diff options
Diffstat (limited to 'fs/proc/vmcore.c')
| -rw-r--r-- | fs/proc/vmcore.c | 1603 |
1 files changed, 1603 insertions, 0 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c new file mode 100644 index 000000000..1ec0647a2 --- /dev/null +++ b/fs/proc/vmcore.c @@ -0,0 +1,1603 @@ +// 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/uio.h> +#include <linux/cc_platform.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; + +static DEFINE_SPINLOCK(vmcore_cb_lock); +DEFINE_STATIC_SRCU(vmcore_cb_srcu); +/* List of registered vmcore callbacks. */ +static LIST_HEAD(vmcore_cb_list); +/* Whether the vmcore has been opened once. */ +static bool vmcore_opened; + +void register_vmcore_cb(struct vmcore_cb *cb) +{ + INIT_LIST_HEAD(&cb->next); + spin_lock(&vmcore_cb_lock); + list_add_tail(&cb->next, &vmcore_cb_list); + /* + * Registering a vmcore callback after the vmcore was opened is + * very unusual (e.g., manual driver loading). + */ + if (vmcore_opened) + pr_warn_once("Unexpected vmcore callback registration\n"); + spin_unlock(&vmcore_cb_lock); +} +EXPORT_SYMBOL_GPL(register_vmcore_cb); + +void unregister_vmcore_cb(struct vmcore_cb *cb) +{ + spin_lock(&vmcore_cb_lock); + list_del_rcu(&cb->next); + /* + * Unregistering a vmcore callback after the vmcore was opened is + * very unusual (e.g., forced driver removal), but we cannot stop + * unregistering. + */ + if (vmcore_opened) + pr_warn_once("Unexpected vmcore callback unregistration\n"); + spin_unlock(&vmcore_cb_lock); + + synchronize_srcu(&vmcore_cb_srcu); +} +EXPORT_SYMBOL_GPL(unregister_vmcore_cb); + +static bool pfn_is_ram(unsigned long pfn) +{ + struct vmcore_cb *cb; + bool ret = true; + + list_for_each_entry_srcu(cb, &vmcore_cb_list, next, + srcu_read_lock_held(&vmcore_cb_srcu)) { + if (unlikely(!cb->pfn_is_ram)) + continue; + ret = cb->pfn_is_ram(cb, pfn); + if (!ret) + break; + } + + return ret; +} + +static int open_vmcore(struct inode *inode, struct file *file) +{ + spin_lock(&vmcore_cb_lock); + vmcore_opened = true; + spin_unlock(&vmcore_cb_lock); + + return 0; +} + +/* Reads a page from the oldmem device from given offset. */ +ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted) +{ + unsigned long pfn, offset; + ssize_t nr_bytes; + ssize_t read = 0, tmp; + int idx; + + if (!count) + return 0; + + offset = (unsigned long)(*ppos % PAGE_SIZE); + pfn = (unsigned long)(*ppos / PAGE_SIZE); + + idx = srcu_read_lock(&vmcore_cb_srcu); + 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)) { + tmp = iov_iter_zero(nr_bytes, iter); + } else { + if (encrypted) + tmp = copy_oldmem_page_encrypted(iter, pfn, + nr_bytes, + offset); + else + tmp = copy_oldmem_page(iter, pfn, nr_bytes, + offset); + } + if (tmp < nr_bytes) { + srcu_read_unlock(&vmcore_cb_srcu, idx); + return -EFAULT; + } + + *ppos += nr_bytes; + count -= nr_bytes; + read += nr_bytes; + ++pfn; + offset = 0; + } while (count); + srcu_read_unlock(&vmcore_cb_srcu, idx); + + 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) +{ + struct kvec kvec = { .iov_base = buf, .iov_len = count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, false); +} + +/* + * Architectures may override this function to read from notes sections + */ +ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) +{ + struct kvec kvec = { .iov_base = buf, .iov_len = count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); +} + +/* + * 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(struct iov_iter *iter, + unsigned long pfn, size_t csize, unsigned long offset) +{ + return copy_oldmem_page(iter, pfn, csize, offset); +} + +#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP +static int vmcoredd_copy_dumps(struct iov_iter *iter, 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 (copy_to_iter(buf, tsz, iter) < tsz) { + ret = -EFAULT; + goto out_unlock; + } + + size -= tsz; + start += 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(struct iov_iter *iter, loff_t *fpos) +{ + ssize_t acc = 0, tmp; + size_t tsz; + u64 start; + struct vmcore *m = NULL; + + if (!iov_iter_count(iter) || *fpos >= vmcore_size) + return 0; + + iov_iter_truncate(iter, vmcore_size - *fpos); + + /* Read ELF core header */ + if (*fpos < elfcorebuf_sz) { + tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); + if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) + return -EFAULT; + *fpos += tsz; + acc += tsz; + + /* leave now if filled buffer already */ + if (!iov_iter_count(iter)) + 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, iov_iter_count(iter)); + start = *fpos - elfcorebuf_sz; + if (vmcoredd_copy_dumps(iter, start, tsz)) + return -EFAULT; + + *fpos += tsz; + acc += tsz; + + /* leave now if filled buffer already */ + if (!iov_iter_count(iter)) + return acc; + } +#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ + + /* Read remaining elf notes */ + tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, + iov_iter_count(iter)); + kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; + if (copy_to_iter(kaddr, tsz, iter) < tsz) + return -EFAULT; + + *fpos += tsz; + acc += tsz; + + /* leave now if filled buffer already */ + if (!iov_iter_count(iter)) + 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, + iov_iter_count(iter)); + start = m->paddr + *fpos - m->offset; + tmp = read_from_oldmem(iter, tsz, &start, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); + if (tmp < 0) + return tmp; + *fpos += tsz; + acc += tsz; + + /* leave now if filled buffer already */ + if (!iov_iter_count(iter)) + return acc; + } + } + + return acc; +} + +static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) +{ + return __read_vmcore(iter, &iocb->ki_pos); +} + +/* + * The vmcore fault handler uses the page cache and fills data using the + * standard __read_vmcore() 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 iov_iter iter; + struct kvec kvec; + struct page *page; + loff_t offset; + 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; + kvec.iov_base = page_address(page); + kvec.iov_len = PAGE_SIZE; + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE); + + rc = __read_vmcore(&iter, &offset); + 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 + * @size: 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) +{ + int ret, idx; + + /* + * Check if a callback was registered to avoid looping over all + * pages without a reason. + */ + idx = srcu_read_lock(&vmcore_cb_srcu); + if (!list_empty(&vmcore_cb_list)) + ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); + else + ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); + srcu_read_unlock(&vmcore_cb_srcu, idx); + return ret; +} + +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_open = open_vmcore, + .proc_read_iter = 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: + vfree(buf); + 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(); +} |