| /* |
| * kexec.c - kexec system call core code. |
| * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> |
| * |
| * This source code is licensed under the GNU General Public License, |
| * Version 2. See the file COPYING for more details. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/capability.h> |
| #include <linux/mm.h> |
| #include <linux/file.h> |
| #include <linux/slab.h> |
| #include <linux/fs.h> |
| #include <linux/kexec.h> |
| #include <linux/mutex.h> |
| #include <linux/list.h> |
| #include <linux/highmem.h> |
| #include <linux/syscalls.h> |
| #include <linux/reboot.h> |
| #include <linux/ioport.h> |
| #include <linux/hardirq.h> |
| #include <linux/elf.h> |
| #include <linux/elfcore.h> |
| #include <linux/utsname.h> |
| #include <linux/numa.h> |
| #include <linux/suspend.h> |
| #include <linux/device.h> |
| #include <linux/freezer.h> |
| #include <linux/pm.h> |
| #include <linux/cpu.h> |
| #include <linux/uaccess.h> |
| #include <linux/io.h> |
| #include <linux/console.h> |
| #include <linux/vmalloc.h> |
| #include <linux/swap.h> |
| #include <linux/syscore_ops.h> |
| #include <linux/compiler.h> |
| #include <linux/hugetlb.h> |
| |
| #include <asm/page.h> |
| #include <asm/sections.h> |
| |
| #include <crypto/hash.h> |
| #include <crypto/sha.h> |
| #include "kexec_internal.h" |
| |
| DEFINE_MUTEX(kexec_mutex); |
| |
| /* Per cpu memory for storing cpu states in case of system crash. */ |
| note_buf_t __percpu *crash_notes; |
| |
| /* vmcoreinfo stuff */ |
| static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; |
| u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; |
| size_t vmcoreinfo_size; |
| size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); |
| |
| /* Flag to indicate we are going to kexec a new kernel */ |
| bool kexec_in_progress = false; |
| |
| |
| /* Location of the reserved area for the crash kernel */ |
| struct resource crashk_res = { |
| .name = "Crash kernel", |
| .start = 0, |
| .end = 0, |
| .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
| .desc = IORES_DESC_CRASH_KERNEL |
| }; |
| struct resource crashk_low_res = { |
| .name = "Crash kernel", |
| .start = 0, |
| .end = 0, |
| .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
| .desc = IORES_DESC_CRASH_KERNEL |
| }; |
| |
| 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 do_exit() 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 |
| * where you can disable the MMU this is trivial, and easy. For |
| * others it is still a simple predictable page table to setup. |
| * |
| * In that environment kexec copies the new kernel to its final |
| * resting place. This means I can only support memory whose |
| * physical address can fit in an unsigned long. In particular |
| * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. |
| * If the assembly stub has more restrictive requirements |
| * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be |
| * defined more restrictively in <asm/kexec.h>. |
| * |
| * The code for the transition from the current kernel to the |
| * the new kernel is placed in the control_code_buffer, whose size |
| * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single |
| * page of memory is necessary, but some architectures require more. |
| * Because this memory must be identity mapped in the transition from |
| * virtual to physical addresses it must live in the range |
| * 0 - TASK_SIZE, as only the user space mappings are arbitrarily |
| * modifiable. |
| * |
| * The assembly stub in the control code buffer is passed a linked list |
| * of descriptor pages detailing the source pages of the new kernel, |
| * and the destination addresses of those source pages. As this data |
| * structure is not used in the context of the current OS, it must |
| * be self-contained. |
| * |
| * The code has been made to work with highmem pages and will use a |
| * destination page in its final resting place (if it happens |
| * to allocate it). The end product of this is that most of the |
| * physical address space, and most of RAM can be used. |
| * |
| * Future directions include: |
| * - allocating a page table with the control code buffer identity |
| * mapped, to simplify machine_kexec and make kexec_on_panic more |
| * reliable. |
| */ |
| |
| /* |
| * KIMAGE_NO_DEST is an impossible destination address..., for |
| * allocating pages whose destination address we do not care about. |
| */ |
| #define KIMAGE_NO_DEST (-1UL) |
| #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) |
| |
| static struct page *kimage_alloc_page(struct kimage *image, |
| gfp_t gfp_mask, |
| unsigned long dest); |
| |
| int sanity_check_segment_list(struct kimage *image) |
| { |
| int i; |
| unsigned long nr_segments = image->nr_segments; |
| unsigned long total_pages = 0; |
| |
| /* |
| * Verify we have good destination addresses. The caller is |
| * responsible for making certain we don't attempt to load |
| * the new image into invalid or reserved areas of RAM. This |
| * just verifies it is an address we can use. |
| * |
| * Since the kernel does everything in page size chunks ensure |
| * the destination addresses are page aligned. Too many |
| * special cases crop of when we don't do this. The most |
| * insidious is getting overlapping destination addresses |
| * simply because addresses are changed to page size |
| * granularity. |
| */ |
| for (i = 0; i < nr_segments; i++) { |
| unsigned long mstart, mend; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz; |
| if (mstart > mend) |
| return -EADDRNOTAVAIL; |
| if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) |
| return -EADDRNOTAVAIL; |
| if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) |
| return -EADDRNOTAVAIL; |
| } |
| |
| /* Verify our destination addresses do not overlap. |
| * If we alloed overlapping destination addresses |
| * through very weird things can happen with no |
| * easy explanation as one segment stops on another. |
| */ |
| for (i = 0; i < nr_segments; i++) { |
| unsigned long mstart, mend; |
| unsigned long j; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz; |
| for (j = 0; j < i; j++) { |
| unsigned long pstart, pend; |
| |
| pstart = image->segment[j].mem; |
| pend = pstart + image->segment[j].memsz; |
| /* Do the segments overlap ? */ |
| if ((mend > pstart) && (mstart < pend)) |
| return -EINVAL; |
| } |
| } |
| |
| /* Ensure our buffer sizes are strictly less than |
| * our memory sizes. This should always be the case, |
| * and it is easier to check up front than to be surprised |
| * later on. |
| */ |
| for (i = 0; i < nr_segments; i++) { |
| if (image->segment[i].bufsz > image->segment[i].memsz) |
| return -EINVAL; |
| } |
| |
| /* |
| * Verify that no more than half of memory will be consumed. If the |
| * request from userspace is too large, a large amount of time will be |
| * wasted allocating pages, which can cause a soft lockup. |
| */ |
| for (i = 0; i < nr_segments; i++) { |
| if (PAGE_COUNT(image->segment[i].memsz) > totalram_pages / 2) |
| return -EINVAL; |
| |
| total_pages += PAGE_COUNT(image->segment[i].memsz); |
| } |
| |
| if (total_pages > totalram_pages / 2) |
| return -EINVAL; |
| |
| /* |
| * Verify we have good destination addresses. Normally |
| * the caller is responsible for making certain we don't |
| * attempt to load the new image into invalid or reserved |
| * areas of RAM. But crash kernels are preloaded into a |
| * reserved area of ram. We must ensure the addresses |
| * are in the reserved area otherwise preloading the |
| * kernel could corrupt things. |
| */ |
| |
| if (image->type == KEXEC_TYPE_CRASH) { |
| for (i = 0; i < nr_segments; i++) { |
| unsigned long mstart, mend; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz - 1; |
| /* Ensure we are within the crash kernel limits */ |
| if ((mstart < phys_to_boot_phys(crashk_res.start)) || |
| (mend > phys_to_boot_phys(crashk_res.end))) |
| return -EADDRNOTAVAIL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| struct kimage *do_kimage_alloc_init(void) |
| { |
| struct kimage *image; |
| |
| /* Allocate a controlling structure */ |
| image = kzalloc(sizeof(*image), GFP_KERNEL); |
| if (!image) |
| return NULL; |
| |
| image->head = 0; |
| image->entry = &image->head; |
| image->last_entry = &image->head; |
| image->control_page = ~0; /* By default this does not apply */ |
| image->type = KEXEC_TYPE_DEFAULT; |
| |
| /* Initialize the list of control pages */ |
| INIT_LIST_HEAD(&image->control_pages); |
| |
| /* Initialize the list of destination pages */ |
| INIT_LIST_HEAD(&image->dest_pages); |
| |
| /* Initialize the list of unusable pages */ |
| INIT_LIST_HEAD(&image->unusable_pages); |
| |
| return image; |
| } |
| |
| int kimage_is_destination_range(struct kimage *image, |
| unsigned long start, |
| unsigned long end) |
| { |
| unsigned long i; |
| |
| for (i = 0; i < image->nr_segments; i++) { |
| unsigned long mstart, mend; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz; |
| if ((end > mstart) && (start < mend)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) |
| { |
| struct page *pages; |
| |
| pages = alloc_pages(gfp_mask, order); |
| if (pages) { |
| unsigned int count, i; |
| |
| pages->mapping = NULL; |
| set_page_private(pages, order); |
| count = 1 << order; |
| for (i = 0; i < count; i++) |
| SetPageReserved(pages + i); |
| } |
| |
| return pages; |
| } |
| |
| static void kimage_free_pages(struct page *page) |
| { |
| unsigned int order, count, i; |
| |
| order = page_private(page); |
| count = 1 << order; |
| for (i = 0; i < count; i++) |
| ClearPageReserved(page + i); |
| __free_pages(page, order); |
| } |
| |
| void kimage_free_page_list(struct list_head *list) |
| { |
| struct page *page, *next; |
| |
| list_for_each_entry_safe(page, next, list, lru) { |
| list_del(&page->lru); |
| kimage_free_pages(page); |
| } |
| } |
| |
| static struct page *kimage_alloc_normal_control_pages(struct kimage *image, |
| unsigned int order) |
| { |
| /* Control pages are special, they are the intermediaries |
| * that are needed while we copy the rest of the pages |
| * to their final resting place. As such they must |
| * not conflict with either the destination addresses |
| * or memory the kernel is already using. |
| * |
| * The only case where we really need more than one of |
| * these are for architectures where we cannot disable |
| * the MMU and must instead generate an identity mapped |
| * page table for all of the memory. |
| * |
| * At worst this runs in O(N) of the image size. |
| */ |
| struct list_head extra_pages; |
| struct page *pages; |
| unsigned int count; |
| |
| count = 1 << order; |
| INIT_LIST_HEAD(&extra_pages); |
| |
| /* Loop while I can allocate a page and the page allocated |
| * is a destination page. |
| */ |
| do { |
| unsigned long pfn, epfn, addr, eaddr; |
| |
| pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order); |
| if (!pages) |
| break; |
| pfn = page_to_boot_pfn(pages); |
| epfn = pfn + count; |
| addr = pfn << PAGE_SHIFT; |
| eaddr = epfn << PAGE_SHIFT; |
| if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || |
| kimage_is_destination_range(image, addr, eaddr)) { |
| list_add(&pages->lru, &extra_pages); |
| pages = NULL; |
| } |
| } while (!pages); |
| |
| if (pages) { |
| /* Remember the allocated page... */ |
| list_add(&pages->lru, &image->control_pages); |
| |
| /* Because the page is already in it's destination |
| * location we will never allocate another page at |
| * that address. Therefore kimage_alloc_pages |
| * will not return it (again) and we don't need |
| * to give it an entry in image->segment[]. |
| */ |
| } |
| /* Deal with the destination pages I have inadvertently allocated. |
| * |
| * Ideally I would convert multi-page allocations into single |
| * page allocations, and add everything to image->dest_pages. |
| * |
| * For now it is simpler to just free the pages. |
| */ |
| kimage_free_page_list(&extra_pages); |
| |
| return pages; |
| } |
| |
| static struct page *kimage_alloc_crash_control_pages(struct kimage *image, |
| unsigned int order) |
| { |
| /* Control pages are special, they are the intermediaries |
| * that are needed while we copy the rest of the pages |
| * to their final resting place. As such they must |
| * not conflict with either the destination addresses |
| * or memory the kernel is already using. |
| * |
| * Control pages are also the only pags we must allocate |
| * when loading a crash kernel. All of the other pages |
| * are specified by the segments and we just memcpy |
| * into them directly. |
| * |
| * The only case where we really need more than one of |
| * these are for architectures where we cannot disable |
| * the MMU and must instead generate an identity mapped |
| * page table for all of the memory. |
| * |
| * Given the low demand this implements a very simple |
| * allocator that finds the first hole of the appropriate |
| * size in the reserved memory region, and allocates all |
| * of the memory up to and including the hole. |
| */ |
| unsigned long hole_start, hole_end, size; |
| struct page *pages; |
| |
| pages = NULL; |
| size = (1 << order) << PAGE_SHIFT; |
| hole_start = (image->control_page + (size - 1)) & ~(size - 1); |
| hole_end = hole_start + size - 1; |
| while (hole_end <= crashk_res.end) { |
| unsigned long i; |
| |
| cond_resched(); |
| |
| if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) |
| break; |
| /* See if I overlap any of the segments */ |
| for (i = 0; i < image->nr_segments; i++) { |
| unsigned long mstart, mend; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz - 1; |
| if ((hole_end >= mstart) && (hole_start <= mend)) { |
| /* Advance the hole to the end of the segment */ |
| hole_start = (mend + (size - 1)) & ~(size - 1); |
| hole_end = hole_start + size - 1; |
| break; |
| } |
| } |
| /* If I don't overlap any segments I have found my hole! */ |
| if (i == image->nr_segments) { |
| pages = pfn_to_page(hole_start >> PAGE_SHIFT); |
| image->control_page = hole_end; |
| break; |
| } |
| } |
| |
| return pages; |
| } |
| |
| |
| struct page *kimage_alloc_control_pages(struct kimage *image, |
| unsigned int order) |
| { |
| struct page *pages = NULL; |
| |
| switch (image->type) { |
| case KEXEC_TYPE_DEFAULT: |
| pages = kimage_alloc_normal_control_pages(image, order); |
| break; |
| case KEXEC_TYPE_CRASH: |
| pages = kimage_alloc_crash_control_pages(image, order); |
| break; |
| } |
| |
| return pages; |
| } |
| |
| static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) |
| { |
| if (*image->entry != 0) |
| image->entry++; |
| |
| if (image->entry == image->last_entry) { |
| kimage_entry_t *ind_page; |
| struct page *page; |
| |
| page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); |
| if (!page) |
| return -ENOMEM; |
| |
| ind_page = page_address(page); |
| *image->entry = virt_to_boot_phys(ind_page) | IND_INDIRECTION; |
| image->entry = ind_page; |
| image->last_entry = ind_page + |
| ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); |
| } |
| *image->entry = entry; |
| image->entry++; |
| *image->entry = 0; |
| |
| return 0; |
| } |
| |
| static int kimage_set_destination(struct kimage *image, |
| unsigned long destination) |
| { |
| int result; |
| |
| destination &= PAGE_MASK; |
| result = kimage_add_entry(image, destination | IND_DESTINATION); |
| |
| return result; |
| } |
| |
| |
| static int kimage_add_page(struct kimage *image, unsigned long page) |
| { |
| int result; |
| |
| page &= PAGE_MASK; |
| result = kimage_add_entry(image, page | IND_SOURCE); |
| |
| return result; |
| } |
| |
| |
| static void kimage_free_extra_pages(struct kimage *image) |
| { |
| /* Walk through and free any extra destination pages I may have */ |
| kimage_free_page_list(&image->dest_pages); |
| |
| /* Walk through and free any unusable pages I have cached */ |
| kimage_free_page_list(&image->unusable_pages); |
| |
| } |
| void kimage_terminate(struct kimage *image) |
| { |
| if (*image->entry != 0) |
| image->entry++; |
| |
| *image->entry = IND_DONE; |
| } |
| |
| #define for_each_kimage_entry(image, ptr, entry) \ |
| for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ |
| ptr = (entry & IND_INDIRECTION) ? \ |
| boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) |
| |
| static void kimage_free_entry(kimage_entry_t entry) |
| { |
| struct page *page; |
| |
| page = boot_pfn_to_page(entry >> PAGE_SHIFT); |
| kimage_free_pages(page); |
| } |
| |
| void kimage_free(struct kimage *image) |
| { |
| kimage_entry_t *ptr, entry; |
| kimage_entry_t ind = 0; |
| |
| if (!image) |
| return; |
| |
| kimage_free_extra_pages(image); |
| for_each_kimage_entry(image, ptr, entry) { |
| if (entry & IND_INDIRECTION) { |
| /* Free the previous indirection page */ |
| if (ind & IND_INDIRECTION) |
| kimage_free_entry(ind); |
| /* Save this indirection page until we are |
| * done with it. |
| */ |
| ind = entry; |
| } else if (entry & IND_SOURCE) |
| kimage_free_entry(entry); |
| } |
| /* Free the final indirection page */ |
| if (ind & IND_INDIRECTION) |
| kimage_free_entry(ind); |
| |
| /* Handle any machine specific cleanup */ |
| machine_kexec_cleanup(image); |
| |
| /* Free the kexec control pages... */ |
| kimage_free_page_list(&image->control_pages); |
| |
| /* |
| * Free up any temporary buffers allocated. This might hit if |
| * error occurred much later after buffer allocation. |
| */ |
| if (image->file_mode) |
| kimage_file_post_load_cleanup(image); |
| |
| kfree(image); |
| } |
| |
| static kimage_entry_t *kimage_dst_used(struct kimage *image, |
| unsigned long page) |
| { |
| kimage_entry_t *ptr, entry; |
| unsigned long destination = 0; |
| |
| for_each_kimage_entry(image, ptr, entry) { |
| if (entry & IND_DESTINATION) |
| destination = entry & PAGE_MASK; |
| else if (entry & IND_SOURCE) { |
| if (page == destination) |
| return ptr; |
| destination += PAGE_SIZE; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static struct page *kimage_alloc_page(struct kimage *image, |
| gfp_t gfp_mask, |
| unsigned long destination) |
| { |
| /* |
| * Here we implement safeguards to ensure that a source page |
| * is not copied to its destination page before the data on |
| * the destination page is no longer useful. |
| * |
| * To do this we maintain the invariant that a source page is |
| * either its own destination page, or it is not a |
| * destination page at all. |
| * |
| * That is slightly stronger than required, but the proof |
| * that no problems will not occur is trivial, and the |
| * implementation is simply to verify. |
| * |
| * When allocating all pages normally this algorithm will run |
| * in O(N) time, but in the worst case it will run in O(N^2) |
| * time. If the runtime is a problem the data structures can |
| * be fixed. |
| */ |
| struct page *page; |
| unsigned long addr; |
| |
| /* |
| * Walk through the list of destination pages, and see if I |
| * have a match. |
| */ |
| list_for_each_entry(page, &image->dest_pages, lru) { |
| addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
| if (addr == destination) { |
| list_del(&page->lru); |
| return page; |
| } |
| } |
| page = NULL; |
| while (1) { |
| kimage_entry_t *old; |
| |
| /* Allocate a page, if we run out of memory give up */ |
| page = kimage_alloc_pages(gfp_mask, 0); |
| if (!page) |
| return NULL; |
| /* If the page cannot be used file it away */ |
| if (page_to_boot_pfn(page) > |
| (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { |
| list_add(&page->lru, &image->unusable_pages); |
| continue; |
| } |
| addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
| |
| /* If it is the destination page we want use it */ |
| if (addr == destination) |
| break; |
| |
| /* If the page is not a destination page use it */ |
| if (!kimage_is_destination_range(image, addr, |
| addr + PAGE_SIZE)) |
| break; |
| |
| /* |
| * I know that the page is someones destination page. |
| * See if there is already a source page for this |
| * destination page. And if so swap the source pages. |
| */ |
| old = kimage_dst_used(image, addr); |
| if (old) { |
| /* If so move it */ |
| unsigned long old_addr; |
| struct page *old_page; |
| |
| old_addr = *old & PAGE_MASK; |
| old_page = boot_pfn_to_page(old_addr >> PAGE_SHIFT); |
| copy_highpage(page, old_page); |
| *old = addr | (*old & ~PAGE_MASK); |
| |
| /* The old page I have found cannot be a |
| * destination page, so return it if it's |
| * gfp_flags honor the ones passed in. |
| */ |
| if (!(gfp_mask & __GFP_HIGHMEM) && |
| PageHighMem(old_page)) { |
| kimage_free_pages(old_page); |
| continue; |
| } |
| addr = old_addr; |
| page = old_page; |
| break; |
| } |
| /* Place the page on the destination list, to be used later */ |
| list_add(&page->lru, &image->dest_pages); |
| } |
| |
| return page; |
| } |
| |
| static int kimage_load_normal_segment(struct kimage *image, |
| struct kexec_segment *segment) |
| { |
| unsigned long maddr; |
| size_t ubytes, mbytes; |
| int result; |
| unsigned char __user *buf = NULL; |
| unsigned char *kbuf = NULL; |
| |
| result = 0; |
| if (image->file_mode) |
| kbuf = segment->kbuf; |
| else |
| buf = segment->buf; |
| ubytes = segment->bufsz; |
| mbytes = segment->memsz; |
| maddr = segment->mem; |
| |
| result = kimage_set_destination(image, maddr); |
| if (result < 0) |
| goto out; |
| |
| while (mbytes) { |
| struct page *page; |
| char *ptr; |
| size_t uchunk, mchunk; |
| |
| page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); |
| if (!page) { |
| result = -ENOMEM; |
| goto out; |
| } |
| result = kimage_add_page(image, page_to_boot_pfn(page) |
| << PAGE_SHIFT); |
| if (result < 0) |
| goto out; |
| |
| ptr = kmap(page); |
| /* Start with a clear page */ |
| clear_page(ptr); |
| ptr += maddr & ~PAGE_MASK; |
| mchunk = min_t(size_t, mbytes, |
| PAGE_SIZE - (maddr & ~PAGE_MASK)); |
| uchunk = min(ubytes, mchunk); |
| |
| /* For file based kexec, source pages are in kernel memory */ |
| if (image->file_mode) |
| memcpy(ptr, kbuf, uchunk); |
| else |
| result = copy_from_user(ptr, buf, uchunk); |
| kunmap(page); |
| if (result) { |
| result = -EFAULT; |
| goto out; |
| } |
| ubytes -= uchunk; |
| maddr += mchunk; |
| if (image->file_mode) |
| kbuf += mchunk; |
| else |
| buf += mchunk; |
| mbytes -= mchunk; |
| } |
| out: |
| return result; |
| } |
| |
| static int kimage_load_crash_segment(struct kimage *image, |
| struct kexec_segment *segment) |
| { |
| /* For crash dumps kernels we simply copy the data from |
| * user space to it's destination. |
| * We do things a page at a time for the sake of kmap. |
| */ |
| unsigned long maddr; |
| size_t ubytes, mbytes; |
| int result; |
| unsigned char __user *buf = NULL; |
| unsigned char *kbuf = NULL; |
| |
| result = 0; |
| if (image->file_mode) |
| kbuf = segment->kbuf; |
| else |
| buf = segment->buf; |
| ubytes = segment->bufsz; |
| mbytes = segment->memsz; |
| maddr = segment->mem; |
| while (mbytes) { |
| struct page *page; |
| char *ptr; |
| size_t uchunk, mchunk; |
| |
| page = boot_pfn_to_page(maddr >> PAGE_SHIFT); |
| if (!page) { |
| result = -ENOMEM; |
| goto out; |
| } |
| ptr = kmap(page); |
| ptr += maddr & ~PAGE_MASK; |
| mchunk = min_t(size_t, mbytes, |
| PAGE_SIZE - (maddr & ~PAGE_MASK)); |
| uchunk = min(ubytes, mchunk); |
| if (mchunk > uchunk) { |
| /* Zero the trailing part of the page */ |
| memset(ptr + uchunk, 0, mchunk - uchunk); |
| } |
| |
| /* For file based kexec, source pages are in kernel memory */ |
| if (image->file_mode) |
| memcpy(ptr, kbuf, uchunk); |
| else |
| result = copy_from_user(ptr, buf, uchunk); |
| kexec_flush_icache_page(page); |
| kunmap(page); |
| if (result) { |
| result = -EFAULT; |
| goto out; |
| } |
| ubytes -= uchunk; |
| maddr += mchunk; |
| if (image->file_mode) |
| kbuf += mchunk; |
| else |
| buf += mchunk; |
| mbytes -= mchunk; |
| } |
| out: |
| return result; |
| } |
| |
| int kimage_load_segment(struct kimage *image, |
| struct kexec_segment *segment) |
| { |
| int result = -ENOMEM; |
| |
| switch (image->type) { |
| case KEXEC_TYPE_DEFAULT: |
| result = kimage_load_normal_segment(image, segment); |
| break; |
| case KEXEC_TYPE_CRASH: |
| result = kimage_load_crash_segment(image, segment); |
| break; |
| } |
| |
| return result; |
| } |
| |
| struct kimage *kexec_image; |
| struct kimage *kexec_crash_image; |
| int kexec_load_disabled; |
| |
| /* |
| * 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 __crash_kexec(struct pt_regs *regs) |
| { |
| /* Take the kexec_mutex 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 (mutex_trylock(&kexec_mutex)) { |
| 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); |
| } |
| mutex_unlock(&kexec_mutex); |
| } |
| } |
| |
| 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. |
| */ |
| this_cpu = raw_smp_processor_id(); |
| old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); |
| if (old_cpu == PANIC_CPU_INVALID) { |
| /* This is the 1st CPU which comes here, so go ahead. */ |
| printk_safe_flush_on_panic(); |
| __crash_kexec(regs); |
| |
| /* |
| * Reset panic_cpu to allow another panic()/crash_kexec() |
| * call. |
| */ |
| atomic_set(&panic_cpu, PANIC_CPU_INVALID); |
| } |
| } |
| |
| size_t crash_get_memory_size(void) |
| { |
| size_t size = 0; |
| |
| mutex_lock(&kexec_mutex); |
| if (crashk_res.end != crashk_res.start) |
| size = resource_size(&crashk_res); |
| mutex_unlock(&kexec_mutex); |
| return size; |
| } |
| |
| void __weak crash_free_reserved_phys_range(unsigned long begin, |
| unsigned long end) |
| { |
| unsigned long addr; |
| |
| for (addr = begin; addr < end; addr += PAGE_SIZE) |
| free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT)); |
| } |
| |
| int crash_shrink_memory(unsigned long new_size) |
| { |
| int ret = 0; |
| unsigned long start, end; |
| unsigned long old_size; |
| struct resource *ram_res; |
| |
| mutex_lock(&kexec_mutex); |
| |
| if (kexec_crash_image) { |
| ret = -ENOENT; |
| goto unlock; |
| } |
| start = crashk_res.start; |
| end = crashk_res.end; |
| old_size = (end == 0) ? 0 : end - start + 1; |
| if (new_size >= old_size) { |
| ret = (new_size == old_size) ? 0 : -EINVAL; |
| goto unlock; |
| } |
| |
| ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); |
| if (!ram_res) { |
| ret = -ENOMEM; |
| goto unlock; |
| } |
| |
| start = roundup(start, KEXEC_CRASH_MEM_ALIGN); |
| end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); |
| |
| crash_free_reserved_phys_range(end, crashk_res.end); |
| |
| if ((start == end) && (crashk_res.parent != NULL)) |
| release_resource(&crashk_res); |
| |
| ram_res->start = end; |
| ram_res->end = crashk_res.end; |
| ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; |
| ram_res->name = "System RAM"; |
| |
| crashk_res.end = end - 1; |
| |
| insert_resource(&iomem_resource, ram_res); |
| |
| unlock: |
| mutex_unlock(&kexec_mutex); |
| return ret; |
| } |
| |
| static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data, |
| size_t data_len) |
| { |
| struct elf_note note; |
| |
| note.n_namesz = strlen(name) + 1; |
| note.n_descsz = data_len; |
| note.n_type = type; |
| memcpy(buf, ¬e, sizeof(note)); |
| buf += (sizeof(note) + 3)/4; |
| memcpy(buf, name, note.n_namesz); |
| buf += (note.n_namesz + 3)/4; |
| memcpy(buf, data, note.n_descsz); |
| buf += (note.n_descsz + 3)/4; |
| |
| return buf; |
| } |
| |
| static void final_note(u32 *buf) |
| { |
| struct elf_note note; |
| |
| note.n_namesz = 0; |
| note.n_descsz = 0; |
| note.n_type = 0; |
| memcpy(buf, ¬e, sizeof(note)); |
| } |
| |
| 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.pr_pid = current->pid; |
| elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); |
| buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, |
| &prstatus, sizeof(prstatus)); |
| final_note(buf); |
| } |
| |
| static int __init crash_notes_memory_init(void) |
| { |
| /* Allocate memory for saving cpu registers. */ |
| size_t size, align; |
| |
| /* |
| * crash_notes could be allocated across 2 vmalloc pages when percpu |
| * is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc |
| * pages are also on 2 continuous physical pages. In this case the |
| * 2nd part of crash_notes in 2nd page could be lost since only the |
| * starting address and size of crash_notes are exported through sysfs. |
| * Here round up the size of crash_notes to the nearest power of two |
| * and pass it to __alloc_percpu as align value. This can make sure |
| * crash_notes is allocated inside one physical page. |
| */ |
| size = sizeof(note_buf_t); |
| align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE); |
| |
| /* |
| * Break compile if size is bigger than PAGE_SIZE since crash_notes |
| * definitely will be in 2 pages with that. |
| */ |
| BUILD_BUG_ON(size > PAGE_SIZE); |
| |
| crash_notes = __alloc_percpu(size, align); |
| if (!crash_notes) { |
| pr_warn("Memory allocation for saving cpu register states failed\n"); |
| return -ENOMEM; |
| } |
| return 0; |
| } |
| subsys_initcall(crash_notes_memory_init); |
| |
| |
| /* |
| * parsing the "crashkernel" commandline |
| * |
| * this code is intended to be called from architecture specific code |
| */ |
| |
| |
| /* |
| * This function parses command lines in the format |
| * |
| * crashkernel=ramsize-range:size[,...][@offset] |
| * |
| * The function returns 0 on success and -EINVAL on failure. |
| */ |
| static int __init parse_crashkernel_mem(char *cmdline, |
| unsigned long long system_ram, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base) |
| { |
| char *cur = cmdline, *tmp; |
| |
| /* for each entry of the comma-separated list */ |
| do { |
| unsigned long long start, end = ULLONG_MAX, size; |
| |
| /* get the start of the range */ |
| start = memparse(cur, &tmp); |
| if (cur == tmp) { |
| pr_warn("crashkernel: Memory value expected\n"); |
| return -EINVAL; |
| } |
| cur = tmp; |
| if (*cur != '-') { |
| pr_warn("crashkernel: '-' expected\n"); |
| return -EINVAL; |
| } |
| cur++; |
| |
| /* if no ':' is here, than we read the end */ |
| if (*cur != ':') { |
| end = memparse(cur, &tmp); |
| if (cur == tmp) { |
| pr_warn("crashkernel: Memory value expected\n"); |
| return -EINVAL; |
| } |
| cur = tmp; |
| if (end <= start) { |
| pr_warn("crashkernel: end <= start\n"); |
| return -EINVAL; |
| } |
| } |
| |
| if (*cur != ':') { |
| pr_warn("crashkernel: ':' expected\n"); |
| return -EINVAL; |
| } |
| cur++; |
| |
| size = memparse(cur, &tmp); |
| if (cur == tmp) { |
| pr_warn("Memory value expected\n"); |
| return -EINVAL; |
| } |
| cur = tmp; |
| if (size >= system_ram) { |
| pr_warn("crashkernel: invalid size\n"); |
| return -EINVAL; |
| } |
| |
| /* match ? */ |
| if (system_ram >= start && system_ram < end) { |
| *crash_size = size; |
| break; |
| } |
| } while (*cur++ == ','); |
| |
| if (*crash_size > 0) { |
| while (*cur && *cur != ' ' && *cur != '@') |
| cur++; |
| if (*cur == '@') { |
| cur++; |
| *crash_base = memparse(cur, &tmp); |
| if (cur == tmp) { |
| pr_warn("Memory value expected after '@'\n"); |
| return -EINVAL; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * That function parses "simple" (old) crashkernel command lines like |
| * |
| * crashkernel=size[@offset] |
| * |
| * It returns 0 on success and -EINVAL on failure. |
| */ |
| static int __init parse_crashkernel_simple(char *cmdline, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base) |
| { |
| char *cur = cmdline; |
| |
| *crash_size = memparse(cmdline, &cur); |
| if (cmdline == cur) { |
| pr_warn("crashkernel: memory value expected\n"); |
| return -EINVAL; |
| } |
| |
| if (*cur == '@') |
| *crash_base = memparse(cur+1, &cur); |
| else if (*cur != ' ' && *cur != '\0') { |
| pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| #define SUFFIX_HIGH 0 |
| #define SUFFIX_LOW 1 |
| #define SUFFIX_NULL 2 |
| static __initdata char *suffix_tbl[] = { |
| [SUFFIX_HIGH] = ",high", |
| [SUFFIX_LOW] = ",low", |
| [SUFFIX_NULL] = NULL, |
| }; |
| |
| /* |
| * That function parses "suffix" crashkernel command lines like |
| * |
| * crashkernel=size,[high|low] |
| * |
| * It returns 0 on success and -EINVAL on failure. |
| */ |
| static int __init parse_crashkernel_suffix(char *cmdline, |
| unsigned long long *crash_size, |
| const char *suffix) |
| { |
| char *cur = cmdline; |
| |
| *crash_size = memparse(cmdline, &cur); |
| if (cmdline == cur) { |
| pr_warn("crashkernel: memory value expected\n"); |
| return -EINVAL; |
| } |
| |
| /* check with suffix */ |
| if (strncmp(cur, suffix, strlen(suffix))) { |
| pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
| return -EINVAL; |
| } |
| cur += strlen(suffix); |
| if (*cur != ' ' && *cur != '\0') { |
| pr_warn("crashkernel: unrecognized char: %c\n", *cur); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static __init char *get_last_crashkernel(char *cmdline, |
| const char *name, |
| const char *suffix) |
| { |
| char *p = cmdline, *ck_cmdline = NULL; |
| |
| /* find crashkernel and use the last one if there are more */ |
| p = strstr(p, name); |
| while (p) { |
| char *end_p = strchr(p, ' '); |
| char *q; |
| |
| if (!end_p) |
| end_p = p + strlen(p); |
| |
| if (!suffix) { |
| int i; |
| |
| /* skip the one with any known suffix */ |
| for (i = 0; suffix_tbl[i]; i++) { |
| q = end_p - strlen(suffix_tbl[i]); |
| if (!strncmp(q, suffix_tbl[i], |
| strlen(suffix_tbl[i]))) |
| goto next; |
| } |
| ck_cmdline = p; |
| } else { |
| q = end_p - strlen(suffix); |
| if (!strncmp(q, suffix, strlen(suffix))) |
| ck_cmdline = p; |
| } |
| next: |
| p = strstr(p+1, name); |
| } |
| |
| if (!ck_cmdline) |
| return NULL; |
| |
| return ck_cmdline; |
| } |
| |
| static int __init __parse_crashkernel(char *cmdline, |
| unsigned long long system_ram, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base, |
| const char *name, |
| const char *suffix) |
| { |
| char *first_colon, *first_space; |
| char *ck_cmdline; |
| |
| BUG_ON(!crash_size || !crash_base); |
| *crash_size = 0; |
| *crash_base = 0; |
| |
| ck_cmdline = get_last_crashkernel(cmdline, name, suffix); |
| |
| if (!ck_cmdline) |
| return -EINVAL; |
| |
| ck_cmdline += strlen(name); |
| |
| if (suffix) |
| return parse_crashkernel_suffix(ck_cmdline, crash_size, |
| suffix); |
| /* |
| * if the commandline contains a ':', then that's the extended |
| * syntax -- if not, it must be the classic syntax |
| */ |
| first_colon = strchr(ck_cmdline, ':'); |
| first_space = strchr(ck_cmdline, ' '); |
| if (first_colon && (!first_space || first_colon < first_space)) |
| return parse_crashkernel_mem(ck_cmdline, system_ram, |
| crash_size, crash_base); |
| |
| return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base); |
| } |
| |
| /* |
| * That function is the entry point for command line parsing and should be |
| * called from the arch-specific code. |
| */ |
| int __init parse_crashkernel(char *cmdline, |
| unsigned long long system_ram, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base) |
| { |
| return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, |
| "crashkernel=", NULL); |
| } |
| |
| int __init parse_crashkernel_high(char *cmdline, |
| unsigned long long system_ram, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base) |
| { |
| return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, |
| "crashkernel=", suffix_tbl[SUFFIX_HIGH]); |
| } |
| |
| int __init parse_crashkernel_low(char *cmdline, |
| unsigned long long system_ram, |
| unsigned long long *crash_size, |
| unsigned long long *crash_base) |
| { |
| return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, |
| "crashkernel=", suffix_tbl[SUFFIX_LOW]); |
| } |
| |
| static void update_vmcoreinfo_note(void) |
| { |
| u32 *buf = vmcoreinfo_note; |
| |
| if (!vmcoreinfo_size) |
| return; |
| buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, |
| vmcoreinfo_size); |
| final_note(buf); |
| } |
| |
| void crash_save_vmcoreinfo(void) |
| { |
| vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds()); |
| update_vmcoreinfo_note(); |
| } |
| |
| void vmcoreinfo_append_str(const char *fmt, ...) |
| { |
| va_list args; |
| char buf[0x50]; |
| size_t r; |
| |
| va_start(args, fmt); |
| r = vscnprintf(buf, sizeof(buf), fmt, args); |
| va_end(args); |
| |
| r = min(r, vmcoreinfo_max_size - vmcoreinfo_size); |
| |
| memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); |
| |
| vmcoreinfo_size += r; |
| } |
| |
| /* |
| * provide an empty default implementation here -- architecture |
| * code may override this |
| */ |
| void __weak arch_crash_save_vmcoreinfo(void) |
| {} |
| |
| phys_addr_t __weak paddr_vmcoreinfo_note(void) |
| { |
| return __pa_symbol((unsigned long)(char *)&vmcoreinfo_note); |
| } |
| |
| static int __init crash_save_vmcoreinfo_init(void) |
| { |
| VMCOREINFO_OSRELEASE(init_uts_ns.name.release); |
| VMCOREINFO_PAGESIZE(PAGE_SIZE); |
| |
| VMCOREINFO_SYMBOL(init_uts_ns); |
| VMCOREINFO_SYMBOL(node_online_map); |
| #ifdef CONFIG_MMU |
| VMCOREINFO_SYMBOL(swapper_pg_dir); |
| #endif |
| VMCOREINFO_SYMBOL(_stext); |
| VMCOREINFO_SYMBOL(vmap_area_list); |
| |
| #ifndef CONFIG_NEED_MULTIPLE_NODES |
| VMCOREINFO_SYMBOL(mem_map); |
| VMCOREINFO_SYMBOL(contig_page_data); |
| #endif |
| #ifdef CONFIG_SPARSEMEM |
| VMCOREINFO_SYMBOL(mem_section); |
| VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); |
| VMCOREINFO_STRUCT_SIZE(mem_section); |
| VMCOREINFO_OFFSET(mem_section, section_mem_map); |
| #endif |
| VMCOREINFO_STRUCT_SIZE(page); |
| VMCOREINFO_STRUCT_SIZE(pglist_data); |
| VMCOREINFO_STRUCT_SIZE(zone); |
| VMCOREINFO_STRUCT_SIZE(free_area); |
| VMCOREINFO_STRUCT_SIZE(list_head); |
| VMCOREINFO_SIZE(nodemask_t); |
| VMCOREINFO_OFFSET(page, flags); |
| VMCOREINFO_OFFSET(page, _refcount); |
| VMCOREINFO_OFFSET(page, mapping); |
| VMCOREINFO_OFFSET(page, lru); |
| VMCOREINFO_OFFSET(page, _mapcount); |
| VMCOREINFO_OFFSET(page, private); |
| VMCOREINFO_OFFSET(page, compound_dtor); |
| VMCOREINFO_OFFSET(page, compound_order); |
| VMCOREINFO_OFFSET(page, compound_head); |
| VMCOREINFO_OFFSET(pglist_data, node_zones); |
| VMCOREINFO_OFFSET(pglist_data, nr_zones); |
| #ifdef CONFIG_FLAT_NODE_MEM_MAP |
| VMCOREINFO_OFFSET(pglist_data, node_mem_map); |
| #endif |
| VMCOREINFO_OFFSET(pglist_data, node_start_pfn); |
| VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); |
| VMCOREINFO_OFFSET(pglist_data, node_id); |
| VMCOREINFO_OFFSET(zone, free_area); |
| VMCOREINFO_OFFSET(zone, vm_stat); |
| VMCOREINFO_OFFSET(zone, spanned_pages); |
| VMCOREINFO_OFFSET(free_area, free_list); |
| VMCOREINFO_OFFSET(list_head, next); |
| VMCOREINFO_OFFSET(list_head, prev); |
| VMCOREINFO_OFFSET(vmap_area, va_start); |
| VMCOREINFO_OFFSET(vmap_area, list); |
| VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); |
| log_buf_kexec_setup(); |
| VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); |
| VMCOREINFO_NUMBER(NR_FREE_PAGES); |
| VMCOREINFO_NUMBER(PG_lru); |
| VMCOREINFO_NUMBER(PG_private); |
| VMCOREINFO_NUMBER(PG_swapcache); |
| VMCOREINFO_NUMBER(PG_slab); |
| #ifdef CONFIG_MEMORY_FAILURE |
| VMCOREINFO_NUMBER(PG_hwpoison); |
| #endif |
| VMCOREINFO_NUMBER(PG_head_mask); |
| VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); |
| #ifdef CONFIG_HUGETLB_PAGE |
| VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); |
| #endif |
| |
| arch_crash_save_vmcoreinfo(); |
| update_vmcoreinfo_note(); |
| |
| return 0; |
| } |
| |
| subsys_initcall(crash_save_vmcoreinfo_init); |
| |
| /* |
| * Move into place and start executing a preloaded standalone |
| * executable. If nothing was preloaded return an error. |
| */ |
| int kernel_kexec(void) |
| { |
| int error = 0; |
| |
| if (!mutex_trylock(&kexec_mutex)) |
| return -EBUSY; |
| if (!kexec_image) { |
| error = -EINVAL; |
| goto Unlock; |
| } |
| |
| #ifdef CONFIG_KEXEC_JUMP |
| if (kexec_image->preserve_context) { |
| lock_system_sleep(); |
| pm_prepare_console(); |
| error = freeze_processes(); |
| if (error) { |
| error = -EBUSY; |
| goto Restore_console; |
| } |
| suspend_console(); |
| error = dpm_suspend_start(PMSG_FREEZE); |
| if (error) |
| goto Resume_console; |
| /* At this point, dpm_suspend_start() has been called, |
| * but *not* dpm_suspend_end(). We *must* call |
| * dpm_suspend_end() now. Otherwise, drivers for |
| * some devices (e.g. interrupt controllers) become |
| * desynchronized with the actual state of the |
| * hardware at resume time, and evil weirdness ensues. |
| */ |
| error = dpm_suspend_end(PMSG_FREEZE); |
| if (error) |
| goto Resume_devices; |
| error = disable_nonboot_cpus(); |
| if (error) |
| goto Enable_cpus; |
| local_irq_disable(); |
| error = syscore_suspend(); |
| if (error) |
| goto Enable_irqs; |
| } else |
| #endif |
| { |
| kexec_in_progress = true; |
| kernel_restart_prepare(NULL); |
| migrate_to_reboot_cpu(); |
| |
| /* |
| * migrate_to_reboot_cpu() disables CPU hotplug assuming that |
| * no further code needs to use CPU hotplug (which is true in |
| * the reboot case). However, the kexec path depends on using |
| * CPU hotplug again; so re-enable it here. |
| */ |
| cpu_hotplug_enable(); |
| pr_emerg("Starting new kernel\n"); |
| machine_shutdown(); |
| } |
| |
| machine_kexec(kexec_image); |
| |
| #ifdef CONFIG_KEXEC_JUMP |
| if (kexec_image->preserve_context) { |
| syscore_resume(); |
| Enable_irqs: |
| local_irq_enable(); |
| Enable_cpus: |
| enable_nonboot_cpus(); |
| dpm_resume_start(PMSG_RESTORE); |
| Resume_devices: |
| dpm_resume_end(PMSG_RESTORE); |
| Resume_console: |
| resume_console(); |
| thaw_processes(); |
| Restore_console: |
| pm_restore_console(); |
| unlock_system_sleep(); |
| } |
| #endif |
| |
| Unlock: |
| mutex_unlock(&kexec_mutex); |
| return error; |
| } |
| |
| /* |
| * Protection mechanism for crashkernel reserved memory after |
| * the kdump kernel is loaded. |
| * |
| * Provide an empty default implementation here -- architecture |
| * code may override this |
| */ |
| void __weak arch_kexec_protect_crashkres(void) |
| {} |
| |
| void __weak arch_kexec_unprotect_crashkres(void) |
| {} |