| /* |
| * kexec.c - kexec system call |
| * 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) "kexec: " 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/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/uaccess.h> |
| #include <asm/io.h> |
| #include <asm/sections.h> |
| |
| #include <crypto/hash.h> |
| #include <crypto/sha.h> |
| |
| /* 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; |
| |
| /* |
| * Declare these symbols weak so that if architecture provides a purgatory, |
| * these will be overridden. |
| */ |
| char __weak kexec_purgatory[0]; |
| size_t __weak kexec_purgatory_size = 0; |
| |
| #ifdef CONFIG_KEXEC_FILE |
| static int kexec_calculate_store_digests(struct kimage *image); |
| #endif |
| |
| /* Location of the reserved area for the crash kernel */ |
| struct resource crashk_res = { |
| .name = "Crash kernel", |
| .start = 0, |
| .end = 0, |
| .flags = IORESOURCE_BUSY | IORESOURCE_MEM |
| }; |
| struct resource crashk_low_res = { |
| .name = "Crash kernel", |
| .start = 0, |
| .end = 0, |
| .flags = IORESOURCE_BUSY | IORESOURCE_MEM |
| }; |
| |
| int kexec_should_crash(struct task_struct *p) |
| { |
| if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * 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) |
| |
| static int kimage_is_destination_range(struct kimage *image, |
| unsigned long start, unsigned long end); |
| static struct page *kimage_alloc_page(struct kimage *image, |
| gfp_t gfp_mask, |
| unsigned long dest); |
| |
| static int copy_user_segment_list(struct kimage *image, |
| unsigned long nr_segments, |
| struct kexec_segment __user *segments) |
| { |
| int ret; |
| size_t segment_bytes; |
| |
| /* Read in the segments */ |
| image->nr_segments = nr_segments; |
| segment_bytes = nr_segments * sizeof(*segments); |
| ret = copy_from_user(image->segment, segments, segment_bytes); |
| if (ret) |
| ret = -EFAULT; |
| |
| return ret; |
| } |
| |
| static int sanity_check_segment_list(struct kimage *image) |
| { |
| int result, i; |
| unsigned long nr_segments = image->nr_segments; |
| |
| /* |
| * 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. |
| */ |
| result = -EADDRNOTAVAIL; |
| for (i = 0; i < nr_segments; i++) { |
| unsigned long mstart, mend; |
| |
| mstart = image->segment[i].mem; |
| mend = mstart + image->segment[i].memsz; |
| if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) |
| return result; |
| if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) |
| return result; |
| } |
| |
| /* 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. |
| */ |
| result = -EINVAL; |
| 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 result; |
| } |
| } |
| |
| /* 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. |
| */ |
| result = -EINVAL; |
| for (i = 0; i < nr_segments; i++) { |
| if (image->segment[i].bufsz > image->segment[i].memsz) |
| return result; |
| } |
| |
| /* |
| * 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) { |
| result = -EADDRNOTAVAIL; |
| 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 < crashk_res.start) || |
| (mend > crashk_res.end)) |
| return result; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static 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; |
| } |
| |
| static void kimage_free_page_list(struct list_head *list); |
| |
| static int kimage_alloc_init(struct kimage **rimage, unsigned long entry, |
| unsigned long nr_segments, |
| struct kexec_segment __user *segments, |
| unsigned long flags) |
| { |
| int ret; |
| struct kimage *image; |
| bool kexec_on_panic = flags & KEXEC_ON_CRASH; |
| |
| if (kexec_on_panic) { |
| /* Verify we have a valid entry point */ |
| if ((entry < crashk_res.start) || (entry > crashk_res.end)) |
| return -EADDRNOTAVAIL; |
| } |
| |
| /* Allocate and initialize a controlling structure */ |
| image = do_kimage_alloc_init(); |
| if (!image) |
| return -ENOMEM; |
| |
| image->start = entry; |
| |
| ret = copy_user_segment_list(image, nr_segments, segments); |
| if (ret) |
| goto out_free_image; |
| |
| ret = sanity_check_segment_list(image); |
| if (ret) |
| goto out_free_image; |
| |
| /* Enable the special crash kernel control page allocation policy. */ |
| if (kexec_on_panic) { |
| image->control_page = crashk_res.start; |
| image->type = KEXEC_TYPE_CRASH; |
| } |
| |
| /* |
| * Find a location for the control code buffer, and add it |
| * the vector of segments so that it's pages will also be |
| * counted as destination pages. |
| */ |
| ret = -ENOMEM; |
| image->control_code_page = kimage_alloc_control_pages(image, |
| get_order(KEXEC_CONTROL_PAGE_SIZE)); |
| if (!image->control_code_page) { |
| pr_err("Could not allocate control_code_buffer\n"); |
| goto out_free_image; |
| } |
| |
| if (!kexec_on_panic) { |
| image->swap_page = kimage_alloc_control_pages(image, 0); |
| if (!image->swap_page) { |
| pr_err("Could not allocate swap buffer\n"); |
| goto out_free_control_pages; |
| } |
| } |
| |
| *rimage = image; |
| return 0; |
| out_free_control_pages: |
| kimage_free_page_list(&image->control_pages); |
| out_free_image: |
| kfree(image); |
| return ret; |
| } |
| |
| #ifdef CONFIG_KEXEC_FILE |
| static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len) |
| { |
| struct fd f = fdget(fd); |
| int ret; |
| struct kstat stat; |
| loff_t pos; |
| ssize_t bytes = 0; |
| |
| if (!f.file) |
| return -EBADF; |
| |
| ret = vfs_getattr(&f.file->f_path, &stat); |
| if (ret) |
| goto out; |
| |
| if (stat.size > INT_MAX) { |
| ret = -EFBIG; |
| goto out; |
| } |
| |
| /* Don't hand 0 to vmalloc, it whines. */ |
| if (stat.size == 0) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| *buf = vmalloc(stat.size); |
| if (!*buf) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| pos = 0; |
| while (pos < stat.size) { |
| bytes = kernel_read(f.file, pos, (char *)(*buf) + pos, |
| stat.size - pos); |
| if (bytes < 0) { |
| vfree(*buf); |
| ret = bytes; |
| goto out; |
| } |
| |
| if (bytes == 0) |
| break; |
| pos += bytes; |
| } |
| |
| if (pos != stat.size) { |
| ret = -EBADF; |
| vfree(*buf); |
| goto out; |
| } |
| |
| *buf_len = pos; |
| out: |
| fdput(f); |
| return ret; |
| } |
| |
| /* Architectures can provide this probe function */ |
| int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| return -ENOEXEC; |
| } |
| |
| void * __weak arch_kexec_kernel_image_load(struct kimage *image) |
| { |
| return ERR_PTR(-ENOEXEC); |
| } |
| |
| void __weak arch_kimage_file_post_load_cleanup(struct kimage *image) |
| { |
| } |
| |
| int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| return -EKEYREJECTED; |
| } |
| |
| /* Apply relocations of type RELA */ |
| int __weak |
| arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, |
| unsigned int relsec) |
| { |
| pr_err("RELA relocation unsupported.\n"); |
| return -ENOEXEC; |
| } |
| |
| /* Apply relocations of type REL */ |
| int __weak |
| arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, |
| unsigned int relsec) |
| { |
| pr_err("REL relocation unsupported.\n"); |
| return -ENOEXEC; |
| } |
| |
| /* |
| * Free up memory used by kernel, initrd, and command line. This is temporary |
| * memory allocation which is not needed any more after these buffers have |
| * been loaded into separate segments and have been copied elsewhere. |
| */ |
| static void kimage_file_post_load_cleanup(struct kimage *image) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| |
| vfree(image->kernel_buf); |
| image->kernel_buf = NULL; |
| |
| vfree(image->initrd_buf); |
| image->initrd_buf = NULL; |
| |
| kfree(image->cmdline_buf); |
| image->cmdline_buf = NULL; |
| |
| vfree(pi->purgatory_buf); |
| pi->purgatory_buf = NULL; |
| |
| vfree(pi->sechdrs); |
| pi->sechdrs = NULL; |
| |
| /* See if architecture has anything to cleanup post load */ |
| arch_kimage_file_post_load_cleanup(image); |
| |
| /* |
| * Above call should have called into bootloader to free up |
| * any data stored in kimage->image_loader_data. It should |
| * be ok now to free it up. |
| */ |
| kfree(image->image_loader_data); |
| image->image_loader_data = NULL; |
| } |
| |
| /* |
| * In file mode list of segments is prepared by kernel. Copy relevant |
| * data from user space, do error checking, prepare segment list |
| */ |
| static int |
| kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, |
| const char __user *cmdline_ptr, |
| unsigned long cmdline_len, unsigned flags) |
| { |
| int ret = 0; |
| void *ldata; |
| |
| ret = copy_file_from_fd(kernel_fd, &image->kernel_buf, |
| &image->kernel_buf_len); |
| if (ret) |
| return ret; |
| |
| /* Call arch image probe handlers */ |
| ret = arch_kexec_kernel_image_probe(image, image->kernel_buf, |
| image->kernel_buf_len); |
| |
| if (ret) |
| goto out; |
| |
| #ifdef CONFIG_KEXEC_VERIFY_SIG |
| ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, |
| image->kernel_buf_len); |
| if (ret) { |
| pr_debug("kernel signature verification failed.\n"); |
| goto out; |
| } |
| pr_debug("kernel signature verification successful.\n"); |
| #endif |
| /* It is possible that there no initramfs is being loaded */ |
| if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { |
| ret = copy_file_from_fd(initrd_fd, &image->initrd_buf, |
| &image->initrd_buf_len); |
| if (ret) |
| goto out; |
| } |
| |
| if (cmdline_len) { |
| image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL); |
| if (!image->cmdline_buf) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = copy_from_user(image->cmdline_buf, cmdline_ptr, |
| cmdline_len); |
| if (ret) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| image->cmdline_buf_len = cmdline_len; |
| |
| /* command line should be a string with last byte null */ |
| if (image->cmdline_buf[cmdline_len - 1] != '\0') { |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| /* Call arch image load handlers */ |
| ldata = arch_kexec_kernel_image_load(image); |
| |
| if (IS_ERR(ldata)) { |
| ret = PTR_ERR(ldata); |
| goto out; |
| } |
| |
| image->image_loader_data = ldata; |
| out: |
| /* In case of error, free up all allocated memory in this function */ |
| if (ret) |
| kimage_file_post_load_cleanup(image); |
| return ret; |
| } |
| |
| static int |
| kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, |
| int initrd_fd, const char __user *cmdline_ptr, |
| unsigned long cmdline_len, unsigned long flags) |
| { |
| int ret; |
| struct kimage *image; |
| bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH; |
| |
| image = do_kimage_alloc_init(); |
| if (!image) |
| return -ENOMEM; |
| |
| image->file_mode = 1; |
| |
| if (kexec_on_panic) { |
| /* Enable special crash kernel control page alloc policy. */ |
| image->control_page = crashk_res.start; |
| image->type = KEXEC_TYPE_CRASH; |
| } |
| |
| ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd, |
| cmdline_ptr, cmdline_len, flags); |
| if (ret) |
| goto out_free_image; |
| |
| ret = sanity_check_segment_list(image); |
| if (ret) |
| goto out_free_post_load_bufs; |
| |
| ret = -ENOMEM; |
| image->control_code_page = kimage_alloc_control_pages(image, |
| get_order(KEXEC_CONTROL_PAGE_SIZE)); |
| if (!image->control_code_page) { |
| pr_err("Could not allocate control_code_buffer\n"); |
| goto out_free_post_load_bufs; |
| } |
| |
| if (!kexec_on_panic) { |
| image->swap_page = kimage_alloc_control_pages(image, 0); |
| if (!image->swap_page) { |
| pr_err("Could not allocate swap buffer\n"); |
| goto out_free_control_pages; |
| } |
| } |
| |
| *rimage = image; |
| return 0; |
| out_free_control_pages: |
| kimage_free_page_list(&image->control_pages); |
| out_free_post_load_bufs: |
| kimage_file_post_load_cleanup(image); |
| out_free_image: |
| kfree(image); |
| return ret; |
| } |
| #else /* CONFIG_KEXEC_FILE */ |
| static inline void kimage_file_post_load_cleanup(struct kimage *image) { } |
| #endif /* CONFIG_KEXEC_FILE */ |
| |
| static 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); |
| } |
| |
| static void kimage_free_page_list(struct list_head *list) |
| { |
| struct list_head *pos, *next; |
| |
| list_for_each_safe(pos, next, list) { |
| struct page *page; |
| |
| page = list_entry(pos, struct page, 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_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; |
| |
| 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); |
| break; |
| } |
| } |
| if (pages) |
| image->control_page = hole_end; |
| |
| 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_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); |
| |
| } |
| static 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) ? \ |
| phys_to_virt((entry & PAGE_MASK)) : ptr + 1) |
| |
| static void kimage_free_entry(kimage_entry_t entry) |
| { |
| struct page *page; |
| |
| page = pfn_to_page(entry >> PAGE_SHIFT); |
| kimage_free_pages(page); |
| } |
| |
| static 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_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_pfn(page) > |
| (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { |
| list_add(&page->lru, &image->unusable_pages); |
| continue; |
| } |
| addr = page_to_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 = 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; |
| } else { |
| /* Place the page on the destination list I |
| * will use it 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_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 = 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; |
| } |
| |
| static 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; |
| } |
| |
| /* |
| * Exec Kernel system call: for obvious reasons only root may call it. |
| * |
| * This call breaks up into three pieces. |
| * - A generic part which loads the new kernel from the current |
| * address space, and very carefully places the data in the |
| * allocated pages. |
| * |
| * - A generic part that interacts with the kernel and tells all of |
| * the devices to shut down. Preventing on-going dmas, and placing |
| * the devices in a consistent state so a later kernel can |
| * reinitialize them. |
| * |
| * - A machine specific part that includes the syscall number |
| * and then copies the image to it's final destination. And |
| * jumps into the image at entry. |
| * |
| * kexec does not sync, or unmount filesystems so if you need |
| * that to happen you need to do that yourself. |
| */ |
| struct kimage *kexec_image; |
| struct kimage *kexec_crash_image; |
| int kexec_load_disabled; |
| |
| static DEFINE_MUTEX(kexec_mutex); |
| |
| SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, |
| struct kexec_segment __user *, segments, unsigned long, flags) |
| { |
| struct kimage **dest_image, *image; |
| int result; |
| |
| /* We only trust the superuser with rebooting the system. */ |
| if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) |
| return -EPERM; |
| |
| /* |
| * Verify we have a legal set of flags |
| * This leaves us room for future extensions. |
| */ |
| if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK)) |
| return -EINVAL; |
| |
| /* Verify we are on the appropriate architecture */ |
| if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) && |
| ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT)) |
| return -EINVAL; |
| |
| /* Put an artificial cap on the number |
| * of segments passed to kexec_load. |
| */ |
| if (nr_segments > KEXEC_SEGMENT_MAX) |
| return -EINVAL; |
| |
| image = NULL; |
| result = 0; |
| |
| /* Because we write directly to the reserved memory |
| * region when loading crash kernels we need a mutex here to |
| * prevent multiple crash kernels from attempting to load |
| * simultaneously, and to prevent a crash kernel from loading |
| * over the top of a in use crash kernel. |
| * |
| * KISS: always take the mutex. |
| */ |
| if (!mutex_trylock(&kexec_mutex)) |
| return -EBUSY; |
| |
| dest_image = &kexec_image; |
| if (flags & KEXEC_ON_CRASH) |
| dest_image = &kexec_crash_image; |
| if (nr_segments > 0) { |
| unsigned long i; |
| |
| if (flags & KEXEC_ON_CRASH) { |
| /* |
| * Loading another kernel to switch to if this one |
| * crashes. Free any current crash dump kernel before |
| * we corrupt it. |
| */ |
| |
| kimage_free(xchg(&kexec_crash_image, NULL)); |
| result = kimage_alloc_init(&image, entry, nr_segments, |
| segments, flags); |
| crash_map_reserved_pages(); |
| } else { |
| /* Loading another kernel to reboot into. */ |
| |
| result = kimage_alloc_init(&image, entry, nr_segments, |
| segments, flags); |
| } |
| if (result) |
| goto out; |
| |
| if (flags & KEXEC_PRESERVE_CONTEXT) |
| image->preserve_context = 1; |
| result = machine_kexec_prepare(image); |
| if (result) |
| goto out; |
| |
| for (i = 0; i < nr_segments; i++) { |
| result = kimage_load_segment(image, &image->segment[i]); |
| if (result) |
| goto out; |
| } |
| kimage_terminate(image); |
| if (flags & KEXEC_ON_CRASH) |
| crash_unmap_reserved_pages(); |
| } |
| /* Install the new kernel, and Uninstall the old */ |
| image = xchg(dest_image, image); |
| |
| out: |
| mutex_unlock(&kexec_mutex); |
| kimage_free(image); |
| |
| return result; |
| } |
| |
| /* |
| * Add and remove page tables for crashkernel memory |
| * |
| * Provide an empty default implementation here -- architecture |
| * code may override this |
| */ |
| void __weak crash_map_reserved_pages(void) |
| {} |
| |
| void __weak crash_unmap_reserved_pages(void) |
| {} |
| |
| #ifdef CONFIG_COMPAT |
| COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, |
| compat_ulong_t, nr_segments, |
| struct compat_kexec_segment __user *, segments, |
| compat_ulong_t, flags) |
| { |
| struct compat_kexec_segment in; |
| struct kexec_segment out, __user *ksegments; |
| unsigned long i, result; |
| |
| /* Don't allow clients that don't understand the native |
| * architecture to do anything. |
| */ |
| if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT) |
| return -EINVAL; |
| |
| if (nr_segments > KEXEC_SEGMENT_MAX) |
| return -EINVAL; |
| |
| ksegments = compat_alloc_user_space(nr_segments * sizeof(out)); |
| for (i = 0; i < nr_segments; i++) { |
| result = copy_from_user(&in, &segments[i], sizeof(in)); |
| if (result) |
| return -EFAULT; |
| |
| out.buf = compat_ptr(in.buf); |
| out.bufsz = in.bufsz; |
| out.mem = in.mem; |
| out.memsz = in.memsz; |
| |
| result = copy_to_user(&ksegments[i], &out, sizeof(out)); |
| if (result) |
| return -EFAULT; |
| } |
| |
| return sys_kexec_load(entry, nr_segments, ksegments, flags); |
| } |
| #endif |
| |
| #ifdef CONFIG_KEXEC_FILE |
| SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, |
| unsigned long, cmdline_len, const char __user *, cmdline_ptr, |
| unsigned long, flags) |
| { |
| int ret = 0, i; |
| struct kimage **dest_image, *image; |
| |
| /* We only trust the superuser with rebooting the system. */ |
| if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) |
| return -EPERM; |
| |
| /* Make sure we have a legal set of flags */ |
| if (flags != (flags & KEXEC_FILE_FLAGS)) |
| return -EINVAL; |
| |
| image = NULL; |
| |
| if (!mutex_trylock(&kexec_mutex)) |
| return -EBUSY; |
| |
| dest_image = &kexec_image; |
| if (flags & KEXEC_FILE_ON_CRASH) |
| dest_image = &kexec_crash_image; |
| |
| if (flags & KEXEC_FILE_UNLOAD) |
| goto exchange; |
| |
| /* |
| * In case of crash, new kernel gets loaded in reserved region. It is |
| * same memory where old crash kernel might be loaded. Free any |
| * current crash dump kernel before we corrupt it. |
| */ |
| if (flags & KEXEC_FILE_ON_CRASH) |
| kimage_free(xchg(&kexec_crash_image, NULL)); |
| |
| ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr, |
| cmdline_len, flags); |
| if (ret) |
| goto out; |
| |
| ret = machine_kexec_prepare(image); |
| if (ret) |
| goto out; |
| |
| ret = kexec_calculate_store_digests(image); |
| if (ret) |
| goto out; |
| |
| for (i = 0; i < image->nr_segments; i++) { |
| struct kexec_segment *ksegment; |
| |
| ksegment = &image->segment[i]; |
| pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n", |
| i, ksegment->buf, ksegment->bufsz, ksegment->mem, |
| ksegment->memsz); |
| |
| ret = kimage_load_segment(image, &image->segment[i]); |
| if (ret) |
| goto out; |
| } |
| |
| kimage_terminate(image); |
| |
| /* |
| * Free up any temporary buffers allocated which are not needed |
| * after image has been loaded |
| */ |
| kimage_file_post_load_cleanup(image); |
| exchange: |
| image = xchg(dest_image, image); |
| out: |
| mutex_unlock(&kexec_mutex); |
| kimage_free(image); |
| return ret; |
| } |
| |
| #endif /* CONFIG_KEXEC_FILE */ |
| |
| 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); |
| } |
| } |
| |
| 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(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_map_reserved_pages(); |
| 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_MEM; |
| ram_res->name = "System RAM"; |
| |
| crashk_res.end = end - 1; |
| |
| insert_resource(&iomem_resource, ram_res); |
| crash_unmap_reserved_pages(); |
| |
| 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. */ |
| crash_notes = alloc_percpu(note_buf_t); |
| if (!crash_notes) { |
| pr_warn("Kexec: 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\n"); |
| 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\n"); |
| return -EINVAL; |
| } |
| cur += strlen(suffix); |
| if (*cur != ' ' && *cur != '\0') { |
| pr_warn("crashkernel: unrecognized char\n"); |
| 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) |
| {} |
| |
| unsigned long __weak paddr_vmcoreinfo_note(void) |
| { |
| return __pa((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, _count); |
| VMCOREINFO_OFFSET(page, mapping); |
| VMCOREINFO_OFFSET(page, lru); |
| VMCOREINFO_OFFSET(page, _mapcount); |
| VMCOREINFO_OFFSET(page, private); |
| 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_HUGETLBFS |
| VMCOREINFO_SYMBOL(free_huge_page); |
| #endif |
| |
| arch_crash_save_vmcoreinfo(); |
| update_vmcoreinfo_note(); |
| |
| return 0; |
| } |
| |
| subsys_initcall(crash_save_vmcoreinfo_init); |
| |
| #ifdef CONFIG_KEXEC_FILE |
| static int locate_mem_hole_top_down(unsigned long start, unsigned long end, |
| struct kexec_buf *kbuf) |
| { |
| struct kimage *image = kbuf->image; |
| unsigned long temp_start, temp_end; |
| |
| temp_end = min(end, kbuf->buf_max); |
| temp_start = temp_end - kbuf->memsz; |
| |
| do { |
| /* align down start */ |
| temp_start = temp_start & (~(kbuf->buf_align - 1)); |
| |
| if (temp_start < start || temp_start < kbuf->buf_min) |
| return 0; |
| |
| temp_end = temp_start + kbuf->memsz - 1; |
| |
| /* |
| * Make sure this does not conflict with any of existing |
| * segments |
| */ |
| if (kimage_is_destination_range(image, temp_start, temp_end)) { |
| temp_start = temp_start - PAGE_SIZE; |
| continue; |
| } |
| |
| /* We found a suitable memory range */ |
| break; |
| } while (1); |
| |
| /* If we are here, we found a suitable memory range */ |
| kbuf->mem = temp_start; |
| |
| /* Success, stop navigating through remaining System RAM ranges */ |
| return 1; |
| } |
| |
| static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, |
| struct kexec_buf *kbuf) |
| { |
| struct kimage *image = kbuf->image; |
| unsigned long temp_start, temp_end; |
| |
| temp_start = max(start, kbuf->buf_min); |
| |
| do { |
| temp_start = ALIGN(temp_start, kbuf->buf_align); |
| temp_end = temp_start + kbuf->memsz - 1; |
| |
| if (temp_end > end || temp_end > kbuf->buf_max) |
| return 0; |
| /* |
| * Make sure this does not conflict with any of existing |
| * segments |
| */ |
| if (kimage_is_destination_range(image, temp_start, temp_end)) { |
| temp_start = temp_start + PAGE_SIZE; |
| continue; |
| } |
| |
| /* We found a suitable memory range */ |
| break; |
| } while (1); |
| |
| /* If we are here, we found a suitable memory range */ |
| kbuf->mem = temp_start; |
| |
| /* Success, stop navigating through remaining System RAM ranges */ |
| return 1; |
| } |
| |
| static int locate_mem_hole_callback(u64 start, u64 end, void *arg) |
| { |
| struct kexec_buf *kbuf = (struct kexec_buf *)arg; |
| unsigned long sz = end - start + 1; |
| |
| /* Returning 0 will take to next memory range */ |
| if (sz < kbuf->memsz) |
| return 0; |
| |
| if (end < kbuf->buf_min || start > kbuf->buf_max) |
| return 0; |
| |
| /* |
| * Allocate memory top down with-in ram range. Otherwise bottom up |
| * allocation. |
| */ |
| if (kbuf->top_down) |
| return locate_mem_hole_top_down(start, end, kbuf); |
| return locate_mem_hole_bottom_up(start, end, kbuf); |
| } |
| |
| /* |
| * Helper function for placing a buffer in a kexec segment. This assumes |
| * that kexec_mutex is held. |
| */ |
| int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, |
| unsigned long memsz, unsigned long buf_align, |
| unsigned long buf_min, unsigned long buf_max, |
| bool top_down, unsigned long *load_addr) |
| { |
| |
| struct kexec_segment *ksegment; |
| struct kexec_buf buf, *kbuf; |
| int ret; |
| |
| /* Currently adding segment this way is allowed only in file mode */ |
| if (!image->file_mode) |
| return -EINVAL; |
| |
| if (image->nr_segments >= KEXEC_SEGMENT_MAX) |
| return -EINVAL; |
| |
| /* |
| * Make sure we are not trying to add buffer after allocating |
| * control pages. All segments need to be placed first before |
| * any control pages are allocated. As control page allocation |
| * logic goes through list of segments to make sure there are |
| * no destination overlaps. |
| */ |
| if (!list_empty(&image->control_pages)) { |
| WARN_ON(1); |
| return -EINVAL; |
| } |
| |
| memset(&buf, 0, sizeof(struct kexec_buf)); |
| kbuf = &buf; |
| kbuf->image = image; |
| kbuf->buffer = buffer; |
| kbuf->bufsz = bufsz; |
| |
| kbuf->memsz = ALIGN(memsz, PAGE_SIZE); |
| kbuf->buf_align = max(buf_align, PAGE_SIZE); |
| kbuf->buf_min = buf_min; |
| kbuf->buf_max = buf_max; |
| kbuf->top_down = top_down; |
| |
| /* Walk the RAM ranges and allocate a suitable range for the buffer */ |
| if (image->type == KEXEC_TYPE_CRASH) |
| ret = walk_iomem_res("Crash kernel", |
| IORESOURCE_MEM | IORESOURCE_BUSY, |
| crashk_res.start, crashk_res.end, kbuf, |
| locate_mem_hole_callback); |
| else |
| ret = walk_system_ram_res(0, -1, kbuf, |
| locate_mem_hole_callback); |
| if (ret != 1) { |
| /* A suitable memory range could not be found for buffer */ |
| return -EADDRNOTAVAIL; |
| } |
| |
| /* Found a suitable memory range */ |
| ksegment = &image->segment[image->nr_segments]; |
| ksegment->kbuf = kbuf->buffer; |
| ksegment->bufsz = kbuf->bufsz; |
| ksegment->mem = kbuf->mem; |
| ksegment->memsz = kbuf->memsz; |
| image->nr_segments++; |
| *load_addr = ksegment->mem; |
| return 0; |
| } |
| |
| /* Calculate and store the digest of segments */ |
| static int kexec_calculate_store_digests(struct kimage *image) |
| { |
| struct crypto_shash *tfm; |
| struct shash_desc *desc; |
| int ret = 0, i, j, zero_buf_sz, sha_region_sz; |
| size_t desc_size, nullsz; |
| char *digest; |
| void *zero_buf; |
| struct kexec_sha_region *sha_regions; |
| struct purgatory_info *pi = &image->purgatory_info; |
| |
| zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT); |
| zero_buf_sz = PAGE_SIZE; |
| |
| tfm = crypto_alloc_shash("sha256", 0, 0); |
| if (IS_ERR(tfm)) { |
| ret = PTR_ERR(tfm); |
| goto out; |
| } |
| |
| desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); |
| desc = kzalloc(desc_size, GFP_KERNEL); |
| if (!desc) { |
| ret = -ENOMEM; |
| goto out_free_tfm; |
| } |
| |
| sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region); |
| sha_regions = vzalloc(sha_region_sz); |
| if (!sha_regions) |
| goto out_free_desc; |
| |
| desc->tfm = tfm; |
| desc->flags = 0; |
| |
| ret = crypto_shash_init(desc); |
| if (ret < 0) |
| goto out_free_sha_regions; |
| |
| digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); |
| if (!digest) { |
| ret = -ENOMEM; |
| goto out_free_sha_regions; |
| } |
| |
| for (j = i = 0; i < image->nr_segments; i++) { |
| struct kexec_segment *ksegment; |
| |
| ksegment = &image->segment[i]; |
| /* |
| * Skip purgatory as it will be modified once we put digest |
| * info in purgatory. |
| */ |
| if (ksegment->kbuf == pi->purgatory_buf) |
| continue; |
| |
| ret = crypto_shash_update(desc, ksegment->kbuf, |
| ksegment->bufsz); |
| if (ret) |
| break; |
| |
| /* |
| * Assume rest of the buffer is filled with zero and |
| * update digest accordingly. |
| */ |
| nullsz = ksegment->memsz - ksegment->bufsz; |
| while (nullsz) { |
| unsigned long bytes = nullsz; |
| |
| if (bytes > zero_buf_sz) |
| bytes = zero_buf_sz; |
| ret = crypto_shash_update(desc, zero_buf, bytes); |
| if (ret) |
| break; |
| nullsz -= bytes; |
| } |
| |
| if (ret) |
| break; |
| |
| sha_regions[j].start = ksegment->mem; |
| sha_regions[j].len = ksegment->memsz; |
| j++; |
| } |
| |
| if (!ret) { |
| ret = crypto_shash_final(desc, digest); |
| if (ret) |
| goto out_free_digest; |
| ret = kexec_purgatory_get_set_symbol(image, "sha_regions", |
| sha_regions, sha_region_sz, 0); |
| if (ret) |
| goto out_free_digest; |
| |
| ret = kexec_purgatory_get_set_symbol(image, "sha256_digest", |
| digest, SHA256_DIGEST_SIZE, 0); |
| if (ret) |
| goto out_free_digest; |
| } |
| |
| out_free_digest: |
| kfree(digest); |
| out_free_sha_regions: |
| vfree(sha_regions); |
| out_free_desc: |
| kfree(desc); |
| out_free_tfm: |
| kfree(tfm); |
| out: |
| return ret; |
| } |
| |
| /* Actually load purgatory. Lot of code taken from kexec-tools */ |
| static int __kexec_load_purgatory(struct kimage *image, unsigned long min, |
| unsigned long max, int top_down) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad; |
| unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset; |
| unsigned char *buf_addr, *src; |
| int i, ret = 0, entry_sidx = -1; |
| const Elf_Shdr *sechdrs_c; |
| Elf_Shdr *sechdrs = NULL; |
| void *purgatory_buf = NULL; |
| |
| /* |
| * sechdrs_c points to section headers in purgatory and are read |
| * only. No modifications allowed. |
| */ |
| sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff; |
| |
| /* |
| * We can not modify sechdrs_c[] and its fields. It is read only. |
| * Copy it over to a local copy where one can store some temporary |
| * data and free it at the end. We need to modify ->sh_addr and |
| * ->sh_offset fields to keep track of permanent and temporary |
| * locations of sections. |
| */ |
| sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr)); |
| if (!sechdrs) |
| return -ENOMEM; |
| |
| memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr)); |
| |
| /* |
| * We seem to have multiple copies of sections. First copy is which |
| * is embedded in kernel in read only section. Some of these sections |
| * will be copied to a temporary buffer and relocated. And these |
| * sections will finally be copied to their final destination at |
| * segment load time. |
| * |
| * Use ->sh_offset to reflect section address in memory. It will |
| * point to original read only copy if section is not allocatable. |
| * Otherwise it will point to temporary copy which will be relocated. |
| * |
| * Use ->sh_addr to contain final address of the section where it |
| * will go during execution time. |
| */ |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| if (sechdrs[i].sh_type == SHT_NOBITS) |
| continue; |
| |
| sechdrs[i].sh_offset = (unsigned long)pi->ehdr + |
| sechdrs[i].sh_offset; |
| } |
| |
| /* |
| * Identify entry point section and make entry relative to section |
| * start. |
| */ |
| entry = pi->ehdr->e_entry; |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| if (!(sechdrs[i].sh_flags & SHF_EXECINSTR)) |
| continue; |
| |
| /* Make entry section relative */ |
| if (sechdrs[i].sh_addr <= pi->ehdr->e_entry && |
| ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > |
| pi->ehdr->e_entry)) { |
| entry_sidx = i; |
| entry -= sechdrs[i].sh_addr; |
| break; |
| } |
| } |
| |
| /* Determine how much memory is needed to load relocatable object. */ |
| buf_align = 1; |
| bss_align = 1; |
| buf_sz = 0; |
| bss_sz = 0; |
| |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| align = sechdrs[i].sh_addralign; |
| if (sechdrs[i].sh_type != SHT_NOBITS) { |
| if (buf_align < align) |
| buf_align = align; |
| buf_sz = ALIGN(buf_sz, align); |
| buf_sz += sechdrs[i].sh_size; |
| } else { |
| /* bss section */ |
| if (bss_align < align) |
| bss_align = align; |
| bss_sz = ALIGN(bss_sz, align); |
| bss_sz += sechdrs[i].sh_size; |
| } |
| } |
| |
| /* Determine the bss padding required to align bss properly */ |
| bss_pad = 0; |
| if (buf_sz & (bss_align - 1)) |
| bss_pad = bss_align - (buf_sz & (bss_align - 1)); |
| |
| memsz = buf_sz + bss_pad + bss_sz; |
| |
| /* Allocate buffer for purgatory */ |
| purgatory_buf = vzalloc(buf_sz); |
| if (!purgatory_buf) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| if (buf_align < bss_align) |
| buf_align = bss_align; |
| |
| /* Add buffer to segment list */ |
| ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz, |
| buf_align, min, max, top_down, |
| &pi->purgatory_load_addr); |
| if (ret) |
| goto out; |
| |
| /* Load SHF_ALLOC sections */ |
| buf_addr = purgatory_buf; |
| load_addr = curr_load_addr = pi->purgatory_load_addr; |
| bss_addr = load_addr + buf_sz + bss_pad; |
| |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| align = sechdrs[i].sh_addralign; |
| if (sechdrs[i].sh_type != SHT_NOBITS) { |
| curr_load_addr = ALIGN(curr_load_addr, align); |
| offset = curr_load_addr - load_addr; |
| /* We already modifed ->sh_offset to keep src addr */ |
| src = (char *) sechdrs[i].sh_offset; |
| memcpy(buf_addr + offset, src, sechdrs[i].sh_size); |
| |
| /* Store load address and source address of section */ |
| sechdrs[i].sh_addr = curr_load_addr; |
| |
| /* |
| * This section got copied to temporary buffer. Update |
| * ->sh_offset accordingly. |
| */ |
| sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); |
| |
| /* Advance to the next address */ |
| curr_load_addr += sechdrs[i].sh_size; |
| } else { |
| bss_addr = ALIGN(bss_addr, align); |
| sechdrs[i].sh_addr = bss_addr; |
| bss_addr += sechdrs[i].sh_size; |
| } |
| } |
| |
| /* Update entry point based on load address of text section */ |
| if (entry_sidx >= 0) |
| entry += sechdrs[entry_sidx].sh_addr; |
| |
| /* Make kernel jump to purgatory after shutdown */ |
| image->start = entry; |
| |
| /* Used later to get/set symbol values */ |
| pi->sechdrs = sechdrs; |
| |
| /* |
| * Used later to identify which section is purgatory and skip it |
| * from checksumming. |
| */ |
| pi->purgatory_buf = purgatory_buf; |
| return ret; |
| out: |
| vfree(sechdrs); |
| vfree(purgatory_buf); |
| return ret; |
| } |
| |
| static int kexec_apply_relocations(struct kimage *image) |
| { |
| int i, ret; |
| struct purgatory_info *pi = &image->purgatory_info; |
| Elf_Shdr *sechdrs = pi->sechdrs; |
| |
| /* Apply relocations */ |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| Elf_Shdr *section, *symtab; |
| |
| if (sechdrs[i].sh_type != SHT_RELA && |
| sechdrs[i].sh_type != SHT_REL) |
| continue; |
| |
| /* |
| * For section of type SHT_RELA/SHT_REL, |
| * ->sh_link contains section header index of associated |
| * symbol table. And ->sh_info contains section header |
| * index of section to which relocations apply. |
| */ |
| if (sechdrs[i].sh_info >= pi->ehdr->e_shnum || |
| sechdrs[i].sh_link >= pi->ehdr->e_shnum) |
| return -ENOEXEC; |
| |
| section = &sechdrs[sechdrs[i].sh_info]; |
| symtab = &sechdrs[sechdrs[i].sh_link]; |
| |
| if (!(section->sh_flags & SHF_ALLOC)) |
| continue; |
| |
| /* |
| * symtab->sh_link contain section header index of associated |
| * string table. |
| */ |
| if (symtab->sh_link >= pi->ehdr->e_shnum) |
| /* Invalid section number? */ |
| continue; |
| |
| /* |
| * Respective architecture needs to provide support for applying |
| * relocations of type SHT_RELA/SHT_REL. |
| */ |
| if (sechdrs[i].sh_type == SHT_RELA) |
| ret = arch_kexec_apply_relocations_add(pi->ehdr, |
| sechdrs, i); |
| else if (sechdrs[i].sh_type == SHT_REL) |
| ret = arch_kexec_apply_relocations(pi->ehdr, |
| sechdrs, i); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /* Load relocatable purgatory object and relocate it appropriately */ |
| int kexec_load_purgatory(struct kimage *image, unsigned long min, |
| unsigned long max, int top_down, |
| unsigned long *load_addr) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| int ret; |
| |
| if (kexec_purgatory_size <= 0) |
| return -EINVAL; |
| |
| if (kexec_purgatory_size < sizeof(Elf_Ehdr)) |
| return -ENOEXEC; |
| |
| pi->ehdr = (Elf_Ehdr *)kexec_purgatory; |
| |
| if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0 |
| || pi->ehdr->e_type != ET_REL |
| || !elf_check_arch(pi->ehdr) |
| || pi->ehdr->e_shentsize != sizeof(Elf_Shdr)) |
| return -ENOEXEC; |
| |
| if (pi->ehdr->e_shoff >= kexec_purgatory_size |
| || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) > |
| kexec_purgatory_size - pi->ehdr->e_shoff)) |
| return -ENOEXEC; |
| |
| ret = __kexec_load_purgatory(image, min, max, top_down); |
| if (ret) |
| return ret; |
| |
| ret = kexec_apply_relocations(image); |
| if (ret) |
| goto out; |
| |
| *load_addr = pi->purgatory_load_addr; |
| return 0; |
| out: |
| vfree(pi->sechdrs); |
| vfree(pi->purgatory_buf); |
| return ret; |
| } |
| |
| static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, |
| const char *name) |
| { |
| Elf_Sym *syms; |
| Elf_Shdr *sechdrs; |
| Elf_Ehdr *ehdr; |
| int i, k; |
| const char *strtab; |
| |
| if (!pi->sechdrs || !pi->ehdr) |
| return NULL; |
| |
| sechdrs = pi->sechdrs; |
| ehdr = pi->ehdr; |
| |
| for (i = 0; i < ehdr->e_shnum; i++) { |
| if (sechdrs[i].sh_type != SHT_SYMTAB) |
| continue; |
| |
| if (sechdrs[i].sh_link >= ehdr->e_shnum) |
| /* Invalid strtab section number */ |
| continue; |
| strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset; |
| syms = (Elf_Sym *)sechdrs[i].sh_offset; |
| |
| /* Go through symbols for a match */ |
| for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) { |
| if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL) |
| continue; |
| |
| if (strcmp(strtab + syms[k].st_name, name) != 0) |
| continue; |
| |
| if (syms[k].st_shndx == SHN_UNDEF || |
| syms[k].st_shndx >= ehdr->e_shnum) { |
| pr_debug("Symbol: %s has bad section index %d.\n", |
| name, syms[k].st_shndx); |
| return NULL; |
| } |
| |
| /* Found the symbol we are looking for */ |
| return &syms[k]; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| Elf_Sym *sym; |
| Elf_Shdr *sechdr; |
| |
| sym = kexec_purgatory_find_symbol(pi, name); |
| if (!sym) |
| return ERR_PTR(-EINVAL); |
| |
| sechdr = &pi->sechdrs[sym->st_shndx]; |
| |
| /* |
| * Returns the address where symbol will finally be loaded after |
| * kexec_load_segment() |
| */ |
| return (void *)(sechdr->sh_addr + sym->st_value); |
| } |
| |
| /* |
| * Get or set value of a symbol. If "get_value" is true, symbol value is |
| * returned in buf otherwise symbol value is set based on value in buf. |
| */ |
| int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, |
| void *buf, unsigned int size, bool get_value) |
| { |
| Elf_Sym *sym; |
| Elf_Shdr *sechdrs; |
| struct purgatory_info *pi = &image->purgatory_info; |
| char *sym_buf; |
| |
| sym = kexec_purgatory_find_symbol(pi, name); |
| if (!sym) |
| return -EINVAL; |
| |
| if (sym->st_size != size) { |
| pr_err("symbol %s size mismatch: expected %lu actual %u\n", |
| name, (unsigned long)sym->st_size, size); |
| return -EINVAL; |
| } |
| |
| sechdrs = pi->sechdrs; |
| |
| if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { |
| pr_err("symbol %s is in a bss section. Cannot %s\n", name, |
| get_value ? "get" : "set"); |
| return -EINVAL; |
| } |
| |
| sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset + |
| sym->st_value; |
| |
| if (get_value) |
| memcpy((void *)buf, sym_buf, size); |
| else |
| memcpy((void *)sym_buf, buf, size); |
| |
| return 0; |
| } |
| #endif /* CONFIG_KEXEC_FILE */ |
| |
| /* |
| * 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; |
| } |