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-rw-r--r--kexec/crashdump-elf.c241
1 files changed, 241 insertions, 0 deletions
diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c
new file mode 100644
index 0000000..b8bb686
--- /dev/null
+++ b/kexec/crashdump-elf.c
@@ -0,0 +1,241 @@
+
+#if !defined(FUNC) || !defined(EHDR) || !defined(PHDR)
+#error FUNC, EHDR and PHDR must be defined
+#endif
+
+#if (ELF_WIDTH == 64)
+#define dbgprintf_phdr(prefix, phdr) \
+do { \
+ dbgprintf("%s: p_type = %u, p_offset = 0x%llx p_paddr = 0x%llx " \
+ "p_vaddr = 0x%llx p_filesz = 0x%llx p_memsz = 0x%llx\n", \
+ (prefix), (phdr)->p_type, \
+ (unsigned long long)((phdr)->p_offset), \
+ (unsigned long long)((phdr)->p_paddr), \
+ (unsigned long long)((phdr)->p_vaddr), \
+ (unsigned long long)((phdr)->p_filesz), \
+ (unsigned long long)((phdr)->p_memsz)); \
+} while(0)
+#else
+#define dbgprintf_phdr(prefix, phdr) \
+do { \
+ dbgprintf("%s: p_type = %u, p_offset = 0x%x " "p_paddr = 0x%x " \
+ "p_vaddr = 0x%x p_filesz = 0x%x p_memsz = 0x%x\n", \
+ (prefix), (phdr)->p_type, (phdr)->p_offset, (phdr)->p_paddr, \
+ (phdr)->p_vaddr, (phdr)->p_filesz, (phdr)->p_memsz); \
+} while(0)
+#endif
+
+/* Prepares the crash memory headers and stores in supplied buffer. */
+int FUNC(struct kexec_info *info,
+ struct crash_elf_info *elf_info,
+ struct memory_range *range, int ranges,
+ void **buf, unsigned long *size, unsigned long align)
+{
+ EHDR *elf;
+ PHDR *phdr;
+ int i;
+ unsigned long sz;
+ char *bufp;
+ long int nr_cpus = 0;
+ uint64_t notes_addr, notes_len;
+ uint64_t vmcoreinfo_addr, vmcoreinfo_len;
+ int has_vmcoreinfo = 0;
+ int (*get_note_info)(int cpu, uint64_t *addr, uint64_t *len);
+ long int count_cpu;
+
+ if (xen_present())
+ nr_cpus = xen_get_nr_phys_cpus();
+ else
+ nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+
+ if (nr_cpus < 0) {
+ return -1;
+ }
+
+ if (xen_present()) {
+ if (!get_xen_vmcoreinfo(&vmcoreinfo_addr, &vmcoreinfo_len))
+ has_vmcoreinfo = 1;
+ } else
+ if (!get_kernel_vmcoreinfo(&vmcoreinfo_addr, &vmcoreinfo_len))
+ has_vmcoreinfo = 1;
+
+ sz = sizeof(EHDR) + (nr_cpus + has_vmcoreinfo) * sizeof(PHDR) +
+ ranges * sizeof(PHDR);
+
+ /*
+ * Certain architectures such as x86_64 and ia64 require a separate
+ * PT_LOAD program header for the kernel. This is controlled through
+ * elf_info->kern_size.
+ *
+ * The separate PT_LOAD program header is required either because the
+ * kernel is mapped at a different location than the rest of the
+ * physical memory or because we need to support relocatable kernels.
+ * Or both as on x86_64.
+ *
+ * In the relocatable kernel case this PT_LOAD segment is used to tell
+ * where the kernel was actually loaded which may be different from
+ * the load address present in the vmlinux file.
+ *
+ * The extra kernel PT_LOAD program header results in a vmcore file
+ * which is larger than the size of the physical memory. This is
+ * because the memory for the kernel is present both in the kernel
+ * PT_LOAD program header and in the physical RAM program headers.
+ */
+
+ if (elf_info->kern_size && !xen_present()) {
+ sz += sizeof(PHDR);
+ }
+
+ /*
+ * Make sure the ELF core header is aligned to at least 1024.
+ * We do this because the secondary kernel gets the ELF core
+ * header address on the kernel command line through the memmap=
+ * option, and this option requires 1k granularity.
+ */
+
+ if (align % ELF_CORE_HEADER_ALIGN) {
+ return -1;
+ }
+
+ sz = _ALIGN(sz, align);
+
+ bufp = xmalloc(sz);
+ memset(bufp, 0, sz);
+
+ *buf = bufp;
+ *size = sz;
+
+ /* Setup ELF Header*/
+ elf = (EHDR *) bufp;
+ bufp += sizeof(EHDR);
+ memcpy(elf->e_ident, ELFMAG, SELFMAG);
+ elf->e_ident[EI_CLASS] = elf_info->class;
+ elf->e_ident[EI_DATA] = elf_info->data;
+ elf->e_ident[EI_VERSION]= EV_CURRENT;
+ elf->e_ident[EI_OSABI] = ELFOSABI_NONE;
+ memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+ elf->e_type = ET_CORE;
+ elf->e_machine = crash_architecture(elf_info);
+ elf->e_version = EV_CURRENT;
+ elf->e_entry = 0;
+ elf->e_phoff = sizeof(EHDR);
+ elf->e_shoff = 0;
+ elf->e_flags = 0;
+ elf->e_ehsize = sizeof(EHDR);
+ elf->e_phentsize= sizeof(PHDR);
+ elf->e_phnum = 0;
+ elf->e_shentsize= 0;
+ elf->e_shnum = 0;
+ elf->e_shstrndx = 0;
+
+ /* Default way to get crash notes is by get_crash_notes_per_cpu() */
+
+ get_note_info = elf_info->get_note_info;
+ if (!get_note_info)
+ get_note_info = get_crash_notes_per_cpu;
+
+ if (xen_present())
+ get_note_info = xen_get_note;
+
+ /* PT_NOTE program headers. One per cpu */
+
+ count_cpu = nr_cpus;
+ for (i = 0; count_cpu > 0; i++) {
+ int ret;
+
+ ret = get_note_info(i, &notes_addr, &notes_len);
+ count_cpu--;
+ if (ret < 0) /* This cpu is not present. Skip it. */
+ continue;
+
+ phdr = (PHDR *) bufp;
+ bufp += sizeof(PHDR);
+ phdr->p_type = PT_NOTE;
+ phdr->p_flags = 0;
+ phdr->p_offset = phdr->p_paddr = notes_addr;
+ phdr->p_vaddr = 0;
+ phdr->p_filesz = phdr->p_memsz = notes_len;
+ /* Do we need any alignment of segments? */
+ phdr->p_align = 0;
+
+ /* Increment number of program headers. */
+ (elf->e_phnum)++;
+ dbgprintf_phdr("Elf header", phdr);
+ }
+
+ if (has_vmcoreinfo && !(info->kexec_flags & KEXEC_PRESERVE_CONTEXT)) {
+ phdr = (PHDR *) bufp;
+ bufp += sizeof(PHDR);
+ phdr->p_type = PT_NOTE;
+ phdr->p_flags = 0;
+ phdr->p_offset = phdr->p_paddr = vmcoreinfo_addr;
+ phdr->p_vaddr = 0;
+ phdr->p_filesz = phdr->p_memsz = vmcoreinfo_len;
+ /* Do we need any alignment of segments? */
+ phdr->p_align = 0;
+
+ (elf->e_phnum)++;
+ dbgprintf_phdr("vmcoreinfo header", phdr);
+ }
+
+ /* Setup an PT_LOAD type program header for the region where
+ * Kernel is mapped if elf_info->kern_size is non-zero.
+ */
+
+ if (elf_info->kern_size && !xen_present()) {
+ phdr = (PHDR *) bufp;
+ bufp += sizeof(PHDR);
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_offset = phdr->p_paddr = elf_info->kern_paddr_start;
+ phdr->p_vaddr = elf_info->kern_vaddr_start;
+ phdr->p_filesz = phdr->p_memsz = elf_info->kern_size;
+ phdr->p_align = 0;
+ (elf->e_phnum)++;
+ dbgprintf_phdr("Kernel text Elf header", phdr);
+ }
+
+ /* Setup PT_LOAD type program header for every system RAM chunk.
+ * A seprate program header for Backup Region*/
+ for (i = 0; i < ranges; i++, range++) {
+ unsigned long long mstart, mend;
+ if (range->type != RANGE_RAM)
+ continue;
+ mstart = range->start;
+ mend = range->end;
+ if (!mstart && !mend)
+ continue;
+ phdr = (PHDR *) bufp;
+ bufp += sizeof(PHDR);
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_offset = mstart;
+
+ if (mstart == info->backup_src_start
+ && (mend - mstart + 1) == info->backup_src_size)
+ phdr->p_offset = info->backup_start;
+
+ /* We already prepared the header for kernel text. Map
+ * rest of the memory segments to kernel linearly mapped
+ * memory region.
+ */
+ phdr->p_paddr = mstart;
+ phdr->p_vaddr = phys_to_virt(elf_info, mstart);
+ phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
+ /* Do we need any alignment of segments? */
+ phdr->p_align = 0;
+
+ /* HIGMEM has a virtual address of -1 */
+
+ if (elf_info->lowmem_limit
+ && (mend > (elf_info->lowmem_limit - 1)))
+ phdr->p_vaddr = -1;
+
+ /* Increment number of program headers. */
+ (elf->e_phnum)++;
+ dbgprintf_phdr("Elf header", phdr);
+ }
+ return 0;
+}
+
+#undef dbgprintf_phdr
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