#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;
/* 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;
+
+static int kexec_calculate_store_digests(struct kimage *image);
+
/* Location of the reserved area for the crash kernel */
struct resource crashk_res = {
.name = "Crash kernel",
{
}
+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 comand line. This is temporary
* memory allocation which is not needed any more after these buffers have
*/
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;
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;
}
/*
if (ret)
goto out;
+#ifdef CONFIG_KEXEC_VERIFY_SIG
+ ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
+ image->kernel_buf_len);
+ if (ret) {
+ pr_debug("kernel signature verification failed.\n");
+ goto out;
+ }
+ pr_debug("kernel signature verification successful.\n");
+#endif
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
{
int ret;
struct kimage *image;
+ bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
image = do_kimage_alloc_init();
if (!image)
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_post_load_bufs;
}
- image->swap_page = kimage_alloc_control_pages(image, 0);
- if (!image->swap_page) {
- pr_err(KERN_ERR "Could not allocate swap buffer\n");
- goto out_free_control_pages;
+ if (!kexec_on_panic) {
+ image->swap_page = kimage_alloc_control_pages(image, 0);
+ if (!image->swap_page) {
+ pr_err(KERN_ERR "Could not allocate swap buffer\n");
+ goto out_free_control_pages;
+ }
}
*rimage = image;
kimage_free_page_list(&image->control_pages);
out_free_post_load_bufs:
kimage_file_post_load_cleanup(image);
- kfree(image->image_loader_data);
out_free_image:
kfree(image);
return ret;
/* Free the kexec control pages... */
kimage_free_page_list(&image->control_pages);
- kfree(image->image_loader_data);
-
/*
* Free up any temporary buffers allocated. This might hit if
* error occurred much later after buffer allocation.
unsigned long maddr;
size_t ubytes, mbytes;
int result;
- unsigned char __user *buf;
+ unsigned char __user *buf = NULL;
+ unsigned char *kbuf = NULL;
result = 0;
- buf = segment->buf;
+ if (image->file_mode)
+ kbuf = segment->kbuf;
+ else
+ buf = segment->buf;
ubytes = segment->bufsz;
mbytes = segment->memsz;
maddr = segment->mem;
/* Zero the trailing part of the page */
memset(ptr + uchunk, 0, mchunk - uchunk);
}
- result = copy_from_user(ptr, buf, 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) {
}
ubytes -= uchunk;
maddr += mchunk;
- buf += mchunk;
+ if (image->file_mode)
+ kbuf += mchunk;
+ else
+ buf += mchunk;
mbytes -= mchunk;
}
out:
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;
kbuf->top_down = top_down;
/* Walk the RAM ranges and allocate a suitable range for the buffer */
- ret = walk_system_ram_res(0, -1, kbuf, locate_mem_hole_callback);
+ 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;
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 archicture needs to provide support for applying
+ * relocations of type SHT_RELA/SHT_REL.
+ */
+ if (sechdrs[i].sh_type == SHT_RELA)
+ ret = arch_kexec_apply_relocations_add(pi->ehdr,
+ sechdrs, i);
+ else if (sechdrs[i].sh_type == SHT_REL)
+ ret = arch_kexec_apply_relocations(pi->ehdr,
+ sechdrs, i);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Load relocatable purgatory object and relocate it appropriately */
+int kexec_load_purgatory(struct kimage *image, unsigned long min,
+ unsigned long max, int top_down,
+ unsigned long *load_addr)
+{
+ struct purgatory_info *pi = &image->purgatory_info;
+ int ret;
+
+ if (kexec_purgatory_size <= 0)
+ return -EINVAL;
+
+ if (kexec_purgatory_size < sizeof(Elf_Ehdr))
+ return -ENOEXEC;
+
+ pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
+
+ if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
+ || pi->ehdr->e_type != ET_REL
+ || !elf_check_arch(pi->ehdr)
+ || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
+ return -ENOEXEC;
+
+ if (pi->ehdr->e_shoff >= kexec_purgatory_size
+ || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
+ kexec_purgatory_size - pi->ehdr->e_shoff))
+ return -ENOEXEC;
+
+ ret = __kexec_load_purgatory(image, min, max, top_down);
+ if (ret)
+ return ret;
+
+ ret = kexec_apply_relocations(image);
+ if (ret)
+ goto out;
+
+ *load_addr = pi->purgatory_load_addr;
+ return 0;
+out:
+ vfree(pi->sechdrs);
+ vfree(pi->purgatory_buf);
+ return ret;
+}
+
+static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
+ const char *name)
+{
+ Elf_Sym *syms;
+ Elf_Shdr *sechdrs;
+ Elf_Ehdr *ehdr;
+ int i, k;
+ const char *strtab;
+
+ if (!pi->sechdrs || !pi->ehdr)
+ return NULL;
+
+ sechdrs = pi->sechdrs;
+ ehdr = pi->ehdr;
+
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (sechdrs[i].sh_type != SHT_SYMTAB)
+ continue;
+
+ if (sechdrs[i].sh_link >= ehdr->e_shnum)
+ /* Invalid strtab section number */
+ continue;
+ strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset;
+ syms = (Elf_Sym *)sechdrs[i].sh_offset;
+
+ /* Go through symbols for a match */
+ for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
+ if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
+ continue;
+
+ if (strcmp(strtab + syms[k].st_name, name) != 0)
+ continue;
+
+ if (syms[k].st_shndx == SHN_UNDEF ||
+ syms[k].st_shndx >= ehdr->e_shnum) {
+ pr_debug("Symbol: %s has bad section index %d.\n",
+ name, syms[k].st_shndx);
+ return NULL;
+ }
+
+ /* Found the symbol we are looking for */
+ return &syms[k];
+ }
+ }
+
+ return NULL;
+}
+
+void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
+{
+ struct purgatory_info *pi = &image->purgatory_info;
+ Elf_Sym *sym;
+ Elf_Shdr *sechdr;
+
+ sym = kexec_purgatory_find_symbol(pi, name);
+ if (!sym)
+ return ERR_PTR(-EINVAL);
+
+ sechdr = &pi->sechdrs[sym->st_shndx];
+
+ /*
+ * Returns the address where symbol will finally be loaded after
+ * kexec_load_segment()
+ */
+ return (void *)(sechdr->sh_addr + sym->st_value);
+}
+
+/*
+ * Get or set value of a symbol. If "get_value" is true, symbol value is
+ * returned in buf otherwise symbol value is set based on value in buf.
+ */
+int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
+ void *buf, unsigned int size, bool get_value)
+{
+ Elf_Sym *sym;
+ Elf_Shdr *sechdrs;
+ struct purgatory_info *pi = &image->purgatory_info;
+ char *sym_buf;
+
+ sym = kexec_purgatory_find_symbol(pi, name);
+ if (!sym)
+ return -EINVAL;
+
+ if (sym->st_size != size) {
+ pr_err("symbol %s size mismatch: expected %lu actual %u\n",
+ name, (unsigned long)sym->st_size, size);
+ return -EINVAL;
+ }
+
+ sechdrs = pi->sechdrs;
+
+ if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
+ pr_err("symbol %s is in a bss section. Cannot %s\n", name,
+ get_value ? "get" : "set");
+ return -EINVAL;
+ }
+
+ sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset +
+ sym->st_value;
+
+ if (get_value)
+ memcpy((void *)buf, sym_buf, size);
+ else
+ memcpy((void *)sym_buf, buf, size);
+
+ return 0;
+}
/*
* Move into place and start executing a preloaded standalone
git.openpandora.org / pandora-kernel.git / blobdiff