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@xxxxxxxxxx> Cc: Scott Wood <oss@xxxxxxxxxxxx> Cc: Diana Craciun <diana.craciun@xxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> --- 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 isdiff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.Sindex 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 blrdiff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.Sindex 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 thediff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.cindex 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.cindex 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_PPC32Can 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() insteadI'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_lockarch/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 randobreak; 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 sizeelsepr_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_PPC64Same, 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 ..
