| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/string.h> |
| #include <linux/elf.h> |
| #include <asm/sections.h> |
| #include <asm/setup.h> |
| #include <asm/kexec.h> |
| #include <asm/sclp.h> |
| #include <asm/diag.h> |
| #include <asm/uv.h> |
| #include "compressed/decompressor.h" |
| #include "boot.h" |
| |
| extern char __boot_data_start[], __boot_data_end[]; |
| extern char __boot_data_preserved_start[], __boot_data_preserved_end[]; |
| unsigned long __bootdata_preserved(__kaslr_offset); |
| |
| /* |
| * Some code and data needs to stay below 2 GB, even when the kernel would be |
| * relocated above 2 GB, because it has to use 31 bit addresses. |
| * Such code and data is part of the .dma section, and its location is passed |
| * over to the decompressed / relocated kernel via the .boot.preserved.data |
| * section. |
| */ |
| extern char _sdma[], _edma[]; |
| extern char _stext_dma[], _etext_dma[]; |
| extern struct exception_table_entry _start_dma_ex_table[]; |
| extern struct exception_table_entry _stop_dma_ex_table[]; |
| unsigned long __bootdata_preserved(__sdma) = __pa(&_sdma); |
| unsigned long __bootdata_preserved(__edma) = __pa(&_edma); |
| unsigned long __bootdata_preserved(__stext_dma) = __pa(&_stext_dma); |
| unsigned long __bootdata_preserved(__etext_dma) = __pa(&_etext_dma); |
| struct exception_table_entry * |
| __bootdata_preserved(__start_dma_ex_table) = _start_dma_ex_table; |
| struct exception_table_entry * |
| __bootdata_preserved(__stop_dma_ex_table) = _stop_dma_ex_table; |
| |
| int _diag210_dma(struct diag210 *addr); |
| int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode); |
| int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode); |
| void _diag0c_dma(struct hypfs_diag0c_entry *entry); |
| void _diag308_reset_dma(void); |
| struct diag_ops __bootdata_preserved(diag_dma_ops) = { |
| .diag210 = _diag210_dma, |
| .diag26c = _diag26c_dma, |
| .diag14 = _diag14_dma, |
| .diag0c = _diag0c_dma, |
| .diag308_reset = _diag308_reset_dma |
| }; |
| static struct diag210 _diag210_tmp_dma __section(".dma.data"); |
| struct diag210 *__bootdata_preserved(__diag210_tmp_dma) = &_diag210_tmp_dma; |
| |
| void error(char *x) |
| { |
| sclp_early_printk("\n\n"); |
| sclp_early_printk(x); |
| sclp_early_printk("\n\n -- System halted"); |
| |
| disabled_wait(); |
| } |
| |
| #ifdef CONFIG_KERNEL_UNCOMPRESSED |
| unsigned long mem_safe_offset(void) |
| { |
| return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size; |
| } |
| #endif |
| |
| static void rescue_initrd(unsigned long addr) |
| { |
| if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) |
| return; |
| if (!INITRD_START || !INITRD_SIZE) |
| return; |
| if (addr <= INITRD_START) |
| return; |
| memmove((void *)addr, (void *)INITRD_START, INITRD_SIZE); |
| INITRD_START = addr; |
| } |
| |
| static void copy_bootdata(void) |
| { |
| if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size) |
| error(".boot.data section size mismatch"); |
| memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size); |
| if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size) |
| error(".boot.preserved.data section size mismatch"); |
| memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size); |
| } |
| |
| static void handle_relocs(unsigned long offset) |
| { |
| Elf64_Rela *rela_start, *rela_end, *rela; |
| int r_type, r_sym, rc; |
| Elf64_Addr loc, val; |
| Elf64_Sym *dynsym; |
| |
| rela_start = (Elf64_Rela *) vmlinux.rela_dyn_start; |
| rela_end = (Elf64_Rela *) vmlinux.rela_dyn_end; |
| dynsym = (Elf64_Sym *) vmlinux.dynsym_start; |
| for (rela = rela_start; rela < rela_end; rela++) { |
| loc = rela->r_offset + offset; |
| val = rela->r_addend; |
| r_sym = ELF64_R_SYM(rela->r_info); |
| if (r_sym) { |
| if (dynsym[r_sym].st_shndx != SHN_UNDEF) |
| val += dynsym[r_sym].st_value + offset; |
| } else { |
| /* |
| * 0 == undefined symbol table index (STN_UNDEF), |
| * used for R_390_RELATIVE, only add KASLR offset |
| */ |
| val += offset; |
| } |
| r_type = ELF64_R_TYPE(rela->r_info); |
| rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0); |
| if (rc) |
| error("Unknown relocation type"); |
| } |
| } |
| |
| /* |
| * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's. |
| */ |
| static void clear_bss_section(void) |
| { |
| memset((void *)vmlinux.default_lma + vmlinux.image_size, 0, vmlinux.bss_size); |
| } |
| |
| void startup_kernel(void) |
| { |
| unsigned long random_lma; |
| unsigned long safe_addr; |
| void *img; |
| |
| store_ipl_parmblock(); |
| safe_addr = mem_safe_offset(); |
| safe_addr = read_ipl_report(safe_addr); |
| uv_query_info(); |
| rescue_initrd(safe_addr); |
| sclp_early_read_info(); |
| setup_boot_command_line(); |
| parse_boot_command_line(); |
| setup_memory_end(); |
| detect_memory(); |
| |
| random_lma = __kaslr_offset = 0; |
| if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) { |
| random_lma = get_random_base(safe_addr); |
| if (random_lma) { |
| __kaslr_offset = random_lma - vmlinux.default_lma; |
| img = (void *)vmlinux.default_lma; |
| vmlinux.default_lma += __kaslr_offset; |
| vmlinux.entry += __kaslr_offset; |
| vmlinux.bootdata_off += __kaslr_offset; |
| vmlinux.bootdata_preserved_off += __kaslr_offset; |
| vmlinux.rela_dyn_start += __kaslr_offset; |
| vmlinux.rela_dyn_end += __kaslr_offset; |
| vmlinux.dynsym_start += __kaslr_offset; |
| } |
| } |
| |
| if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) { |
| img = decompress_kernel(); |
| memmove((void *)vmlinux.default_lma, img, vmlinux.image_size); |
| } else if (__kaslr_offset) |
| memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size); |
| |
| clear_bss_section(); |
| copy_bootdata(); |
| if (IS_ENABLED(CONFIG_RELOCATABLE)) |
| handle_relocs(__kaslr_offset); |
| |
| if (__kaslr_offset) { |
| /* |
| * Save KASLR offset for early dumps, before vmcore_info is set. |
| * Mark as uneven to distinguish from real vmcore_info pointer. |
| */ |
| S390_lowcore.vmcore_info = __kaslr_offset | 0x1UL; |
| /* Clear non-relocated kernel */ |
| if (IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) |
| memset(img, 0, vmlinux.image_size); |
| } |
| vmlinux.entry(); |
| } |