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
22 const 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
s390_verify_sig(const char * kernel,unsigned long kernel_len)29 int 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(kernel + kernel_len - marker_len, MODULE_SIG_STRING,
44 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(kernel, kernel_len,
70 kernel + kernel_len, sig_len,
71 VERIFY_USE_SECONDARY_KEYRING,
72 VERIFYING_MODULE_SIGNATURE,
73 NULL, NULL);
74 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
75 ret = verify_pkcs7_signature(kernel, kernel_len,
76 kernel + kernel_len, sig_len,
77 VERIFY_USE_PLATFORM_KEYRING,
78 VERIFYING_MODULE_SIGNATURE,
79 NULL, NULL);
80 return ret;
81 }
82 #endif /* CONFIG_KEXEC_SIG */
83
kexec_file_update_purgatory(struct kimage * image,struct s390_load_data * data)84 static 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, "kernel_entry", &entry,
99 sizeof(entry), false);
100 if (ret)
101 return ret;
102
103 ret = kexec_purgatory_get_set_symbol(image, "kernel_type", &type,
104 sizeof(type), false);
105 if (ret)
106 return ret;
107
108 if (image->type == KEXEC_TYPE_CRASH) {
109 u64 crash_size;
110
111 ret = kexec_purgatory_get_set_symbol(image, "crash_start",
112 &crashk_res.start,
113 sizeof(crashk_res.start),
114 false);
115 if (ret)
116 return ret;
117
118 crash_size = crashk_res.end - crashk_res.start + 1;
119 ret = kexec_purgatory_get_set_symbol(image, "crash_size",
120 &crash_size,
121 sizeof(crash_size),
122 false);
123 }
124 return ret;
125 }
126
kexec_file_add_purgatory(struct kimage * image,struct s390_load_data * data)127 static int kexec_file_add_purgatory(struct kimage *image,
128 struct s390_load_data *data)
129 {
130 struct kexec_buf buf;
131 int ret;
132
133 buf.image = image;
134
135 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
136 buf.mem = data->memsz;
137 if (image->type == KEXEC_TYPE_CRASH)
138 buf.mem += crashk_res.start;
139
140 ret = kexec_load_purgatory(image, &buf);
141 if (ret)
142 return ret;
143 data->memsz += buf.memsz;
144
145 return kexec_file_update_purgatory(image, data);
146 }
147
kexec_file_add_initrd(struct kimage * image,struct s390_load_data * data)148 static int kexec_file_add_initrd(struct kimage *image,
149 struct s390_load_data *data)
150 {
151 struct kexec_buf buf;
152 int ret;
153
154 buf.image = image;
155
156 buf.buffer = image->initrd_buf;
157 buf.bufsz = image->initrd_buf_len;
158
159 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
160 buf.mem = data->memsz;
161 if (image->type == KEXEC_TYPE_CRASH)
162 buf.mem += crashk_res.start;
163 buf.memsz = buf.bufsz;
164
165 data->parm->initrd_start = data->memsz;
166 data->parm->initrd_size = buf.memsz;
167 data->memsz += buf.memsz;
168
169 ret = kexec_add_buffer(&buf);
170 if (ret)
171 return ret;
172
173 return ipl_report_add_component(data->report, &buf, 0, 0);
174 }
175
kexec_file_add_ipl_report(struct kimage * image,struct s390_load_data * data)176 static int kexec_file_add_ipl_report(struct kimage *image,
177 struct s390_load_data *data)
178 {
179 __u32 *lc_ipl_parmblock_ptr;
180 unsigned int len, ncerts;
181 struct kexec_buf buf;
182 unsigned long addr;
183 void *ptr, *end;
184 int ret;
185
186 buf.image = image;
187
188 data->memsz = ALIGN(data->memsz, PAGE_SIZE);
189 buf.mem = data->memsz;
190
191 ptr = (void *)ipl_cert_list_addr;
192 end = ptr + ipl_cert_list_size;
193 ncerts = 0;
194 while (ptr < end) {
195 ncerts++;
196 len = *(unsigned int *)ptr;
197 ptr += sizeof(len);
198 ptr += len;
199 }
200
201 addr = data->memsz + data->report->size;
202 addr += ncerts * sizeof(struct ipl_rb_certificate_entry);
203 ptr = (void *)ipl_cert_list_addr;
204 while (ptr < end) {
205 len = *(unsigned int *)ptr;
206 ptr += sizeof(len);
207 ipl_report_add_certificate(data->report, ptr, addr, len);
208 addr += len;
209 ptr += len;
210 }
211
212 ret = -ENOMEM;
213 buf.buffer = ipl_report_finish(data->report);
214 if (!buf.buffer)
215 goto out;
216 buf.bufsz = data->report->size;
217 buf.memsz = buf.bufsz;
218 image->arch.ipl_buf = buf.buffer;
219
220 data->memsz += buf.memsz;
221
222 lc_ipl_parmblock_ptr =
223 data->kernel_buf + offsetof(struct lowcore, ipl_parmblock_ptr);
224 *lc_ipl_parmblock_ptr = (__u32)buf.mem;
225
226 if (image->type == KEXEC_TYPE_CRASH)
227 buf.mem += crashk_res.start;
228
229 ret = kexec_add_buffer(&buf);
230 out:
231 return ret;
232 }
233
kexec_file_add_components(struct kimage * image,int (* add_kernel)(struct kimage * image,struct s390_load_data * data))234 void *kexec_file_add_components(struct kimage *image,
235 int (*add_kernel)(struct kimage *image,
236 struct s390_load_data *data))
237 {
238 unsigned long max_command_line_size = LEGACY_COMMAND_LINE_SIZE;
239 struct s390_load_data data = {0};
240 unsigned long minsize;
241 int ret;
242
243 data.report = ipl_report_init(&ipl_block);
244 if (IS_ERR(data.report))
245 return data.report;
246
247 ret = add_kernel(image, &data);
248 if (ret)
249 goto out;
250
251 ret = -EINVAL;
252 minsize = PARMAREA + offsetof(struct parmarea, command_line);
253 if (image->kernel_buf_len < minsize)
254 goto out;
255
256 if (data.parm->max_command_line_size)
257 max_command_line_size = data.parm->max_command_line_size;
258
259 if (minsize + max_command_line_size < minsize)
260 goto out;
261
262 if (image->kernel_buf_len < minsize + max_command_line_size)
263 goto out;
264
265 if (image->cmdline_buf_len >= max_command_line_size)
266 goto out;
267
268 memcpy(data.parm->command_line, image->cmdline_buf,
269 image->cmdline_buf_len);
270
271 if (image->type == KEXEC_TYPE_CRASH) {
272 data.parm->oldmem_base = crashk_res.start;
273 data.parm->oldmem_size = crashk_res.end - crashk_res.start + 1;
274 }
275
276 if (image->initrd_buf) {
277 ret = kexec_file_add_initrd(image, &data);
278 if (ret)
279 goto out;
280 }
281
282 ret = kexec_file_add_purgatory(image, &data);
283 if (ret)
284 goto out;
285
286 if (data.kernel_mem == 0) {
287 unsigned long restart_psw = 0x0008000080000000UL;
288 restart_psw += image->start;
289 memcpy(data.kernel_buf, &restart_psw, sizeof(restart_psw));
290 image->start = 0;
291 }
292
293 ret = kexec_file_add_ipl_report(image, &data);
294 out:
295 ipl_report_free(data.report);
296 return ERR_PTR(ret);
297 }
298
arch_kexec_apply_relocations_add(struct purgatory_info * pi,Elf_Shdr * section,const Elf_Shdr * relsec,const Elf_Shdr * symtab)299 int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
300 Elf_Shdr *section,
301 const Elf_Shdr *relsec,
302 const Elf_Shdr *symtab)
303 {
304 const char *strtab, *name, *shstrtab;
305 const Elf_Shdr *sechdrs;
306 Elf_Rela *relas;
307 int i, r_type;
308 int ret;
309
310 /* String & section header string table */
311 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
312 strtab = (char *)pi->ehdr + sechdrs[symtab->sh_link].sh_offset;
313 shstrtab = (char *)pi->ehdr + sechdrs[pi->ehdr->e_shstrndx].sh_offset;
314
315 relas = (void *)pi->ehdr + relsec->sh_offset;
316
317 for (i = 0; i < relsec->sh_size / sizeof(*relas); i++) {
318 const Elf_Sym *sym; /* symbol to relocate */
319 unsigned long addr; /* final location after relocation */
320 unsigned long val; /* relocated symbol value */
321 void *loc; /* tmp location to modify */
322
323 sym = (void *)pi->ehdr + symtab->sh_offset;
324 sym += ELF64_R_SYM(relas[i].r_info);
325
326 if (sym->st_name)
327 name = strtab + sym->st_name;
328 else
329 name = shstrtab + sechdrs[sym->st_shndx].sh_name;
330
331 if (sym->st_shndx == SHN_UNDEF) {
332 pr_err("Undefined symbol: %s\n", name);
333 return -ENOEXEC;
334 }
335
336 if (sym->st_shndx == SHN_COMMON) {
337 pr_err("symbol '%s' in common section\n", name);
338 return -ENOEXEC;
339 }
340
341 if (sym->st_shndx >= pi->ehdr->e_shnum &&
342 sym->st_shndx != SHN_ABS) {
343 pr_err("Invalid section %d for symbol %s\n",
344 sym->st_shndx, name);
345 return -ENOEXEC;
346 }
347
348 loc = pi->purgatory_buf;
349 loc += section->sh_offset;
350 loc += relas[i].r_offset;
351
352 val = sym->st_value;
353 if (sym->st_shndx != SHN_ABS)
354 val += pi->sechdrs[sym->st_shndx].sh_addr;
355 val += relas[i].r_addend;
356
357 addr = section->sh_addr + relas[i].r_offset;
358
359 r_type = ELF64_R_TYPE(relas[i].r_info);
360
361 if (r_type == R_390_PLT32DBL)
362 r_type = R_390_PC32DBL;
363
364 ret = arch_kexec_do_relocs(r_type, loc, val, addr);
365 if (ret) {
366 pr_err("Unknown rela relocation: %d\n", r_type);
367 return -ENOEXEC;
368 }
369 }
370 return 0;
371 }
372
arch_kimage_file_post_load_cleanup(struct kimage * image)373 int arch_kimage_file_post_load_cleanup(struct kimage *image)
374 {
375 vfree(image->arch.ipl_buf);
376 image->arch.ipl_buf = NULL;
377
378 return kexec_image_post_load_cleanup_default(image);
379 }
380