diff options
| -rw-r--r-- | arch/s390/Kconfig | 13 | ||||
| -rw-r--r-- | arch/s390/configs/default_defconfig | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/compat_wrapper.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/machine_kexec_file.c | 126 | ||||
| -rw-r--r-- | arch/s390/kernel/syscalls/syscall.tbl | 1 |
6 files changed, 144 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 5b8d0859b317..3223ce0680c0 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -51,6 +51,19 @@ config KEXEC def_bool y select KEXEC_CORE +config KEXEC_FILE + bool "kexec file based system call" + select KEXEC_CORE + select BUILD_BIN2C + depends on CRYPTO + depends on CRYPTO_SHA256 + depends on CRYPTO_SHA256_S390 + ---help--- + This is new version of kexec system call. This system call is + file based and takes file descriptors as system call argument + for kernel and initramfs as opposed to list of segments as + accepted by previous system call. + config ARCH_HAS_KEXEC_PURGATORY def_bool y depends on KEXEC_FILE diff --git a/arch/s390/configs/default_defconfig b/arch/s390/configs/default_defconfig index 5af8458951cf..2310315b0744 100644 --- a/arch/s390/configs/default_defconfig +++ b/arch/s390/configs/default_defconfig @@ -719,3 +719,4 @@ CONFIG_APPLDATA_BASE=y CONFIG_KVM=m CONFIG_KVM_S390_UCONTROL=y CONFIG_VHOST_NET=m +CONFIG_KEXEC_FILE=y diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index b06a6f79c1ec..35bec1ab84e3 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -82,6 +82,8 @@ obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_UPROBES) += uprobes.o +obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o + obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_cpum_cf.o perf_cpum_sf.o obj-$(CONFIG_PERF_EVENTS) += perf_cpum_cf_events.o perf_regs.o diff --git a/arch/s390/kernel/compat_wrapper.c b/arch/s390/kernel/compat_wrapper.c index 11e9d8b5c1b0..607c5e9fba3d 100644 --- a/arch/s390/kernel/compat_wrapper.c +++ b/arch/s390/kernel/compat_wrapper.c @@ -182,3 +182,4 @@ COMPAT_SYSCALL_WRAP6(copy_file_range, int, fd_in, loff_t __user *, off_in, int, COMPAT_SYSCALL_WRAP2(s390_guarded_storage, int, command, struct gs_cb *, gs_cb); COMPAT_SYSCALL_WRAP5(statx, int, dfd, const char __user *, path, unsigned, flags, unsigned, mask, struct statx __user *, buffer); COMPAT_SYSCALL_WRAP4(s390_sthyi, unsigned long, code, void __user *, info, u64 __user *, rc, unsigned long, flags); +COMPAT_SYSCALL_WRAP5(kexec_file_load, int, kernel_fd, int, initrd_fd, unsigned long, cmdline_len, const char __user *, cmdline_ptr, unsigned long, flags) diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c new file mode 100644 index 000000000000..d9b4f9d23e9f --- /dev/null +++ b/arch/s390/kernel/machine_kexec_file.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * s390 code for kexec_file_load system call + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/elf.h> +#include <linux/kexec.h> +#include <asm/setup.h> + +const struct kexec_file_ops * const kexec_file_loaders[] = { + NULL, +}; + +/* + * The kernel is loaded to a fixed location. Turn off kexec_locate_mem_hole + * and provide kbuf->mem by hand. + */ +int arch_kexec_walk_mem(struct kexec_buf *kbuf, + int (*func)(struct resource *, void *)) +{ + return 1; +} + +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab) +{ + Elf_Rela *relas; + int i; + + relas = (void *)pi->ehdr + relsec->sh_offset; + + for (i = 0; i < relsec->sh_size / sizeof(*relas); i++) { + const Elf_Sym *sym; /* symbol to relocate */ + unsigned long addr; /* final location after relocation */ + unsigned long val; /* relocated symbol value */ + void *loc; /* tmp location to modify */ + + sym = (void *)pi->ehdr + symtab->sh_offset; + sym += ELF64_R_SYM(relas[i].r_info); + + if (sym->st_shndx == SHN_UNDEF) + return -ENOEXEC; + + if (sym->st_shndx == SHN_COMMON) + return -ENOEXEC; + + if (sym->st_shndx >= pi->ehdr->e_shnum && + sym->st_shndx != SHN_ABS) + return -ENOEXEC; + + loc = pi->purgatory_buf; + loc += section->sh_offset; + loc += relas[i].r_offset; + + val = sym->st_value; + if (sym->st_shndx != SHN_ABS) + val += pi->sechdrs[sym->st_shndx].sh_addr; + val += relas[i].r_addend; + + addr = section->sh_addr + relas[i].r_offset; + + switch (ELF64_R_TYPE(relas[i].r_info)) { + case R_390_8: /* Direct 8 bit. */ + *(u8 *)loc = val; + break; + case R_390_12: /* Direct 12 bit. */ + *(u16 *)loc &= 0xf000; + *(u16 *)loc |= val & 0xfff; + break; + case R_390_16: /* Direct 16 bit. */ + *(u16 *)loc = val; + break; + case R_390_20: /* Direct 20 bit. */ + *(u32 *)loc &= 0xf00000ff; + *(u32 *)loc |= (val & 0xfff) << 16; /* DL */ + *(u32 *)loc |= (val & 0xff000) >> 4; /* DH */ + break; + case R_390_32: /* Direct 32 bit. */ + *(u32 *)loc = val; + break; + case R_390_64: /* Direct 64 bit. */ + *(u64 *)loc = val; + break; + case R_390_PC16: /* PC relative 16 bit. */ + *(u16 *)loc = (val - addr); + break; + case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ + *(u16 *)loc = (val - addr) >> 1; + break; + case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ + *(u32 *)loc = (val - addr) >> 1; + break; + case R_390_PC32: /* PC relative 32 bit. */ + *(u32 *)loc = (val - addr); + break; + case R_390_PC64: /* PC relative 64 bit. */ + *(u64 *)loc = (val - addr); + break; + default: + break; + } + } + return 0; +} + +int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, + unsigned long buf_len) +{ + /* A kernel must be at least large enough to contain head.S. During + * load memory in head.S will be accessed, e.g. to register the next + * command line. If the next kernel were smaller the current kernel + * will panic at load. + * + * 0x11000 = sizeof(head.S) + */ + if (buf_len < 0x11000) + return -ENOEXEC; + + return kexec_image_probe_default(image, buf, buf_len); +} diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index b38d48464368..8b210ead7956 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -388,3 +388,4 @@ 378 common s390_guarded_storage sys_s390_guarded_storage compat_sys_s390_guarded_storage 379 common statx sys_statx compat_sys_statx 380 common s390_sthyi sys_s390_sthyi compat_sys_s390_sthyi +381 common kexec_file_load sys_kexec_file_load compat_sys_kexec_file_load |