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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/boot/compressed/misc.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/boot/compressed/misc.c')
-rw-r--r-- | arch/x86/boot/compressed/misc.c | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c new file mode 100644 index 000000000..cf690d871 --- /dev/null +++ b/arch/x86/boot/compressed/misc.c @@ -0,0 +1,472 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * misc.c + * + * This is a collection of several routines used to extract the kernel + * which includes KASLR relocation, decompression, ELF parsing, and + * relocation processing. Additionally included are the screen and serial + * output functions and related debugging support functions. + * + * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 + * puts by Nick Holloway 1993, better puts by Martin Mares 1995 + * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 + */ + +#include "misc.h" +#include "error.h" +#include "pgtable.h" +#include "../string.h" +#include "../voffset.h" +#include <asm/bootparam_utils.h> + +/* + * WARNING!! + * This code is compiled with -fPIC and it is relocated dynamically at + * run time, but no relocation processing is performed. This means that + * it is not safe to place pointers in static structures. + */ + +/* Macros used by the included decompressor code below. */ +#define STATIC static +/* Define an externally visible malloc()/free(). */ +#define MALLOC_VISIBLE +#include <linux/decompress/mm.h> + +/* + * Provide definitions of memzero and memmove as some of the decompressors will + * try to define their own functions if these are not defined as macros. + */ +#define memzero(s, n) memset((s), 0, (n)) +#ifndef memmove +#define memmove memmove +/* Functions used by the included decompressor code below. */ +void *memmove(void *dest, const void *src, size_t n); +#endif + +/* + * This is set up by the setup-routine at boot-time + */ +struct boot_params *boot_params; + +struct port_io_ops pio_ops; + +memptr free_mem_ptr; +memptr free_mem_end_ptr; + +static char *vidmem; +static int vidport; + +/* These might be accessed before .bss is cleared, so use .data instead. */ +static int lines __section(".data"); +static int cols __section(".data"); + +#ifdef CONFIG_KERNEL_GZIP +#include "../../../../lib/decompress_inflate.c" +#endif + +#ifdef CONFIG_KERNEL_BZIP2 +#include "../../../../lib/decompress_bunzip2.c" +#endif + +#ifdef CONFIG_KERNEL_LZMA +#include "../../../../lib/decompress_unlzma.c" +#endif + +#ifdef CONFIG_KERNEL_XZ +#include "../../../../lib/decompress_unxz.c" +#endif + +#ifdef CONFIG_KERNEL_LZO +#include "../../../../lib/decompress_unlzo.c" +#endif + +#ifdef CONFIG_KERNEL_LZ4 +#include "../../../../lib/decompress_unlz4.c" +#endif + +#ifdef CONFIG_KERNEL_ZSTD +#include "../../../../lib/decompress_unzstd.c" +#endif +/* + * NOTE: When adding a new decompressor, please update the analysis in + * ../header.S. + */ + +static void scroll(void) +{ + int i; + + memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2); + for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2) + vidmem[i] = ' '; +} + +#define XMTRDY 0x20 + +#define TXR 0 /* Transmit register (WRITE) */ +#define LSR 5 /* Line Status */ +static void serial_putchar(int ch) +{ + unsigned timeout = 0xffff; + + while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) + cpu_relax(); + + outb(ch, early_serial_base + TXR); +} + +void __putstr(const char *s) +{ + int x, y, pos; + char c; + + if (early_serial_base) { + const char *str = s; + while (*str) { + if (*str == '\n') + serial_putchar('\r'); + serial_putchar(*str++); + } + } + + if (lines == 0 || cols == 0) + return; + + x = boot_params->screen_info.orig_x; + y = boot_params->screen_info.orig_y; + + while ((c = *s++) != '\0') { + if (c == '\n') { + x = 0; + if (++y >= lines) { + scroll(); + y--; + } + } else { + vidmem[(x + cols * y) * 2] = c; + if (++x >= cols) { + x = 0; + if (++y >= lines) { + scroll(); + y--; + } + } + } + } + + boot_params->screen_info.orig_x = x; + boot_params->screen_info.orig_y = y; + + pos = (x + cols * y) * 2; /* Update cursor position */ + outb(14, vidport); + outb(0xff & (pos >> 9), vidport+1); + outb(15, vidport); + outb(0xff & (pos >> 1), vidport+1); +} + +void __puthex(unsigned long value) +{ + char alpha[2] = "0"; + int bits; + + for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) { + unsigned long digit = (value >> bits) & 0xf; + + if (digit < 0xA) + alpha[0] = '0' + digit; + else + alpha[0] = 'a' + (digit - 0xA); + + __putstr(alpha); + } +} + +#ifdef CONFIG_X86_NEED_RELOCS +static void handle_relocations(void *output, unsigned long output_len, + unsigned long virt_addr) +{ + int *reloc; + unsigned long delta, map, ptr; + unsigned long min_addr = (unsigned long)output; + unsigned long max_addr = min_addr + (VO___bss_start - VO__text); + + /* + * Calculate the delta between where vmlinux was linked to load + * and where it was actually loaded. + */ + delta = min_addr - LOAD_PHYSICAL_ADDR; + + /* + * The kernel contains a table of relocation addresses. Those + * addresses have the final load address of the kernel in virtual + * memory. We are currently working in the self map. So we need to + * create an adjustment for kernel memory addresses to the self map. + * This will involve subtracting out the base address of the kernel. + */ + map = delta - __START_KERNEL_map; + + /* + * 32-bit always performs relocations. 64-bit relocations are only + * needed if KASLR has chosen a different starting address offset + * from __START_KERNEL_map. + */ + if (IS_ENABLED(CONFIG_X86_64)) + delta = virt_addr - LOAD_PHYSICAL_ADDR; + + if (!delta) { + debug_putstr("No relocation needed... "); + return; + } + debug_putstr("Performing relocations... "); + + /* + * Process relocations: 32 bit relocations first then 64 bit after. + * Three sets of binary relocations are added to the end of the kernel + * before compression. Each relocation table entry is the kernel + * address of the location which needs to be updated stored as a + * 32-bit value which is sign extended to 64 bits. + * + * Format is: + * + * kernel bits... + * 0 - zero terminator for 64 bit relocations + * 64 bit relocation repeated + * 0 - zero terminator for inverse 32 bit relocations + * 32 bit inverse relocation repeated + * 0 - zero terminator for 32 bit relocations + * 32 bit relocation repeated + * + * So we work backwards from the end of the decompressed image. + */ + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("32-bit relocation outside of kernel!\n"); + + *(uint32_t *)ptr += delta; + } +#ifdef CONFIG_X86_64 + while (*--reloc) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("inverse 32-bit relocation outside of kernel!\n"); + + *(int32_t *)ptr -= delta; + } + for (reloc--; *reloc; reloc--) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("64-bit relocation outside of kernel!\n"); + + *(uint64_t *)ptr += delta; + } +#endif +} +#else +static inline void handle_relocations(void *output, unsigned long output_len, + unsigned long virt_addr) +{ } +#endif + +static void parse_elf(void *output) +{ +#ifdef CONFIG_X86_64 + Elf64_Ehdr ehdr; + Elf64_Phdr *phdrs, *phdr; +#else + Elf32_Ehdr ehdr; + Elf32_Phdr *phdrs, *phdr; +#endif + void *dest; + int i; + + memcpy(&ehdr, output, sizeof(ehdr)); + if (ehdr.e_ident[EI_MAG0] != ELFMAG0 || + ehdr.e_ident[EI_MAG1] != ELFMAG1 || + ehdr.e_ident[EI_MAG2] != ELFMAG2 || + ehdr.e_ident[EI_MAG3] != ELFMAG3) { + error("Kernel is not a valid ELF file"); + return; + } + + debug_putstr("Parsing ELF... "); + + phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum); + if (!phdrs) + error("Failed to allocate space for phdrs"); + + memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum); + + for (i = 0; i < ehdr.e_phnum; i++) { + phdr = &phdrs[i]; + + switch (phdr->p_type) { + case PT_LOAD: +#ifdef CONFIG_X86_64 + if ((phdr->p_align % 0x200000) != 0) + error("Alignment of LOAD segment isn't multiple of 2MB"); +#endif +#ifdef CONFIG_RELOCATABLE + dest = output; + dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR); +#else + dest = (void *)(phdr->p_paddr); +#endif + memmove(dest, output + phdr->p_offset, phdr->p_filesz); + break; + default: /* Ignore other PT_* */ break; + } + } + + free(phdrs); +} + +/* + * The compressed kernel image (ZO), has been moved so that its position + * is against the end of the buffer used to hold the uncompressed kernel + * image (VO) and the execution environment (.bss, .brk), which makes sure + * there is room to do the in-place decompression. (See header.S for the + * calculations.) + * + * |-----compressed kernel image------| + * V V + * 0 extract_offset +INIT_SIZE + * |-----------|---------------|-------------------------|--------| + * | | | | + * VO__text startup_32 of ZO VO__end ZO__end + * ^ ^ + * |-------uncompressed kernel image---------| + * + */ +asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, + unsigned char *input_data, + unsigned long input_len, + unsigned char *output, + unsigned long output_len) +{ + const unsigned long kernel_total_size = VO__end - VO__text; + unsigned long virt_addr = LOAD_PHYSICAL_ADDR; + unsigned long needed_size; + + /* Retain x86 boot parameters pointer passed from startup_32/64. */ + boot_params = rmode; + + /* Clear flags intended for solely in-kernel use. */ + boot_params->hdr.loadflags &= ~KASLR_FLAG; + + sanitize_boot_params(boot_params); + + if (boot_params->screen_info.orig_video_mode == 7) { + vidmem = (char *) 0xb0000; + vidport = 0x3b4; + } else { + vidmem = (char *) 0xb8000; + vidport = 0x3d4; + } + + lines = boot_params->screen_info.orig_video_lines; + cols = boot_params->screen_info.orig_video_cols; + + init_default_io_ops(); + + /* + * Detect TDX guest environment. + * + * It has to be done before console_init() in order to use + * paravirtualized port I/O operations if needed. + */ + early_tdx_detect(); + + console_init(); + + /* + * Save RSDP address for later use. Have this after console_init() + * so that early debugging output from the RSDP parsing code can be + * collected. + */ + boot_params->acpi_rsdp_addr = get_rsdp_addr(); + + debug_putstr("early console in extract_kernel\n"); + + free_mem_ptr = heap; /* Heap */ + free_mem_end_ptr = heap + BOOT_HEAP_SIZE; + + /* + * The memory hole needed for the kernel is the larger of either + * the entire decompressed kernel plus relocation table, or the + * entire decompressed kernel plus .bss and .brk sections. + * + * On X86_64, the memory is mapped with PMD pages. Round the + * size up so that the full extent of PMD pages mapped is + * included in the check against the valid memory table + * entries. This ensures the full mapped area is usable RAM + * and doesn't include any reserved areas. + */ + needed_size = max(output_len, kernel_total_size); +#ifdef CONFIG_X86_64 + needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN); +#endif + + /* Report initial kernel position details. */ + debug_putaddr(input_data); + debug_putaddr(input_len); + debug_putaddr(output); + debug_putaddr(output_len); + debug_putaddr(kernel_total_size); + debug_putaddr(needed_size); + +#ifdef CONFIG_X86_64 + /* Report address of 32-bit trampoline */ + debug_putaddr(trampoline_32bit); +#endif + + choose_random_location((unsigned long)input_data, input_len, + (unsigned long *)&output, + needed_size, + &virt_addr); + + /* Validate memory location choices. */ + if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1)) + error("Destination physical address inappropriately aligned"); + if (virt_addr & (MIN_KERNEL_ALIGN - 1)) + error("Destination virtual address inappropriately aligned"); +#ifdef CONFIG_X86_64 + if (heap > 0x3fffffffffffUL) + error("Destination address too large"); + if (virt_addr + max(output_len, kernel_total_size) > KERNEL_IMAGE_SIZE) + error("Destination virtual address is beyond the kernel mapping area"); +#else + if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff)) + error("Destination address too large"); +#endif +#ifndef CONFIG_RELOCATABLE + if (virt_addr != LOAD_PHYSICAL_ADDR) + error("Destination virtual address changed when not relocatable"); +#endif + + debug_putstr("\nDecompressing Linux... "); + __decompress(input_data, input_len, NULL, NULL, output, output_len, + NULL, error); + parse_elf(output); + handle_relocations(output, output_len, virt_addr); + debug_putstr("done.\nBooting the kernel.\n"); + + /* Disable exception handling before booting the kernel */ + cleanup_exception_handling(); + + return output; +} + +void fortify_panic(const char *name) +{ + error("detected buffer overflow"); +} |