On Fri, Nov 30, 2018 at 09:24:54AM +0800, Chao Fan wrote: > On Thu, Nov 29, 2018 at 12:55:21PM -0500, Masayoshi Mizuma wrote: > >On Thu, Nov 29, 2018 at 04:16:30PM +0800, Chao Fan wrote: > >> To fix the conflict between KASLR and memory-hotremove, SRAT table > >> should be parsed by RSDP pointer, then find the immovable > >> memory regions and store them in an array called immovable_mem[]. > >> The array called immovable_mem[] will extern to KASLR, then > >> KASLR will avoid to extract kernel to these regions. > >> > >> Add 'CONFIG_EARLY_PARSE_RSDP' which depends on RANDOMIZE_BASE && > >> MEMORY_HOTREMOVE, cause only when both KASLR and memory-hotremove > >> are enabled, RSDP needs to be parsed in compressed period. > >> > >> Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com> > >> --- > >> arch/x86/Kconfig | 10 +++ > >> arch/x86/boot/compressed/Makefile | 2 + > >> arch/x86/boot/compressed/acpitb.c | 125 ++++++++++++++++++++++++++++++ > >> arch/x86/boot/compressed/kaslr.c | 4 - > >> arch/x86/boot/compressed/misc.h | 20 +++++ > >> 5 files changed, 157 insertions(+), 4 deletions(-) > >> > >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > >> index a29d49ef4d56..bc775968557b 100644 > >> --- a/arch/x86/Kconfig > >> +++ b/arch/x86/Kconfig > >> @@ -2146,6 +2146,16 @@ config X86_NEED_RELOCS > >> def_bool y > >> depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) > >> > > > >> +config CONFIG_EARLY_PARSE_RSDP > > > >config EARLY_PARSE_RSDP > > > >> + bool "Parse RSDP pointer on compressed period for KASLR" > >> + def_bool n > > > >Should be def_bool y? > > I will change it to y. > > >It is better to enable EARLY_PARSE_RSDP by default if > >RANDOMIZE_BASE and MEMORY_HOTREMOVE are enabled. > > > >> + depends on RANDOMIZE_BASE && MEMORY_HOTREMOVE > >> + help > >> + This option parses RSDP pointer in compressed period. Works > >> + for KASLR to get memory information by SRAT table and choose > >> + immovable memory to extract kernel. > >> + Say Y if you want to use both KASLR and memory-hotremove. > >> + > >> config PHYSICAL_ALIGN > >> hex "Alignment value to which kernel should be aligned" > >> default "0x200000" > >> diff --git a/arch/x86/boot/compressed/Makefile > >> b/arch/x86/boot/compressed/Makefile > >> index 466f66c8a7f8..4cbfb58bf083 100644 > >> --- a/arch/x86/boot/compressed/Makefile > >> +++ b/arch/x86/boot/compressed/Makefile > >> @@ -84,6 +84,8 @@ ifdef CONFIG_X86_64 > >> vmlinux-objs-y += $(obj)/pgtable_64.o > >> endif > >> > >> +vmlinux-objs-$(CONFIG_EARLY_PARSE_RSDP) += $(obj)/acpitb.o > >> + > >> $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone > >> > >> vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o > >> $(obj)/efi_stub_$(BITS).o \ > >> diff --git a/arch/x86/boot/compressed/acpitb.c > >> b/arch/x86/boot/compressed/acpitb.c > >> index 82d27c4b8978..023b33d0cd3b 100644 > >> --- a/arch/x86/boot/compressed/acpitb.c > >> +++ b/arch/x86/boot/compressed/acpitb.c > >> @@ -195,3 +195,128 @@ static acpi_physical_address bios_get_rsdp_addr(void) > >> return (acpi_physical_address)address; > >> } > >> } > >> + > >> +/* Used to determine RSDP table, based on acpi_os_get_root_pointer(). */ > >> +static acpi_physical_address get_rsdp_addr(void) > >> +{ > >> + acpi_physical_address pa = 0; > >> + > >> + pa = get_acpi_rsdp(); > >> + > >> + if (!pa) > >> + pa = efi_get_rsdp_addr(); > >> + > >> + if (!pa) > >> + pa = bios_get_rsdp_addr(); > >> + > >> + return pa; > >> +} > >> + > >> +/* Compute SRAT table from RSDP. */ > >> +static struct acpi_table_header *get_acpi_srat_table(void) > >> +{ > >> + acpi_physical_address acpi_table; > >> + acpi_physical_address root_table; > >> + struct acpi_table_header *header; > >> + struct acpi_table_rsdp *rsdp; > >> + int num_entries; > >> + char arg[10]; > >> + u8 *entry; > >> + u32 size; > >> + u32 len; > >> + > >> + rsdp = (struct acpi_table_rsdp *)get_rsdp_addr(); > >> + if (!rsdp) > >> + return NULL; > >> + > >> + /* Get RSDT or XSDT from RSDP. */ > > > >> + if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 && > >> + !strncmp(arg, "rsdt", 4)) && > >> + rsdp->xsdt_physical_address && > >> + rsdp->revision > 1) { > >> + root_table = rsdp->xsdt_physical_address; > >> + size = ACPI_XSDT_ENTRY_SIZE; > >> + } else { > >> + root_table = rsdp->rsdt_physical_address; > >> + size = ACPI_RSDT_ENTRY_SIZE; > >> + } > >> + > >> + /* Get ACPI root table from RSDT or XSDT.*/ > >> + header = (struct acpi_table_header *)root_table; > >> + if (!header) > >> + return NULL; > >> + > >> + len = header->length; > >> + num_entries = (u32)((len - sizeof(struct acpi_table_header)) / size); > > > >> + if (num_entries > MAX_ACPI_SIG) > >> + return NULL; > > > >I think this check isn't needed... > > > >> + > >> + entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header)); > >> + > >> + while (num_entries--) { > >> + u64 address64; > >> + > >> + if (size == ACPI_RSDT_ENTRY_SIZE) > >> + acpi_table = ((acpi_physical_address) > >> + (*ACPI_CAST_PTR(u32, entry))); > >> + else { > >> + *(u64 *)(void *)&address64 = *(u64 *)(void *)entry; > >> + acpi_table = (acpi_physical_address) address64; > >> + } > >> + > >> + if (acpi_table) { > >> + header = (struct acpi_table_header *)acpi_table; > >> + > >> + if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT)) > >> + return header; > >> + } > >> + entry += size; > >> + } > >> + return NULL; > >> +} > >> + > >> +/* > >> + * According to ACPI table, filter the immovable memory regions > >> + * and store them in immovable_mem[]. > >> + */ > >> +void get_immovable_mem(void) > >> +{ > >> + struct acpi_table_header *table_header; > >> + struct acpi_subtable_header *table; > >> + struct acpi_srat_mem_affinity *ma; > >> + unsigned long table_end; > >> + char arg[10]; > >> + int i = 0; > >> + > >> + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 && > >> + !strncmp(arg, "off", 3)) > >> + return; > >> + > >> + table_header = get_acpi_srat_table(); > >> + if (!table_header) > >> + return; > >> + > >> + table_end = (unsigned long)table_header + table_header->length; > >> + table = (struct acpi_subtable_header *) > >> + ((unsigned long)table_header + sizeof(struct acpi_table_srat)); > >> + > >> + while (((unsigned long)table) + > >> + sizeof(struct acpi_subtable_header) < table_end) { > >> + if (table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) { > >> + ma = (struct acpi_srat_mem_affinity *)table; > >> + if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)) { > >> + immovable_mem[i].start = ma->base_address; > >> + immovable_mem[i].size = ma->length; > >> + i++; > >> + } > >> + > >> + if (i >= MAX_NUMNODES*2) { > >> + debug_putstr("Too many immovable memory > >> regions, aborting.\n"); > >> + return; > >> + } > >> + } > >> + table = (struct acpi_subtable_header *) > >> + ((unsigned long)table + table->length); > >> + } > >> + num_immovable_mem = i; > >> +} > >> diff --git a/arch/x86/boot/compressed/kaslr.c > >> b/arch/x86/boot/compressed/kaslr.c > >> index 9ed9709d9947..b251572e77af 100644 > >> --- a/arch/x86/boot/compressed/kaslr.c > >> +++ b/arch/x86/boot/compressed/kaslr.c > >> @@ -87,10 +87,6 @@ static unsigned long get_boot_seed(void) > >> #define KASLR_COMPRESSED_BOOT > >> #include "../../lib/kaslr.c" > >> > >> -struct mem_vector { > >> - unsigned long long start; > >> - unsigned long long size; > >> -}; > >> > >> /* Only supporting at most 4 unusable memmap regions with kaslr */ > >> #define MAX_MEMMAP_REGIONS 4 > >> diff --git a/arch/x86/boot/compressed/misc.h > >> b/arch/x86/boot/compressed/misc.h > >> index 809c31effa4b..d94e2a419c13 100644 > >> --- a/arch/x86/boot/compressed/misc.h > >> +++ b/arch/x86/boot/compressed/misc.h > >> @@ -77,6 +77,11 @@ void choose_random_location(unsigned long input, > >> unsigned long *output, > >> unsigned long output_size, > >> unsigned long *virt_addr); > >> +struct mem_vector { > >> + unsigned long long start; > >> + unsigned long long size; > >> +}; > >> + > >> /* cpuflags.c */ > >> bool has_cpuflag(int flag); > >> #else > >> @@ -118,5 +123,20 @@ void set_sev_encryption_mask(void); > >> #endif > >> > >> /* acpitb.c */ > >> +#ifdef CONFIG_RANDOMIZE_BASE > >> +/* Store the amount of immovable memory regions */ > >> +int num_immovable_mem; > >> +#endif > >> + > >> +#ifdef CONFIG_EARLY_PARSE_RSDP > >> +void get_immovable_mem(void); > > > >> +/* There are 72 kinds of ACPI_SIG in head file of ACPI. */ > >> +#define MAX_ACPI_SIG 72 > > > >The 72 isn't the specification of ACPI, right? So the number > > Yes, it's from ACPI code, include/acpi/actbl*h. > Boris said there should be a check for the num_entries, > I didn't get a good idea, so I use the max number to check it. > So do you have some advice?
Ah, got it. How about adding the check for len to prevent the wrap? Like as: len = header->length; if (len <= sizeof(struct acpi_table_header)) return NULL; num_entries = (u32)((len - sizeof(struct acpi_table_header)) / size); Thanks, Masa