KASLR should choose the memory region of immovable node to extract kernel. So get ACPI SRAT table and store the memory region of movable node which kaslr shold avoid.
Signed-off-by: Chao Fan <[email protected]> --- arch/x86/boot/compressed/kaslr.c | 231 +++++++++++++++++++++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 27 +++++ 2 files changed, 258 insertions(+) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 7de23bb279ce..3b8c111b8a84 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -45,6 +45,11 @@ #define STATIC #include <linux/decompress/mm.h> +#include <linux/efi.h> +#include <linux/acpi.h> +#include <linux/numa.h> +#include <asm/efi.h> + extern unsigned long get_cmd_line_ptr(void); /* Simplified build-specific string for starting entropy. */ @@ -94,6 +99,18 @@ static bool memmap_too_large; /* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */ unsigned long long mem_limit = ULLONG_MAX; +/* Store the max numbers of acpi tables */ +#define ACPI_MAX_TABLES 128 + +/* Store the movable memory */ +static struct { + u64 start; + u64 end; +} movable_mem[MAX_NUMNODES*2]; + +/* Store the num of movable mem affinity */ +static int num_movable_ma; + enum mem_avoid_index { MEM_AVOID_ZO_RANGE = 0, @@ -257,6 +274,180 @@ static int handle_mem_memmap(void) return 0; } +static void handle_movable_node(void) +{ + struct acpi_table_desc table_descs[ACPI_MAX_TABLES]; + struct acpi_table_header *table_header; + struct acpi_srat_mem_affinity *ma; + struct acpi_subtable_header *asth; + acpi_physical_address root_table; + acpi_physical_address acpi_table; + acpi_physical_address rsdp_addr; + struct acpi_table_header *th; + efi_system_table_t *systab; + unsigned long table_size; + unsigned long table_end; + bool use_rsdt = false; + bool acpi_20 = false; + bool efi_64 = false; + void *config_tables; + int size, total_size; + u32 table_entry_size; + struct efi_info *e; + u8 *table_entry; + u32 table_count; + char *args; + char *sig; + u32 len; + int i, j; + + args = (char *)get_cmd_line_ptr(); + if (!strstr(args, "movable_node")) + return; + + e = &boot_params->efi_info; + sig = (char *)&e->efi_loader_signature; + + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) + efi_64 = true; + else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) + efi_64 = false; + else { + debug_putstr("Wrong efi loader signature.\n"); + return; + } + + // Get systab from boot params +#ifdef CONFIG_X86_32 + if (e->efi_systab_hi || e->efi_memmap_hi) { + debug_putstr("Table located above 4GB, disabling EFI.\n"); + return; + } + systab = (efi_system_table_t *)e->efi_systab; +#else + systab = (efi_system_table_t *)(e->efi_systab | + ((__u64)e->efi_systab_hi<<32)); +#endif + + // Get efi tables from systab + size = efi_64 ? sizeof(efi_config_table_64_t) : + sizeof(efi_config_table_32_t); + total_size = systab->nr_tables * size; + + for (i = 0; i < systab->nr_tables; i++) { + efi_guid_t guid; + unsigned long table; + + config_tables = (void *)(systab->tables + size * i); + if (efi_64) { + efi_config_table_64_t *tmp_table; + + tmp_table = (efi_config_table_64_t *)config_tables; + guid = tmp_table->guid; + table = tmp_table->table; +#ifndef CONFIG_64BIT + if (table >> 32) { + debug_putstr + ("Table located above 4G, disabling EFI.\n"); + return -EINVAL; + } +#endif + } else { + efi_config_table_32_t *tmp_table; + + tmp_table = (efi_config_table_32_t *)config_tables; + guid = tmp_table->guid; + table = tmp_table->table; + } + + // Get rsdp from efi tables + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)) && !acpi_20) { + rsdp_addr = (acpi_physical_address)table; + acpi_20 = false; + } else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) { + rsdp_addr = (acpi_physical_address)table; + acpi_20 = true; + } + } + + // Get rsdt or xsdt from rsdp + if (strstr(args, "acpi=rsdt")) + use_rsdt = true; + + if (!(use_rsdt) && (acpi_20) && + ((((struct acpi_table_rsdp *)rsdp_addr)->revision) > 1)) { + root_table = ((struct acpi_table_rsdp *) + rsdp_addr)->xsdt_physical_address; + table_entry_size = ACPI_XSDT_ENTRY_SIZE; + } else { + root_table = ((struct acpi_table_rsdp *) + rsdp_addr)->rsdt_physical_address; + table_entry_size = ACPI_RSDT_ENTRY_SIZE; + } + + // Get acpi root table from rsdt or xsdt + th = (struct acpi_table_header *)root_table; + len = th->length; + table_count = (u32)((len - sizeof(struct acpi_table_header)) / + table_entry_size); + table_entry = ACPI_ADD_PTR(u8, th, sizeof(struct acpi_table_header)); + + for (i = 0; i < table_count; i++) { + u64 address64; + + memset(&table_descs[i], 0, sizeof(struct acpi_table_desc)); + if (table_entry_size == ACPI_RSDT_ENTRY_SIZE) + acpi_table = ((acpi_physical_address) + (*ACPI_CAST_PTR(u32, table_entry))); + else { + ACPI_MOVE_64_TO_64(&address64, table_entry); + acpi_table = (acpi_physical_address) address64; + } + + if (acpi_table) { + table_descs[i].address = acpi_table; + table_descs[i].length = + sizeof(struct acpi_table_header); + table_descs[i].pointer = + (struct acpi_table_header *)acpi_table; + for (j = 0; j < 4; j++) + table_descs[i].signature.ascii[j] = + ((struct acpi_table_header *) + acpi_table)->signature[j]; + } + + if (!strncmp(table_descs[i].signature.ascii, "SRAT", 4)) { + table_header = table_descs[i].pointer; + break; + } + + table_entry += table_entry_size; + } + + // Get acpi srat mem affinity frpm acpi root table + table_size = sizeof(struct acpi_table_srat); + table_end = (unsigned long)table_header + table_header->length; + asth = (struct acpi_subtable_header *) + ((unsigned long)table_header + table_size); + j = 0; + + while (((unsigned long)asth) + + sizeof(struct acpi_subtable_header) < table_end) { + if (asth->type == 1) { + ma = (struct acpi_srat_mem_affinity *)asth; + if (ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) { + movable_mem[j].start = ma->base_address; + movable_mem[j].end = ma->base_address + + ma->length - 1; + j++; + } + } + asth = (struct acpi_subtable_header *) + ((unsigned long)asth + asth->length); + } + num_movable_ma = j; +} + /* * In theory, KASLR can put the kernel anywhere in the range of [16M, 64T). * The mem_avoid array is used to store the ranges that need to be avoided @@ -380,6 +571,11 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, /* Mark the memmap regions we need to avoid */ handle_mem_memmap(); +#ifdef CONFIG_EFI + /* Mark the hotplug SB regions we need choose */ + handle_movable_node(); +#endif + #ifdef CONFIG_X86_VERBOSE_BOOTUP /* Make sure video RAM can be used. */ add_identity_map(0, PMD_SIZE); @@ -481,6 +677,36 @@ static unsigned long slots_fetch_random(void) return 0; } +static int check_movable_memory(struct mem_vector *entry) +{ + int i; + unsigned long long start; + unsigned long long end; + + start = entry->start; + end = entry->start + entry->size - 1; + + if (num_movable_ma == 0) + return 0; + + for (i = 0; i < num_movable_ma; i++) { + if ((start >= movable_mem[i].start) && + (start <= movable_mem[i].end)) + return 1; + + if ((end >= movable_mem[i].start) && + (end <= movable_mem[i].end)) + return 1; + + if (start > movable_mem[i].end) + continue; + + if (end < movable_mem[i].start) + break; + } + return 0; +} + static void process_mem_region(struct mem_vector *entry, unsigned long minimum, unsigned long image_size) @@ -502,6 +728,11 @@ static void process_mem_region(struct mem_vector *entry, end = min(entry->size + entry->start, mem_limit); if (entry->start >= end) return; + + /* Ignore the memory region of movable_node */ + if (check_movable_memory(entry)) + return; + cur_entry.start = entry->start; cur_entry.size = end - entry->start; diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 766a5211f827..5f514959b2f1 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -109,3 +109,30 @@ static inline void console_init(void) #endif #endif + +#ifdef ACPI_BIG_ENDIAN +#define ACPI_MOVE_64_TO_64(d, s) \ +{((u8 *)(void *)(d))[0] = ((u8 *)(void *)(s))[7]; \ +((u8 *)(void *)(d))[1] = ((u8 *)(void *)(s))[6]; \ +((u8 *)(void *)(d))[2] = ((u8 *)(void *)(s))[5]; \ +((u8 *)(void *)(d))[3] = ((u8 *)(void *)(s))[4]; \ +((u8 *)(void *)(d))[4] = ((u8 *)(void *)(s))[3]; \ +((u8 *)(void *)(d))[5] = ((u8 *)(void *)(s))[2]; \ +((u8 *)(void *)(d))[6] = ((u8 *)(void *)(s))[1]; \ +((u8 *)(void *)(d))[7] = ((u8 *)(void *)(s))[0]; } +#else +#ifndef ACPI_MISALIGNMENT_NOT_SUPPORTED +#define ACPI_MOVE_64_TO_64(d, s) \ +{*(u64 *)(void *)(d) = *(u64 *)(void *)(s)} +#else +#define ACPI_MOVE_64_TO_64(d, s) \ +{((u8 *)(void *)(d))[0] = ((u8 *)(void *)(s))[0]; \ +((u8 *)(void *)(d))[1] = ((u8 *)(void *)(s))[1]; \ +((u8 *)(void *)(d))[2] = ((u8 *)(void *)(s))[2]; \ +((u8 *)(void *)(d))[3] = ((u8 *)(void *)(s))[3]; \ +((u8 *)(void *)(d))[4] = ((u8 *)(void *)(s))[4]; \ +((u8 *)(void *)(d))[5] = ((u8 *)(void *)(s))[5]; \ +((u8 *)(void *)(d))[6] = ((u8 *)(void *)(s))[6]; \ +((u8 *)(void *)(d))[7] = ((u8 *)(void *)(s))[7]; } +#endif +#endif -- 2.13.4
