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![David Hildenbrand](/assets/img/avatar_default.png)
To clear a user buffer we cannot simply use memset, we have to use
clear_user(). With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":
systemd[1]: Starting Kdump Vmcore Save Service...
kdump[420]: Kdump is using the default log level(3).
kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
kdump[465]: saving vmcore-dmesg.txt complete
kdump[467]: saving vmcore
BUG: unable to handle page fault for address: 00007f2374e01000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
Oops: 0003 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
FS: 00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
Call Trace:
read_vmcore+0x236/0x2c0
proc_reg_read+0x55/0xa0
vfs_read+0x95/0x190
ksys_read+0x4f/0xc0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access. In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().
To fix, properly use clear_user() when we're dealing with a user buffer.
Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 997c136f51
("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1625 lines
41 KiB
C
1625 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* fs/proc/vmcore.c Interface for accessing the crash
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* dump from the system's previous life.
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* Heavily borrowed from fs/proc/kcore.c
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* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
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* Copyright (C) IBM Corporation, 2004. All rights reserved
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*
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*/
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#include <linux/mm.h>
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#include <linux/kcore.h>
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#include <linux/user.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/highmem.h>
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#include <linux/printk.h>
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#include <linux/memblock.h>
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#include <linux/init.h>
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#include <linux/crash_dump.h>
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#include <linux/list.h>
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#include <linux/moduleparam.h>
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#include <linux/mutex.h>
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#include <linux/vmalloc.h>
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#include <linux/pagemap.h>
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#include <linux/uaccess.h>
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#include <linux/cc_platform.h>
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#include <asm/io.h>
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#include "internal.h"
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/* List representing chunks of contiguous memory areas and their offsets in
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* vmcore file.
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*/
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static LIST_HEAD(vmcore_list);
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/* Stores the pointer to the buffer containing kernel elf core headers. */
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static char *elfcorebuf;
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static size_t elfcorebuf_sz;
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static size_t elfcorebuf_sz_orig;
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static char *elfnotes_buf;
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static size_t elfnotes_sz;
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/* Size of all notes minus the device dump notes */
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static size_t elfnotes_orig_sz;
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/* Total size of vmcore file. */
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static u64 vmcore_size;
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static struct proc_dir_entry *proc_vmcore;
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#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
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/* Device Dump list and mutex to synchronize access to list */
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static LIST_HEAD(vmcoredd_list);
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static DEFINE_MUTEX(vmcoredd_mutex);
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static bool vmcoredd_disabled;
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core_param(novmcoredd, vmcoredd_disabled, bool, 0);
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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
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/* Device Dump Size */
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static size_t vmcoredd_orig_sz;
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static DECLARE_RWSEM(vmcore_cb_rwsem);
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/* List of registered vmcore callbacks. */
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static LIST_HEAD(vmcore_cb_list);
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/* Whether we had a surprise unregistration of a callback. */
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static bool vmcore_cb_unstable;
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/* Whether the vmcore has been opened once. */
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static bool vmcore_opened;
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void register_vmcore_cb(struct vmcore_cb *cb)
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{
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down_write(&vmcore_cb_rwsem);
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INIT_LIST_HEAD(&cb->next);
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list_add_tail(&cb->next, &vmcore_cb_list);
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/*
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* Registering a vmcore callback after the vmcore was opened is
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* very unusual (e.g., manual driver loading).
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*/
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if (vmcore_opened)
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pr_warn_once("Unexpected vmcore callback registration\n");
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up_write(&vmcore_cb_rwsem);
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}
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EXPORT_SYMBOL_GPL(register_vmcore_cb);
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void unregister_vmcore_cb(struct vmcore_cb *cb)
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{
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down_write(&vmcore_cb_rwsem);
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list_del(&cb->next);
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/*
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* Unregistering a vmcore callback after the vmcore was opened is
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* very unusual (e.g., forced driver removal), but we cannot stop
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* unregistering.
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*/
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if (vmcore_opened) {
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pr_warn_once("Unexpected vmcore callback unregistration\n");
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vmcore_cb_unstable = true;
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}
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up_write(&vmcore_cb_rwsem);
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}
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EXPORT_SYMBOL_GPL(unregister_vmcore_cb);
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static bool pfn_is_ram(unsigned long pfn)
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{
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struct vmcore_cb *cb;
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bool ret = true;
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lockdep_assert_held_read(&vmcore_cb_rwsem);
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if (unlikely(vmcore_cb_unstable))
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return false;
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list_for_each_entry(cb, &vmcore_cb_list, next) {
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if (unlikely(!cb->pfn_is_ram))
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continue;
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ret = cb->pfn_is_ram(cb, pfn);
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if (!ret)
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break;
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}
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return ret;
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}
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static int open_vmcore(struct inode *inode, struct file *file)
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{
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down_read(&vmcore_cb_rwsem);
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vmcore_opened = true;
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up_read(&vmcore_cb_rwsem);
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return 0;
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}
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/* Reads a page from the oldmem device from given offset. */
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ssize_t read_from_oldmem(char *buf, size_t count,
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u64 *ppos, int userbuf,
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bool encrypted)
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{
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unsigned long pfn, offset;
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size_t nr_bytes;
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ssize_t read = 0, tmp;
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if (!count)
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return 0;
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offset = (unsigned long)(*ppos % PAGE_SIZE);
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pfn = (unsigned long)(*ppos / PAGE_SIZE);
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down_read(&vmcore_cb_rwsem);
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do {
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if (count > (PAGE_SIZE - offset))
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nr_bytes = PAGE_SIZE - offset;
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else
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nr_bytes = count;
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/* If pfn is not ram, return zeros for sparse dump files */
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if (!pfn_is_ram(pfn)) {
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tmp = 0;
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if (!userbuf)
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memset(buf, 0, nr_bytes);
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else if (clear_user(buf, nr_bytes))
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tmp = -EFAULT;
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} else {
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if (encrypted)
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tmp = copy_oldmem_page_encrypted(pfn, buf,
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nr_bytes,
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offset,
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userbuf);
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else
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tmp = copy_oldmem_page(pfn, buf, nr_bytes,
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offset, userbuf);
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}
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if (tmp < 0) {
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up_read(&vmcore_cb_rwsem);
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return tmp;
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}
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*ppos += nr_bytes;
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count -= nr_bytes;
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buf += nr_bytes;
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read += nr_bytes;
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++pfn;
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offset = 0;
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} while (count);
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up_read(&vmcore_cb_rwsem);
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return read;
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}
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/*
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* Architectures may override this function to allocate ELF header in 2nd kernel
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*/
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int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
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{
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return 0;
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}
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/*
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* Architectures may override this function to free header
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*/
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void __weak elfcorehdr_free(unsigned long long addr)
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{}
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/*
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* Architectures may override this function to read from ELF header
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*/
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ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
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{
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return read_from_oldmem(buf, count, ppos, 0, false);
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}
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/*
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* Architectures may override this function to read from notes sections
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*/
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ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
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{
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return read_from_oldmem(buf, count, ppos, 0, cc_platform_has(CC_ATTR_MEM_ENCRYPT));
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}
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/*
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* Architectures may override this function to map oldmem
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*/
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int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
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unsigned long from, unsigned long pfn,
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unsigned long size, pgprot_t prot)
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{
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prot = pgprot_encrypted(prot);
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return remap_pfn_range(vma, from, pfn, size, prot);
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}
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/*
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* Architectures which support memory encryption override this.
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*/
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ssize_t __weak
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copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
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unsigned long offset, int userbuf)
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{
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return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
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}
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/*
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* Copy to either kernel or user space
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*/
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static int copy_to(void *target, void *src, size_t size, int userbuf)
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{
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if (userbuf) {
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if (copy_to_user((char __user *) target, src, size))
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return -EFAULT;
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} else {
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memcpy(target, src, size);
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}
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return 0;
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}
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#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
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static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
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{
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struct vmcoredd_node *dump;
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u64 offset = 0;
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int ret = 0;
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size_t tsz;
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char *buf;
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mutex_lock(&vmcoredd_mutex);
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list_for_each_entry(dump, &vmcoredd_list, list) {
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if (start < offset + dump->size) {
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tsz = min(offset + (u64)dump->size - start, (u64)size);
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buf = dump->buf + start - offset;
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if (copy_to(dst, buf, tsz, userbuf)) {
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ret = -EFAULT;
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goto out_unlock;
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}
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size -= tsz;
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start += tsz;
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dst += tsz;
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/* Leave now if buffer filled already */
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if (!size)
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goto out_unlock;
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}
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offset += dump->size;
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}
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out_unlock:
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mutex_unlock(&vmcoredd_mutex);
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return ret;
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}
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#ifdef CONFIG_MMU
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static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
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u64 start, size_t size)
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{
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struct vmcoredd_node *dump;
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u64 offset = 0;
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int ret = 0;
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size_t tsz;
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char *buf;
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mutex_lock(&vmcoredd_mutex);
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list_for_each_entry(dump, &vmcoredd_list, list) {
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if (start < offset + dump->size) {
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tsz = min(offset + (u64)dump->size - start, (u64)size);
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buf = dump->buf + start - offset;
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if (remap_vmalloc_range_partial(vma, dst, buf, 0,
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tsz)) {
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ret = -EFAULT;
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goto out_unlock;
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}
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size -= tsz;
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start += tsz;
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dst += tsz;
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/* Leave now if buffer filled already */
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if (!size)
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goto out_unlock;
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}
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offset += dump->size;
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}
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out_unlock:
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mutex_unlock(&vmcoredd_mutex);
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return ret;
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}
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#endif /* CONFIG_MMU */
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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
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/* Read from the ELF header and then the crash dump. On error, negative value is
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* returned otherwise number of bytes read are returned.
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*/
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static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
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int userbuf)
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{
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ssize_t acc = 0, tmp;
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size_t tsz;
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u64 start;
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struct vmcore *m = NULL;
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if (buflen == 0 || *fpos >= vmcore_size)
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return 0;
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/* trim buflen to not go beyond EOF */
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if (buflen > vmcore_size - *fpos)
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buflen = vmcore_size - *fpos;
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/* Read ELF core header */
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if (*fpos < elfcorebuf_sz) {
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tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
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if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
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return -EFAULT;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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/* leave now if filled buffer already */
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if (buflen == 0)
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return acc;
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}
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/* Read Elf note segment */
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if (*fpos < elfcorebuf_sz + elfnotes_sz) {
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void *kaddr;
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/* We add device dumps before other elf notes because the
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* other elf notes may not fill the elf notes buffer
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* completely and we will end up with zero-filled data
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* between the elf notes and the device dumps. Tools will
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* then try to decode this zero-filled data as valid notes
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* and we don't want that. Hence, adding device dumps before
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* the other elf notes ensure that zero-filled data can be
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* avoided.
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*/
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#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
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/* Read device dumps */
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if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
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tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
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(size_t)*fpos, buflen);
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start = *fpos - elfcorebuf_sz;
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if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf))
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return -EFAULT;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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/* leave now if filled buffer already */
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if (!buflen)
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return acc;
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}
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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
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/* Read remaining elf notes */
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tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
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kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
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if (copy_to(buffer, kaddr, tsz, userbuf))
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return -EFAULT;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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/* leave now if filled buffer already */
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if (buflen == 0)
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return acc;
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}
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list_for_each_entry(m, &vmcore_list, list) {
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if (*fpos < m->offset + m->size) {
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tsz = (size_t)min_t(unsigned long long,
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m->offset + m->size - *fpos,
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buflen);
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start = m->paddr + *fpos - m->offset;
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tmp = read_from_oldmem(buffer, tsz, &start,
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userbuf, cc_platform_has(CC_ATTR_MEM_ENCRYPT));
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if (tmp < 0)
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return tmp;
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buflen -= tsz;
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*fpos += tsz;
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buffer += tsz;
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acc += tsz;
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/* leave now if filled buffer already */
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if (buflen == 0)
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return acc;
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}
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}
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return acc;
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}
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|
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static ssize_t read_vmcore(struct file *file, char __user *buffer,
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size_t buflen, loff_t *fpos)
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{
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return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
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}
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|
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/*
|
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* The vmcore fault handler uses the page cache and fills data using the
|
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* standard __vmcore_read() function.
|
|
*
|
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* On s390 the fault handler is used for memory regions that can't be mapped
|
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* directly with remap_pfn_range().
|
|
*/
|
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static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
|
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{
|
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#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)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* Check if oldmem_pfn_is_ram was registered to avoid
|
|
* looping over all pages without a reason.
|
|
*/
|
|
down_read(&vmcore_cb_rwsem);
|
|
if (!list_empty(&vmcore_cb_list) || vmcore_cb_unstable)
|
|
ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
|
|
else
|
|
ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot);
|
|
up_read(&vmcore_cb_rwsem);
|
|
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 = 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();
|
|
}
|