diff options
| -rw-r--r-- | kernel/kexec_file.c | 200 |
1 files changed, 103 insertions, 97 deletions
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 5c70f7f2bae3..878b97bd3067 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -710,39 +710,97 @@ out: } #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 }; + const Elf_Shdr *sechdrs; + unsigned long bss_align; + unsigned long bss_sz; + unsigned long align; + int i, ret; - /* - * sechdrs_c points to section headers in purgatory and are read - * only. No modifications allowed. - */ - sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff; + sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; + bss_align = 1; + 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; + pi->purgatory_load_addr = kbuf->mem; + + 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 curr_load_addr; + unsigned long load_addr; + unsigned long bss_addr; + unsigned long offset; + unsigned char *buf_addr; + unsigned char *src; + Elf_Shdr *sechdrs; + int entry_sidx = -1; + int i; - /* - * 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)); + memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, + pi->ehdr->e_shnum * sizeof(Elf_Shdr)); + pi->sechdrs = sechdrs; /* * We seem to have multiple copies of sections. First copy is which @@ -770,7 +828,7 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, * Identify entry point section and make entry relative to section * start. */ - entry = pi->ehdr->e_entry; + kbuf->image->start = pi->ehdr->e_entry; for (i = 0; i < pi->ehdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) continue; @@ -783,63 +841,19 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > pi->ehdr->e_entry)) { entry_sidx = i; - entry -= sechdrs[i].sh_addr; + kbuf->image->start -= sechdrs[i].sh_addr; break; } } - /* Determine how much memory is needed to load relocatable object. */ - bss_align = 1; - 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 { - /* 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 (kbuf.bufsz & (bss_align - 1)) - bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1)); - - kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz; - - /* Allocate buffer for purgatory */ - kbuf.buffer = vzalloc(kbuf.bufsz); - if (!kbuf.buffer) { - ret = -ENOMEM; - goto out; - } - - if (kbuf.buf_align < bss_align) - kbuf.buf_align = bss_align; - - /* Add buffer to segment list */ - ret = kexec_add_buffer(&kbuf); - if (ret) - goto out; - pi->purgatory_load_addr = kbuf.mem; - /* 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; + buf_addr = kbuf->buffer; + load_addr = curr_load_addr = kbuf->mem; + bss_addr = load_addr + kbuf->bufsz; for (i = 0; i < pi->ehdr->e_shnum; i++) { + unsigned long align; + if (!(sechdrs[i].sh_flags & SHF_ALLOC)) continue; @@ -871,24 +885,9 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, /* 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; + kbuf->image->start += sechdrs[entry_sidx].sh_addr; - /* - * 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) @@ -958,16 +957,23 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, { struct purgatory_info *pi = &image->purgatory_info; int ret; + struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1, + .buf_min = min, .buf_max = max, + .top_down = top_down }; if (kexec_purgatory_size <= 0) return -EINVAL; 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; @@ -977,7 +983,7 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, out: vfree(pi->sechdrs); pi->sechdrs = NULL; - +out_free_kbuf: vfree(pi->purgatory_buf); pi->purgatory_buf = NULL; return ret; |