/*
- * kexec.c - kexec system call
+ * kexec.c - kexec_load 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
+#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/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)
+#include <linux/slab.h>
-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);
+#include "kexec_internal.h"
static int copy_user_segment_list(struct kimage *image,
unsigned long nr_segments,
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,
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.
+ * 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.
*/
-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;
+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;
- vfree(pi->purgatory_buf);
- pi->purgatory_buf = NULL;
+ /* We only trust the superuser with rebooting the system. */
+ if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
+ return -EPERM;
- vfree(pi->sechdrs);
- pi->sechdrs = NULL;
+ /*
+ * 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;
- /* See if architecture has anything to cleanup post load */
- arch_kimage_file_post_load_cleanup(image);
+ /* Verify we are on the appropriate architecture */
+ if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
+ ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
+ return -EINVAL;
- /*
- * 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.
+ /* Put an artificial cap on the number
+ * of segments passed to kexec_load.
*/
- kfree(image->image_loader_data);
- image->image_loader_data = NULL;
-}
+ if (nr_segments > KEXEC_SEGMENT_MAX)
+ return -EINVAL;
-/*
- * 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;
+ image = NULL;
+ result = 0;
- ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
- &image->kernel_buf_len);
- if (ret)
- return ret;
+ /* 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;
- /* Call arch image probe handlers */
- ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
- image->kernel_buf_len);
+ dest_image = &kexec_image;
+ if (flags & KEXEC_ON_CRASH)
+ dest_image = &kexec_crash_image;
+ if (nr_segments > 0) {
+ unsigned long i;
- if (ret)
- goto out;
+ 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.
+ */
-#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;
- }
+ 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. */
- if (cmdline_len) {
- image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL);
- if (!image->cmdline_buf) {
- ret = -ENOMEM;
- goto out;
+ result = kimage_alloc_init(&image, entry, nr_segments,
+ segments, flags);
}
-
- ret = copy_from_user(image->cmdline_buf, cmdline_ptr,
- cmdline_len);
- if (ret) {
- ret = -EFAULT;
+ if (result)
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;
+ if (flags & KEXEC_PRESERVE_CONTEXT)
+ image->preserve_context = 1;
+ result = machine_kexec_prepare(image);
+ if (result)
goto out;
- }
- }
-
- /* Call arch image load handlers */
- ldata = arch_kexec_kernel_image_load(image);
- if (IS_ERR(ldata)) {
- ret = PTR_ERR(ldata);
- 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);
- 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;
+ mutex_unlock(&kexec_mutex);
+ kimage_free(image);
+
+ return result;
}
-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)
+#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)
{
- int ret;
- struct kimage *image;
- bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
-
- image = do_kimage_alloc_init();
- if (!image)
- return -ENOMEM;
+ struct compat_kexec_segment in;
+ struct kexec_segment out, __user *ksegments;
+ unsigned long i, result;
- image->file_mode = 1;
+ /* 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 (kexec_on_panic) {
- /* Enable special crash kernel control page alloc policy. */
- image->control_page = crashk_res.start;
- image->type = KEXEC_TYPE_CRASH;
- }
+ if (nr_segments > KEXEC_SEGMENT_MAX)
+ return -EINVAL;
- ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
- cmdline_ptr, cmdline_len, flags);
- if (ret)
- goto out_free_image;
+ 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;
- 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;
+ out.buf = compat_ptr(in.buf);
+ out.bufsz = in.bufsz;
+ out.mem = in.mem;
+ out.memsz = in.memsz;
- 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;
+ result = copy_to_user(&ksegments[i], &out, sizeof(out));
+ if (result)
+ return -EFAULT;
}
- 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;
+ return sys_kexec_load(entry, nr_segments, ksegments, flags);
}
-#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;
-}
Code Review / kvmfornfv.git / blobdiff