SRAT should be parsed by RSDP to fix the conflict between KASLR and memory-hotremove, then find the immovable memory regions and store them in an array called immovable_mem[]. With immovable_mem[], KASLR can avoid to extract kernel to specific regions.
Since 'RANDOMIZE_BASE' && 'MEMORY_HOTREMOVE' is needed, introduce 'CONFIG_EARLY_PARSE_RSDP' to make ifdeffery clear. Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com> --- arch/x86/Kconfig | 12 +++ arch/x86/boot/compressed/Makefile | 2 + arch/x86/boot/compressed/acpi.c | 128 ++++++++++++++++++++++++++++++ arch/x86/boot/compressed/kaslr.c | 4 - arch/x86/boot/compressed/misc.h | 19 +++++ 5 files changed, 161 insertions(+), 4 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ba7e3464ee92..333c383478b7 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2149,6 +2149,18 @@ config X86_NEED_RELOCS def_bool y depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) +config EARLY_SRAT_PARSE + bool "Early SRAT table parsing" + def_bool y + depends on RANDOMIZE_BASE && MEMORY_HOTREMOVE + help + This option enables early SRAT parsing in compressed boot stage + so that memory hot-remove ranges do not overlap with KASLR + chosen ranges. Kernel won't be extracted in hot-removable + memory, so that make sure memory-hotremove works well with + KASLR enabled. + 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..23491d74939d 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_SRAT_PARSE) += $(obj)/acpi.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/acpi.c b/arch/x86/boot/compressed/acpi.c index 795a78559a58..89ed72fb664f 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -11,6 +11,9 @@ /* Max length of 64-bit hex address string is 18, prefix "0x" + 16 hex digit. */ #define MAX_ADDRESS_LENGTH 18 +/* Immovable memory regions. */ +struct mem_vector immovable_mem[MAX_NUMNODES*2]; + static acpi_physical_address get_acpi_rsdp(void) { #ifdef CONFIG_KEXEC @@ -193,3 +196,128 @@ static acpi_physical_address bios_get_rsdp_addr(void) } return 0; } + +/* Determine RSDP, based on acpi_os_get_root_pointer(). */ +static acpi_physical_address get_rsdp_addr(void) +{ + acpi_physical_address pa; + + 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; + u32 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; + if (len < sizeof(struct acpi_table_header) + size) + return NULL; + + num_entries = (u32)((len - sizeof(struct acpi_table_header)) / size); + 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 a1d5918765f3..b49748366a5b 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 @@ -116,3 +121,17 @@ static inline void console_init(void) void set_sev_encryption_mask(void); #endif + +/* acpi.c */ +#ifdef CONFIG_RANDOMIZE_BASE +/* Amount of immovable memory regions */ +int num_immovable_mem; +#endif + +#ifdef CONFIG_EARLY_SRAT_PARSE +void get_immovable_mem(void); +#else +static void get_immovable_mem(void) +{ +} +#endif -- 2.19.2