}
#endif
-/* Apply relocations of type RELA */
+/*
+ * 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(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
- unsigned int relsec)
+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;
}
-/* Apply relocations of type REL */
+/*
+ * 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(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
- unsigned int relsec)
+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;
}
#ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
-/* 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)
+/*
+ * 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)
{
- struct purgatory_info *pi = &image->purgatory_info;
- unsigned long align, bss_align, bss_sz, bss_pad;
- unsigned long 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;
- struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1,
- .buf_min = min, .buf_max = max,
- .top_down = top_down };
-
- /*
- * 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;
- }
- }
+ const Elf_Shdr *sechdrs;
+ unsigned long bss_align;
+ unsigned long bss_sz;
+ unsigned long align;
+ int i, ret;
- /* Determine how much memory is needed to load relocatable object. */
- bss_align = 1;
- bss_sz = 0;
+ 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))
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;
+ if (kbuf->buf_align < align)
+ kbuf->buf_align = align;
+ kbuf->bufsz = ALIGN(kbuf->bufsz, align);
+ kbuf->bufsz += 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;
}
}
+ kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
+ kbuf->memsz = kbuf->bufsz + bss_sz;
+ if (kbuf->buf_align < bss_align)
+ kbuf->buf_align = bss_align;
- /* Determine the bss padding required to align bss properly */
- bss_pad = 0;
- if (kbuf.bufsz & (bss_align - 1))
- bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1));
-
- kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz;
+ kbuf->buffer = vzalloc(kbuf->bufsz);
+ if (!kbuf->buffer)
+ return -ENOMEM;
+ pi->purgatory_buf = kbuf->buffer;
- /* Allocate buffer for purgatory */
- kbuf.buffer = vzalloc(kbuf.bufsz);
- if (!kbuf.buffer) {
- ret = -ENOMEM;
+ ret = kexec_add_buffer(kbuf);
+ if (ret)
goto out;
- }
- if (kbuf.buf_align < bss_align)
- kbuf.buf_align = bss_align;
+ return 0;
+out:
+ vfree(pi->purgatory_buf);
+ pi->purgatory_buf = NULL;
+ return ret;
+}
- /* Add buffer to segment list */
- ret = kexec_add_buffer(&kbuf);
- if (ret)
- goto out;
- pi->purgatory_load_addr = kbuf.mem;
+/*
+ * 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(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
+ if (!sechdrs)
+ return -ENOMEM;
+ memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
+ pi->ehdr->e_shnum * sizeof(Elf_Shdr));
+ pi->sechdrs = sechdrs;
- /* Load SHF_ALLOC sections */
- buf_addr = kbuf.buffer;
- load_addr = curr_load_addr = pi->purgatory_load_addr;
- bss_addr = load_addr + kbuf.bufsz + bss_pad;
+ 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) {
- 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 {
+ 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;
}
- }
- /* Update entry point based on load address of text section */
- if (entry_sidx >= 0)
- entry += sechdrs[entry_sidx].sh_addr;
+ 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;
+ }
- /* Make kernel jump to purgatory after shutdown */
- image->start = entry;
+ src = (void *)pi->ehdr + sechdrs[i].sh_offset;
+ dst = pi->purgatory_buf + offset;
+ memcpy(dst, src, sechdrs[i].sh_size);
- /* Used later to get/set symbol values */
- pi->sechdrs = sechdrs;
+ sechdrs[i].sh_addr = kbuf->mem + offset;
+ sechdrs[i].sh_offset = offset;
+ offset += sechdrs[i].sh_size;
+ }
- /*
- * Used later to identify which section is purgatory and skip it
- * from checksumming.
- */
- pi->purgatory_buf = kbuf.buffer;
- return ret;
-out:
- vfree(sechdrs);
- vfree(kbuf.buffer);
- return ret;
+ return 0;
}
static int kexec_apply_relocations(struct kimage *image)
{
int i, ret;
struct purgatory_info *pi = &image->purgatory_info;
- Elf_Shdr *sechdrs = pi->sechdrs;
+ const Elf_Shdr *sechdrs;
+
+ sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
- /* Apply relocations */
for (i = 0; i < pi->ehdr->e_shnum; i++) {
- Elf_Shdr *section, *symtab;
+ const Elf_Shdr *relsec;
+ const Elf_Shdr *symtab;
+ Elf_Shdr *section;
- if (sechdrs[i].sh_type != SHT_RELA &&
- sechdrs[i].sh_type != SHT_REL)
+ relsec = sechdrs + i;
+
+ if (relsec->sh_type != SHT_RELA &&
+ relsec->sh_type != SHT_REL)
continue;
/*
* 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)
+ if (relsec->sh_info >= pi->ehdr->e_shnum ||
+ relsec->sh_link >= pi->ehdr->e_shnum)
return -ENOEXEC;
- section = &sechdrs[sechdrs[i].sh_info];
- symtab = &sechdrs[sechdrs[i].sh_link];
+ section = pi->sechdrs + relsec->sh_info;
+ symtab = sechdrs + relsec->sh_link;
if (!(section->sh_flags & SHF_ALLOC))
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 (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;
}
-/* 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)
+/*
+ * 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;
pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
- ret = __kexec_load_purgatory(image, min, max, top_down);
+ 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;
- *load_addr = pi->purgatory_load_addr;
return 0;
out:
vfree(pi->sechdrs);
pi->sechdrs = NULL;
-
+out_free_kbuf:
vfree(pi->purgatory_buf);
pi->purgatory_buf = NULL;
return ret;
return -EINVAL;
}
- sym_buf = (char *)sec->sh_offset + sym->st_value;
+ sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
if (get_value)
memcpy((void *)buf, sym_buf, size);
projects / linux-2.6-block.git / blobdiff