diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 75 |
1 files changed, 66 insertions, 9 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 9cc76e631759..6cf89314209a 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -141,7 +141,8 @@ static void copy_bootdata(void) memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size); } -static void handle_relocs(unsigned long offset) +#ifdef CONFIG_PIE_BUILD +static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr, unsigned long offset) { Elf64_Rela *rela_start, *rela_end, *rela; int r_type, r_sym, rc; @@ -172,6 +173,54 @@ static void handle_relocs(unsigned long offset) } } +static void kaslr_adjust_got(unsigned long offset) {} +static void rescue_relocs(void) {} +static void free_relocs(void) {} +#else +static int *vmlinux_relocs_64_start; +static int *vmlinux_relocs_64_end; + +static void rescue_relocs(void) +{ + unsigned long size = __vmlinux_relocs_64_end - __vmlinux_relocs_64_start; + + vmlinux_relocs_64_start = (void *)physmem_alloc_top_down(RR_RELOC, size, 0); + vmlinux_relocs_64_end = (void *)vmlinux_relocs_64_start + size; + memmove(vmlinux_relocs_64_start, __vmlinux_relocs_64_start, size); +} + +static void free_relocs(void) +{ + physmem_free(RR_RELOC); +} + +static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr, unsigned long offset) +{ + int *reloc; + long loc; + + /* Adjust R_390_64 relocations */ + for (reloc = vmlinux_relocs_64_start; reloc < vmlinux_relocs_64_end; reloc++) { + loc = (long)*reloc + offset; + if (loc < min_addr || loc > max_addr) + error("64-bit relocation outside of kernel!\n"); + *(u64 *)loc += offset; + } +} + +static void kaslr_adjust_got(unsigned long offset) +{ + u64 *entry; + + /* + * Even without -fPIE, Clang still uses a global offset table for some + * reason. Adjust the GOT entries. + */ + for (entry = (u64 *)vmlinux.got_start; entry < (u64 *)vmlinux.got_end; entry++) + *entry += offset; +} +#endif + /* * Merge information from several sources into a single ident_map_size value. * "ident_map_size" represents the upper limit of physical memory we may ever @@ -299,14 +348,19 @@ static void setup_vmalloc_size(void) vmalloc_size = max(size, vmalloc_size); } -static void offset_vmlinux_info(unsigned long offset) +static void kaslr_adjust_vmlinux_info(unsigned long offset) { *(unsigned long *)(&vmlinux.entry) += offset; vmlinux.bootdata_off += offset; vmlinux.bootdata_preserved_off += offset; +#ifdef CONFIG_PIE_BUILD vmlinux.rela_dyn_start += offset; vmlinux.rela_dyn_end += offset; vmlinux.dynsym_start += offset; +#else + vmlinux.got_start += offset; + vmlinux.got_end += offset; +#endif vmlinux.init_mm_off += offset; vmlinux.swapper_pg_dir_off += offset; vmlinux.invalid_pg_dir_off += offset; @@ -361,6 +415,7 @@ void startup_kernel(void) detect_physmem_online_ranges(max_physmem_end); save_ipl_cert_comp_list(); rescue_initrd(safe_addr, ident_map_size); + rescue_relocs(); if (kaslr_enabled()) { vmlinux_lma = randomize_within_range(vmlinux.image_size + vmlinux.bss_size, @@ -368,7 +423,7 @@ void startup_kernel(void) ident_map_size); if (vmlinux_lma) { __kaslr_offset = vmlinux_lma - vmlinux.default_lma; - offset_vmlinux_info(__kaslr_offset); + kaslr_adjust_vmlinux_info(__kaslr_offset); } } vmlinux_lma = vmlinux_lma ?: vmlinux.default_lma; @@ -393,18 +448,20 @@ void startup_kernel(void) /* * The order of the following operations is important: * - * - handle_relocs() must follow clear_bss_section() to establish static - * memory references to data in .bss to be used by setup_vmem() + * - kaslr_adjust_relocs() must follow clear_bss_section() to establish + * static memory references to data in .bss to be used by setup_vmem() * (i.e init_mm.pgd) * - * - setup_vmem() must follow handle_relocs() to be able using + * - setup_vmem() must follow kaslr_adjust_relocs() to be able using * static memory references to data in .bss (i.e init_mm.pgd) * - * - copy_bootdata() must follow setup_vmem() to propagate changes to - * bootdata made by setup_vmem() + * - copy_bootdata() must follow setup_vmem() to propagate changes + * to bootdata made by setup_vmem() */ clear_bss_section(vmlinux_lma); - handle_relocs(__kaslr_offset); + kaslr_adjust_relocs(vmlinux_lma, vmlinux_lma + vmlinux.image_size, __kaslr_offset); + kaslr_adjust_got(__kaslr_offset); + free_relocs(); setup_vmem(asce_limit); copy_bootdata(); |