137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ELF loader for kexec_file_load system call.
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*
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* Copyright IBM Corp. 2018
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*
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* Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com>
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*/
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <asm/ipl.h>
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#include <asm/setup.h>
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static int kexec_file_add_kernel_elf(struct kimage *image,
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struct s390_load_data *data)
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{
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struct kexec_buf buf;
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const Elf_Ehdr *ehdr;
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const Elf_Phdr *phdr;
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Elf_Addr entry;
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void *kernel;
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int i, ret;
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kernel = image->kernel_buf;
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ehdr = (Elf_Ehdr *)kernel;
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buf.image = image;
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if (image->type == KEXEC_TYPE_CRASH)
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entry = STARTUP_KDUMP_OFFSET;
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else
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entry = ehdr->e_entry;
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phdr = (void *)ehdr + ehdr->e_phoff;
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for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
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if (phdr->p_type != PT_LOAD)
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continue;
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buf.buffer = kernel + phdr->p_offset;
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buf.bufsz = phdr->p_filesz;
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buf.mem = ALIGN(phdr->p_paddr, phdr->p_align);
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if (image->type == KEXEC_TYPE_CRASH)
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buf.mem += crashk_res.start;
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buf.memsz = phdr->p_memsz;
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data->memsz = ALIGN(data->memsz, phdr->p_align) + buf.memsz;
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if (entry - phdr->p_paddr < phdr->p_memsz) {
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data->kernel_buf = buf.buffer;
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data->kernel_mem = buf.mem;
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data->parm = buf.buffer + PARMAREA;
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}
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ipl_report_add_component(data->report, &buf,
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IPL_RB_COMPONENT_FLAG_SIGNED |
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IPL_RB_COMPONENT_FLAG_VERIFIED,
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IPL_RB_CERT_UNKNOWN);
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ret = kexec_add_buffer(&buf);
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if (ret)
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return ret;
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}
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return data->memsz ? 0 : -EINVAL;
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}
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static void *s390_elf_load(struct kimage *image,
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char *kernel, unsigned long kernel_len,
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char *initrd, unsigned long initrd_len,
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char *cmdline, unsigned long cmdline_len)
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{
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const Elf_Ehdr *ehdr;
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const Elf_Phdr *phdr;
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size_t size;
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int i;
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/* image->fobs->probe already checked for valid ELF magic number. */
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ehdr = (Elf_Ehdr *)kernel;
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if (ehdr->e_type != ET_EXEC ||
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ehdr->e_ident[EI_CLASS] != ELFCLASS64 ||
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!elf_check_arch(ehdr))
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return ERR_PTR(-EINVAL);
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if (!ehdr->e_phnum || ehdr->e_phentsize != sizeof(Elf_Phdr))
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return ERR_PTR(-EINVAL);
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size = ehdr->e_ehsize + ehdr->e_phoff;
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size += ehdr->e_phentsize * ehdr->e_phnum;
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if (size > kernel_len)
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return ERR_PTR(-EINVAL);
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phdr = (void *)ehdr + ehdr->e_phoff;
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size = ALIGN(size, phdr->p_align);
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for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
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if (phdr->p_type == PT_INTERP)
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return ERR_PTR(-EINVAL);
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if (phdr->p_offset > kernel_len)
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return ERR_PTR(-EINVAL);
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size += ALIGN(phdr->p_filesz, phdr->p_align);
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}
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if (size > kernel_len)
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return ERR_PTR(-EINVAL);
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return kexec_file_add_components(image, kexec_file_add_kernel_elf);
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}
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static int s390_elf_probe(const char *buf, unsigned long len)
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{
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const Elf_Ehdr *ehdr;
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if (len < sizeof(Elf_Ehdr))
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return -ENOEXEC;
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ehdr = (Elf_Ehdr *)buf;
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/* Only check the ELF magic number here and do proper validity check
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* in the loader. Any check here that fails would send the erroneous
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* ELF file to the image loader that does not care what it gets.
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* (Most likely) causing behavior not intended by the user.
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*/
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if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0)
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return -ENOEXEC;
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return 0;
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}
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const struct kexec_file_ops s390_kexec_elf_ops = {
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.probe = s390_elf_probe,
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.load = s390_elf_load,
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#ifdef CONFIG_KEXEC_SIG
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.verify_sig = s390_verify_sig,
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#endif /* CONFIG_KEXEC_SIG */
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};
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