Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
5033cba0 | 2 | /* |
62a31a03 | 3 | * Architecture specific (i386/x86_64) functions for kexec based crash dumps. |
5033cba0 EB |
4 | * |
5 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
6 | * | |
7 | * Copyright (C) IBM Corporation, 2004. All rights reserved. | |
dd5f7260 VG |
8 | * Copyright (C) Red Hat Inc., 2014. All rights reserved. |
9 | * Authors: | |
10 | * Vivek Goyal <vgoyal@redhat.com> | |
5033cba0 EB |
11 | * |
12 | */ | |
13 | ||
dd5f7260 VG |
14 | #define pr_fmt(fmt) "kexec: " fmt |
15 | ||
5033cba0 EB |
16 | #include <linux/types.h> |
17 | #include <linux/kernel.h> | |
18 | #include <linux/smp.h> | |
5033cba0 EB |
19 | #include <linux/reboot.h> |
20 | #include <linux/kexec.h> | |
5033cba0 EB |
21 | #include <linux/delay.h> |
22 | #include <linux/elf.h> | |
23 | #include <linux/elfcore.h> | |
186f4360 | 24 | #include <linux/export.h> |
dd5f7260 | 25 | #include <linux/slab.h> |
d6472302 | 26 | #include <linux/vmalloc.h> |
5033cba0 EB |
27 | |
28 | #include <asm/processor.h> | |
29 | #include <asm/hardirq.h> | |
30 | #include <asm/nmi.h> | |
31 | #include <asm/hw_irq.h> | |
19842d67 | 32 | #include <asm/apic.h> |
5520b7e7 | 33 | #include <asm/e820/types.h> |
8643e28d | 34 | #include <asm/io_apic.h> |
0c1b2724 | 35 | #include <asm/hpet.h> |
1eeb66a1 | 36 | #include <linux/kdebug.h> |
96b89dc6 | 37 | #include <asm/cpu.h> |
ed23dc6f | 38 | #include <asm/reboot.h> |
2340b62f | 39 | #include <asm/virtext.h> |
da06a43d | 40 | #include <asm/intel_pt.h> |
89f579ce | 41 | #include <asm/crash.h> |
8e294786 | 42 | |
dd5f7260 VG |
43 | /* Used while preparing memory map entries for second kernel */ |
44 | struct crash_memmap_data { | |
45 | struct boot_params *params; | |
46 | /* Type of memory */ | |
47 | unsigned int type; | |
48 | }; | |
49 | ||
f23d1f4a ZY |
50 | /* |
51 | * This is used to VMCLEAR all VMCSs loaded on the | |
52 | * processor. And when loading kvm_intel module, the | |
53 | * callback function pointer will be assigned. | |
54 | * | |
55 | * protected by rcu. | |
56 | */ | |
0ca0d818 | 57 | crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss = NULL; |
f23d1f4a | 58 | EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss); |
dd5f7260 | 59 | unsigned long crash_zero_bytes; |
f23d1f4a ZY |
60 | |
61 | static inline void cpu_crash_vmclear_loaded_vmcss(void) | |
62 | { | |
0ca0d818 | 63 | crash_vmclear_fn *do_vmclear_operation = NULL; |
f23d1f4a ZY |
64 | |
65 | rcu_read_lock(); | |
66 | do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss); | |
67 | if (do_vmclear_operation) | |
68 | do_vmclear_operation(); | |
69 | rcu_read_unlock(); | |
70 | } | |
71 | ||
b2bbe71b EH |
72 | #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) |
73 | ||
9c48f1c6 | 74 | static void kdump_nmi_callback(int cpu, struct pt_regs *regs) |
c4ac4263 | 75 | { |
1fb473d8 | 76 | #ifdef CONFIG_X86_32 |
4d55476c | 77 | struct pt_regs fixed_regs; |
a7d41820 | 78 | |
f39b6f0e | 79 | if (!user_mode(regs)) { |
a7d41820 EH |
80 | crash_fixup_ss_esp(&fixed_regs, regs); |
81 | regs = &fixed_regs; | |
82 | } | |
83 | #endif | |
84 | crash_save_cpu(regs, cpu); | |
85 | ||
f23d1f4a ZY |
86 | /* |
87 | * VMCLEAR VMCSs loaded on all cpus if needed. | |
88 | */ | |
89 | cpu_crash_vmclear_loaded_vmcss(); | |
90 | ||
2340b62f EH |
91 | /* Disable VMX or SVM if needed. |
92 | * | |
93 | * We need to disable virtualization on all CPUs. | |
94 | * Having VMX or SVM enabled on any CPU may break rebooting | |
95 | * after the kdump kernel has finished its task. | |
96 | */ | |
97 | cpu_emergency_vmxoff(); | |
98 | cpu_emergency_svm_disable(); | |
99 | ||
da06a43d TI |
100 | /* |
101 | * Disable Intel PT to stop its logging | |
102 | */ | |
103 | cpu_emergency_stop_pt(); | |
104 | ||
a7d41820 EH |
105 | disable_local_APIC(); |
106 | } | |
107 | ||
0ee59413 | 108 | void kdump_nmi_shootdown_cpus(void) |
d1e7b91c | 109 | { |
8e294786 | 110 | nmi_shootdown_cpus(kdump_nmi_callback); |
d1e7b91c | 111 | |
19842d67 | 112 | disable_local_APIC(); |
c4ac4263 | 113 | } |
d1e7b91c | 114 | |
0ee59413 HK |
115 | /* Override the weak function in kernel/panic.c */ |
116 | void crash_smp_send_stop(void) | |
117 | { | |
118 | static int cpus_stopped; | |
119 | ||
120 | if (cpus_stopped) | |
121 | return; | |
122 | ||
123 | if (smp_ops.crash_stop_other_cpus) | |
124 | smp_ops.crash_stop_other_cpus(); | |
125 | else | |
126 | smp_send_stop(); | |
127 | ||
128 | cpus_stopped = 1; | |
129 | } | |
130 | ||
c4ac4263 | 131 | #else |
0ee59413 | 132 | void crash_smp_send_stop(void) |
c4ac4263 EB |
133 | { |
134 | /* There are no cpus to shootdown */ | |
135 | } | |
136 | #endif | |
137 | ||
ed23dc6f | 138 | void native_machine_crash_shutdown(struct pt_regs *regs) |
5033cba0 EB |
139 | { |
140 | /* This function is only called after the system | |
f18190bd | 141 | * has panicked or is otherwise in a critical state. |
5033cba0 EB |
142 | * The minimum amount of code to allow a kexec'd kernel |
143 | * to run successfully needs to happen here. | |
144 | * | |
145 | * In practice this means shooting down the other cpus in | |
146 | * an SMP system. | |
147 | */ | |
c4ac4263 EB |
148 | /* The kernel is broken so disable interrupts */ |
149 | local_irq_disable(); | |
a3ea8ac8 | 150 | |
0ee59413 | 151 | crash_smp_send_stop(); |
2340b62f | 152 | |
f23d1f4a ZY |
153 | /* |
154 | * VMCLEAR VMCSs loaded on this cpu if needed. | |
155 | */ | |
156 | cpu_crash_vmclear_loaded_vmcss(); | |
157 | ||
2340b62f EH |
158 | /* Booting kdump kernel with VMX or SVM enabled won't work, |
159 | * because (among other limitations) we can't disable paging | |
160 | * with the virt flags. | |
161 | */ | |
162 | cpu_emergency_vmxoff(); | |
163 | cpu_emergency_svm_disable(); | |
164 | ||
da06a43d TI |
165 | /* |
166 | * Disable Intel PT to stop its logging | |
167 | */ | |
168 | cpu_emergency_stop_pt(); | |
169 | ||
17405453 YY |
170 | #ifdef CONFIG_X86_IO_APIC |
171 | /* Prevent crash_kexec() from deadlocking on ioapic_lock. */ | |
172 | ioapic_zap_locks(); | |
339b2ae0 | 173 | clear_IO_APIC(); |
0c1b2724 | 174 | #endif |
522e6646 | 175 | lapic_shutdown(); |
339b2ae0 | 176 | restore_boot_irq_mode(); |
0c1b2724 OH |
177 | #ifdef CONFIG_HPET_TIMER |
178 | hpet_disable(); | |
19842d67 | 179 | #endif |
85916f81 | 180 | crash_save_cpu(regs, safe_smp_processor_id()); |
5033cba0 | 181 | } |
dd5f7260 | 182 | |
74ca317c | 183 | #ifdef CONFIG_KEXEC_FILE |
1d2e733b | 184 | static int get_nr_ram_ranges_callback(struct resource *res, void *arg) |
dd5f7260 | 185 | { |
e3c41e37 | 186 | unsigned int *nr_ranges = arg; |
dd5f7260 VG |
187 | |
188 | (*nr_ranges)++; | |
189 | return 0; | |
190 | } | |
191 | ||
dd5f7260 | 192 | /* Gather all the required information to prepare elf headers for ram regions */ |
8d5f894a | 193 | static struct crash_mem *fill_up_crash_elf_data(void) |
dd5f7260 VG |
194 | { |
195 | unsigned int nr_ranges = 0; | |
8d5f894a | 196 | struct crash_mem *cmem; |
dd5f7260 | 197 | |
e3c41e37 | 198 | walk_system_ram_res(0, -1, &nr_ranges, |
dd5f7260 | 199 | get_nr_ram_ranges_callback); |
8d5f894a AT |
200 | if (!nr_ranges) |
201 | return NULL; | |
dd5f7260 | 202 | |
8d5f894a AT |
203 | /* |
204 | * Exclusion of crash region and/or crashk_low_res may cause | |
205 | * another range split. So add extra two slots here. | |
206 | */ | |
207 | nr_ranges += 2; | |
4df43095 | 208 | cmem = vzalloc(struct_size(cmem, ranges, nr_ranges)); |
8d5f894a AT |
209 | if (!cmem) |
210 | return NULL; | |
dd5f7260 | 211 | |
8d5f894a AT |
212 | cmem->max_nr_ranges = nr_ranges; |
213 | cmem->nr_ranges = 0; | |
dd5f7260 | 214 | |
8d5f894a | 215 | return cmem; |
dd5f7260 VG |
216 | } |
217 | ||
dd5f7260 VG |
218 | /* |
219 | * Look for any unwanted ranges between mstart, mend and remove them. This | |
8d5f894a | 220 | * might lead to split and split ranges are put in cmem->ranges[] array |
dd5f7260 | 221 | */ |
8d5f894a | 222 | static int elf_header_exclude_ranges(struct crash_mem *cmem) |
dd5f7260 | 223 | { |
dd5f7260 VG |
224 | int ret = 0; |
225 | ||
dd5f7260 | 226 | /* Exclude crashkernel region */ |
babac4a8 | 227 | ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); |
dd5f7260 VG |
228 | if (ret) |
229 | return ret; | |
230 | ||
a2d6aa8f | 231 | if (crashk_low_res.end) { |
babac4a8 AT |
232 | ret = crash_exclude_mem_range(cmem, crashk_low_res.start, |
233 | crashk_low_res.end); | |
a2d6aa8f BH |
234 | if (ret) |
235 | return ret; | |
236 | } | |
dd5f7260 | 237 | |
dd5f7260 VG |
238 | return ret; |
239 | } | |
240 | ||
1d2e733b | 241 | static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) |
dd5f7260 | 242 | { |
8d5f894a | 243 | struct crash_mem *cmem = arg; |
dd5f7260 | 244 | |
cbe66016 AT |
245 | cmem->ranges[cmem->nr_ranges].start = res->start; |
246 | cmem->ranges[cmem->nr_ranges].end = res->end; | |
247 | cmem->nr_ranges++; | |
dd5f7260 | 248 | |
cbe66016 | 249 | return 0; |
dd5f7260 VG |
250 | } |
251 | ||
dd5f7260 VG |
252 | /* Prepare elf headers. Return addr and size */ |
253 | static int prepare_elf_headers(struct kimage *image, void **addr, | |
254 | unsigned long *sz) | |
255 | { | |
8d5f894a | 256 | struct crash_mem *cmem; |
cbe66016 AT |
257 | Elf64_Ehdr *ehdr; |
258 | Elf64_Phdr *phdr; | |
259 | int ret, i; | |
dd5f7260 | 260 | |
8d5f894a AT |
261 | cmem = fill_up_crash_elf_data(); |
262 | if (!cmem) | |
dd5f7260 VG |
263 | return -ENOMEM; |
264 | ||
8d5f894a | 265 | ret = walk_system_ram_res(0, -1, cmem, |
cbe66016 AT |
266 | prepare_elf64_ram_headers_callback); |
267 | if (ret) | |
268 | goto out; | |
269 | ||
270 | /* Exclude unwanted mem ranges */ | |
8d5f894a | 271 | ret = elf_header_exclude_ranges(cmem); |
cbe66016 AT |
272 | if (ret) |
273 | goto out; | |
274 | ||
dd5f7260 | 275 | /* By default prepare 64bit headers */ |
babac4a8 AT |
276 | ret = crash_prepare_elf64_headers(cmem, |
277 | IS_ENABLED(CONFIG_X86_64), addr, sz); | |
cbe66016 AT |
278 | if (ret) |
279 | goto out; | |
280 | ||
281 | /* | |
282 | * If a range matches backup region, adjust offset to backup | |
283 | * segment. | |
284 | */ | |
285 | ehdr = (Elf64_Ehdr *)*addr; | |
286 | phdr = (Elf64_Phdr *)(ehdr + 1); | |
287 | for (i = 0; i < ehdr->e_phnum; phdr++, i++) | |
288 | if (phdr->p_type == PT_LOAD && | |
289 | phdr->p_paddr == image->arch.backup_src_start && | |
290 | phdr->p_memsz == image->arch.backup_src_sz) { | |
291 | phdr->p_offset = image->arch.backup_load_addr; | |
292 | break; | |
293 | } | |
294 | out: | |
8d5f894a | 295 | vfree(cmem); |
dd5f7260 VG |
296 | return ret; |
297 | } | |
298 | ||
8ec67d97 | 299 | static int add_e820_entry(struct boot_params *params, struct e820_entry *entry) |
dd5f7260 VG |
300 | { |
301 | unsigned int nr_e820_entries; | |
302 | ||
303 | nr_e820_entries = params->e820_entries; | |
08b46d5d | 304 | if (nr_e820_entries >= E820_MAX_ENTRIES_ZEROPAGE) |
dd5f7260 VG |
305 | return 1; |
306 | ||
61a50101 | 307 | memcpy(¶ms->e820_table[nr_e820_entries], entry, |
8ec67d97 | 308 | sizeof(struct e820_entry)); |
dd5f7260 VG |
309 | params->e820_entries++; |
310 | return 0; | |
311 | } | |
312 | ||
1d2e733b | 313 | static int memmap_entry_callback(struct resource *res, void *arg) |
dd5f7260 VG |
314 | { |
315 | struct crash_memmap_data *cmd = arg; | |
316 | struct boot_params *params = cmd->params; | |
8ec67d97 | 317 | struct e820_entry ei; |
dd5f7260 | 318 | |
1d2e733b | 319 | ei.addr = res->start; |
9275b933 | 320 | ei.size = resource_size(res); |
dd5f7260 VG |
321 | ei.type = cmd->type; |
322 | add_e820_entry(params, &ei); | |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
327 | static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem, | |
328 | unsigned long long mstart, | |
329 | unsigned long long mend) | |
330 | { | |
331 | unsigned long start, end; | |
332 | int ret = 0; | |
333 | ||
334 | cmem->ranges[0].start = mstart; | |
335 | cmem->ranges[0].end = mend; | |
336 | cmem->nr_ranges = 1; | |
337 | ||
338 | /* Exclude Backup region */ | |
339 | start = image->arch.backup_load_addr; | |
340 | end = start + image->arch.backup_src_sz - 1; | |
babac4a8 | 341 | ret = crash_exclude_mem_range(cmem, start, end); |
dd5f7260 VG |
342 | if (ret) |
343 | return ret; | |
344 | ||
345 | /* Exclude elf header region */ | |
346 | start = image->arch.elf_load_addr; | |
347 | end = start + image->arch.elf_headers_sz - 1; | |
babac4a8 | 348 | return crash_exclude_mem_range(cmem, start, end); |
dd5f7260 VG |
349 | } |
350 | ||
351 | /* Prepare memory map for crash dump kernel */ | |
352 | int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) | |
353 | { | |
354 | int i, ret = 0; | |
355 | unsigned long flags; | |
8ec67d97 | 356 | struct e820_entry ei; |
dd5f7260 VG |
357 | struct crash_memmap_data cmd; |
358 | struct crash_mem *cmem; | |
359 | ||
360 | cmem = vzalloc(sizeof(struct crash_mem)); | |
361 | if (!cmem) | |
362 | return -ENOMEM; | |
363 | ||
364 | memset(&cmd, 0, sizeof(struct crash_memmap_data)); | |
365 | cmd.params = params; | |
366 | ||
367 | /* Add first 640K segment */ | |
368 | ei.addr = image->arch.backup_src_start; | |
369 | ei.size = image->arch.backup_src_sz; | |
09821ff1 | 370 | ei.type = E820_TYPE_RAM; |
dd5f7260 VG |
371 | add_e820_entry(params, &ei); |
372 | ||
373 | /* Add ACPI tables */ | |
09821ff1 | 374 | cmd.type = E820_TYPE_ACPI; |
dd5f7260 | 375 | flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
f0f4711a | 376 | walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1, &cmd, |
dd5f7260 VG |
377 | memmap_entry_callback); |
378 | ||
379 | /* Add ACPI Non-volatile Storage */ | |
09821ff1 | 380 | cmd.type = E820_TYPE_NVS; |
f0f4711a | 381 | walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, &cmd, |
dd5f7260 VG |
382 | memmap_entry_callback); |
383 | ||
384 | /* Add crashk_low_res region */ | |
385 | if (crashk_low_res.end) { | |
386 | ei.addr = crashk_low_res.start; | |
387 | ei.size = crashk_low_res.end - crashk_low_res.start + 1; | |
09821ff1 | 388 | ei.type = E820_TYPE_RAM; |
dd5f7260 VG |
389 | add_e820_entry(params, &ei); |
390 | } | |
391 | ||
392 | /* Exclude some ranges from crashk_res and add rest to memmap */ | |
393 | ret = memmap_exclude_ranges(image, cmem, crashk_res.start, | |
394 | crashk_res.end); | |
395 | if (ret) | |
396 | goto out; | |
397 | ||
398 | for (i = 0; i < cmem->nr_ranges; i++) { | |
399 | ei.size = cmem->ranges[i].end - cmem->ranges[i].start + 1; | |
400 | ||
401 | /* If entry is less than a page, skip it */ | |
402 | if (ei.size < PAGE_SIZE) | |
403 | continue; | |
404 | ei.addr = cmem->ranges[i].start; | |
09821ff1 | 405 | ei.type = E820_TYPE_RAM; |
dd5f7260 VG |
406 | add_e820_entry(params, &ei); |
407 | } | |
408 | ||
409 | out: | |
410 | vfree(cmem); | |
411 | return ret; | |
412 | } | |
413 | ||
1d2e733b | 414 | static int determine_backup_region(struct resource *res, void *arg) |
dd5f7260 VG |
415 | { |
416 | struct kimage *image = arg; | |
417 | ||
1d2e733b | 418 | image->arch.backup_src_start = res->start; |
9275b933 | 419 | image->arch.backup_src_sz = resource_size(res); |
dd5f7260 VG |
420 | |
421 | /* Expecting only one range for backup region */ | |
422 | return 1; | |
423 | } | |
424 | ||
425 | int crash_load_segments(struct kimage *image) | |
426 | { | |
dd5f7260 | 427 | int ret; |
ec2b9bfa TJB |
428 | struct kexec_buf kbuf = { .image = image, .buf_min = 0, |
429 | .buf_max = ULONG_MAX, .top_down = false }; | |
dd5f7260 VG |
430 | |
431 | /* | |
432 | * Determine and load a segment for backup area. First 640K RAM | |
433 | * region is backup source | |
434 | */ | |
435 | ||
436 | ret = walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END, | |
437 | image, determine_backup_region); | |
438 | ||
439 | /* Zero or postive return values are ok */ | |
440 | if (ret < 0) | |
441 | return ret; | |
442 | ||
dd5f7260 | 443 | /* Add backup segment. */ |
ec2b9bfa TJB |
444 | if (image->arch.backup_src_sz) { |
445 | kbuf.buffer = &crash_zero_bytes; | |
446 | kbuf.bufsz = sizeof(crash_zero_bytes); | |
447 | kbuf.memsz = image->arch.backup_src_sz; | |
448 | kbuf.buf_align = PAGE_SIZE; | |
dd5f7260 VG |
449 | /* |
450 | * Ideally there is no source for backup segment. This is | |
451 | * copied in purgatory after crash. Just add a zero filled | |
452 | * segment for now to make sure checksum logic works fine. | |
453 | */ | |
ec2b9bfa | 454 | ret = kexec_add_buffer(&kbuf); |
dd5f7260 VG |
455 | if (ret) |
456 | return ret; | |
ec2b9bfa | 457 | image->arch.backup_load_addr = kbuf.mem; |
dd5f7260 | 458 | pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n", |
ec2b9bfa TJB |
459 | image->arch.backup_load_addr, |
460 | image->arch.backup_src_start, kbuf.memsz); | |
dd5f7260 VG |
461 | } |
462 | ||
463 | /* Prepare elf headers and add a segment */ | |
ec2b9bfa | 464 | ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz); |
dd5f7260 VG |
465 | if (ret) |
466 | return ret; | |
467 | ||
ec2b9bfa TJB |
468 | image->arch.elf_headers = kbuf.buffer; |
469 | image->arch.elf_headers_sz = kbuf.bufsz; | |
dd5f7260 | 470 | |
ec2b9bfa TJB |
471 | kbuf.memsz = kbuf.bufsz; |
472 | kbuf.buf_align = ELF_CORE_HEADER_ALIGN; | |
993a1103 | 473 | kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; |
ec2b9bfa | 474 | ret = kexec_add_buffer(&kbuf); |
dd5f7260 VG |
475 | if (ret) { |
476 | vfree((void *)image->arch.elf_headers); | |
477 | return ret; | |
478 | } | |
ec2b9bfa | 479 | image->arch.elf_load_addr = kbuf.mem; |
dd5f7260 | 480 | pr_debug("Loaded ELF headers at 0x%lx bufsz=0x%lx memsz=0x%lx\n", |
ec2b9bfa | 481 | image->arch.elf_load_addr, kbuf.bufsz, kbuf.bufsz); |
dd5f7260 VG |
482 | |
483 | return ret; | |
484 | } | |
74ca317c | 485 | #endif /* CONFIG_KEXEC_FILE */ |