long)_stext; > > offset = kaslr_choose_location(dt_ptr, size, kernel_sz); > @@ -372,6 +394,7 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > kernstart_virt_addr += offset; > kernstart_addr += offset; > > +#ifdef CONFIG_PPC32 > is_second_reloc = 1; > > if (offset >= SZ_64M) { > @@ -381,6 +404,10 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > /* Create kernel map to relocate in */ > create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); > } > +#else > + *__kaslr_offset = kernstart_virt_addr - KERNELBASE; > + *__run_at_load = 1; > +#endif > > /* Copy the kernel to it's new location and run */ > memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz); > Christophe
在 2020/2/20 21:48, Christophe Leroy 写道: > > > Le 06/02/2020 à 03:58, Jason Yan a écrit : >> The implementation for Freescale BookE64 is similar as BookE32. One >> difference is that Freescale BookE64 set up a TLB mapping of 1G during >> booting. Another difference is that ppc64 needs the kernel to be >> 64K-aligned. So we can randomize the kernel in this 1G mapping and make >> it 64K-aligned. This can save some code to creat another TLB map at >> early boot. The disadvantage is that we only have about 1G/64K = 16384 >> slots to put the kernel in. >> >> To support secondary cpu boot up, a variable __kaslr_offset was added in >> first_256B section. This can help secondary cpu get the kaslr offset >> before the 1:1 mapping has been setup. >> >> Signed-off-by: Jason Yan <yanaijie@huawei.com> >> Cc: Scott Wood <oss@buserror.net> >> 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/Kconfig | 2 +- >> arch/powerpc/kernel/exceptions-64e.S | 10 +++++++++ >> arch/powerpc/kernel/head_64.S | 7 ++++++ >> arch/powerpc/kernel/setup_64.c | 4 +++- >> arch/powerpc/mm/mmu_decl.h | 16 +++++++------- >> arch/powerpc/mm/nohash/kaslr_booke.c | 33 +++++++++++++++++++++++++--- >> 6 files changed, 59 insertions(+), 13 deletions(-) >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index c150a9d49343..754aeb96bb1c 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -568,7 +568,7 @@ config RELOCATABLE >> config RANDOMIZE_BASE >> bool "Randomize the address of the kernel image" >> - depends on (FSL_BOOKE && FLATMEM && PPC32) >> + depends on (PPC_FSL_BOOK3E && FLATMEM) >> depends on RELOCATABLE >> help >> Randomizes the virtual address at which the kernel image is >> diff --git a/arch/powerpc/kernel/exceptions-64e.S >> b/arch/powerpc/kernel/exceptions-64e.S >> index 1b9b174bee86..c1c05b8684ca 100644 >> --- a/arch/powerpc/kernel/exceptions-64e.S >> +++ b/arch/powerpc/kernel/exceptions-64e.S >> @@ -1378,6 +1378,7 @@ skpinv: addi r6,r6,1 /* >> Increment */ >> 1: mflr r6 >> addi r6,r6,(2f - 1b) >> tovirt(r6,r6) >> + add r6,r6,r19 >> lis r7,MSR_KERNEL@h >> ori r7,r7,MSR_KERNEL@l >> mtspr SPRN_SRR0,r6 >> @@ -1400,6 +1401,7 @@ skpinv: addi r6,r6,1 /* >> Increment */ >> /* We translate LR and return */ >> tovirt(r8,r8) >> + add r8,r8,r19 >> mtlr r8 >> blr >> @@ -1528,6 +1530,7 @@ a2_tlbinit_code_end: >> */ >> _GLOBAL(start_initialization_book3e) >> mflr r28 >> + li r19, 0 >> /* First, we need to setup some initial TLBs to map the kernel >> * text, data and bss at PAGE_OFFSET. We don't have a real mode >> @@ -1570,6 +1573,12 @@ _GLOBAL(book3e_secondary_core_init) >> cmplwi r4,0 >> bne 2f >> + li r19, 0 >> +#ifdef CONFIG_RANDOMIZE_BASE >> + LOAD_REG_ADDR_PIC(r19, __kaslr_offset) >> + lwz r19,0(r19) >> + rlwinm r19,r19,0,0,5 >> +#endif >> /* Setup TLB for this core */ >> bl initial_tlb_book3e >> @@ -1602,6 +1611,7 @@ _GLOBAL(book3e_secondary_core_init) >> lis r3,PAGE_OFFSET@highest >> sldi r3,r3,32 >> or r28,r28,r3 >> + add r28,r28,r19 >> 1: mtlr r28 >> blr >> diff --git a/arch/powerpc/kernel/head_64.S >> b/arch/powerpc/kernel/head_64.S >> index ad79fddb974d..744624140fb8 100644 >> --- a/arch/powerpc/kernel/head_64.S >> +++ b/arch/powerpc/kernel/head_64.S >> @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: >> .8byte 0x0 >> #ifdef CONFIG_RELOCATABLE >> +#ifdef CONFIG_RANDOMIZE_BASE >> + . = 0x58 >> + .globl __kaslr_offset >> +__kaslr_offset: >> +DEFINE_FIXED_SYMBOL(__kaslr_offset) >> + .long 0 >> +#endif >> /* This flag is set to 1 by a loader if the kernel should run >> * at the loaded address instead of the linked address. This >> * is used by kexec-tools to keep the the kdump kernel in the >> diff --git a/arch/powerpc/kernel/setup_64.c >> b/arch/powerpc/kernel/setup_64.c >> index 6104917a282d..a16b970a8d1a 100644 >> --- a/arch/powerpc/kernel/setup_64.c >> +++ b/arch/powerpc/kernel/setup_64.c >> @@ -66,7 +66,7 @@ >> #include <asm/feature-fixups.h> >> #include <asm/kup.h> >> #include <asm/early_ioremap.h> >> - > > Why remove this new line which clearly separates things in asm/ and > things in local dir ? Sorry to break this. I will add the new line back. > >> +#include <mm/mmu_decl.h> >> #include "setup.h" >> int spinning_secondaries; >> @@ -300,6 +300,8 @@ void __init early_setup(unsigned long dt_ptr) >> /* Enable early debugging if any specified (see udbg.h) */ >> udbg_early_init(); >> + kaslr_early_init(__va(dt_ptr), 0); >> + >> udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); >> /* >> diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h >> index 3e1c85c7d10b..bbd721d1e3d7 100644 >> --- a/arch/powerpc/mm/mmu_decl.h >> +++ b/arch/powerpc/mm/mmu_decl.h >> @@ -147,14 +147,6 @@ void reloc_kernel_entry(void *fdt, long addr); >> extern void loadcam_entry(unsigned int index); >> extern void loadcam_multi(int first_idx, int num, int tmp_idx); >> -#ifdef CONFIG_RANDOMIZE_BASE >> -void kaslr_early_init(void *dt_ptr, phys_addr_t size); >> -void kaslr_late_init(void); >> -#else >> -static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} >> -static inline void kaslr_late_init(void) {} >> -#endif >> - >> struct tlbcam { >> u32 MAS0; >> u32 MAS1; >> @@ -164,6 +156,14 @@ struct tlbcam { >> }; >> #endif >> +#ifdef CONFIG_RANDOMIZE_BASE >> +void kaslr_early_init(void *dt_ptr, phys_addr_t size); >> +void kaslr_late_init(void); >> +#else >> +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} >> +static inline void kaslr_late_init(void) {} >> +#endif >> + >> #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_FSL_BOOKE) || >> defined(CONFIG_PPC_8xx) >> /* 6xx have BATS */ >> /* FSL_BOOKE have TLBCAM */ >> diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c >> b/arch/powerpc/mm/nohash/kaslr_booke.c >> index 07b036e98353..c6f5c1db1394 100644 >> --- a/arch/powerpc/mm/nohash/kaslr_booke.c >> +++ b/arch/powerpc/mm/nohash/kaslr_booke.c >> @@ -231,7 +231,7 @@ static __init unsigned long >> get_usable_address(const void *fdt, >> unsigned long pa; >> unsigned long pa_end; >> - for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { >> + for (pa = offset; (long)pa > (long)start; pa -= SZ_64K) { > > Doesn't this modify the behaviour for PPC32 too ? Oh, yes. I will fix this. > >> pa_end = pa + regions.kernel_size; >> if (overlaps_region(fdt, pa, pa_end)) >> continue; >> @@ -265,14 +265,14 @@ static unsigned long __init >> kaslr_legal_offset(void *dt_ptr, unsigned long rando >> { >> unsigned long koffset = 0; >> unsigned long start; >> - unsigned long index; >> unsigned long offset; >> +#ifdef CONFIG_PPC32 > > Can we use > > if (IS_ENABLED(CONFIG_PPC32)) { > /* 32 bits stuff */ > } else { > /* 64 bits stuff */ > } Thansk for the suggestion. I will consider to use IS_ENABLED() instead. > >> /* >> * Decide which 64M we want to start >> * Only use the low 8 bits of the random seed >> */ >> - index = random & 0xFF; >> + unsigned long index = random & 0xFF; > > That's not good in terms of readability, index declaration should remain > at the top of the function, should be possible if using IS_ENABLED() > instead I'm wondering how to declare a variable inside a code block such as if (IS_ENABLED(CONFIG_PPC32)) at the top of the function and use the variable in another if (IS_ENABLED(CONFIG_PPC32)). Is there any good idea? > >> index %= regions.linear_sz / SZ_64M; >> /* Decide offset inside 64M */ >> @@ -287,6 +287,15 @@ static unsigned long __init >> kaslr_legal_offset(void *dt_ptr, unsigned long rando >> break; >> index--; >> } >> +#else >> + /* Decide kernel offset inside 1G */ >> + offset = random % (SZ_1G - regions.kernel_size); >> + offset = round_down(offset, SZ_64K); >> + >> + start = memstart_addr; >> + offset = memstart_addr + offset; >> + koffset = get_usable_address(dt_ptr, start, offset); >> +#endif >> if (koffset != 0) >> koffset -= memstart_addr; >> @@ -325,6 +334,7 @@ static unsigned long __init >> kaslr_choose_location(void *dt_ptr, phys_addr_t size >> else >> pr_warn("KASLR: No safe seed for randomizing the kernel >> base.\n"); >> +#ifdef CONFIG_PPC32 >> ram = min_t(phys_addr_t, __max_low_memory, size); >> ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); >> linear_sz = min_t(unsigned long, ram, SZ_512M); >> @@ -332,6 +342,7 @@ static unsigned long __init >> kaslr_choose_location(void *dt_ptr, phys_addr_t size >> /* If the linear size is smaller than 64M, do not randmize */ >> if (linear_sz < SZ_64M) >> return 0; >> +#endif >> /* check for a reserved-memory node and record its cell sizes */ >> regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); >> @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void >> *dt_ptr, phys_addr_t size) >> unsigned long offset; >> unsigned long kernel_sz; >> +#ifdef CONFIG_PPC64 > > Same, can we use a standard C if/else sequence with > IS_ENABLED(CONFIG_PPC64) ? OK, I will try to do this if I can deal with the declaration of variables in different if/else sequence. Thanks, Jason > >> + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); >> + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); >> + >> + if (*__run_at_load == 1) >> + return; >> + >> + /* Setup flat device-tree pointer */ >> + initial_boot_params = dt_ptr; >> +#endif >> + >> kernel_sz = (unsigned long)_end - (unsigned long)_stext; >> offset = kaslr_choose_location(dt_ptr, size, kernel_sz); >> @@ -372,6 +394,7 @@ notrace void __init kaslr_early_init(void *dt_ptr, >> phys_addr_t size) >> kernstart_virt_addr += offset; >> kernstart_addr += offset; >> +#ifdef CONFIG_PPC32 >> is_second_reloc = 1; >> if (offset >= SZ_64M) { >> @@ -381,6 +404,10 @@ notrace void __init kaslr_early_init(void >> *dt_ptr, phys_addr_t size) >> /* Create kernel map to relocate in */ >> create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); >> } >> +#else >> + *__kaslr_offset = kernstart_virt_addr - KERNELBASE; >> + *__run_at_load = 1; >> +#endif >> /* Copy the kernel to it's new location and run */ >> memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz); >> > > Christophe > > .
在 2020/2/26 10:40, Jason Yan 写道: > > > 在 2020/2/20 21:48, Christophe Leroy 写道: >> >> >> Le 06/02/2020 à 03:58, Jason Yan a écrit : >>> The implementation for Freescale BookE64 is similar as BookE32. One >>> difference is that Freescale BookE64 set up a TLB mapping of 1G during >>> booting. Another difference is that ppc64 needs the kernel to be >>> 64K-aligned. So we can randomize the kernel in this 1G mapping and make >>> it 64K-aligned. This can save some code to creat another TLB map at >>> early boot. The disadvantage is that we only have about 1G/64K = 16384 >>> slots to put the kernel in. >>> >>> To support secondary cpu boot up, a variable __kaslr_offset was added in >>> first_256B section. This can help secondary cpu get the kaslr offset >>> before the 1:1 mapping has been setup. >>> >>> Signed-off-by: Jason Yan <yanaijie@huawei.com> >>> Cc: Scott Wood <oss@buserror.net> >>> 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/Kconfig | 2 +- >>> arch/powerpc/kernel/exceptions-64e.S | 10 +++++++++ >>> arch/powerpc/kernel/head_64.S | 7 ++++++ >>> arch/powerpc/kernel/setup_64.c | 4 +++- >>> arch/powerpc/mm/mmu_decl.h | 16 +++++++------- >>> arch/powerpc/mm/nohash/kaslr_booke.c | 33 +++++++++++++++++++++++++--- >>> 6 files changed, 59 insertions(+), 13 deletions(-) >>> >>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >>> index c150a9d49343..754aeb96bb1c 100644 >>> --- a/arch/powerpc/Kconfig >>> +++ b/arch/powerpc/Kconfig >>> @@ -568,7 +568,7 @@ config RELOCATABLE >>> config RANDOMIZE_BASE >>> bool "Randomize the address of the kernel image" >>> - depends on (FSL_BOOKE && FLATMEM && PPC32) >>> + depends on (PPC_FSL_BOOK3E && FLATMEM) >>> depends on RELOCATABLE >>> help >>> Randomizes the virtual address at which the kernel image is >>> diff --git a/arch/powerpc/kernel/exceptions-64e.S >>> b/arch/powerpc/kernel/exceptions-64e.S >>> index 1b9b174bee86..c1c05b8684ca 100644 >>> --- a/arch/powerpc/kernel/exceptions-64e.S >>> +++ b/arch/powerpc/kernel/exceptions-64e.S >>> @@ -1378,6 +1378,7 @@ skpinv: addi r6,r6,1 /* >>> Increment */ >>> 1: mflr r6 >>> addi r6,r6,(2f - 1b) >>> tovirt(r6,r6) >>> + add r6,r6,r19 >>> lis r7,MSR_KERNEL@h >>> ori r7,r7,MSR_KERNEL@l >>> mtspr SPRN_SRR0,r6 >>> @@ -1400,6 +1401,7 @@ skpinv: addi r6,r6,1 /* >>> Increment */ >>> /* We translate LR and return */ >>> tovirt(r8,r8) >>> + add r8,r8,r19 >>> mtlr r8 >>> blr >>> @@ -1528,6 +1530,7 @@ a2_tlbinit_code_end: >>> */ >>> _GLOBAL(start_initialization_book3e) >>> mflr r28 >>> + li r19, 0 >>> /* First, we need to setup some initial TLBs to map the kernel >>> * text, data and bss at PAGE_OFFSET. We don't have a real mode >>> @@ -1570,6 +1573,12 @@ _GLOBAL(book3e_secondary_core_init) >>> cmplwi r4,0 >>> bne 2f >>> + li r19, 0 >>> +#ifdef CONFIG_RANDOMIZE_BASE >>> + LOAD_REG_ADDR_PIC(r19, __kaslr_offset) >>> + lwz r19,0(r19) >>> + rlwinm r19,r19,0,0,5 >>> +#endif >>> /* Setup TLB for this core */ >>> bl initial_tlb_book3e >>> @@ -1602,6 +1611,7 @@ _GLOBAL(book3e_secondary_core_init) >>> lis r3,PAGE_OFFSET@highest >>> sldi r3,r3,32 >>> or r28,r28,r3 >>> + add r28,r28,r19 >>> 1: mtlr r28 >>> blr >>> diff --git a/arch/powerpc/kernel/head_64.S >>> b/arch/powerpc/kernel/head_64.S >>> index ad79fddb974d..744624140fb8 100644 >>> --- a/arch/powerpc/kernel/head_64.S >>> +++ b/arch/powerpc/kernel/head_64.S >>> @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: >>> .8byte 0x0 >>> #ifdef CONFIG_RELOCATABLE >>> +#ifdef CONFIG_RANDOMIZE_BASE >>> + . = 0x58 >>> + .globl __kaslr_offset >>> +__kaslr_offset: >>> +DEFINE_FIXED_SYMBOL(__kaslr_offset) >>> + .long 0 >>> +#endif >>> /* This flag is set to 1 by a loader if the kernel should run >>> * at the loaded address instead of the linked address. This >>> * is used by kexec-tools to keep the the kdump kernel in the >>> diff --git a/arch/powerpc/kernel/setup_64.c >>> b/arch/powerpc/kernel/setup_64.c >>> index 6104917a282d..a16b970a8d1a 100644 >>> --- a/arch/powerpc/kernel/setup_64.c >>> +++ b/arch/powerpc/kernel/setup_64.c >>> @@ -66,7 +66,7 @@ >>> #include <asm/feature-fixups.h> >>> #include <asm/kup.h> >>> #include <asm/early_ioremap.h> >>> - >> >> Why remove this new line which clearly separates things in asm/ and >> things in local dir ? > > Sorry to break this. I will add the new line back. > >> >>> +#include <mm/mmu_decl.h> >>> #include "setup.h" >>> int spinning_secondaries; >>> @@ -300,6 +300,8 @@ void __init early_setup(unsigned long dt_ptr) >>> /* Enable early debugging if any specified (see udbg.h) */ >>> udbg_early_init(); >>> + kaslr_early_init(__va(dt_ptr), 0); >>> + >>> udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); >>> /* >>> diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h >>> index 3e1c85c7d10b..bbd721d1e3d7 100644 >>> --- a/arch/powerpc/mm/mmu_decl.h >>> +++ b/arch/powerpc/mm/mmu_decl.h >>> @@ -147,14 +147,6 @@ void reloc_kernel_entry(void *fdt, long addr); >>> extern void loadcam_entry(unsigned int index); >>> extern void loadcam_multi(int first_idx, int num, int tmp_idx); >>> -#ifdef CONFIG_RANDOMIZE_BASE >>> -void kaslr_early_init(void *dt_ptr, phys_addr_t size); >>> -void kaslr_late_init(void); >>> -#else >>> -static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} >>> -static inline void kaslr_late_init(void) {} >>> -#endif >>> - >>> struct tlbcam { >>> u32 MAS0; >>> u32 MAS1; >>> @@ -164,6 +156,14 @@ struct tlbcam { >>> }; >>> #endif >>> +#ifdef CONFIG_RANDOMIZE_BASE >>> +void kaslr_early_init(void *dt_ptr, phys_addr_t size); >>> +void kaslr_late_init(void); >>> +#else >>> +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} >>> +static inline void kaslr_late_init(void) {} >>> +#endif >>> + >>> #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_FSL_BOOKE) || >>> defined(CONFIG_PPC_8xx) >>> /* 6xx have BATS */ >>> /* FSL_BOOKE have TLBCAM */ >>> diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c >>> b/arch/powerpc/mm/nohash/kaslr_booke.c >>> index 07b036e98353..c6f5c1db1394 100644 >>> --- a/arch/powerpc/mm/nohash/kaslr_booke.c >>> +++ b/arch/powerpc/mm/nohash/kaslr_booke.c >>> @@ -231,7 +231,7 @@ static __init unsigned long >>> get_usable_address(const void *fdt, >>> unsigned long pa; >>> unsigned long pa_end; >>> - for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { >>> + for (pa = offset; (long)pa > (long)start; pa -= SZ_64K) { >> >> Doesn't this modify the behaviour for PPC32 too ? > > Oh, yes. I will fix this. > >> >>> pa_end = pa + regions.kernel_size; >>> if (overlaps_region(fdt, pa, pa_end)) >>> continue; >>> @@ -265,14 +265,14 @@ static unsigned long __init >>> kaslr_legal_offset(void *dt_ptr, unsigned long rando >>> { >>> unsigned long koffset = 0; >>> unsigned long start; >>> - unsigned long index; >>> unsigned long offset; >>> +#ifdef CONFIG_PPC32 >> >> Can we use >> >> if (IS_ENABLED(CONFIG_PPC32)) { >> /* 32 bits stuff */ >> } else { >> /* 64 bits stuff */ >> } > > Thansk for the suggestion. I will consider to use IS_ENABLED() instead. > >> >>> /* >>> * Decide which 64M we want to start >>> * Only use the low 8 bits of the random seed >>> */ >>> - index = random & 0xFF; >>> + unsigned long index = random & 0xFF; >> >> That's not good in terms of readability, index declaration should >> remain at the top of the function, should be possible if using >> IS_ENABLED() instead > > I'm wondering how to declare a variable inside a code block such as if > (IS_ENABLED(CONFIG_PPC32)) at the top of the function and use the > variable in another if (IS_ENABLED(CONFIG_PPC32)). Is there any good idea? > Hi Christophe, When using a standard C if/else, all code compiled for PPC32 and PPC64, but this will bring some build error because not all variables both defined for PPC32 and PPC64. [yanaijie@138 linux]$ sh ppc64build.sh CALL scripts/atomic/check-atomics.sh CALL scripts/checksyscalls.sh CHK include/generated/compile.h CC arch/powerpc/mm/nohash/kaslr_booke.o arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_choose_location': arch/powerpc/mm/nohash/kaslr_booke.c:341:30: error: 'CONFIG_LOWMEM_CAM_NUM' undeclared (first use in this function); did you mean 'CONFIG_FLATMEM_MANUAL'? ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); ^~~~~~~~~~~~~~~~~~~~~ CONFIG_FLATMEM_MANUAL arch/powerpc/mm/nohash/kaslr_booke.c:341:30: note: each undeclared identifier is reported only once for each function it appears in arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_early_init': arch/powerpc/mm/nohash/kaslr_booke.c:404:3: error: 'is_second_reloc' undeclared (first use in this function); did you mean '__cond_lock'? is_second_reloc = 1; ^~~~~~~~~~~~~~~ __cond_lock arch/powerpc/mm/nohash/kaslr_booke.c:411:4: error: implicit declaration of function 'create_kaslr_tlb_entry'; did you mean 'reloc_kernel_entry'? [-Werror=implicit-function-declaration] create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); ^~~~~~~~~~~~~~~~~~~~~~ reloc_kernel_entry cc1: all warnings being treated as errors make[3]: *** [scripts/Makefile.build:268: arch/powerpc/mm/nohash/kaslr_booke.o] Error 1 make[2]: *** [scripts/Makefile.build:505: arch/powerpc/mm/nohash] Error 2 make[1]: *** [scripts/Makefile.build:505: arch/powerpc/mm] Error 2 make: *** [Makefile:1681: arch/powerpc] Error 2 Thanks, Jason >> >>> index %= regions.linear_sz / SZ_64M; >>> /* Decide offset inside 64M */ >>> @@ -287,6 +287,15 @@ static unsigned long __init >>> kaslr_legal_offset(void *dt_ptr, unsigned long rando >>> break; >>> index--; >>> } >>> +#else >>> + /* Decide kernel offset inside 1G */ >>> + offset = random % (SZ_1G - regions.kernel_size); >>> + offset = round_down(offset, SZ_64K); >>> + >>> + start = memstart_addr; >>> + offset = memstart_addr + offset; >>> + koffset = get_usable_address(dt_ptr, start, offset); >>> +#endif >>> if (koffset != 0) >>> koffset -= memstart_addr; >>> @@ -325,6 +334,7 @@ static unsigned long __init >>> kaslr_choose_location(void *dt_ptr, phys_addr_t size >>> else >>> pr_warn("KASLR: No safe seed for randomizing the kernel >>> base.\n"); >>> +#ifdef CONFIG_PPC32 >>> ram = min_t(phys_addr_t, __max_low_memory, size); >>> ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); >>> linear_sz = min_t(unsigned long, ram, SZ_512M); >>> @@ -332,6 +342,7 @@ static unsigned long __init >>> kaslr_choose_location(void *dt_ptr, phys_addr_t size >>> /* If the linear size is smaller than 64M, do not randmize */ >>> if (linear_sz < SZ_64M) >>> return 0; >>> +#endif >>> /* check for a reserved-memory node and record its cell sizes */ >>> regions.reserved_mem = fdt_path_offset(dt_ptr, >>> "/reserved-memory"); >>> @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void >>> *dt_ptr, phys_addr_t size) >>> unsigned long offset; >>> unsigned long kernel_sz; >>> +#ifdef CONFIG_PPC64 >> >> Same, can we use a standard C if/else sequence with >> IS_ENABLED(CONFIG_PPC64) ? > > OK, I will try to do this if I can deal with the declaration of > variables in different if/else sequence. > > Thanks, > Jason > > >> >>> + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); >>> + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); >>> + >>> + if (*__run_at_load == 1) >>> + return; >>> + >>> + /* Setup flat device-tree pointer */ >>> + initial_boot_params = dt_ptr; >>> +#endif >>> + >>> kernel_sz = (unsigned long)_end - (unsigned long)_stext; >>> offset = kaslr_choose_location(dt_ptr, size, kernel_sz); >>> @@ -372,6 +394,7 @@ notrace void __init kaslr_early_init(void >>> *dt_ptr, phys_addr_t size) >>> kernstart_virt_addr += offset; >>> kernstart_addr += offset; >>> +#ifdef CONFIG_PPC32 >>> is_second_reloc = 1; >>> if (offset >= SZ_64M) { >>> @@ -381,6 +404,10 @@ notrace void __init kaslr_early_init(void >>> *dt_ptr, phys_addr_t size) >>> /* Create kernel map to relocate in */ >>> create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); >>> } >>> +#else >>> + *__kaslr_offset = kernstart_virt_addr - KERNELBASE; >>> + *__run_at_load = 1; >>> +#endif >>> /* Copy the kernel to it's new location and run */ >>> memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz); >>> >> >> Christophe >> >> . > > > .
Le 26/02/2020 à 03:40, Jason Yan a écrit : > > > 在 2020/2/20 21:48, Christophe Leroy 写道: >> >> >> Le 06/02/2020 à 03:58, Jason Yan a écrit : >>> /* >>> * Decide which 64M we want to start >>> * Only use the low 8 bits of the random seed >>> */ >>> - index = random & 0xFF; >>> + unsigned long index = random & 0xFF; >> >> That's not good in terms of readability, index declaration should >> remain at the top of the function, should be possible if using >> IS_ENABLED() instead > > I'm wondering how to declare a variable inside a code block such as if > (IS_ENABLED(CONFIG_PPC32)) at the top of the function and use the > variable in another if (IS_ENABLED(CONFIG_PPC32)). Is there any good idea? You declare it outside the block as usual: unsigned long some_var; if (condition) { some_var = something; } do_many_things(); do_other_things(); if (condition) return some_var; else return 0; Christophe
Le 26/02/2020 à 04:33, Jason Yan a écrit : > > > 在 2020/2/26 10:40, Jason Yan 写道: >> >> >> 在 2020/2/20 21:48, Christophe Leroy 写道: >>> >>> >>> Le 06/02/2020 à 03:58, Jason Yan a écrit : > Hi Christophe, > > When using a standard C if/else, all code compiled for PPC32 and PPC64, > but this will bring some build error because not all variables both > defined for PPC32 and PPC64. > > [yanaijie@138 linux]$ sh ppc64build.sh > CALL scripts/atomic/check-atomics.sh > CALL scripts/checksyscalls.sh > CHK include/generated/compile.h > CC arch/powerpc/mm/nohash/kaslr_booke.o > arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_choose_location': > arch/powerpc/mm/nohash/kaslr_booke.c:341:30: error: > 'CONFIG_LOWMEM_CAM_NUM' undeclared (first use in this function); did you > mean 'CONFIG_FLATMEM_MANUAL'? > ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); > ^~~~~~~~~~~~~~~~~~~~~ > CONFIG_FLATMEM_MANUAL This one has to remain inside an #ifdef. That's the only one that has to remain. > arch/powerpc/mm/nohash/kaslr_booke.c:341:30: note: each undeclared > identifier is reported only once for each function it appears in > arch/powerpc/mm/nohash/kaslr_booke.c: In function 'kaslr_early_init': > arch/powerpc/mm/nohash/kaslr_booke.c:404:3: error: 'is_second_reloc' In mmu_decl.h, put the declaration outside the #ifdef CONFIG_PPC32 > undeclared (first use in this function); did you mean '__cond_lock'? > is_second_reloc = 1; > ^~~~~~~~~~~~~~~ > __cond_lock > arch/powerpc/mm/nohash/kaslr_booke.c:411:4: error: implicit declaration > of function 'create_kaslr_tlb_entry'; did you mean 'reloc_kernel_entry'? Same, put the declaration outside of the #ifdef > [-Werror=implicit-function-declaration] > create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); > ^~~~~~~~~~~~~~~~~~~~~~ > reloc_kernel_entry > cc1: all warnings being treated as errors > make[3]: *** [scripts/Makefile.build:268: > arch/powerpc/mm/nohash/kaslr_booke.o] Error 1 > make[2]: *** [scripts/Makefile.build:505: arch/powerpc/mm/nohash] Error 2 > make[1]: *** [scripts/Makefile.build:505: arch/powerpc/mm] Error 2 > make: *** [Makefile:1681: arch/powerpc] Error 2 See the patch I sent you. It builds ok for me. Christophe
On Thu, 2020-02-06 at 10:58 +0800, Jason Yan wrote: > The implementation for Freescale BookE64 is similar as BookE32. One > difference is that Freescale BookE64 set up a TLB mapping of 1G during > booting. Another difference is that ppc64 needs the kernel to be > 64K-aligned. So we can randomize the kernel in this 1G mapping and make > it 64K-aligned. This can save some code to creat another TLB map at > early boot. The disadvantage is that we only have about 1G/64K = 16384 > slots to put the kernel in. > > To support secondary cpu boot up, a variable __kaslr_offset was added in > first_256B section. This can help secondary cpu get the kaslr offset > before the 1:1 mapping has been setup. What specifically requires __kaslr_offset instead of using kernstart_virt_addr like 32-bit does? > > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S > index ad79fddb974d..744624140fb8 100644 > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: > .8byte 0x0 > > #ifdef CONFIG_RELOCATABLE > +#ifdef CONFIG_RANDOMIZE_BASE > + . = 0x58 > + .globl __kaslr_offset > +__kaslr_offset: > +DEFINE_FIXED_SYMBOL(__kaslr_offset) > + .long 0 > +#endif > /* This flag is set to 1 by a loader if the kernel should run > * at the loaded address instead of the linked address. This > * is used by kexec-tools to keep the the kdump kernel in the Why does it need to go here at a fixed address? > > /* check for a reserved-memory node and record its cell sizes */ > regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); > @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void *dt_ptr, > phys_addr_t size) > unsigned long offset; > unsigned long kernel_sz; > > +#ifdef CONFIG_PPC64 > + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); > + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); Why are you referencing these by magic offset rather than by symbol? > + /* Setup flat device-tree pointer */ > + initial_boot_params = dt_ptr; > +#endif Why does 64-bit need this but 32-bit doesn't? -Scott
在 2020/3/5 5:44, Scott Wood 写道: > On Thu, 2020-02-06 at 10:58 +0800, Jason Yan wrote: >> The implementation for Freescale BookE64 is similar as BookE32. One >> difference is that Freescale BookE64 set up a TLB mapping of 1G during >> booting. Another difference is that ppc64 needs the kernel to be >> 64K-aligned. So we can randomize the kernel in this 1G mapping and make >> it 64K-aligned. This can save some code to creat another TLB map at >> early boot. The disadvantage is that we only have about 1G/64K = 16384 >> slots to put the kernel in. >> >> To support secondary cpu boot up, a variable __kaslr_offset was added in >> first_256B section. This can help secondary cpu get the kaslr offset >> before the 1:1 mapping has been setup. > > What specifically requires __kaslr_offset instead of using kernstart_virt_addr > like 32-bit does? > kernstart_virt_addr is in the data section. At the early boot we only have a 64M tlb mapping. For the 32-bit I limited the kernel in a 64M-aligned region so that we can always get kernstart_virt_addr. But for the 64-bit the kernel is bigger and not suitable to limit it in a 64M-aligned region. So if we use kernstart_virt_addr and the kernel is randomized like below , the secondary cpus will not boot up: +------------+------------+ | 64M | 64M | +------------+------------+ ^ ^ | kernel | ^ kernstart_virt_addr So I have to put the kernel offset in the first 64K along with the init text. >> >> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S >> index ad79fddb974d..744624140fb8 100644 >> --- a/arch/powerpc/kernel/head_64.S >> +++ b/arch/powerpc/kernel/head_64.S >> @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: >> .8byte 0x0 >> >> #ifdef CONFIG_RELOCATABLE >> +#ifdef CONFIG_RANDOMIZE_BASE >> + . = 0x58 >> + .globl __kaslr_offset >> +__kaslr_offset: >> +DEFINE_FIXED_SYMBOL(__kaslr_offset) >> + .long 0 >> +#endif >> /* This flag is set to 1 by a loader if the kernel should run >> * at the loaded address instead of the linked address. This >> * is used by kexec-tools to keep the the kdump kernel in the > > Why does it need to go here at a fixed address? > It does not need to be at a fixed address. I just want to keep consistent and stay along with __run_at_load. > >> >> /* check for a reserved-memory node and record its cell sizes */ >> regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); >> @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void *dt_ptr, >> phys_addr_t size) >> unsigned long offset; >> unsigned long kernel_sz; >> >> +#ifdef CONFIG_PPC64 >> + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); >> + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); > > Why are you referencing these by magic offset rather than by symbol? > I'm not sure if relocat works for fixed symbols. I will have a test and swith to reference them by symbols if it works fine. > >> + /* Setup flat device-tree pointer */ >> + initial_boot_params = dt_ptr; >> +#endif > > Why does 64-bit need this but 32-bit doesn't? 32-bit called early_get_first_memblock_info() very early which implicitly setup the device-tree pointer. > > -Scott > > > > . >
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c150a9d49343..754aeb96bb1c 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -568,7 +568,7 @@ config RELOCATABLE config RANDOMIZE_BASE bool "Randomize the address of the kernel image" - depends on (FSL_BOOKE && FLATMEM && PPC32) + depends on (PPC_FSL_BOOK3E && FLATMEM) depends on RELOCATABLE help Randomizes the virtual address at which the kernel image is diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 1b9b174bee86..c1c05b8684ca 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -1378,6 +1378,7 @@ skpinv: addi r6,r6,1 /* Increment */ 1: mflr r6 addi r6,r6,(2f - 1b) tovirt(r6,r6) + add r6,r6,r19 lis r7,MSR_KERNEL@h ori r7,r7,MSR_KERNEL@l mtspr SPRN_SRR0,r6 @@ -1400,6 +1401,7 @@ skpinv: addi r6,r6,1 /* Increment */ /* We translate LR and return */ tovirt(r8,r8) + add r8,r8,r19 mtlr r8 blr @@ -1528,6 +1530,7 @@ a2_tlbinit_code_end: */ _GLOBAL(start_initialization_book3e) mflr r28 + li r19, 0 /* First, we need to setup some initial TLBs to map the kernel * text, data and bss at PAGE_OFFSET. We don't have a real mode @@ -1570,6 +1573,12 @@ _GLOBAL(book3e_secondary_core_init) cmplwi r4,0 bne 2f + li r19, 0 +#ifdef CONFIG_RANDOMIZE_BASE + LOAD_REG_ADDR_PIC(r19, __kaslr_offset) + lwz r19,0(r19) + rlwinm r19,r19,0,0,5 +#endif /* Setup TLB for this core */ bl initial_tlb_book3e @@ -1602,6 +1611,7 @@ _GLOBAL(book3e_secondary_core_init) lis r3,PAGE_OFFSET@highest sldi r3,r3,32 or r28,r28,r3 + add r28,r28,r19 1: mtlr r28 blr diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index ad79fddb974d..744624140fb8 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: .8byte 0x0 #ifdef CONFIG_RELOCATABLE +#ifdef CONFIG_RANDOMIZE_BASE + . = 0x58 + .globl __kaslr_offset +__kaslr_offset: +DEFINE_FIXED_SYMBOL(__kaslr_offset) + .long 0 +#endif /* This flag is set to 1 by a loader if the kernel should run * at the loaded address instead of the linked address. This * is used by kexec-tools to keep the the kdump kernel in the diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 6104917a282d..a16b970a8d1a 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -66,7 +66,7 @@ #include <asm/feature-fixups.h> #include <asm/kup.h> #include <asm/early_ioremap.h> - +#include <mm/mmu_decl.h> #include "setup.h" int spinning_secondaries; @@ -300,6 +300,8 @@ void __init early_setup(unsigned long dt_ptr) /* Enable early debugging if any specified (see udbg.h) */ udbg_early_init(); + kaslr_early_init(__va(dt_ptr), 0); + udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); /* diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 3e1c85c7d10b..bbd721d1e3d7 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -147,14 +147,6 @@ void reloc_kernel_entry(void *fdt, long addr); extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx); -#ifdef CONFIG_RANDOMIZE_BASE -void kaslr_early_init(void *dt_ptr, phys_addr_t size); -void kaslr_late_init(void); -#else -static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} -static inline void kaslr_late_init(void) {} -#endif - struct tlbcam { u32 MAS0; u32 MAS1; @@ -164,6 +156,14 @@ struct tlbcam { }; #endif +#ifdef CONFIG_RANDOMIZE_BASE +void kaslr_early_init(void *dt_ptr, phys_addr_t size); +void kaslr_late_init(void); +#else +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} +static inline void kaslr_late_init(void) {} +#endif + #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_FSL_BOOKE) || defined(CONFIG_PPC_8xx) /* 6xx have BATS */ /* FSL_BOOKE have TLBCAM */ diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 07b036e98353..c6f5c1db1394 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -231,7 +231,7 @@ static __init unsigned long get_usable_address(const void *fdt, unsigned long pa; unsigned long pa_end; - for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { + for (pa = offset; (long)pa > (long)start; pa -= SZ_64K) { pa_end = pa + regions.kernel_size; if (overlaps_region(fdt, pa, pa_end)) continue; @@ -265,14 +265,14 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando { unsigned long koffset = 0; unsigned long start; - unsigned long index; unsigned long offset; +#ifdef CONFIG_PPC32 /* * Decide which 64M we want to start * Only use the low 8 bits of the random seed */ - index = random & 0xFF; + unsigned long index = random & 0xFF; index %= regions.linear_sz / SZ_64M; /* Decide offset inside 64M */ @@ -287,6 +287,15 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando break; index--; } +#else + /* Decide kernel offset inside 1G */ + offset = random % (SZ_1G - regions.kernel_size); + offset = round_down(offset, SZ_64K); + + start = memstart_addr; + offset = memstart_addr + offset; + koffset = get_usable_address(dt_ptr, start, offset); +#endif if (koffset != 0) koffset -= memstart_addr; @@ -325,6 +334,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size else pr_warn("KASLR: No safe seed for randomizing the kernel base.\n"); +#ifdef CONFIG_PPC32 ram = min_t(phys_addr_t, __max_low_memory, size); ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); linear_sz = min_t(unsigned long, ram, SZ_512M); @@ -332,6 +342,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size /* If the linear size is smaller than 64M, do not randmize */ if (linear_sz < SZ_64M) return 0; +#endif /* check for a reserved-memory node and record its cell sizes */ regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) unsigned long offset; unsigned long kernel_sz; +#ifdef CONFIG_PPC64 + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); + + if (*__run_at_load == 1) + return; + + /* Setup flat device-tree pointer */ + initial_boot_params = dt_ptr; +#endif + kernel_sz = (unsigned long)_end - (unsigned long)_stext; offset = kaslr_choose_location(dt_ptr, size, kernel_sz); @@ -372,6 +394,7 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) kernstart_virt_addr += offset; kernstart_addr += offset; +#ifdef CONFIG_PPC32 is_second_reloc = 1; if (offset >= SZ_64M) { @@ -381,6 +404,10 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) /* Create kernel map to relocate in */ create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); } +#else + *__kaslr_offset = kernstart_virt_addr - KERNELBASE; + *__run_at_load = 1; +#endif /* Copy the kernel to it's new location and run */ memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz);
The implementation for Freescale BookE64 is similar as BookE32. One difference is that Freescale BookE64 set up a TLB mapping of 1G during booting. Another difference is that ppc64 needs the kernel to be 64K-aligned. So we can randomize the kernel in this 1G mapping and make it 64K-aligned. This can save some code to creat another TLB map at early boot. The disadvantage is that we only have about 1G/64K = 16384 slots to put the kernel in. To support secondary cpu boot up, a variable __kaslr_offset was added in first_256B section. This can help secondary cpu get the kaslr offset before the 1:1 mapping has been setup. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: Scott Wood <oss@buserror.net> 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/Kconfig | 2 +- arch/powerpc/kernel/exceptions-64e.S | 10 +++++++++ arch/powerpc/kernel/head_64.S | 7 ++++++ arch/powerpc/kernel/setup_64.c | 4 +++- arch/powerpc/mm/mmu_decl.h | 16 +++++++------- arch/powerpc/mm/nohash/kaslr_booke.c | 33 +++++++++++++++++++++++++--- 6 files changed, 59 insertions(+), 13 deletions(-)