12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
294c3aac5SMimi Zohar /*
394c3aac5SMimi Zohar * Copyright (C) 2016 IBM Corporation
494c3aac5SMimi Zohar *
594c3aac5SMimi Zohar * Authors:
694c3aac5SMimi Zohar * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
794c3aac5SMimi Zohar * Mimi Zohar <zohar@linux.vnet.ibm.com>
894c3aac5SMimi Zohar */
9de636769SPetr Vorel
107b8589ccSMimi Zohar #include <linux/seq_file.h>
117b8589ccSMimi Zohar #include <linux/vmalloc.h>
127b8589ccSMimi Zohar #include <linux/kexec.h>
13fee3ff99SLakshmi Ramasubramanian #include <linux/of.h>
14c6791349SLakshmi Ramasubramanian #include <linux/ima.h>
1594c3aac5SMimi Zohar #include "ima.h"
1694c3aac5SMimi Zohar
177b8589ccSMimi Zohar #ifdef CONFIG_IMA_KEXEC
ima_dump_measurement_list(unsigned long * buffer_size,void ** buffer,unsigned long segment_size)187b8589ccSMimi Zohar static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
197b8589ccSMimi Zohar unsigned long segment_size)
207b8589ccSMimi Zohar {
217b8589ccSMimi Zohar struct ima_queue_entry *qe;
227b8589ccSMimi Zohar struct seq_file file;
23d68a6fe9SMimi Zohar struct ima_kexec_hdr khdr;
247b8589ccSMimi Zohar int ret = 0;
257b8589ccSMimi Zohar
267b8589ccSMimi Zohar /* segment size can't change between kexec load and execute */
277b8589ccSMimi Zohar file.buf = vmalloc(segment_size);
287b8589ccSMimi Zohar if (!file.buf) {
297b8589ccSMimi Zohar ret = -ENOMEM;
307b8589ccSMimi Zohar goto out;
317b8589ccSMimi Zohar }
327b8589ccSMimi Zohar
337b8589ccSMimi Zohar file.size = segment_size;
347b8589ccSMimi Zohar file.read_pos = 0;
357b8589ccSMimi Zohar file.count = sizeof(khdr); /* reserved space */
367b8589ccSMimi Zohar
37d68a6fe9SMimi Zohar memset(&khdr, 0, sizeof(khdr));
38d68a6fe9SMimi Zohar khdr.version = 1;
397b8589ccSMimi Zohar list_for_each_entry_rcu(qe, &ima_measurements, later) {
407b8589ccSMimi Zohar if (file.count < file.size) {
417b8589ccSMimi Zohar khdr.count++;
427b8589ccSMimi Zohar ima_measurements_show(&file, qe);
437b8589ccSMimi Zohar } else {
447b8589ccSMimi Zohar ret = -EINVAL;
457b8589ccSMimi Zohar break;
467b8589ccSMimi Zohar }
477b8589ccSMimi Zohar }
487b8589ccSMimi Zohar
497b8589ccSMimi Zohar if (ret < 0)
507b8589ccSMimi Zohar goto out;
517b8589ccSMimi Zohar
527b8589ccSMimi Zohar /*
537b8589ccSMimi Zohar * fill in reserved space with some buffer details
547b8589ccSMimi Zohar * (eg. version, buffer size, number of measurements)
557b8589ccSMimi Zohar */
567b8589ccSMimi Zohar khdr.buffer_size = file.count;
57d68a6fe9SMimi Zohar if (ima_canonical_fmt) {
58d68a6fe9SMimi Zohar khdr.version = cpu_to_le16(khdr.version);
59d68a6fe9SMimi Zohar khdr.count = cpu_to_le64(khdr.count);
60d68a6fe9SMimi Zohar khdr.buffer_size = cpu_to_le64(khdr.buffer_size);
61d68a6fe9SMimi Zohar }
627b8589ccSMimi Zohar memcpy(file.buf, &khdr, sizeof(khdr));
63d68a6fe9SMimi Zohar
64520451e9SBruno Meneguele print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1,
65520451e9SBruno Meneguele file.buf, file.count < 100 ? file.count : 100,
66520451e9SBruno Meneguele true);
677b8589ccSMimi Zohar
687b8589ccSMimi Zohar *buffer_size = file.count;
697b8589ccSMimi Zohar *buffer = file.buf;
707b8589ccSMimi Zohar out:
717b8589ccSMimi Zohar if (ret == -EINVAL)
727b8589ccSMimi Zohar vfree(file.buf);
737b8589ccSMimi Zohar return ret;
747b8589ccSMimi Zohar }
757b8589ccSMimi Zohar
767b8589ccSMimi Zohar /*
777b8589ccSMimi Zohar * Called during kexec_file_load so that IMA can add a segment to the kexec
787b8589ccSMimi Zohar * image for the measurement list for the next kernel.
797b8589ccSMimi Zohar *
80*55e2b696SWenyu Liu * This function assumes that kexec_lock is held.
817b8589ccSMimi Zohar */
ima_add_kexec_buffer(struct kimage * image)827b8589ccSMimi Zohar void ima_add_kexec_buffer(struct kimage *image)
837b8589ccSMimi Zohar {
847b8589ccSMimi Zohar struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE,
857b8589ccSMimi Zohar .buf_min = 0, .buf_max = ULONG_MAX,
867b8589ccSMimi Zohar .top_down = true };
877b8589ccSMimi Zohar unsigned long binary_runtime_size;
887b8589ccSMimi Zohar
897b8589ccSMimi Zohar /* use more understandable variable names than defined in kbuf */
907b8589ccSMimi Zohar void *kexec_buffer = NULL;
917b8589ccSMimi Zohar size_t kexec_buffer_size;
927b8589ccSMimi Zohar size_t kexec_segment_size;
937b8589ccSMimi Zohar int ret;
947b8589ccSMimi Zohar
957b8589ccSMimi Zohar /*
967b8589ccSMimi Zohar * Reserve an extra half page of memory for additional measurements
977b8589ccSMimi Zohar * added during the kexec load.
987b8589ccSMimi Zohar */
997b8589ccSMimi Zohar binary_runtime_size = ima_get_binary_runtime_size();
1007b8589ccSMimi Zohar if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE)
1017b8589ccSMimi Zohar kexec_segment_size = ULONG_MAX;
1027b8589ccSMimi Zohar else
1037b8589ccSMimi Zohar kexec_segment_size = ALIGN(ima_get_binary_runtime_size() +
1047b8589ccSMimi Zohar PAGE_SIZE / 2, PAGE_SIZE);
1057b8589ccSMimi Zohar if ((kexec_segment_size == ULONG_MAX) ||
106ca79b0c2SArun KS ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) {
1077b8589ccSMimi Zohar pr_err("Binary measurement list too large.\n");
1087b8589ccSMimi Zohar return;
1097b8589ccSMimi Zohar }
1107b8589ccSMimi Zohar
1117b8589ccSMimi Zohar ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer,
1127b8589ccSMimi Zohar kexec_segment_size);
1137b8589ccSMimi Zohar if (!kexec_buffer) {
1147b8589ccSMimi Zohar pr_err("Not enough memory for the kexec measurement buffer.\n");
1157b8589ccSMimi Zohar return;
1167b8589ccSMimi Zohar }
1177b8589ccSMimi Zohar
1187b8589ccSMimi Zohar kbuf.buffer = kexec_buffer;
1197b8589ccSMimi Zohar kbuf.bufsz = kexec_buffer_size;
1207b8589ccSMimi Zohar kbuf.memsz = kexec_segment_size;
1217b8589ccSMimi Zohar ret = kexec_add_buffer(&kbuf);
1227b8589ccSMimi Zohar if (ret) {
1237b8589ccSMimi Zohar pr_err("Error passing over kexec measurement buffer.\n");
1246d14c651SLakshmi Ramasubramanian vfree(kexec_buffer);
1257b8589ccSMimi Zohar return;
1267b8589ccSMimi Zohar }
1277b8589ccSMimi Zohar
1280c605158SLakshmi Ramasubramanian image->ima_buffer_addr = kbuf.mem;
1290c605158SLakshmi Ramasubramanian image->ima_buffer_size = kexec_segment_size;
130f31e3386SLakshmi Ramasubramanian image->ima_buffer = kexec_buffer;
131f31e3386SLakshmi Ramasubramanian
1327b8589ccSMimi Zohar pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
1337b8589ccSMimi Zohar kbuf.mem);
1347b8589ccSMimi Zohar }
1357b8589ccSMimi Zohar #endif /* IMA_KEXEC */
1367b8589ccSMimi Zohar
13794c3aac5SMimi Zohar /*
13894c3aac5SMimi Zohar * Restore the measurement list from the previous kernel.
13994c3aac5SMimi Zohar */
ima_load_kexec_buffer(void)140b69a2afdSJonathan McDowell void __init ima_load_kexec_buffer(void)
14194c3aac5SMimi Zohar {
14294c3aac5SMimi Zohar void *kexec_buffer = NULL;
14394c3aac5SMimi Zohar size_t kexec_buffer_size = 0;
14494c3aac5SMimi Zohar int rc;
14594c3aac5SMimi Zohar
14694c3aac5SMimi Zohar rc = ima_get_kexec_buffer(&kexec_buffer, &kexec_buffer_size);
14794c3aac5SMimi Zohar switch (rc) {
14894c3aac5SMimi Zohar case 0:
14994c3aac5SMimi Zohar rc = ima_restore_measurement_list(kexec_buffer_size,
15094c3aac5SMimi Zohar kexec_buffer);
15194c3aac5SMimi Zohar if (rc != 0)
15294c3aac5SMimi Zohar pr_err("Failed to restore the measurement list: %d\n",
15394c3aac5SMimi Zohar rc);
15494c3aac5SMimi Zohar
15594c3aac5SMimi Zohar ima_free_kexec_buffer();
15694c3aac5SMimi Zohar break;
15794c3aac5SMimi Zohar case -ENOTSUPP:
15894c3aac5SMimi Zohar pr_debug("Restoring the measurement list not supported\n");
15994c3aac5SMimi Zohar break;
16094c3aac5SMimi Zohar case -ENOENT:
16194c3aac5SMimi Zohar pr_debug("No measurement list to restore\n");
16294c3aac5SMimi Zohar break;
16394c3aac5SMimi Zohar default:
16494c3aac5SMimi Zohar pr_debug("Error restoring the measurement list: %d\n", rc);
16594c3aac5SMimi Zohar }
16694c3aac5SMimi Zohar }
167