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Diffstat (limited to 'arch/s390/kernel/machine_kexec_file.c')
-rw-r--r--arch/s390/kernel/machine_kexec_file.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
new file mode 100644
index 000000000000..f413f57f8d20
--- /dev/null
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -0,0 +1,245 @@
+// 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[] = {
+ &s390_kexec_elf_ops,
+ &s390_kexec_image_ops,
+ NULL,
+};
+
+int *kexec_file_update_kernel(struct kimage *image,
+ struct s390_load_data *data)
+{
+ unsigned long *loc;
+
+ if (image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE)
+ return ERR_PTR(-EINVAL);
+
+ if (image->cmdline_buf_len)
+ memcpy(data->kernel_buf + COMMAND_LINE_OFFSET,
+ image->cmdline_buf, image->cmdline_buf_len);
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ loc = (unsigned long *)(data->kernel_buf + OLDMEM_BASE_OFFSET);
+ *loc = crashk_res.start;
+
+ loc = (unsigned long *)(data->kernel_buf + OLDMEM_SIZE_OFFSET);
+ *loc = crashk_res.end - crashk_res.start + 1;
+ }
+
+ if (image->initrd_buf) {
+ loc = (unsigned long *)(data->kernel_buf + INITRD_START_OFFSET);
+ *loc = data->initrd_load_addr;
+
+ loc = (unsigned long *)(data->kernel_buf + INITRD_SIZE_OFFSET);
+ *loc = image->initrd_buf_len;
+ }
+
+ return NULL;
+}
+
+static int kexec_file_update_purgatory(struct kimage *image)
+{
+ u64 entry, type;
+ int ret;
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ entry = STARTUP_KDUMP_OFFSET;
+ type = KEXEC_TYPE_CRASH;
+ } else {
+ entry = STARTUP_NORMAL_OFFSET;
+ type = KEXEC_TYPE_DEFAULT;
+ }
+
+ ret = kexec_purgatory_get_set_symbol(image, "kernel_entry", &entry,
+ sizeof(entry), false);
+ if (ret)
+ return ret;
+
+ ret = kexec_purgatory_get_set_symbol(image, "kernel_type", &type,
+ sizeof(type), false);
+ if (ret)
+ return ret;
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ u64 crash_size;
+
+ ret = kexec_purgatory_get_set_symbol(image, "crash_start",
+ &crashk_res.start,
+ sizeof(crashk_res.start),
+ false);
+ if (ret)
+ return ret;
+
+ crash_size = crashk_res.end - crashk_res.start + 1;
+ ret = kexec_purgatory_get_set_symbol(image, "crash_size",
+ &crash_size,
+ sizeof(crash_size),
+ false);
+ }
+ return ret;
+}
+
+int kexec_file_add_purgatory(struct kimage *image, struct s390_load_data *data)
+{
+ struct kexec_buf buf;
+ int ret;
+
+ buf.image = image;
+
+ data->memsz = ALIGN(data->memsz, PAGE_SIZE);
+ buf.mem = data->memsz;
+ if (image->type == KEXEC_TYPE_CRASH)
+ buf.mem += crashk_res.start;
+
+ ret = kexec_load_purgatory(image, &buf);
+ if (ret)
+ return ret;
+
+ ret = kexec_file_update_purgatory(image);
+ return ret;
+}
+
+int kexec_file_add_initrd(struct kimage *image, struct s390_load_data *data,
+ char *initrd, unsigned long initrd_len)
+{
+ struct kexec_buf buf;
+ int ret;
+
+ buf.image = image;
+
+ buf.buffer = initrd;
+ buf.bufsz = initrd_len;
+
+ data->memsz = ALIGN(data->memsz, PAGE_SIZE);
+ buf.mem = data->memsz;
+ if (image->type == KEXEC_TYPE_CRASH)
+ buf.mem += crashk_res.start;
+ buf.memsz = buf.bufsz;
+
+ data->initrd_load_addr = buf.mem;
+ data->memsz += buf.memsz;
+
+ ret = kexec_add_buffer(&buf);
+ return ret;
+}
+
+/*
+ * 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);
+}