diff options
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/acpi.c | 338 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/cmdline.c | 4 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 13 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 75 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 3 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.h | 23 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/pgtable_64.c | 19 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/vmlinux.lds.S | 2 | ||||
| -rw-r--r-- | arch/x86/boot/setup.ld | 2 | ||||
| -rw-r--r-- | arch/x86/boot/string.c | 141 | ||||
| -rw-r--r-- | arch/x86/boot/string.h | 1 |
13 files changed, 593 insertions, 32 deletions
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 9b5adae9cc40..e2839b5c246c 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -100,7 +100,7 @@ $(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE AFLAGS_header.o += -I$(objtree)/$(obj) $(obj)/header.o: $(obj)/zoffset.h -LDFLAGS_setup.elf := -T +LDFLAGS_setup.elf := -m elf_i386 -T $(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE $(call if_changed,ld) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index f0515ac895a4..6b84afdd7538 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_ACPI) += $(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 new file mode 100644 index 000000000000..0ef4ad55b29b --- /dev/null +++ b/arch/x86/boot/compressed/acpi.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: GPL-2.0 +#define BOOT_CTYPE_H +#include "misc.h" +#include "error.h" +#include "../string.h" + +#include <linux/numa.h> +#include <linux/efi.h> +#include <asm/efi.h> + +/* + * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0' + * for termination. + */ +#define MAX_ACPI_ARG_LENGTH 10 + +/* + * Immovable memory regions representation. Max amount of memory regions is + * MAX_NUMNODES*2. + */ +struct mem_vector immovable_mem[MAX_NUMNODES*2]; + +/* + * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex + * digits, and '\0' for termination. + */ +#define MAX_ADDR_LEN 19 + +static acpi_physical_address get_acpi_rsdp(void) +{ + acpi_physical_address addr = 0; + +#ifdef CONFIG_KEXEC + char val[MAX_ADDR_LEN] = { }; + int ret; + + ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN); + if (ret < 0) + return 0; + + if (kstrtoull(val, 16, &addr)) + return 0; +#endif + return addr; +} + +/* Search EFI system tables for RSDP. */ +static acpi_physical_address efi_get_rsdp_addr(void) +{ + acpi_physical_address rsdp_addr = 0; + +#ifdef CONFIG_EFI + unsigned long systab, systab_tables, config_tables; + unsigned int nr_tables; + struct efi_info *ei; + bool efi_64; + int size, i; + char *sig; + + ei = &boot_params->efi_info; + sig = (char *)&ei->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 0; + } + + /* Get systab from boot params. */ +#ifdef CONFIG_X86_64 + systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); +#else + if (ei->efi_systab_hi || ei->efi_memmap_hi) { + debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); + return 0; + } + systab = ei->efi_systab; +#endif + if (!systab) + error("EFI system table not found."); + + /* Handle EFI bitness properly */ + if (efi_64) { + efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab; + + config_tables = stbl->tables; + nr_tables = stbl->nr_tables; + size = sizeof(efi_config_table_64_t); + } else { + efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab; + + config_tables = stbl->tables; + nr_tables = stbl->nr_tables; + size = sizeof(efi_config_table_32_t); + } + + if (!config_tables) + error("EFI config tables not found."); + + /* Get EFI tables from systab. */ + for (i = 0; i < nr_tables; i++) { + acpi_physical_address table; + efi_guid_t guid; + + config_tables += size; + + if (efi_64) { + efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables; + + guid = tbl->guid; + table = tbl->table; + + if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { + debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); + return 0; + } + } else { + efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables; + + guid = tbl->guid; + table = tbl->table; + } + + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) + rsdp_addr = table; + else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) + return table; + } +#endif + return rsdp_addr; +} + +static u8 compute_checksum(u8 *buffer, u32 length) +{ + u8 *end = buffer + length; + u8 sum = 0; + + while (buffer < end) + sum += *(buffer++); + + return sum; +} + +/* Search a block of memory for the RSDP signature. */ +static u8 *scan_mem_for_rsdp(u8 *start, u32 length) +{ + struct acpi_table_rsdp *rsdp; + u8 *address, *end; + + end = start + length; + + /* Search from given start address for the requested length */ + for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) { + /* + * Both RSDP signature and checksum must be correct. + * Note: Sometimes there exists more than one RSDP in memory; + * the valid RSDP has a valid checksum, all others have an + * invalid checksum. + */ + rsdp = (struct acpi_table_rsdp *)address; + + /* BAD Signature */ + if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) + continue; + + /* Check the standard checksum */ + if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH)) + continue; + + /* Check extended checksum if table version >= 2 */ + if ((rsdp->revision >= 2) && + (compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH))) + continue; + + /* Signature and checksum valid, we have found a real RSDP */ + return address; + } + return NULL; +} + +/* Search RSDP address in EBDA. */ +static acpi_physical_address bios_get_rsdp_addr(void) +{ + unsigned long address; + u8 *rsdp; + + /* Get the location of the Extended BIOS Data Area (EBDA) */ + address = *(u16 *)ACPI_EBDA_PTR_LOCATION; + address <<= 4; + + /* + * Search EBDA paragraphs (EBDA is required to be a minimum of + * 1K length) + */ + if (address > 0x400) { + rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + } + + /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */ + rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE, + ACPI_HI_RSDP_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + + return 0; +} + +/* Return RSDP address on success, otherwise 0. */ +acpi_physical_address get_rsdp_addr(void) +{ + acpi_physical_address pa; + + pa = get_acpi_rsdp(); + + if (!pa) + pa = boot_params->acpi_rsdp_addr; + + if (!pa) + pa = efi_get_rsdp_addr(); + + if (!pa) + pa = bios_get_rsdp_addr(); + + return pa; +} + +#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) +/* Compute SRAT address from RSDP. */ +static unsigned long get_acpi_srat_table(void) +{ + unsigned long root_table, acpi_table; + struct acpi_table_header *header; + struct acpi_table_rsdp *rsdp; + u32 num_entries, size, len; + char arg[10]; + u8 *entry; + + rsdp = (struct acpi_table_rsdp *)(long)boot_params->acpi_rsdp_addr; + if (!rsdp) + return 0; + + /* Get ACPI root table 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; + } + + if (!root_table) + return 0; + + header = (struct acpi_table_header *)root_table; + len = header->length; + if (len < sizeof(struct acpi_table_header) + size) + return 0; + + num_entries = (len - sizeof(struct acpi_table_header)) / size; + entry = (u8 *)(root_table + sizeof(struct acpi_table_header)); + + while (num_entries--) { + if (size == ACPI_RSDT_ENTRY_SIZE) + acpi_table = *(u32 *)entry; + else + acpi_table = *(u64 *)entry; + + if (acpi_table) { + header = (struct acpi_table_header *)acpi_table; + + if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT)) + return acpi_table; + } + entry += size; + } + return 0; +} + +/** + * count_immovable_mem_regions - Parse SRAT and cache the immovable + * memory regions into the immovable_mem array. + * + * Return the number of immovable memory regions on success, 0 on failure: + * + * - Too many immovable memory regions + * - ACPI off or no SRAT found + * - No immovable memory region found. + */ +int count_immovable_mem_regions(void) +{ + unsigned long table_addr, table_end, table; + struct acpi_subtable_header *sub_table; + struct acpi_table_header *table_header; + char arg[MAX_ACPI_ARG_LENGTH]; + int num = 0; + + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 && + !strncmp(arg, "off", 3)) + return 0; + + table_addr = get_acpi_srat_table(); + if (!table_addr) + return 0; + + table_header = (struct acpi_table_header *)table_addr; + table_end = table_addr + table_header->length; + table = table_addr + sizeof(struct acpi_table_srat); + + while (table + sizeof(struct acpi_subtable_header) < table_end) { + sub_table = (struct acpi_subtable_header *)table; + if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) { + struct acpi_srat_mem_affinity *ma; + + ma = (struct acpi_srat_mem_affinity *)sub_table; + if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) { + immovable_mem[num].start = ma->base_address; + immovable_mem[num].size = ma->length; + num++; + } + + if (num >= MAX_NUMNODES*2) { + debug_putstr("Too many immovable memory regions, aborting.\n"); + return 0; + } + } + table += sub_table->length; + } + return num; +} +#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */ diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c index af6cda0b7900..f1add5d85da9 100644 --- a/arch/x86/boot/compressed/cmdline.c +++ b/arch/x86/boot/compressed/cmdline.c @@ -1,8 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include "misc.h" -#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE || CONFIG_X86_5LEVEL - static unsigned long fs; static inline void set_fs(unsigned long seg) { @@ -30,5 +28,3 @@ int cmdline_find_option_bool(const char *option) { return __cmdline_find_option_bool(get_cmd_line_ptr(), option); } - -#endif diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index f105ae8651c9..fafb75c6c592 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -358,8 +358,11 @@ ENTRY(startup_64) * paging_prepare() sets up the trampoline and checks if we need to * enable 5-level paging. * - * Address of the trampoline is returned in RAX. - * Non zero RDX on return means we need to enable 5-level paging. + * paging_prepare() returns a two-quadword structure which lands + * into RDX:RAX: + * - Address of the trampoline is returned in RAX. + * - Non zero RDX means trampoline needs to enable 5-level + * paging. * * RSI holds real mode data and needs to be preserved across * this function call. @@ -565,7 +568,7 @@ adjust_got: * * RDI contains the return address (might be above 4G). * ECX contains the base address of the trampoline memory. - * Non zero RDX on return means we need to enable 5-level paging. + * Non zero RDX means trampoline needs to enable 5-level paging. */ ENTRY(trampoline_32bit_src) /* Set up data and stack segments */ @@ -602,10 +605,12 @@ ENTRY(trampoline_32bit_src) 3: /* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */ pushl %ecx + pushl %edx movl $MSR_EFER, %ecx rdmsr btsl $_EFER_LME, %eax wrmsr + popl %edx popl %ecx /* Enable PAE and LA57 (if required) paging modes */ @@ -653,8 +658,6 @@ no_longmode: .data gdt64: .word gdt_end - gdt - .long 0 - .word 0 .quad 0 gdt: .word gdt_end - gdt diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 9ed9709d9947..2e53c056ba20 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 @@ -101,6 +97,8 @@ static bool memmap_too_large; /* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */ static unsigned long long mem_limit = ULLONG_MAX; +/* Number of immovable memory regions */ +static int num_immovable_mem; enum mem_avoid_index { MEM_AVOID_ZO_RANGE = 0, @@ -417,6 +415,9 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, /* Mark the memmap regions we need to avoid */ handle_mem_options(); + /* Enumerate the immovable memory regions */ + num_immovable_mem = count_immovable_mem_regions(); + #ifdef CONFIG_X86_VERBOSE_BOOTUP /* Make sure video RAM can be used. */ add_identity_map(0, PMD_SIZE); @@ -572,9 +573,9 @@ static unsigned long slots_fetch_random(void) return 0; } -static void process_mem_region(struct mem_vector *entry, - unsigned long minimum, - unsigned long image_size) +static void __process_mem_region(struct mem_vector *entry, + unsigned long minimum, + unsigned long image_size) { struct mem_vector region, overlap; unsigned long start_orig, end; @@ -650,6 +651,56 @@ static void process_mem_region(struct mem_vector *entry, } } +static bool process_mem_region(struct mem_vector *region, + unsigned long long minimum, + unsigned long long image_size) +{ + int i; + /* + * If no immovable memory found, or MEMORY_HOTREMOVE disabled, + * use @region directly. + */ + if (!num_immovable_mem) { + __process_mem_region(region, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); + return 1; + } + return 0; + } + +#if defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI) + /* + * If immovable memory found, filter the intersection between + * immovable memory and @region. + */ + for (i = 0; i < num_immovable_mem; i++) { + unsigned long long start, end, entry_end, region_end; + struct mem_vector entry; + + if (!mem_overlaps(region, &immovable_mem[i])) + continue; + + start = immovable_mem[i].start; + end = start + immovable_mem[i].size; + region_end = region->start + region->size; + + entry.start = clamp(region->start, start, end); + entry_end = clamp(region_end, start, end); + entry.size = entry_end - entry.start; + + __process_mem_region(&entry, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan when walking immovable regions(slot_areas full)!\n"); + return 1; + } + } +#endif + return 0; +} + #ifdef CONFIG_EFI /* * Returns true if mirror region found (and must have been processed @@ -715,11 +766,8 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) region.start = md->phys_addr; region.size = md->num_pages << EFI_PAGE_SHIFT; - process_mem_region(®ion, minimum, image_size); - if (slot_area_index == MAX_SLOT_AREA) { - debug_putstr("Aborted EFI scan (slot_areas full)!\n"); + if (process_mem_region(®ion, minimum, image_size)) break; - } } return true; } @@ -746,11 +794,8 @@ static void process_e820_entries(unsigned long minimum, continue; region.start = entry->addr; region.size = entry->size; - process_mem_region(®ion, minimum, image_size); - if (slot_area_index == MAX_SLOT_AREA) { - debug_putstr("Aborted e820 scan (slot_areas full)!\n"); + if (process_mem_region(®ion, minimum, image_size)) break; - } } } diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 8dd1d5ccae58..c0d6c560df69 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -351,6 +351,9 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, /* Clear flags intended for solely in-kernel use. */ boot_params->hdr.loadflags &= ~KASLR_FLAG; + /* Save RSDP address for later use. */ + boot_params->acpi_rsdp_addr = get_rsdp_addr(); + sanitize_boot_params(boot_params); if (boot_params->screen_info.orig_video_mode == 7) { diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index a1d5918765f3..fd13655e0f9b 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -25,6 +25,9 @@ #include <asm/bootparam.h> #include <asm/bootparam_utils.h> +#define BOOT_CTYPE_H +#include <linux/acpi.h> + #define BOOT_BOOT_H #include "../ctype.h" @@ -63,12 +66,14 @@ static inline void debug_puthex(const char *s) #endif -#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE /* cmdline.c */ int cmdline_find_option(const char *option, char *buffer, int bufsize); int cmdline_find_option_bool(const char *option); -#endif +struct mem_vector { + unsigned long long start; + unsigned long long size; +}; #if CONFIG_RANDOMIZE_BASE /* kaslr.c */ @@ -116,3 +121,17 @@ static inline void console_init(void) void set_sev_encryption_mask(void); #endif + +/* acpi.c */ +#ifdef CONFIG_ACPI +acpi_physical_address get_rsdp_addr(void); +#else +static inline acpi_physical_address get_rsdp_addr(void) { return 0; } +#endif + +#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI) +extern struct mem_vector immovable_mem[MAX_NUMNODES*2]; +int count_immovable_mem_regions(void); +#else +static inline int count_immovable_mem_regions(void) { return 0; } +#endif diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index 9e2157371491..f8debf7aeb4c 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -1,5 +1,7 @@ +#include <linux/efi.h> #include <asm/e820/types.h> #include <asm/processor.h> +#include <asm/efi.h> #include "pgtable.h" #include "../string.h" @@ -37,9 +39,10 @@ int cmdline_find_option_bool(const char *option); static unsigned long find_trampoline_placement(void) { - unsigned long bios_start, ebda_start; + unsigned long bios_start = 0, ebda_start = 0; unsigned long trampoline_start; struct boot_e820_entry *entry; + char *signature; int i; /* @@ -47,8 +50,18 @@ static unsigned long find_trampoline_placement(void) * This code is based on reserve_bios_regions(). */ - ebda_start = *(unsigned short *)0x40e << 4; - bios_start = *(unsigned short *)0x413 << 10; + /* + * EFI systems may not provide legacy ROM. The memory may not be mapped + * at all. + * + * Only look for values in the legacy ROM for non-EFI system. + */ + signature = (char *)&boot_params->efi_info.efi_loader_signature; + if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) && + strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) { + ebda_start = *(unsigned short *)0x40e << 4; + bios_start = *(unsigned short *)0x413 << 10; + } if (bios_start < BIOS_START_MIN || bios_start > BIOS_START_MAX) bios_start = BIOS_START_MAX; diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index f491bbde8493..508cfa6828c5 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -1,7 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include <asm-generic/vmlinux.lds.h> -OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT) +OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT) #undef i386 diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld index 96a6c7563538..0149e41d42c2 100644 --- a/arch/x86/boot/setup.ld +++ b/arch/x86/boot/setup.ld @@ -3,7 +3,7 @@ * * Linker script for the i386 setup code */ -OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_FORMAT("elf32-i386") OUTPUT_ARCH(i386) ENTRY(_start) diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c index c4428a176973..315a67b8896b 100644 --- a/arch/x86/boot/string.c +++ b/arch/x86/boot/string.c @@ -13,10 +13,14 @@ */ #include <linux/types.h> +#include <linux/kernel.h> +#include <linux/errno.h> #include <asm/asm.h> #include "ctype.h" #include "string.h" +#define KSTRTOX_OVERFLOW (1U << 31) + /* * Undef these macros so that the functions that we provide * here will have the correct names regardless of how string.h @@ -187,3 +191,140 @@ char *strchr(const char *s, int c) return NULL; return (char *)s; } + +static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) +{ + union { + u64 v64; + u32 v32[2]; + } d = { dividend }; + u32 upper; + + upper = d.v32[1]; + d.v32[1] = 0; + if (upper >= divisor) { + d.v32[1] = upper / divisor; + upper %= divisor; + } + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : + "rm" (divisor), "0" (d.v32[0]), "1" (upper)); + return d.v64; +} + +static inline u64 __div_u64(u64 dividend, u32 divisor) +{ + u32 remainder; + + return __div_u64_rem(dividend, divisor, &remainder); +} + +static inline char _tolower(const char c) +{ + return c | 0x20; +} + +static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) +{ + if (*base == 0) { + if (s[0] == '0') { + if (_tolower(s[1]) == 'x' && isxdigit(s[2])) + *base = 16; + else + *base = 8; + } else + *base = 10; + } + if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') + s += 2; + return s; +} + +/* + * Convert non-negative integer string representation in explicitly given radix + * to an integer. + * Return number of characters consumed maybe or-ed with overflow bit. + * If overflow occurs, result integer (incorrect) is still returned. + * + * Don't you dare use this function. + */ +static unsigned int _parse_integer(const char *s, + unsigned int base, + unsigned long long *p) +{ + unsigned long long res; + unsigned int rv; + + res = 0; + rv = 0; + while (1) { + unsigned int c = *s; + unsigned int lc = c | 0x20; /* don't tolower() this line */ + unsigned int val; + + if ('0' <= c && c <= '9') + val = c - '0'; + else if ('a' <= lc && lc <= 'f') + val = lc - 'a' + 10; + else + break; + + if (val >= base) + break; + /* + * Check for overflow only if we are within range of + * it in the max base we support (16) + */ + if (unlikely(res & (~0ull << 60))) { + if (res > __div_u64(ULLONG_MAX - val, base)) + rv |= KSTRTOX_OVERFLOW; + } + res = res * base + val; + rv++; + s++; + } + *p = res; + return rv; +} + +static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) +{ + unsigned long long _res; + unsigned int rv; + + s = _parse_integer_fixup_radix(s, &base); + rv = _parse_integer(s, base, &_res); + if (rv & KSTRTOX_OVERFLOW) + return -ERANGE; + if (rv == 0) + return -EINVAL; + s += rv; + if (*s == '\n') + s++; + if (*s) + return -EINVAL; + *res = _res; + return 0; +} + +/** + * kstrtoull - convert a string to an unsigned long long + * @s: The start of the string. The string must be null-terminated, and may also + * include a single newline before its terminating null. The first character + * may also be a plus sign, but not a minus sign. + * @base: The number base to use. The maximum supported base is 16. If base is + * given as 0, then the base of the string is automatically detected with the + * conventional semantics - If it begins with 0x the number will be parsed as a + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be + * parsed as an octal number. Otherwise it will be parsed as a decimal. + * @res: Where to write the result of the conversion on success. + * + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. + * Used as a replacement for the obsolete simple_strtoull. Return code must + * be checked. + */ +int kstrtoull(const char *s, unsigned int base, unsigned long long *res) +{ + if (s[0] == '+') + s++; + return _kstrtoull(s, base, res); +} diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h index 3d78e27077f4..38d8f2f5e47e 100644 --- a/arch/x86/boot/string.h +++ b/arch/x86/boot/string.h @@ -29,4 +29,5 @@ extern unsigned int atou(const char *s); extern unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base); +int kstrtoull(const char *s, unsigned int base, unsigned long long *res); #endif /* BOOT_STRING_H */ |