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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /fs/proc/vmcore.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/proc/vmcore.c')
-rw-r--r--fs/proc/vmcore.c1589
1 files changed, 1589 insertions, 0 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
new file mode 100644
index 000000000..0e4278d4a
--- /dev/null
+++ b/fs/proc/vmcore.c
@@ -0,0 +1,1589 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fs/proc/vmcore.c Interface for accessing the crash
+ * dump from the system's previous life.
+ * Heavily borrowed from fs/proc/kcore.c
+ * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
+ * Copyright (C) IBM Corporation, 2004. All rights reserved
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/kcore.h>
+#include <linux/user.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/printk.h>
+#include <linux/memblock.h>
+#include <linux/init.h>
+#include <linux/crash_dump.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+#include <linux/mem_encrypt.h>
+#include <asm/io.h>
+#include "internal.h"
+
+/* List representing chunks of contiguous memory areas and their offsets in
+ * vmcore file.
+ */
+static LIST_HEAD(vmcore_list);
+
+/* Stores the pointer to the buffer containing kernel elf core headers. */
+static char *elfcorebuf;
+static size_t elfcorebuf_sz;
+static size_t elfcorebuf_sz_orig;
+
+static char *elfnotes_buf;
+static size_t elfnotes_sz;
+/* Size of all notes minus the device dump notes */
+static size_t elfnotes_orig_sz;
+
+/* Total size of vmcore file. */
+static u64 vmcore_size;
+
+static struct proc_dir_entry *proc_vmcore;
+
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+/* Device Dump list and mutex to synchronize access to list */
+static LIST_HEAD(vmcoredd_list);
+static DEFINE_MUTEX(vmcoredd_mutex);
+
+static bool vmcoredd_disabled;
+core_param(novmcoredd, vmcoredd_disabled, bool, 0);
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+
+/* Device Dump Size */
+static size_t vmcoredd_orig_sz;
+
+/*
+ * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
+ * The called function has to take care of module refcounting.
+ */
+static int (*oldmem_pfn_is_ram)(unsigned long pfn);
+
+int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
+{
+ if (oldmem_pfn_is_ram)
+ return -EBUSY;
+ oldmem_pfn_is_ram = fn;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
+
+void unregister_oldmem_pfn_is_ram(void)
+{
+ oldmem_pfn_is_ram = NULL;
+ wmb();
+}
+EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
+
+static int pfn_is_ram(unsigned long pfn)
+{
+ int (*fn)(unsigned long pfn);
+ /* pfn is ram unless fn() checks pagetype */
+ int ret = 1;
+
+ /*
+ * Ask hypervisor if the pfn is really ram.
+ * A ballooned page contains no data and reading from such a page
+ * will cause high load in the hypervisor.
+ */
+ fn = oldmem_pfn_is_ram;
+ if (fn)
+ ret = fn(pfn);
+
+ return ret;
+}
+
+/* Reads a page from the oldmem device from given offset. */
+ssize_t read_from_oldmem(char *buf, size_t count,
+ u64 *ppos, int userbuf,
+ bool encrypted)
+{
+ unsigned long pfn, offset;
+ size_t nr_bytes;
+ ssize_t read = 0, tmp;
+
+ if (!count)
+ return 0;
+
+ offset = (unsigned long)(*ppos % PAGE_SIZE);
+ pfn = (unsigned long)(*ppos / PAGE_SIZE);
+
+ do {
+ if (count > (PAGE_SIZE - offset))
+ nr_bytes = PAGE_SIZE - offset;
+ else
+ nr_bytes = count;
+
+ /* If pfn is not ram, return zeros for sparse dump files */
+ if (pfn_is_ram(pfn) == 0) {
+ tmp = 0;
+ if (!userbuf)
+ memset(buf, 0, nr_bytes);
+ else if (clear_user(buf, nr_bytes))
+ tmp = -EFAULT;
+ } else {
+ if (encrypted)
+ tmp = copy_oldmem_page_encrypted(pfn, buf,
+ nr_bytes,
+ offset,
+ userbuf);
+ else
+ tmp = copy_oldmem_page(pfn, buf, nr_bytes,
+ offset, userbuf);
+ }
+ if (tmp < 0)
+ return tmp;
+
+ *ppos += nr_bytes;
+ count -= nr_bytes;
+ buf += nr_bytes;
+ read += nr_bytes;
+ ++pfn;
+ offset = 0;
+ } while (count);
+
+ return read;
+}
+
+/*
+ * Architectures may override this function to allocate ELF header in 2nd kernel
+ */
+int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
+{
+ return 0;
+}
+
+/*
+ * Architectures may override this function to free header
+ */
+void __weak elfcorehdr_free(unsigned long long addr)
+{}
+
+/*
+ * Architectures may override this function to read from ELF header
+ */
+ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+ return read_from_oldmem(buf, count, ppos, 0, false);
+}
+
+/*
+ * Architectures may override this function to read from notes sections
+ */
+ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
+{
+ return read_from_oldmem(buf, count, ppos, 0, mem_encrypt_active());
+}
+
+/*
+ * Architectures may override this function to map oldmem
+ */
+int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
+ unsigned long from, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ prot = pgprot_encrypted(prot);
+ return remap_pfn_range(vma, from, pfn, size, prot);
+}
+
+/*
+ * Architectures which support memory encryption override this.
+ */
+ssize_t __weak
+copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
+ unsigned long offset, int userbuf)
+{
+ return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
+}
+
+/*
+ * Copy to either kernel or user space
+ */
+static int copy_to(void *target, void *src, size_t size, int userbuf)
+{
+ if (userbuf) {
+ if (copy_to_user((char __user *) target, src, size))
+ return -EFAULT;
+ } else {
+ memcpy(target, src, size);
+ }
+ return 0;
+}
+
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
+{
+ struct vmcoredd_node *dump;
+ u64 offset = 0;
+ int ret = 0;
+ size_t tsz;
+ char *buf;
+
+ mutex_lock(&vmcoredd_mutex);
+ list_for_each_entry(dump, &vmcoredd_list, list) {
+ if (start < offset + dump->size) {
+ tsz = min(offset + (u64)dump->size - start, (u64)size);
+ buf = dump->buf + start - offset;
+ if (copy_to(dst, buf, tsz, userbuf)) {
+ ret = -EFAULT;
+ goto out_unlock;
+ }
+
+ size -= tsz;
+ start += tsz;
+ dst += tsz;
+
+ /* Leave now if buffer filled already */
+ if (!size)
+ goto out_unlock;
+ }
+ offset += dump->size;
+ }
+
+out_unlock:
+ mutex_unlock(&vmcoredd_mutex);
+ return ret;
+}
+
+#ifdef CONFIG_MMU
+static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
+ u64 start, size_t size)
+{
+ struct vmcoredd_node *dump;
+ u64 offset = 0;
+ int ret = 0;
+ size_t tsz;
+ char *buf;
+
+ mutex_lock(&vmcoredd_mutex);
+ list_for_each_entry(dump, &vmcoredd_list, list) {
+ if (start < offset + dump->size) {
+ tsz = min(offset + (u64)dump->size - start, (u64)size);
+ buf = dump->buf + start - offset;
+ if (remap_vmalloc_range_partial(vma, dst, buf, 0,
+ tsz)) {
+ ret = -EFAULT;
+ goto out_unlock;
+ }
+
+ size -= tsz;
+ start += tsz;
+ dst += tsz;
+
+ /* Leave now if buffer filled already */
+ if (!size)
+ goto out_unlock;
+ }
+ offset += dump->size;
+ }
+
+out_unlock:
+ mutex_unlock(&vmcoredd_mutex);
+ return ret;
+}
+#endif /* CONFIG_MMU */
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+
+/* Read from the ELF header and then the crash dump. On error, negative value is
+ * returned otherwise number of bytes read are returned.
+ */
+static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
+ int userbuf)
+{
+ ssize_t acc = 0, tmp;
+ size_t tsz;
+ u64 start;
+ struct vmcore *m = NULL;
+
+ if (buflen == 0 || *fpos >= vmcore_size)
+ return 0;
+
+ /* trim buflen to not go beyond EOF */
+ if (buflen > vmcore_size - *fpos)
+ buflen = vmcore_size - *fpos;
+
+ /* Read ELF core header */
+ if (*fpos < elfcorebuf_sz) {
+ tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
+ if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
+ return -EFAULT;
+ buflen -= tsz;
+ *fpos += tsz;
+ buffer += tsz;
+ acc += tsz;
+
+ /* leave now if filled buffer already */
+ if (buflen == 0)
+ return acc;
+ }
+
+ /* Read Elf note segment */
+ if (*fpos < elfcorebuf_sz + elfnotes_sz) {
+ void *kaddr;
+
+ /* We add device dumps before other elf notes because the
+ * other elf notes may not fill the elf notes buffer
+ * completely and we will end up with zero-filled data
+ * between the elf notes and the device dumps. Tools will
+ * then try to decode this zero-filled data as valid notes
+ * and we don't want that. Hence, adding device dumps before
+ * the other elf notes ensure that zero-filled data can be
+ * avoided.
+ */
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+ /* Read device dumps */
+ if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
+ tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
+ (size_t)*fpos, buflen);
+ start = *fpos - elfcorebuf_sz;
+ if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf))
+ return -EFAULT;
+
+ buflen -= tsz;
+ *fpos += tsz;
+ buffer += tsz;
+ acc += tsz;
+
+ /* leave now if filled buffer already */
+ if (!buflen)
+ return acc;
+ }
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+
+ /* Read remaining elf notes */
+ tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
+ kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
+ if (copy_to(buffer, kaddr, tsz, userbuf))
+ return -EFAULT;
+
+ buflen -= tsz;
+ *fpos += tsz;
+ buffer += tsz;
+ acc += tsz;
+
+ /* leave now if filled buffer already */
+ if (buflen == 0)
+ return acc;
+ }
+
+ list_for_each_entry(m, &vmcore_list, list) {
+ if (*fpos < m->offset + m->size) {
+ tsz = (size_t)min_t(unsigned long long,
+ m->offset + m->size - *fpos,
+ buflen);
+ start = m->paddr + *fpos - m->offset;
+ tmp = read_from_oldmem(buffer, tsz, &start,
+ userbuf, mem_encrypt_active());
+ if (tmp < 0)
+ return tmp;
+ buflen -= tsz;
+ *fpos += tsz;
+ buffer += tsz;
+ acc += tsz;
+
+ /* leave now if filled buffer already */
+ if (buflen == 0)
+ return acc;
+ }
+ }
+
+ return acc;
+}
+
+static ssize_t read_vmcore(struct file *file, char __user *buffer,
+ size_t buflen, loff_t *fpos)
+{
+ return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
+}
+
+/*
+ * The vmcore fault handler uses the page cache and fills data using the
+ * standard __vmcore_read() function.
+ *
+ * On s390 the fault handler is used for memory regions that can't be mapped
+ * directly with remap_pfn_range().
+ */
+static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
+{
+#ifdef CONFIG_S390
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ pgoff_t index = vmf->pgoff;
+ struct page *page;
+ loff_t offset;
+ char *buf;
+ int rc;
+
+ page = find_or_create_page(mapping, index, GFP_KERNEL);
+ if (!page)
+ return VM_FAULT_OOM;
+ if (!PageUptodate(page)) {
+ offset = (loff_t) index << PAGE_SHIFT;
+ buf = __va((page_to_pfn(page) << PAGE_SHIFT));
+ rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
+ if (rc < 0) {
+ unlock_page(page);
+ put_page(page);
+ return vmf_error(rc);
+ }
+ SetPageUptodate(page);
+ }
+ unlock_page(page);
+ vmf->page = page;
+ return 0;
+#else
+ return VM_FAULT_SIGBUS;
+#endif
+}
+
+static const struct vm_operations_struct vmcore_mmap_ops = {
+ .fault = mmap_vmcore_fault,
+};
+
+/**
+ * vmcore_alloc_buf - allocate buffer in vmalloc memory
+ * @sizez: size of buffer
+ *
+ * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
+ * the buffer to user-space by means of remap_vmalloc_range().
+ *
+ * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
+ * disabled and there's no need to allow users to mmap the buffer.
+ */
+static inline char *vmcore_alloc_buf(size_t size)
+{
+#ifdef CONFIG_MMU
+ return vmalloc_user(size);
+#else
+ return vzalloc(size);
+#endif
+}
+
+/*
+ * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
+ * essential for mmap_vmcore() in order to map physically
+ * non-contiguous objects (ELF header, ELF note segment and memory
+ * regions in the 1st kernel pointed to by PT_LOAD entries) into
+ * virtually contiguous user-space in ELF layout.
+ */
+#ifdef CONFIG_MMU
+/*
+ * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
+ * reported as not being ram with the zero page.
+ *
+ * @vma: vm_area_struct describing requested mapping
+ * @from: start remapping from
+ * @pfn: page frame number to start remapping to
+ * @size: remapping size
+ * @prot: protection bits
+ *
+ * Returns zero on success, -EAGAIN on failure.
+ */
+static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,
+ unsigned long from, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ unsigned long map_size;
+ unsigned long pos_start, pos_end, pos;
+ unsigned long zeropage_pfn = my_zero_pfn(0);
+ size_t len = 0;
+
+ pos_start = pfn;
+ pos_end = pfn + (size >> PAGE_SHIFT);
+
+ for (pos = pos_start; pos < pos_end; ++pos) {
+ if (!pfn_is_ram(pos)) {
+ /*
+ * We hit a page which is not ram. Remap the continuous
+ * region between pos_start and pos-1 and replace
+ * the non-ram page at pos with the zero page.
+ */
+ if (pos > pos_start) {
+ /* Remap continuous region */
+ map_size = (pos - pos_start) << PAGE_SHIFT;
+ if (remap_oldmem_pfn_range(vma, from + len,
+ pos_start, map_size,
+ prot))
+ goto fail;
+ len += map_size;
+ }
+ /* Remap the zero page */
+ if (remap_oldmem_pfn_range(vma, from + len,
+ zeropage_pfn,
+ PAGE_SIZE, prot))
+ goto fail;
+ len += PAGE_SIZE;
+ pos_start = pos + 1;
+ }
+ }
+ if (pos > pos_start) {
+ /* Remap the rest */
+ map_size = (pos - pos_start) << PAGE_SHIFT;
+ if (remap_oldmem_pfn_range(vma, from + len, pos_start,
+ map_size, prot))
+ goto fail;
+ }
+ return 0;
+fail:
+ do_munmap(vma->vm_mm, from, len, NULL);
+ return -EAGAIN;
+}
+
+static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
+ unsigned long from, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ /*
+ * Check if oldmem_pfn_is_ram was registered to avoid
+ * looping over all pages without a reason.
+ */
+ if (oldmem_pfn_is_ram)
+ return remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
+ else
+ return remap_oldmem_pfn_range(vma, from, pfn, size, prot);
+}
+
+static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
+{
+ size_t size = vma->vm_end - vma->vm_start;
+ u64 start, end, len, tsz;
+ struct vmcore *m;
+
+ start = (u64)vma->vm_pgoff << PAGE_SHIFT;
+ end = start + size;
+
+ if (size > vmcore_size || end > vmcore_size)
+ return -EINVAL;
+
+ if (vma->vm_flags & (VM_WRITE | VM_EXEC))
+ return -EPERM;
+
+ vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
+ vma->vm_flags |= VM_MIXEDMAP;
+ vma->vm_ops = &vmcore_mmap_ops;
+
+ len = 0;
+
+ if (start < elfcorebuf_sz) {
+ u64 pfn;
+
+ tsz = min(elfcorebuf_sz - (size_t)start, size);
+ pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
+ if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
+ vma->vm_page_prot))
+ return -EAGAIN;
+ size -= tsz;
+ start += tsz;
+ len += tsz;
+
+ if (size == 0)
+ return 0;
+ }
+
+ if (start < elfcorebuf_sz + elfnotes_sz) {
+ void *kaddr;
+
+ /* We add device dumps before other elf notes because the
+ * other elf notes may not fill the elf notes buffer
+ * completely and we will end up with zero-filled data
+ * between the elf notes and the device dumps. Tools will
+ * then try to decode this zero-filled data as valid notes
+ * and we don't want that. Hence, adding device dumps before
+ * the other elf notes ensure that zero-filled data can be
+ * avoided. This also ensures that the device dumps and
+ * other elf notes can be properly mmaped at page aligned
+ * address.
+ */
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+ /* Read device dumps */
+ if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
+ u64 start_off;
+
+ tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
+ (size_t)start, size);
+ start_off = start - elfcorebuf_sz;
+ if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,
+ start_off, tsz))
+ goto fail;
+
+ size -= tsz;
+ start += tsz;
+ len += tsz;
+
+ /* leave now if filled buffer already */
+ if (!size)
+ return 0;
+ }
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+
+ /* Read remaining elf notes */
+ tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
+ kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
+ if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
+ kaddr, 0, tsz))
+ goto fail;
+
+ size -= tsz;
+ start += tsz;
+ len += tsz;
+
+ if (size == 0)
+ return 0;
+ }
+
+ list_for_each_entry(m, &vmcore_list, list) {
+ if (start < m->offset + m->size) {
+ u64 paddr = 0;
+
+ tsz = (size_t)min_t(unsigned long long,
+ m->offset + m->size - start, size);
+ paddr = m->paddr + start - m->offset;
+ if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
+ paddr >> PAGE_SHIFT, tsz,
+ vma->vm_page_prot))
+ goto fail;
+ size -= tsz;
+ start += tsz;
+ len += tsz;
+
+ if (size == 0)
+ return 0;
+ }
+ }
+
+ return 0;
+fail:
+ do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
+ return -EAGAIN;
+}
+#else
+static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
+{
+ return -ENOSYS;
+}
+#endif
+
+static const struct proc_ops vmcore_proc_ops = {
+ .proc_read = read_vmcore,
+ .proc_lseek = default_llseek,
+ .proc_mmap = mmap_vmcore,
+};
+
+static struct vmcore* __init get_new_element(void)
+{
+ return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
+}
+
+static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
+ struct list_head *vc_list)
+{
+ u64 size;
+ struct vmcore *m;
+
+ size = elfsz + elfnotesegsz;
+ list_for_each_entry(m, vc_list, list) {
+ size += m->size;
+ }
+ return size;
+}
+
+/**
+ * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
+{
+ int i, rc=0;
+ Elf64_Phdr *phdr_ptr;
+ Elf64_Nhdr *nhdr_ptr;
+
+ phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ void *notes_section;
+ u64 offset, max_sz, sz, real_sz = 0;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ max_sz = phdr_ptr->p_memsz;
+ offset = phdr_ptr->p_offset;
+ notes_section = kmalloc(max_sz, GFP_KERNEL);
+ if (!notes_section)
+ return -ENOMEM;
+ rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
+ if (rc < 0) {
+ kfree(notes_section);
+ return rc;
+ }
+ nhdr_ptr = notes_section;
+ while (nhdr_ptr->n_namesz != 0) {
+ sz = sizeof(Elf64_Nhdr) +
+ (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
+ (((u64)nhdr_ptr->n_descsz + 3) & ~3);
+ if ((real_sz + sz) > max_sz) {
+ pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
+ nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
+ break;
+ }
+ real_sz += sz;
+ nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
+ }
+ kfree(notes_section);
+ phdr_ptr->p_memsz = real_sz;
+ if (real_sz == 0) {
+ pr_warn("Warning: Zero PT_NOTE entries found\n");
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * get_note_number_and_size_elf64 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
+ int *nr_ptnote, u64 *sz_ptnote)
+{
+ int i;
+ Elf64_Phdr *phdr_ptr;
+
+ *nr_ptnote = *sz_ptnote = 0;
+
+ phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ *nr_ptnote += 1;
+ *sz_ptnote += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/**
+ * copy_notes_elf64 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf64
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
+{
+ int i, rc=0;
+ Elf64_Phdr *phdr_ptr;
+
+ phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 offset;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ offset = phdr_ptr->p_offset;
+ rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
+ &offset);
+ if (rc < 0)
+ return rc;
+ notes_buf += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
+ char **notes_buf, size_t *notes_sz)
+{
+ int i, nr_ptnote=0, rc=0;
+ char *tmp;
+ Elf64_Ehdr *ehdr_ptr;
+ Elf64_Phdr phdr;
+ u64 phdr_sz = 0, note_off;
+
+ ehdr_ptr = (Elf64_Ehdr *)elfptr;
+
+ rc = update_note_header_size_elf64(ehdr_ptr);
+ if (rc < 0)
+ return rc;
+
+ rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
+ if (rc < 0)
+ return rc;
+
+ *notes_sz = roundup(phdr_sz, PAGE_SIZE);
+ *notes_buf = vmcore_alloc_buf(*notes_sz);
+ if (!*notes_buf)
+ return -ENOMEM;
+
+ rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
+ if (rc < 0)
+ return rc;
+
+ /* Prepare merged PT_NOTE program header. */
+ phdr.p_type = PT_NOTE;
+ phdr.p_flags = 0;
+ note_off = sizeof(Elf64_Ehdr) +
+ (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
+ phdr.p_offset = roundup(note_off, PAGE_SIZE);
+ phdr.p_vaddr = phdr.p_paddr = 0;
+ phdr.p_filesz = phdr.p_memsz = phdr_sz;
+ phdr.p_align = 0;
+
+ /* Add merged PT_NOTE program header*/
+ tmp = elfptr + sizeof(Elf64_Ehdr);
+ memcpy(tmp, &phdr, sizeof(phdr));
+ tmp += sizeof(phdr);
+
+ /* Remove unwanted PT_NOTE program headers. */
+ i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
+ *elfsz = *elfsz - i;
+ memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
+ memset(elfptr + *elfsz, 0, i);
+ *elfsz = roundup(*elfsz, PAGE_SIZE);
+
+ /* Modify e_phnum to reflect merged headers. */
+ ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
+
+ /* Store the size of all notes. We need this to update the note
+ * header when the device dumps will be added.
+ */
+ elfnotes_orig_sz = phdr.p_memsz;
+
+ return 0;
+}
+
+/**
+ * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
+ *
+ * @ehdr_ptr: ELF header
+ *
+ * This function updates p_memsz member of each PT_NOTE entry in the
+ * program header table pointed to by @ehdr_ptr to real size of ELF
+ * note segment.
+ */
+static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
+{
+ int i, rc=0;
+ Elf32_Phdr *phdr_ptr;
+ Elf32_Nhdr *nhdr_ptr;
+
+ phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ void *notes_section;
+ u64 offset, max_sz, sz, real_sz = 0;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ max_sz = phdr_ptr->p_memsz;
+ offset = phdr_ptr->p_offset;
+ notes_section = kmalloc(max_sz, GFP_KERNEL);
+ if (!notes_section)
+ return -ENOMEM;
+ rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
+ if (rc < 0) {
+ kfree(notes_section);
+ return rc;
+ }
+ nhdr_ptr = notes_section;
+ while (nhdr_ptr->n_namesz != 0) {
+ sz = sizeof(Elf32_Nhdr) +
+ (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
+ (((u64)nhdr_ptr->n_descsz + 3) & ~3);
+ if ((real_sz + sz) > max_sz) {
+ pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
+ nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
+ break;
+ }
+ real_sz += sz;
+ nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
+ }
+ kfree(notes_section);
+ phdr_ptr->p_memsz = real_sz;
+ if (real_sz == 0) {
+ pr_warn("Warning: Zero PT_NOTE entries found\n");
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * get_note_number_and_size_elf32 - get the number of PT_NOTE program
+ * headers and sum of real size of their ELF note segment headers and
+ * data.
+ *
+ * @ehdr_ptr: ELF header
+ * @nr_ptnote: buffer for the number of PT_NOTE program headers
+ * @sz_ptnote: buffer for size of unique PT_NOTE program header
+ *
+ * This function is used to merge multiple PT_NOTE program headers
+ * into a unique single one. The resulting unique entry will have
+ * @sz_ptnote in its phdr->p_mem.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
+ int *nr_ptnote, u64 *sz_ptnote)
+{
+ int i;
+ Elf32_Phdr *phdr_ptr;
+
+ *nr_ptnote = *sz_ptnote = 0;
+
+ phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ *nr_ptnote += 1;
+ *sz_ptnote += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/**
+ * copy_notes_elf32 - copy ELF note segments in a given buffer
+ *
+ * @ehdr_ptr: ELF header
+ * @notes_buf: buffer into which ELF note segments are copied
+ *
+ * This function is used to copy ELF note segment in the 1st kernel
+ * into the buffer @notes_buf in the 2nd kernel. It is assumed that
+ * size of the buffer @notes_buf is equal to or larger than sum of the
+ * real ELF note segment headers and data.
+ *
+ * It is assumed that program headers with PT_NOTE type pointed to by
+ * @ehdr_ptr has already been updated by update_note_header_size_elf32
+ * and each of PT_NOTE program headers has actual ELF note segment
+ * size in its p_memsz member.
+ */
+static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
+{
+ int i, rc=0;
+ Elf32_Phdr *phdr_ptr;
+
+ phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 offset;
+ if (phdr_ptr->p_type != PT_NOTE)
+ continue;
+ offset = phdr_ptr->p_offset;
+ rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
+ &offset);
+ if (rc < 0)
+ return rc;
+ notes_buf += phdr_ptr->p_memsz;
+ }
+
+ return 0;
+}
+
+/* Merges all the PT_NOTE headers into one. */
+static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
+ char **notes_buf, size_t *notes_sz)
+{
+ int i, nr_ptnote=0, rc=0;
+ char *tmp;
+ Elf32_Ehdr *ehdr_ptr;
+ Elf32_Phdr phdr;
+ u64 phdr_sz = 0, note_off;
+
+ ehdr_ptr = (Elf32_Ehdr *)elfptr;
+
+ rc = update_note_header_size_elf32(ehdr_ptr);
+ if (rc < 0)
+ return rc;
+
+ rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
+ if (rc < 0)
+ return rc;
+
+ *notes_sz = roundup(phdr_sz, PAGE_SIZE);
+ *notes_buf = vmcore_alloc_buf(*notes_sz);
+ if (!*notes_buf)
+ return -ENOMEM;
+
+ rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
+ if (rc < 0)
+ return rc;
+
+ /* Prepare merged PT_NOTE program header. */
+ phdr.p_type = PT_NOTE;
+ phdr.p_flags = 0;
+ note_off = sizeof(Elf32_Ehdr) +
+ (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
+ phdr.p_offset = roundup(note_off, PAGE_SIZE);
+ phdr.p_vaddr = phdr.p_paddr = 0;
+ phdr.p_filesz = phdr.p_memsz = phdr_sz;
+ phdr.p_align = 0;
+
+ /* Add merged PT_NOTE program header*/
+ tmp = elfptr + sizeof(Elf32_Ehdr);
+ memcpy(tmp, &phdr, sizeof(phdr));
+ tmp += sizeof(phdr);
+
+ /* Remove unwanted PT_NOTE program headers. */
+ i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
+ *elfsz = *elfsz - i;
+ memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
+ memset(elfptr + *elfsz, 0, i);
+ *elfsz = roundup(*elfsz, PAGE_SIZE);
+
+ /* Modify e_phnum to reflect merged headers. */
+ ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
+
+ /* Store the size of all notes. We need this to update the note
+ * header when the device dumps will be added.
+ */
+ elfnotes_orig_sz = phdr.p_memsz;
+
+ return 0;
+}
+
+/* Add memory chunks represented by program headers to vmcore list. Also update
+ * the new offset fields of exported program headers. */
+static int __init process_ptload_program_headers_elf64(char *elfptr,
+ size_t elfsz,
+ size_t elfnotes_sz,
+ struct list_head *vc_list)
+{
+ int i;
+ Elf64_Ehdr *ehdr_ptr;
+ Elf64_Phdr *phdr_ptr;
+ loff_t vmcore_off;
+ struct vmcore *new;
+
+ ehdr_ptr = (Elf64_Ehdr *)elfptr;
+ phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
+
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 paddr, start, end, size;
+
+ if (phdr_ptr->p_type != PT_LOAD)
+ continue;
+
+ paddr = phdr_ptr->p_offset;
+ start = rounddown(paddr, PAGE_SIZE);
+ end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+ size = end - start;
+
+ /* Add this contiguous chunk of memory to vmcore list.*/
+ new = get_new_element();
+ if (!new)
+ return -ENOMEM;
+ new->paddr = start;
+ new->size = size;
+ list_add_tail(&new->list, vc_list);
+
+ /* Update the program header offset. */
+ phdr_ptr->p_offset = vmcore_off + (paddr - start);
+ vmcore_off = vmcore_off + size;
+ }
+ return 0;
+}
+
+static int __init process_ptload_program_headers_elf32(char *elfptr,
+ size_t elfsz,
+ size_t elfnotes_sz,
+ struct list_head *vc_list)
+{
+ int i;
+ Elf32_Ehdr *ehdr_ptr;
+ Elf32_Phdr *phdr_ptr;
+ loff_t vmcore_off;
+ struct vmcore *new;
+
+ ehdr_ptr = (Elf32_Ehdr *)elfptr;
+ phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
+
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
+
+ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 paddr, start, end, size;
+
+ if (phdr_ptr->p_type != PT_LOAD)
+ continue;
+
+ paddr = phdr_ptr->p_offset;
+ start = rounddown(paddr, PAGE_SIZE);
+ end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
+ size = end - start;
+
+ /* Add this contiguous chunk of memory to vmcore list.*/
+ new = get_new_element();
+ if (!new)
+ return -ENOMEM;
+ new->paddr = start;
+ new->size = size;
+ list_add_tail(&new->list, vc_list);
+
+ /* Update the program header offset */
+ phdr_ptr->p_offset = vmcore_off + (paddr - start);
+ vmcore_off = vmcore_off + size;
+ }
+ return 0;
+}
+
+/* Sets offset fields of vmcore elements. */
+static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
+ struct list_head *vc_list)
+{
+ loff_t vmcore_off;
+ struct vmcore *m;
+
+ /* Skip Elf header, program headers and Elf note segment. */
+ vmcore_off = elfsz + elfnotes_sz;
+
+ list_for_each_entry(m, vc_list, list) {
+ m->offset = vmcore_off;
+ vmcore_off += m->size;
+ }
+}
+
+static void free_elfcorebuf(void)
+{
+ free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
+ elfcorebuf = NULL;
+ vfree(elfnotes_buf);
+ elfnotes_buf = NULL;
+}
+
+static int __init parse_crash_elf64_headers(void)
+{
+ int rc=0;
+ Elf64_Ehdr ehdr;
+ u64 addr;
+
+ addr = elfcorehdr_addr;
+
+ /* Read Elf header */
+ rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
+ if (rc < 0)
+ return rc;
+
+ /* Do some basic Verification. */
+ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
+ (ehdr.e_type != ET_CORE) ||
+ !vmcore_elf64_check_arch(&ehdr) ||
+ ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
+ ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
+ ehdr.e_version != EV_CURRENT ||
+ ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
+ ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
+ ehdr.e_phnum == 0) {
+ pr_warn("Warning: Core image elf header is not sane\n");
+ return -EINVAL;
+ }
+
+ /* Read in all elf headers. */
+ elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
+ ehdr.e_phnum * sizeof(Elf64_Phdr);
+ elfcorebuf_sz = elfcorebuf_sz_orig;
+ elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(elfcorebuf_sz_orig));
+ if (!elfcorebuf)
+ return -ENOMEM;
+ addr = elfcorehdr_addr;
+ rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
+ if (rc < 0)
+ goto fail;
+
+ /* Merge all PT_NOTE headers into one. */
+ rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
+ &elfnotes_buf, &elfnotes_sz);
+ if (rc)
+ goto fail;
+ rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
+ elfnotes_sz, &vmcore_list);
+ if (rc)
+ goto fail;
+ set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
+ return 0;
+fail:
+ free_elfcorebuf();
+ return rc;
+}
+
+static int __init parse_crash_elf32_headers(void)
+{
+ int rc=0;
+ Elf32_Ehdr ehdr;
+ u64 addr;
+
+ addr = elfcorehdr_addr;
+
+ /* Read Elf header */
+ rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
+ if (rc < 0)
+ return rc;
+
+ /* Do some basic Verification. */
+ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
+ (ehdr.e_type != ET_CORE) ||
+ !vmcore_elf32_check_arch(&ehdr) ||
+ ehdr.e_ident[EI_CLASS] != ELFCLASS32||
+ ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
+ ehdr.e_version != EV_CURRENT ||
+ ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
+ ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
+ ehdr.e_phnum == 0) {
+ pr_warn("Warning: Core image elf header is not sane\n");
+ return -EINVAL;
+ }
+
+ /* Read in all elf headers. */
+ elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
+ elfcorebuf_sz = elfcorebuf_sz_orig;
+ elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(elfcorebuf_sz_orig));
+ if (!elfcorebuf)
+ return -ENOMEM;
+ addr = elfcorehdr_addr;
+ rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
+ if (rc < 0)
+ goto fail;
+
+ /* Merge all PT_NOTE headers into one. */
+ rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
+ &elfnotes_buf, &elfnotes_sz);
+ if (rc)
+ goto fail;
+ rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
+ elfnotes_sz, &vmcore_list);
+ if (rc)
+ goto fail;
+ set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
+ return 0;
+fail:
+ free_elfcorebuf();
+ return rc;
+}
+
+static int __init parse_crash_elf_headers(void)
+{
+ unsigned char e_ident[EI_NIDENT];
+ u64 addr;
+ int rc=0;
+
+ addr = elfcorehdr_addr;
+ rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
+ if (rc < 0)
+ return rc;
+ if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
+ pr_warn("Warning: Core image elf header not found\n");
+ return -EINVAL;
+ }
+
+ if (e_ident[EI_CLASS] == ELFCLASS64) {
+ rc = parse_crash_elf64_headers();
+ if (rc)
+ return rc;
+ } else if (e_ident[EI_CLASS] == ELFCLASS32) {
+ rc = parse_crash_elf32_headers();
+ if (rc)
+ return rc;
+ } else {
+ pr_warn("Warning: Core image elf header is not sane\n");
+ return -EINVAL;
+ }
+
+ /* Determine vmcore size. */
+ vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
+ &vmcore_list);
+
+ return 0;
+}
+
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+/**
+ * vmcoredd_write_header - Write vmcore device dump header at the
+ * beginning of the dump's buffer.
+ * @buf: Output buffer where the note is written
+ * @data: Dump info
+ * @size: Size of the dump
+ *
+ * Fills beginning of the dump's buffer with vmcore device dump header.
+ */
+static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,
+ u32 size)
+{
+ struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;
+
+ vdd_hdr->n_namesz = sizeof(vdd_hdr->name);
+ vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
+ vdd_hdr->n_type = NT_VMCOREDD;
+
+ strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME,
+ sizeof(vdd_hdr->name));
+ memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name));
+}
+
+/**
+ * vmcoredd_update_program_headers - Update all Elf program headers
+ * @elfptr: Pointer to elf header
+ * @elfnotesz: Size of elf notes aligned to page size
+ * @vmcoreddsz: Size of device dumps to be added to elf note header
+ *
+ * Determine type of Elf header (Elf64 or Elf32) and update the elf note size.
+ * Also update the offsets of all the program headers after the elf note header.
+ */
+static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz,
+ size_t vmcoreddsz)
+{
+ unsigned char *e_ident = (unsigned char *)elfptr;
+ u64 start, end, size;
+ loff_t vmcore_off;
+ u32 i;
+
+ vmcore_off = elfcorebuf_sz + elfnotesz;
+
+ if (e_ident[EI_CLASS] == ELFCLASS64) {
+ Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr;
+ Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr));
+
+ /* Update all program headers */
+ for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+ if (phdr->p_type == PT_NOTE) {
+ /* Update note size */
+ phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
+ phdr->p_filesz = phdr->p_memsz;
+ continue;
+ }
+
+ start = rounddown(phdr->p_offset, PAGE_SIZE);
+ end = roundup(phdr->p_offset + phdr->p_memsz,
+ PAGE_SIZE);
+ size = end - start;
+ phdr->p_offset = vmcore_off + (phdr->p_offset - start);
+ vmcore_off += size;
+ }
+ } else {
+ Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr;
+ Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr));
+
+ /* Update all program headers */
+ for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+ if (phdr->p_type == PT_NOTE) {
+ /* Update note size */
+ phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
+ phdr->p_filesz = phdr->p_memsz;
+ continue;
+ }
+
+ start = rounddown(phdr->p_offset, PAGE_SIZE);
+ end = roundup(phdr->p_offset + phdr->p_memsz,
+ PAGE_SIZE);
+ size = end - start;
+ phdr->p_offset = vmcore_off + (phdr->p_offset - start);
+ vmcore_off += size;
+ }
+ }
+}
+
+/**
+ * vmcoredd_update_size - Update the total size of the device dumps and update
+ * Elf header
+ * @dump_size: Size of the current device dump to be added to total size
+ *
+ * Update the total size of all the device dumps and update the Elf program
+ * headers. Calculate the new offsets for the vmcore list and update the
+ * total vmcore size.
+ */
+static void vmcoredd_update_size(size_t dump_size)
+{
+ vmcoredd_orig_sz += dump_size;
+ elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz;
+ vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz,
+ vmcoredd_orig_sz);
+
+ /* Update vmcore list offsets */
+ set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
+
+ vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
+ &vmcore_list);
+ proc_vmcore->size = vmcore_size;
+}
+
+/**
+ * vmcore_add_device_dump - Add a buffer containing device dump to vmcore
+ * @data: dump info.
+ *
+ * Allocate a buffer and invoke the calling driver's dump collect routine.
+ * Write Elf note at the beginning of the buffer to indicate vmcore device
+ * dump and add the dump to global list.
+ */
+int vmcore_add_device_dump(struct vmcoredd_data *data)
+{
+ struct vmcoredd_node *dump;
+ void *buf = NULL;
+ size_t data_size;
+ int ret;
+
+ if (vmcoredd_disabled) {
+ pr_err_once("Device dump is disabled\n");
+ return -EINVAL;
+ }
+
+ if (!data || !strlen(data->dump_name) ||
+ !data->vmcoredd_callback || !data->size)
+ return -EINVAL;
+
+ dump = vzalloc(sizeof(*dump));
+ if (!dump) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ /* Keep size of the buffer page aligned so that it can be mmaped */
+ data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
+ PAGE_SIZE);
+
+ /* Allocate buffer for driver's to write their dumps */
+ buf = vmcore_alloc_buf(data_size);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ vmcoredd_write_header(buf, data, data_size -
+ sizeof(struct vmcoredd_header));
+
+ /* Invoke the driver's dump collection routing */
+ ret = data->vmcoredd_callback(data, buf +
+ sizeof(struct vmcoredd_header));
+ if (ret)
+ goto out_err;
+
+ dump->buf = buf;
+ dump->size = data_size;
+
+ /* Add the dump to driver sysfs list */
+ mutex_lock(&vmcoredd_mutex);
+ list_add_tail(&dump->list, &vmcoredd_list);
+ mutex_unlock(&vmcoredd_mutex);
+
+ vmcoredd_update_size(data_size);
+ return 0;
+
+out_err:
+ if (buf)
+ vfree(buf);
+
+ if (dump)
+ vfree(dump);
+
+ return ret;
+}
+EXPORT_SYMBOL(vmcore_add_device_dump);
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+
+/* Free all dumps in vmcore device dump list */
+static void vmcore_free_device_dumps(void)
+{
+#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
+ mutex_lock(&vmcoredd_mutex);
+ while (!list_empty(&vmcoredd_list)) {
+ struct vmcoredd_node *dump;
+
+ dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
+ list);
+ list_del(&dump->list);
+ vfree(dump->buf);
+ vfree(dump);
+ }
+ mutex_unlock(&vmcoredd_mutex);
+#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
+}
+
+/* Init function for vmcore module. */
+static int __init vmcore_init(void)
+{
+ int rc = 0;
+
+ /* Allow architectures to allocate ELF header in 2nd kernel */
+ rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
+ if (rc)
+ return rc;
+ /*
+ * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
+ * then capture the dump.
+ */
+ if (!(is_vmcore_usable()))
+ return rc;
+ rc = parse_crash_elf_headers();
+ if (rc) {
+ pr_warn("Kdump: vmcore not initialized\n");
+ return rc;
+ }
+ elfcorehdr_free(elfcorehdr_addr);
+ elfcorehdr_addr = ELFCORE_ADDR_ERR;
+
+ proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
+ if (proc_vmcore)
+ proc_vmcore->size = vmcore_size;
+ return 0;
+}
+fs_initcall(vmcore_init);
+
+/* Cleanup function for vmcore module. */
+void vmcore_cleanup(void)
+{
+ if (proc_vmcore) {
+ proc_remove(proc_vmcore);
+ proc_vmcore = NULL;
+ }
+
+ /* clear the vmcore list. */
+ while (!list_empty(&vmcore_list)) {
+ struct vmcore *m;
+
+ m = list_first_entry(&vmcore_list, struct vmcore, list);
+ list_del(&m->list);
+ kfree(m);
+ }
+ free_elfcorebuf();
+
+ /* clear vmcore device dump list */
+ vmcore_free_device_dumps();
+}