diff options
Diffstat (limited to 'kernel/kexec_core.c')
| -rw-r--r-- | kernel/kexec_core.c | 250 |
1 files changed, 12 insertions, 238 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index d08fc7b5db97..ce3429e7972c 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -54,30 +54,6 @@ bool kexec_in_progress = false; bool kexec_file_dbg_print; -int kexec_should_crash(struct task_struct *p) -{ - /* - * If crash_kexec_post_notifiers is enabled, don't run - * crash_kexec() here yet, which must be run after panic - * notifiers in panic(). - */ - if (crash_kexec_post_notifiers) - return 0; - /* - * There are 4 panic() calls in make_task_dead() path, each of which - * corresponds to each of these 4 conditions. - */ - if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) - return 1; - return 0; -} - -int kexec_crash_loaded(void) -{ - return !!kexec_crash_image; -} -EXPORT_SYMBOL_GPL(kexec_crash_loaded); - /* * When kexec transitions to the new kernel there is a one-to-one * mapping between physical and virtual addresses. On processors @@ -209,6 +185,7 @@ int sanity_check_segment_list(struct kimage *image) if (total_pages > nr_pages / 2) return -EINVAL; +#ifdef CONFIG_CRASH_DUMP /* * Verify we have good destination addresses. Normally * the caller is responsible for making certain we don't @@ -231,6 +208,7 @@ int sanity_check_segment_list(struct kimage *image) return -EADDRNOTAVAIL; } } +#endif return 0; } @@ -403,6 +381,7 @@ static struct page *kimage_alloc_normal_control_pages(struct kimage *image, return pages; } +#ifdef CONFIG_CRASH_DUMP static struct page *kimage_alloc_crash_control_pages(struct kimage *image, unsigned int order) { @@ -468,6 +447,7 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image, return pages; } +#endif struct page *kimage_alloc_control_pages(struct kimage *image, @@ -479,48 +459,16 @@ struct page *kimage_alloc_control_pages(struct kimage *image, case KEXEC_TYPE_DEFAULT: pages = kimage_alloc_normal_control_pages(image, order); break; +#ifdef CONFIG_CRASH_DUMP case KEXEC_TYPE_CRASH: pages = kimage_alloc_crash_control_pages(image, order); break; +#endif } return pages; } -int kimage_crash_copy_vmcoreinfo(struct kimage *image) -{ - struct page *vmcoreinfo_page; - void *safecopy; - - if (image->type != KEXEC_TYPE_CRASH) - return 0; - - /* - * For kdump, allocate one vmcoreinfo safe copy from the - * crash memory. as we have arch_kexec_protect_crashkres() - * after kexec syscall, we naturally protect it from write - * (even read) access under kernel direct mapping. But on - * the other hand, we still need to operate it when crash - * happens to generate vmcoreinfo note, hereby we rely on - * vmap for this purpose. - */ - vmcoreinfo_page = kimage_alloc_control_pages(image, 0); - if (!vmcoreinfo_page) { - pr_warn("Could not allocate vmcoreinfo buffer\n"); - return -ENOMEM; - } - safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL); - if (!safecopy) { - pr_warn("Could not vmap vmcoreinfo buffer\n"); - return -ENOMEM; - } - - image->vmcoreinfo_data_copy = safecopy; - crash_update_vmcoreinfo_safecopy(safecopy); - - return 0; -} - static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) { if (*image->entry != 0) @@ -603,10 +551,12 @@ void kimage_free(struct kimage *image) if (!image) return; +#ifdef CONFIG_CRASH_DUMP if (image->vmcoreinfo_data_copy) { crash_update_vmcoreinfo_safecopy(NULL); vunmap(image->vmcoreinfo_data_copy); } +#endif kimage_free_extra_pages(image); for_each_kimage_entry(image, ptr, entry) { @@ -824,6 +774,7 @@ out: return result; } +#ifdef CONFIG_CRASH_DUMP static int kimage_load_crash_segment(struct kimage *image, struct kexec_segment *segment) { @@ -891,6 +842,7 @@ static int kimage_load_crash_segment(struct kimage *image, out: return result; } +#endif int kimage_load_segment(struct kimage *image, struct kexec_segment *segment) @@ -901,9 +853,11 @@ int kimage_load_segment(struct kimage *image, case KEXEC_TYPE_DEFAULT: result = kimage_load_normal_segment(image, segment); break; +#ifdef CONFIG_CRASH_DUMP case KEXEC_TYPE_CRASH: result = kimage_load_crash_segment(image, segment); break; +#endif } return result; @@ -1028,186 +982,6 @@ bool kexec_load_permitted(int kexec_image_type) } /* - * No panic_cpu check version of crash_kexec(). This function is called - * only when panic_cpu holds the current CPU number; this is the only CPU - * which processes crash_kexec routines. - */ -void __noclone __crash_kexec(struct pt_regs *regs) -{ - /* Take the kexec_lock here to prevent sys_kexec_load - * running on one cpu from replacing the crash kernel - * we are using after a panic on a different cpu. - * - * If the crash kernel was not located in a fixed area - * of memory the xchg(&kexec_crash_image) would be - * sufficient. But since I reuse the memory... - */ - if (kexec_trylock()) { - if (kexec_crash_image) { - struct pt_regs fixed_regs; - - crash_setup_regs(&fixed_regs, regs); - crash_save_vmcoreinfo(); - machine_crash_shutdown(&fixed_regs); - machine_kexec(kexec_crash_image); - } - kexec_unlock(); - } -} -STACK_FRAME_NON_STANDARD(__crash_kexec); - -__bpf_kfunc void crash_kexec(struct pt_regs *regs) -{ - int old_cpu, this_cpu; - - /* - * Only one CPU is allowed to execute the crash_kexec() code as with - * panic(). Otherwise parallel calls of panic() and crash_kexec() - * may stop each other. To exclude them, we use panic_cpu here too. - */ - old_cpu = PANIC_CPU_INVALID; - this_cpu = raw_smp_processor_id(); - - if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) { - /* This is the 1st CPU which comes here, so go ahead. */ - __crash_kexec(regs); - - /* - * Reset panic_cpu to allow another panic()/crash_kexec() - * call. - */ - atomic_set(&panic_cpu, PANIC_CPU_INVALID); - } -} - -static inline resource_size_t crash_resource_size(const struct resource *res) -{ - return !res->end ? 0 : resource_size(res); -} - -ssize_t crash_get_memory_size(void) -{ - ssize_t size = 0; - - if (!kexec_trylock()) - return -EBUSY; - - size += crash_resource_size(&crashk_res); - size += crash_resource_size(&crashk_low_res); - - kexec_unlock(); - return size; -} - -static int __crash_shrink_memory(struct resource *old_res, - unsigned long new_size) -{ - struct resource *ram_res; - - ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); - if (!ram_res) - return -ENOMEM; - - ram_res->start = old_res->start + new_size; - ram_res->end = old_res->end; - ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; - ram_res->name = "System RAM"; - - if (!new_size) { - release_resource(old_res); - old_res->start = 0; - old_res->end = 0; - } else { - crashk_res.end = ram_res->start - 1; - } - - crash_free_reserved_phys_range(ram_res->start, ram_res->end); - insert_resource(&iomem_resource, ram_res); - - return 0; -} - -int crash_shrink_memory(unsigned long new_size) -{ - int ret = 0; - unsigned long old_size, low_size; - - if (!kexec_trylock()) - return -EBUSY; - - if (kexec_crash_image) { - ret = -ENOENT; - goto unlock; - } - - low_size = crash_resource_size(&crashk_low_res); - old_size = crash_resource_size(&crashk_res) + low_size; - new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN); - if (new_size >= old_size) { - ret = (new_size == old_size) ? 0 : -EINVAL; - goto unlock; - } - - /* - * (low_size > new_size) implies that low_size is greater than zero. - * This also means that if low_size is zero, the else branch is taken. - * - * If low_size is greater than 0, (low_size > new_size) indicates that - * crashk_low_res also needs to be shrunken. Otherwise, only crashk_res - * needs to be shrunken. - */ - if (low_size > new_size) { - ret = __crash_shrink_memory(&crashk_res, 0); - if (ret) - goto unlock; - - ret = __crash_shrink_memory(&crashk_low_res, new_size); - } else { - ret = __crash_shrink_memory(&crashk_res, new_size - low_size); - } - - /* Swap crashk_res and crashk_low_res if needed */ - if (!crashk_res.end && crashk_low_res.end) { - crashk_res.start = crashk_low_res.start; - crashk_res.end = crashk_low_res.end; - release_resource(&crashk_low_res); - crashk_low_res.start = 0; - crashk_low_res.end = 0; - insert_resource(&iomem_resource, &crashk_res); - } - -unlock: - kexec_unlock(); - return ret; -} - -void crash_save_cpu(struct pt_regs *regs, int cpu) -{ - struct elf_prstatus prstatus; - u32 *buf; - - if ((cpu < 0) || (cpu >= nr_cpu_ids)) - return; - - /* Using ELF notes here is opportunistic. - * I need a well defined structure format - * for the data I pass, and I need tags - * on the data to indicate what information I have - * squirrelled away. ELF notes happen to provide - * all of that, so there is no need to invent something new. - */ - buf = (u32 *)per_cpu_ptr(crash_notes, cpu); - if (!buf) - return; - memset(&prstatus, 0, sizeof(prstatus)); - prstatus.common.pr_pid = current->pid; - elf_core_copy_regs(&prstatus.pr_reg, regs); - buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, - &prstatus, sizeof(prstatus)); - final_note(buf); -} - -/* * Move into place and start executing a preloaded standalone * executable. If nothing was preloaded return an error. */ |