1// SPDX-License-Identifier: GPL-2.0
2/*
3 * s390 code for kexec_file_load system call
4 *
5 * Copyright IBM Corp. 2018
6 *
7 * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com>
8 */
9
10#define pr_fmt(fmt) "kexec: " fmt
11
12#include <linux/elf.h>
13#include <linux/errno.h>
14#include <linux/kexec.h>
15#include <linux/module_signature.h>
16#include <linux/verification.h>
17#include <linux/vmalloc.h>
18#include <asm/boot_data.h>
19#include <asm/ipl.h>
20#include <asm/setup.h>
21
22const struct kexec_file_ops * const kexec_file_loaders[] = {
23 &s390_kexec_elf_ops,
24 &s390_kexec_image_ops,
25 NULL,
26};
27
28#ifdef CONFIG_KEXEC_SIG
29int s390_verify_sig(const char *kernel, unsigned long kernel_len)
30{
31 const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
32 struct module_signature *ms;
33 unsigned long sig_len;
34 int ret;
35
36 /* Skip signature verification when not secure IPLed. */
37 if (!ipl_secure_flag)
38 return 0;
39
40 if (marker_len > kernel_len)
41 return -EKEYREJECTED;
42
43 if (memcmp(p: kernel + kernel_len - marker_len, MODULE_SIG_STRING,
44 size: marker_len))
45 return -EKEYREJECTED;
46 kernel_len -= marker_len;
47
48 ms = (void *)kernel + kernel_len - sizeof(*ms);
49 kernel_len -= sizeof(*ms);
50
51 sig_len = be32_to_cpu(ms->sig_len);
52 if (sig_len >= kernel_len)
53 return -EKEYREJECTED;
54 kernel_len -= sig_len;
55
56 if (ms->id_type != PKEY_ID_PKCS7)
57 return -EKEYREJECTED;
58
59 if (ms->algo != 0 ||
60 ms->hash != 0 ||
61 ms->signer_len != 0 ||
62 ms->key_id_len != 0 ||
63 ms->__pad[0] != 0 ||
64 ms->__pad[1] != 0 ||
65 ms->__pad[2] != 0) {
66 return -EBADMSG;
67 }
68
69 ret = verify_pkcs7_signature(data: kernel, len: kernel_len,
70 raw_pkcs7: kernel + kernel_len, pkcs7_len: sig_len,
71 VERIFY_USE_SECONDARY_KEYRING,
72 usage: VERIFYING_MODULE_SIGNATURE,
73 NULL, NULL);
74 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
75 ret = verify_pkcs7_signature(data: kernel, len: kernel_len,
76 raw_pkcs7: kernel + kernel_len, pkcs7_len: sig_len,
77 VERIFY_USE_PLATFORM_KEYRING,
78 usage: VERIFYING_MODULE_SIGNATURE,
79 NULL, NULL);
80 return ret;
81}
82#endif /* CONFIG_KEXEC_SIG */
83
84static int kexec_file_update_purgatory(struct kimage *image,
85 struct s390_load_data *data)
86{
87 u64 entry, type;
88 int ret;
89
90 if (image->type == KEXEC_TYPE_CRASH) {
91 entry = STARTUP_KDUMP_OFFSET;
92 type = KEXEC_TYPE_CRASH;
93 } else {
94 entry = STARTUP_NORMAL_OFFSET;
95 type = KEXEC_TYPE_DEFAULT;
96 }
97
98 ret = kexec_purgatory_get_set_symbol(image, name: "kernel_entry", buf: &entry,
99 size: sizeof(entry), get_value: false);
100 if (ret)
101 return ret;
102
103 ret = kexec_purgatory_get_set_symbol(image, name: "kernel_type", buf: &type,
104 size: sizeof(type), get_value: false);
105 if (ret)
106 return ret;
107
108#ifdef CONFIG_CRASH_DUMP
109 if (image->type == KEXEC_TYPE_CRASH) {
110 u64 crash_size;
111
112 ret = kexec_purgatory_get_set_symbol(image, name: "crash_start",
113 buf: &crashk_res.start,
114 size: sizeof(crashk_res.start),
115 get_value: false);
116 if (ret)
117 return ret;
118
119 crash_size = crashk_res.end - crashk_res.start + 1;
120 ret = kexec_purgatory_get_set_symbol(image, name: "crash_size",
121 buf: &crash_size,
122 size: sizeof(crash_size),
123 get_value: false);
124 }
125#endif
126 return ret;
127}
128
129static int kexec_file_add_purgatory(struct kimage *image,
130 struct s390_load_data *data)
131{
132 struct kexec_buf buf = {};
133 int ret;
134
135 buf.image = image;
136
137 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
138 buf.mem = data->memsz;
139#ifdef CONFIG_CRASH_DUMP
140 if (image->type == KEXEC_TYPE_CRASH)
141 buf.mem += crashk_res.start;
142#endif
143
144 ret = kexec_load_purgatory(image, kbuf: &buf);
145 if (ret)
146 return ret;
147 data->memsz += buf.memsz;
148
149 return kexec_file_update_purgatory(image, data);
150}
151
152static int kexec_file_add_initrd(struct kimage *image,
153 struct s390_load_data *data)
154{
155 struct kexec_buf buf = {};
156 int ret;
157
158 buf.image = image;
159
160 buf.buffer = image->initrd_buf;
161 buf.bufsz = image->initrd_buf_len;
162
163 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
164 buf.mem = data->memsz;
165#ifdef CONFIG_CRASH_DUMP
166 if (image->type == KEXEC_TYPE_CRASH)
167 buf.mem += crashk_res.start;
168#endif
169 buf.memsz = buf.bufsz;
170
171 data->parm->initrd_start = data->memsz;
172 data->parm->initrd_size = buf.memsz;
173 data->memsz += buf.memsz;
174
175 ret = kexec_add_buffer(kbuf: &buf);
176 if (ret)
177 return ret;
178
179 return ipl_report_add_component(data->report, &buf, 0, 0);
180}
181
182static int kexec_file_add_ipl_report(struct kimage *image,
183 struct s390_load_data *data)
184{
185 __u32 *lc_ipl_parmblock_ptr;
186 unsigned int len, ncerts;
187 struct kexec_buf buf = {};
188 unsigned long addr;
189 void *ptr, *end;
190 int ret;
191
192 buf.image = image;
193
194 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
195 buf.mem = data->memsz;
196
197 ptr = __va(ipl_cert_list_addr);
198 end = ptr + ipl_cert_list_size;
199 ncerts = 0;
200 while (ptr < end) {
201 ncerts++;
202 len = *(unsigned int *)ptr;
203 ptr += sizeof(len);
204 ptr += len;
205 }
206
207 addr = data->memsz + data->report->size;
208 addr += ncerts * sizeof(struct ipl_rb_certificate_entry);
209 ptr = __va(ipl_cert_list_addr);
210 while (ptr < end) {
211 len = *(unsigned int *)ptr;
212 ptr += sizeof(len);
213 ipl_report_add_certificate(data->report, ptr, addr, len);
214 addr += len;
215 ptr += len;
216 }
217
218 ret = -ENOMEM;
219 buf.buffer = ipl_report_finish(data->report);
220 if (!buf.buffer)
221 goto out;
222 buf.bufsz = data->report->size;
223 buf.memsz = buf.bufsz;
224 image->arch.ipl_buf = buf.buffer;
225
226 data->memsz += buf.memsz;
227
228 lc_ipl_parmblock_ptr =
229 data->kernel_buf + offsetof(struct lowcore, ipl_parmblock_ptr);
230 *lc_ipl_parmblock_ptr = (__u32)buf.mem;
231
232#ifdef CONFIG_CRASH_DUMP
233 if (image->type == KEXEC_TYPE_CRASH)
234 buf.mem += crashk_res.start;
235#endif
236
237 ret = kexec_add_buffer(kbuf: &buf);
238out:
239 return ret;
240}
241
242void *kexec_file_add_components(struct kimage *image,
243 int (*add_kernel)(struct kimage *image,
244 struct s390_load_data *data))
245{
246 unsigned long max_command_line_size = LEGACY_COMMAND_LINE_SIZE;
247 struct s390_load_data data = {0};
248 unsigned long minsize;
249 int ret;
250
251 data.report = ipl_report_init(&ipl_block);
252 if (IS_ERR(ptr: data.report))
253 return data.report;
254
255 ret = add_kernel(image, &data);
256 if (ret)
257 goto out;
258
259 ret = -EINVAL;
260 minsize = PARMAREA + offsetof(struct parmarea, command_line);
261 if (image->kernel_buf_len < minsize)
262 goto out;
263
264 if (data.parm->max_command_line_size)
265 max_command_line_size = data.parm->max_command_line_size;
266
267 if (minsize + max_command_line_size < minsize)
268 goto out;
269
270 if (image->kernel_buf_len < minsize + max_command_line_size)
271 goto out;
272
273 if (image->cmdline_buf_len >= max_command_line_size)
274 goto out;
275
276 memcpy(data.parm->command_line, image->cmdline_buf,
277 image->cmdline_buf_len);
278
279#ifdef CONFIG_CRASH_DUMP
280 if (image->type == KEXEC_TYPE_CRASH) {
281 data.parm->oldmem_base = crashk_res.start;
282 data.parm->oldmem_size = crashk_res.end - crashk_res.start + 1;
283 }
284#endif
285
286 if (image->initrd_buf) {
287 ret = kexec_file_add_initrd(image, data: &data);
288 if (ret)
289 goto out;
290 }
291
292 ret = kexec_file_add_purgatory(image, data: &data);
293 if (ret)
294 goto out;
295
296 if (data.kernel_mem == 0) {
297 unsigned long restart_psw = 0x0008000080000000UL;
298 restart_psw += image->start;
299 memcpy(data.kernel_buf, &restart_psw, sizeof(restart_psw));
300 image->start = 0;
301 }
302
303 ret = kexec_file_add_ipl_report(image, data: &data);
304out:
305 ipl_report_free(data.report);
306 return ERR_PTR(error: ret);
307}
308
309int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
310 Elf_Shdr *section,
311 const Elf_Shdr *relsec,
312 const Elf_Shdr *symtab)
313{
314 const char *strtab, *name, *shstrtab;
315 const Elf_Shdr *sechdrs;
316 Elf_Rela *relas;
317 int i, r_type;
318 int ret;
319
320 /* String & section header string table */
321 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
322 strtab = (char *)pi->ehdr + sechdrs[symtab->sh_link].sh_offset;
323 shstrtab = (char *)pi->ehdr + sechdrs[pi->ehdr->e_shstrndx].sh_offset;
324
325 relas = (void *)pi->ehdr + relsec->sh_offset;
326
327 for (i = 0; i < relsec->sh_size / sizeof(*relas); i++) {
328 const Elf_Sym *sym; /* symbol to relocate */
329 unsigned long addr; /* final location after relocation */
330 unsigned long val; /* relocated symbol value */
331 void *loc; /* tmp location to modify */
332
333 sym = (void *)pi->ehdr + symtab->sh_offset;
334 sym += ELF64_R_SYM(relas[i].r_info);
335
336 if (sym->st_name)
337 name = strtab + sym->st_name;
338 else
339 name = shstrtab + sechdrs[sym->st_shndx].sh_name;
340
341 if (sym->st_shndx == SHN_UNDEF) {
342 pr_err("Undefined symbol: %s\n", name);
343 return -ENOEXEC;
344 }
345
346 if (sym->st_shndx == SHN_COMMON) {
347 pr_err("symbol '%s' in common section\n", name);
348 return -ENOEXEC;
349 }
350
351 if (sym->st_shndx >= pi->ehdr->e_shnum &&
352 sym->st_shndx != SHN_ABS) {
353 pr_err("Invalid section %d for symbol %s\n",
354 sym->st_shndx, name);
355 return -ENOEXEC;
356 }
357
358 loc = pi->purgatory_buf;
359 loc += section->sh_offset;
360 loc += relas[i].r_offset;
361
362 val = sym->st_value;
363 if (sym->st_shndx != SHN_ABS)
364 val += pi->sechdrs[sym->st_shndx].sh_addr;
365 val += relas[i].r_addend;
366
367 addr = section->sh_addr + relas[i].r_offset;
368
369 r_type = ELF64_R_TYPE(relas[i].r_info);
370
371 if (r_type == R_390_PLT32DBL)
372 r_type = R_390_PC32DBL;
373
374 ret = arch_kexec_do_relocs(r_type, loc, val, addr);
375 if (ret) {
376 pr_err("Unknown rela relocation: %d\n", r_type);
377 return -ENOEXEC;
378 }
379 }
380 return 0;
381}
382
383int arch_kimage_file_post_load_cleanup(struct kimage *image)
384{
385 vfree(addr: image->arch.ipl_buf);
386 image->arch.ipl_buf = NULL;
387
388 return kexec_image_post_load_cleanup_default(image);
389}
390

source code of linux/arch/s390/kernel/machine_kexec_file.c