1 files changed, 353 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 000000000..bf0596749
--- /dev/null
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -0,0 +1,353 @@
+// 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/errno.h>
+#include <linux/kexec.h>
+#include <linux/module_signature.h>
+#include <linux/verification.h>
+#include <linux/vmalloc.h>
+#include <asm/boot_data.h>
+#include <asm/ipl.h>
+#include <asm/setup.h>
+
+const struct kexec_file_ops * const kexec_file_loaders[] = {
+	&s390_kexec_elf_ops,
+	&s390_kexec_image_ops,
+	NULL,
+};
+
+#ifdef CONFIG_KEXEC_SIG
+int s390_verify_sig(const char *kernel, unsigned long kernel_len)
+{
+	const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
+	struct module_signature *ms;
+	unsigned long sig_len;
+	int ret;
+
+	/* Skip signature verification when not secure IPLed. */
+	if (!ipl_secure_flag)
+		return 0;
+
+	if (marker_len > kernel_len)
+		return -EKEYREJECTED;
+
+	if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING,
+		   marker_len))
+		return -EKEYREJECTED;
+	kernel_len -= marker_len;
+
+	ms = (void *)kernel + kernel_len - sizeof(*ms);
+	kernel_len -= sizeof(*ms);
+
+	sig_len = be32_to_cpu(ms->sig_len);
+	if (sig_len >= kernel_len)
+		return -EKEYREJECTED;
+	kernel_len -= sig_len;
+
+	if (ms->id_type != PKEY_ID_PKCS7)
+		return -EKEYREJECTED;
+
+	if (ms->algo != 0 ||
+	    ms->hash != 0 ||
+	    ms->signer_len != 0 ||
+	    ms->key_id_len != 0 ||
+	    ms->__pad[0] != 0 ||
+	    ms->__pad[1] != 0 ||
+	    ms->__pad[2] != 0) {
+		return -EBADMSG;
+	}
+
+	ret = verify_pkcs7_signature(kernel, kernel_len,
+				     kernel + kernel_len, sig_len,
+				     VERIFY_USE_SECONDARY_KEYRING,
+				     VERIFYING_MODULE_SIGNATURE,
+				     NULL, NULL);
+	if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
+		ret = verify_pkcs7_signature(kernel, kernel_len,
+					     kernel + kernel_len, sig_len,
+					     VERIFY_USE_PLATFORM_KEYRING,
+					     VERIFYING_MODULE_SIGNATURE,
+					     NULL, NULL);
+	return ret;
+}
+#endif /* CONFIG_KEXEC_SIG */
+
+static int kexec_file_update_purgatory(struct kimage *image,
+				       struct s390_load_data *data)
+{
+	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;
+}
+
+static 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;
+	data->memsz += buf.memsz;
+
+	return kexec_file_update_purgatory(image, data);
+}
+
+static int kexec_file_add_initrd(struct kimage *image,
+				 struct s390_load_data *data)
+{
+	struct kexec_buf buf;
+	int ret;
+
+	buf.image = image;
+
+	buf.buffer = image->initrd_buf;
+	buf.bufsz = image->initrd_buf_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->parm->initrd_start = data->memsz;
+	data->parm->initrd_size = buf.memsz;
+	data->memsz += buf.memsz;
+
+	ret = kexec_add_buffer(&buf);
+	if (ret)
+		return ret;
+
+	return ipl_report_add_component(data->report, &buf, 0, 0);
+}
+
+static int kexec_file_add_ipl_report(struct kimage *image,
+				     struct s390_load_data *data)
+{
+	__u32 *lc_ipl_parmblock_ptr;
+	unsigned int len, ncerts;
+	struct kexec_buf buf;
+	unsigned long addr;
+	void *ptr, *end;
+	int ret;
+
+	buf.image = image;
+
+	data->memsz = ALIGN(data->memsz, PAGE_SIZE);
+	buf.mem = data->memsz;
+
+	ptr = (void *)ipl_cert_list_addr;
+	end = ptr + ipl_cert_list_size;
+	ncerts = 0;
+	while (ptr < end) {
+		ncerts++;
+		len = *(unsigned int *)ptr;
+		ptr += sizeof(len);
+		ptr += len;
+	}
+
+	addr = data->memsz + data->report->size;
+	addr += ncerts * sizeof(struct ipl_rb_certificate_entry);
+	ptr = (void *)ipl_cert_list_addr;
+	while (ptr < end) {
+		len = *(unsigned int *)ptr;
+		ptr += sizeof(len);
+		ipl_report_add_certificate(data->report, ptr, addr, len);
+		addr += len;
+		ptr += len;
+	}
+
+	ret = -ENOMEM;
+	buf.buffer = ipl_report_finish(data->report);
+	if (!buf.buffer)
+		goto out;
+	buf.bufsz = data->report->size;
+	buf.memsz = buf.bufsz;
+	image->arch.ipl_buf = buf.buffer;
+
+	data->memsz += buf.memsz;
+
+	lc_ipl_parmblock_ptr =
+		data->kernel_buf + offsetof(struct lowcore, ipl_parmblock_ptr);
+	*lc_ipl_parmblock_ptr = (__u32)buf.mem;
+
+	if (image->type == KEXEC_TYPE_CRASH)
+		buf.mem += crashk_res.start;
+
+	ret = kexec_add_buffer(&buf);
+out:
+	return ret;
+}
+
+void *kexec_file_add_components(struct kimage *image,
+				int (*add_kernel)(struct kimage *image,
+						  struct s390_load_data *data))
+{
+	struct s390_load_data data = {0};
+	int ret;
+
+	data.report = ipl_report_init(&ipl_block);
+	if (IS_ERR(data.report))
+		return data.report;
+
+	ret = add_kernel(image, &data);
+	if (ret)
+		goto out;
+
+	if (image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+	memcpy(data.parm->command_line, image->cmdline_buf,
+	       image->cmdline_buf_len);
+
+	if (image->type == KEXEC_TYPE_CRASH) {
+		data.parm->oldmem_base = crashk_res.start;
+		data.parm->oldmem_size = crashk_res.end - crashk_res.start + 1;
+	}
+
+	if (image->initrd_buf) {
+		ret = kexec_file_add_initrd(image, &data);
+		if (ret)
+			goto out;
+	}
+
+	ret = kexec_file_add_purgatory(image, &data);
+	if (ret)
+		goto out;
+
+	if (data.kernel_mem == 0) {
+		unsigned long restart_psw =  0x0008000080000000UL;
+		restart_psw += image->start;
+		memcpy(data.kernel_buf, &restart_psw, sizeof(restart_psw));
+		image->start = 0;
+	}
+
+	ret = kexec_file_add_ipl_report(image, &data);
+out:
+	ipl_report_free(data.report);
+	return ERR_PTR(ret);
+}
+
+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, r_type;
+	int ret;
+
+	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;
+
+		r_type = ELF64_R_TYPE(relas[i].r_info);
+		ret = arch_kexec_do_relocs(r_type, loc, val, addr);
+		if (ret) {
+			pr_err("Unknown rela relocation: %d\n", r_type);
+			return -ENOEXEC;
+		}
+	}
+	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.
+	 */
+	if (buf_len < HEAD_END)
+		return -ENOEXEC;
+
+	return kexec_image_probe_default(image, buf, buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	vfree(image->arch.ipl_buf);
+	image->arch.ipl_buf = NULL;
+
+	return kexec_image_post_load_cleanup_default(image);
+}