v4.19.13 snapshot.
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
new file mode 100644
index 0000000..c6a3b68
--- /dev/null
+++ b/kernel/kexec_file.c
@@ -0,0 +1,1229 @@
+/*
+ * kexec: kexec_file_load system call
+ *
+ * Copyright (C) 2014 Red Hat Inc.
+ * Authors:
+ * Vivek Goyal <vgoyal@redhat.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/ima.h>
+#include <crypto/hash.h>
+#include <crypto/sha.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/vmalloc.h>
+#include "kexec_internal.h"
+
+static int kexec_calculate_store_digests(struct kimage *image);
+
+/*
+ * Currently this is the only default function that is exported as some
+ * architectures need it to do additional handlings.
+ * In the future, other default functions may be exported too if required.
+ */
+int kexec_image_probe_default(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ const struct kexec_file_ops * const *fops;
+ int ret = -ENOEXEC;
+
+ for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
+ ret = (*fops)->probe(buf, buf_len);
+ if (!ret) {
+ image->fops = *fops;
+ return ret;
+ }
+ }
+
+ 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 kexec_image_probe_default(image, buf, buf_len);
+}
+
+static void *kexec_image_load_default(struct kimage *image)
+{
+ if (!image->fops || !image->fops->load)
+ return ERR_PTR(-ENOEXEC);
+
+ return image->fops->load(image, image->kernel_buf,
+ image->kernel_buf_len, image->initrd_buf,
+ image->initrd_buf_len, image->cmdline_buf,
+ image->cmdline_buf_len);
+}
+
+void * __weak arch_kexec_kernel_image_load(struct kimage *image)
+{
+ return kexec_image_load_default(image);
+}
+
+static int kexec_image_post_load_cleanup_default(struct kimage *image)
+{
+ if (!image->fops || !image->fops->cleanup)
+ return 0;
+
+ return image->fops->cleanup(image->image_loader_data);
+}
+
+int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+ return kexec_image_post_load_cleanup_default(image);
+}
+
+#ifdef CONFIG_KEXEC_VERIFY_SIG
+static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ if (!image->fops || !image->fops->verify_sig) {
+ pr_debug("kernel loader does not support signature verification.\n");
+ return -EKEYREJECTED;
+ }
+
+ return image->fops->verify_sig(buf, buf_len);
+}
+
+int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ return kexec_image_verify_sig_default(image, buf, buf_len);
+}
+#endif
+
+/*
+ * arch_kexec_apply_relocations_add - apply relocations of type RELA
+ * @pi: Purgatory to be relocated.
+ * @section: Section relocations applying to.
+ * @relsec: Section containing RELAs.
+ * @symtab: Corresponding symtab.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak
+arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
+ const Elf_Shdr *relsec, const Elf_Shdr *symtab)
+{
+ pr_err("RELA relocation unsupported.\n");
+ return -ENOEXEC;
+}
+
+/*
+ * arch_kexec_apply_relocations - apply relocations of type REL
+ * @pi: Purgatory to be relocated.
+ * @section: Section relocations applying to.
+ * @relsec: Section containing RELs.
+ * @symtab: Corresponding symtab.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak
+arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
+ const Elf_Shdr *relsec, const Elf_Shdr *symtab)
+{
+ 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.
+ */
+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;
+ loff_t size;
+
+ ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
+ &size, INT_MAX, READING_KEXEC_IMAGE);
+ if (ret)
+ return ret;
+ image->kernel_buf_len = size;
+
+ /* IMA needs to pass the measurement list to the next kernel. */
+ ima_add_kexec_buffer(image);
+
+ /* 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 = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
+ &size, INT_MAX,
+ READING_KEXEC_INITRAMFS);
+ if (ret)
+ goto out;
+ image->initrd_buf_len = size;
+ }
+
+ if (cmdline_len) {
+ image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
+ if (IS_ERR(image->cmdline_buf)) {
+ ret = PTR_ERR(image->cmdline_buf);
+ image->cmdline_buf = NULL;
+ 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;
+}
+
+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 (kexec_crash_image)
+ arch_kexec_unprotect_crashkres();
+ }
+
+ 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;
+
+ /*
+ * Some architecture(like S390) may touch the crash memory before
+ * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
+ */
+ ret = kimage_crash_copy_vmcoreinfo(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:
+ if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
+ arch_kexec_protect_crashkres();
+
+ mutex_unlock(&kexec_mutex);
+ kimage_free(image);
+ return ret;
+}
+
+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(struct resource *res, void *arg)
+{
+ struct kexec_buf *kbuf = (struct kexec_buf *)arg;
+ u64 start = res->start, end = res->end;
+ 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);
+}
+
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf: Context info for the search. Also passed to @func.
+ * @func: Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+ int (*func)(struct resource *, void *))
+{
+ if (kbuf->image->type == KEXEC_TYPE_CRASH)
+ return walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+ crashk_res.start, crashk_res.end,
+ kbuf, func);
+ else
+ return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
+/**
+ * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
+ * @kbuf: Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+ int ret;
+
+ ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+
+ return ret == 1 ? 0 : -EADDRNOTAVAIL;
+}
+
+/**
+ * kexec_add_buffer - place a buffer in a kexec segment
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_add_buffer(struct kexec_buf *kbuf)
+{
+
+ struct kexec_segment *ksegment;
+ int ret;
+
+ /* Currently adding segment this way is allowed only in file mode */
+ if (!kbuf->image->file_mode)
+ return -EINVAL;
+
+ if (kbuf->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(&kbuf->image->control_pages)) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
+ /* Ensure minimum alignment needed for segments. */
+ kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
+ kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
+
+ /* Walk the RAM ranges and allocate a suitable range for the buffer */
+ ret = kexec_locate_mem_hole(kbuf);
+ if (ret)
+ return ret;
+
+ /* Found a suitable memory range */
+ ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
+ ksegment->kbuf = kbuf->buffer;
+ ksegment->bufsz = kbuf->bufsz;
+ ksegment->mem = kbuf->mem;
+ ksegment->memsz = kbuf->memsz;
+ kbuf->image->nr_segments++;
+ 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;
+
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
+ return 0;
+
+ 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, "purgatory_sha_regions",
+ sha_regions, sha_region_sz, 0);
+ if (ret)
+ goto out_free_digest;
+
+ ret = kexec_purgatory_get_set_symbol(image, "purgatory_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;
+}
+
+#ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
+/*
+ * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
+ * @pi: Purgatory to be loaded.
+ * @kbuf: Buffer to setup.
+ *
+ * Allocates the memory needed for the buffer. Caller is responsible to free
+ * the memory after use.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
+ struct kexec_buf *kbuf)
+{
+ const Elf_Shdr *sechdrs;
+ unsigned long bss_align;
+ unsigned long bss_sz;
+ unsigned long align;
+ int i, ret;
+
+ sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
+ kbuf->buf_align = bss_align = 1;
+ kbuf->bufsz = 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 (kbuf->buf_align < align)
+ kbuf->buf_align = align;
+ kbuf->bufsz = ALIGN(kbuf->bufsz, align);
+ kbuf->bufsz += sechdrs[i].sh_size;
+ } else {
+ if (bss_align < align)
+ bss_align = align;
+ bss_sz = ALIGN(bss_sz, align);
+ bss_sz += sechdrs[i].sh_size;
+ }
+ }
+ kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
+ kbuf->memsz = kbuf->bufsz + bss_sz;
+ if (kbuf->buf_align < bss_align)
+ kbuf->buf_align = bss_align;
+
+ kbuf->buffer = vzalloc(kbuf->bufsz);
+ if (!kbuf->buffer)
+ return -ENOMEM;
+ pi->purgatory_buf = kbuf->buffer;
+
+ ret = kexec_add_buffer(kbuf);
+ if (ret)
+ goto out;
+
+ return 0;
+out:
+ vfree(pi->purgatory_buf);
+ pi->purgatory_buf = NULL;
+ return ret;
+}
+
+/*
+ * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
+ * @pi: Purgatory to be loaded.
+ * @kbuf: Buffer prepared to store purgatory.
+ *
+ * Allocates the memory needed for the buffer. Caller is responsible to free
+ * the memory after use.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
+ struct kexec_buf *kbuf)
+{
+ unsigned long bss_addr;
+ unsigned long offset;
+ Elf_Shdr *sechdrs;
+ int i;
+
+ /*
+ * The section headers in kexec_purgatory are read-only. In order to
+ * have them modifiable make a temporary copy.
+ */
+ sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
+ if (!sechdrs)
+ return -ENOMEM;
+ memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
+ pi->ehdr->e_shnum * sizeof(Elf_Shdr));
+ pi->sechdrs = sechdrs;
+
+ offset = 0;
+ bss_addr = kbuf->mem + kbuf->bufsz;
+ kbuf->image->start = pi->ehdr->e_entry;
+
+ for (i = 0; i < pi->ehdr->e_shnum; i++) {
+ unsigned long align;
+ void *src, *dst;
+
+ if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+ continue;
+
+ align = sechdrs[i].sh_addralign;
+ if (sechdrs[i].sh_type == SHT_NOBITS) {
+ bss_addr = ALIGN(bss_addr, align);
+ sechdrs[i].sh_addr = bss_addr;
+ bss_addr += sechdrs[i].sh_size;
+ continue;
+ }
+
+ offset = ALIGN(offset, align);
+ if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
+ pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
+ pi->ehdr->e_entry < (sechdrs[i].sh_addr
+ + sechdrs[i].sh_size)) {
+ kbuf->image->start -= sechdrs[i].sh_addr;
+ kbuf->image->start += kbuf->mem + offset;
+ }
+
+ src = (void *)pi->ehdr + sechdrs[i].sh_offset;
+ dst = pi->purgatory_buf + offset;
+ memcpy(dst, src, sechdrs[i].sh_size);
+
+ sechdrs[i].sh_addr = kbuf->mem + offset;
+ sechdrs[i].sh_offset = offset;
+ offset += sechdrs[i].sh_size;
+ }
+
+ return 0;
+}
+
+static int kexec_apply_relocations(struct kimage *image)
+{
+ int i, ret;
+ struct purgatory_info *pi = &image->purgatory_info;
+ const Elf_Shdr *sechdrs;
+
+ sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
+
+ for (i = 0; i < pi->ehdr->e_shnum; i++) {
+ const Elf_Shdr *relsec;
+ const Elf_Shdr *symtab;
+ Elf_Shdr *section;
+
+ relsec = sechdrs + i;
+
+ if (relsec->sh_type != SHT_RELA &&
+ relsec->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 (relsec->sh_info >= pi->ehdr->e_shnum ||
+ relsec->sh_link >= pi->ehdr->e_shnum)
+ return -ENOEXEC;
+
+ section = pi->sechdrs + relsec->sh_info;
+ symtab = sechdrs + relsec->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 (relsec->sh_type == SHT_RELA)
+ ret = arch_kexec_apply_relocations_add(pi, section,
+ relsec, symtab);
+ else if (relsec->sh_type == SHT_REL)
+ ret = arch_kexec_apply_relocations(pi, section,
+ relsec, symtab);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * kexec_load_purgatory - Load and relocate the purgatory object.
+ * @image: Image to add the purgatory to.
+ * @kbuf: Memory parameters to use.
+ *
+ * Allocates the memory needed for image->purgatory_info.sechdrs and
+ * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
+ * to free the memory after use.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
+{
+ struct purgatory_info *pi = &image->purgatory_info;
+ int ret;
+
+ if (kexec_purgatory_size <= 0)
+ return -EINVAL;
+
+ pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
+
+ ret = kexec_purgatory_setup_kbuf(pi, kbuf);
+ if (ret)
+ return ret;
+
+ ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
+ if (ret)
+ goto out_free_kbuf;
+
+ ret = kexec_apply_relocations(image);
+ if (ret)
+ goto out;
+
+ return 0;
+out:
+ vfree(pi->sechdrs);
+ pi->sechdrs = NULL;
+out_free_kbuf:
+ vfree(pi->purgatory_buf);
+ pi->purgatory_buf = NULL;
+ return ret;
+}
+
+/*
+ * kexec_purgatory_find_symbol - find a symbol in the purgatory
+ * @pi: Purgatory to search in.
+ * @name: Name of the symbol.
+ *
+ * Return: pointer to symbol in read-only symtab on success, NULL on error.
+ */
+static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
+ const char *name)
+{
+ const Elf_Shdr *sechdrs;
+ const Elf_Ehdr *ehdr;
+ const Elf_Sym *syms;
+ const char *strtab;
+ int i, k;
+
+ if (!pi->ehdr)
+ return NULL;
+
+ ehdr = pi->ehdr;
+ sechdrs = (void *)ehdr + ehdr->e_shoff;
+
+ 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 = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
+ syms = (void *)ehdr + 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;
+ const 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)
+{
+ struct purgatory_info *pi = &image->purgatory_info;
+ const Elf_Sym *sym;
+ Elf_Shdr *sec;
+ 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;
+ }
+
+ sec = pi->sechdrs + sym->st_shndx;
+
+ if (sec->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 = (char *)pi->purgatory_buf + sec->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_ARCH_HAS_KEXEC_PURGATORY */
+
+int crash_exclude_mem_range(struct crash_mem *mem,
+ unsigned long long mstart, unsigned long long mend)
+{
+ int i, j;
+ unsigned long long start, end;
+ struct crash_mem_range temp_range = {0, 0};
+
+ for (i = 0; i < mem->nr_ranges; i++) {
+ start = mem->ranges[i].start;
+ end = mem->ranges[i].end;
+
+ if (mstart > end || mend < start)
+ continue;
+
+ /* Truncate any area outside of range */
+ if (mstart < start)
+ mstart = start;
+ if (mend > end)
+ mend = end;
+
+ /* Found completely overlapping range */
+ if (mstart == start && mend == end) {
+ mem->ranges[i].start = 0;
+ mem->ranges[i].end = 0;
+ if (i < mem->nr_ranges - 1) {
+ /* Shift rest of the ranges to left */
+ for (j = i; j < mem->nr_ranges - 1; j++) {
+ mem->ranges[j].start =
+ mem->ranges[j+1].start;
+ mem->ranges[j].end =
+ mem->ranges[j+1].end;
+ }
+ }
+ mem->nr_ranges--;
+ return 0;
+ }
+
+ if (mstart > start && mend < end) {
+ /* Split original range */
+ mem->ranges[i].end = mstart - 1;
+ temp_range.start = mend + 1;
+ temp_range.end = end;
+ } else if (mstart != start)
+ mem->ranges[i].end = mstart - 1;
+ else
+ mem->ranges[i].start = mend + 1;
+ break;
+ }
+
+ /* If a split happened, add the split to array */
+ if (!temp_range.end)
+ return 0;
+
+ /* Split happened */
+ if (i == mem->max_nr_ranges - 1)
+ return -ENOMEM;
+
+ /* Location where new range should go */
+ j = i + 1;
+ if (j < mem->nr_ranges) {
+ /* Move over all ranges one slot towards the end */
+ for (i = mem->nr_ranges - 1; i >= j; i--)
+ mem->ranges[i + 1] = mem->ranges[i];
+ }
+
+ mem->ranges[j].start = temp_range.start;
+ mem->ranges[j].end = temp_range.end;
+ mem->nr_ranges++;
+ return 0;
+}
+
+int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
+ void **addr, unsigned long *sz)
+{
+ Elf64_Ehdr *ehdr;
+ Elf64_Phdr *phdr;
+ unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
+ unsigned char *buf;
+ unsigned int cpu, i;
+ unsigned long long notes_addr;
+ unsigned long mstart, mend;
+
+ /* extra phdr for vmcoreinfo elf note */
+ nr_phdr = nr_cpus + 1;
+ nr_phdr += mem->nr_ranges;
+
+ /*
+ * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
+ * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
+ * I think this is required by tools like gdb. So same physical
+ * memory will be mapped in two elf headers. One will contain kernel
+ * text virtual addresses and other will have __va(physical) addresses.
+ */
+
+ nr_phdr++;
+ elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
+ elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
+
+ buf = vzalloc(elf_sz);
+ if (!buf)
+ return -ENOMEM;
+
+ ehdr = (Elf64_Ehdr *)buf;
+ phdr = (Elf64_Phdr *)(ehdr + 1);
+ memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+ ehdr->e_ident[EI_CLASS] = ELFCLASS64;
+ ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+ ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+ ehdr->e_ident[EI_OSABI] = ELF_OSABI;
+ memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
+ ehdr->e_type = ET_CORE;
+ ehdr->e_machine = ELF_ARCH;
+ ehdr->e_version = EV_CURRENT;
+ ehdr->e_phoff = sizeof(Elf64_Ehdr);
+ ehdr->e_ehsize = sizeof(Elf64_Ehdr);
+ ehdr->e_phentsize = sizeof(Elf64_Phdr);
+
+ /* Prepare one phdr of type PT_NOTE for each present cpu */
+ for_each_present_cpu(cpu) {
+ phdr->p_type = PT_NOTE;
+ notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
+ phdr->p_offset = phdr->p_paddr = notes_addr;
+ phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
+ (ehdr->e_phnum)++;
+ phdr++;
+ }
+
+ /* Prepare one PT_NOTE header for vmcoreinfo */
+ phdr->p_type = PT_NOTE;
+ phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
+ phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
+ (ehdr->e_phnum)++;
+ phdr++;
+
+ /* Prepare PT_LOAD type program header for kernel text region */
+ if (kernel_map) {
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_vaddr = (Elf64_Addr)_text;
+ phdr->p_filesz = phdr->p_memsz = _end - _text;
+ phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
+ ehdr->e_phnum++;
+ phdr++;
+ }
+
+ /* Go through all the ranges in mem->ranges[] and prepare phdr */
+ for (i = 0; i < mem->nr_ranges; i++) {
+ mstart = mem->ranges[i].start;
+ mend = mem->ranges[i].end;
+
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_offset = mstart;
+
+ phdr->p_paddr = mstart;
+ phdr->p_vaddr = (unsigned long long) __va(mstart);
+ phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
+ phdr->p_align = 0;
+ ehdr->e_phnum++;
+ phdr++;
+ pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
+ phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
+ ehdr->e_phnum, phdr->p_offset);
+ }
+
+ *addr = buf;
+ *sz = elf_sz;
+ return 0;
+}