Changelog
crash (7.1.4-1) unstable; urgency=medium
* New upstream version 7.1.4, upstream changelog follows:
* Fix for the ARM64 "vtop" command when translating kernel virtual addresses
within a 2MB or 512MB huge page in which the PGD or PMD contains
software-defined PTE bits. Without the patch, the "PAGE:" address value
will show the software-defined bits, the command will not display the
related page structure translation, and will end with the message
"WARNING: sparsemem: invalid section number: <number>".
* Fix for the X86_64 "bt" command in Linux 4.2 and later kernels that are
configured with both CONFIG_HAVE_COPY_THREAD_TLS and CONFIG_FRAME_POINTER.
Without the patch, the fact that the kernel was compiled with
framepointers is not recognized, which may result in backtraces containing
stale frame references.
* Fix for the "dis" command to support three new x86 instruction extensions
that have been added to the Intel instruction set for hardware platforms
that support them. The newly-added instructions "clflushopt", "clwb", and
"pcommit" prepend 0x66 as a prefix byte to the "clflush", "xsaveopt" and
"sfence" instructions respectively. Without the patch:
"clflushopt" is disassembled as: "data16" followed by "clflush" "clwb" is
disassembled as: "data16" followed by "xsaveopt" "pcommit" is disassembled
as: "data16" followed by "sfence"
The "clflushopt" instruction was introduced in Linux 3.15 in the
clflushopt() function. The "clwb" and "pcommit" instructions were
introduced in Linux 4.1 in the clwb() and pcommit_sfence() functions.
* Fix for the extensions/trace.c extension module for Linux 4.2 and later
kernels. Without the patch, the module fails to load, with the message
"failed to init the offset, struct:ftrace_event_call, member:list".
* For many years, Xen Dom0 dumps could only be saved in ELF format. Since
makedumpfile commit 349a0ed1, it is now possible to save Xen dumps in
compressed kdump format. This patch set adds support for these files.
Two new files, xen_dom0.c and xen_dom0.h, have been added to provide the
common functionality required by both ELF and compressed kdump formats.
* Since Linux v4.1, specifically, "MIPS: Rearrange PTE bits into fixed
positions.", commit be0c37c985eddc46d0d67543898c086f60460e2e, the MIPS PTE
bits are at fixed locations. Since they are macros in the kernel, this
patch adds an explicit kernel version check in order to determine and set
their values.
* Display a machine-type mismatch warning if a little-endian PPC64
compressed kdump created by makedumpfile(8) is used as an argument with a
non-PPC64 crash utility binary. Without the patch, the dumpfile is
accepted, and the session subsequently fails with a message indicating
that that the vmlinux and dumpfile do not match.
* Fix for bitmap-handling in SADUMP dumpfiles, which associate each bit in a
bitmap with a physical page in the reverse order that is used in
kdump-compressed format. The bug had not been detected for a long time
because bitmaps in SADUMP formats consist mostly of 0x00 and 0xff
excluding a very limited amount of memory space for firmware.
* Fix for the behavior of the --zero_excluded option when used with SADUMP
dumpfiles. Without the patch, the behavior of --zero_excluded option is
the opposite to what is expected: reads of filtered pages return
successfully with zero-filled memory, while reads of filtered filtered
pages fail when --zero_excluded option has been specified.
* Fix for the "kmem -i" command in Linux 2.6.27 and later kernels to prevent
the possibility that an arbitrary address may be accessed when calculating
the number of total huge pages. Without the patch, the command's "COMMIT
LIMIT" and "COMMITTED" values may be invalid.
* Added recognition of the new DUMP_DH_EXCLUDED_VMEMMAP flag in the header
of compressed kdumps, which is set by the new -e option to the
makedumpfile(8) facility. The -e option excludes kernel pages that
contain nothing but kernel page structures for pages that are not being
included in the dump. If the bit is set in the dumpfile, the crash
utility will issue a warning that the dumpfile is known to be incomplete
during initialization, just prior to the system banner display.
* Fix for the handling of compound pages in Linux 4.4 and later kernels,
which contain this kernel commit:
commit 1d798ca3f16437c71ff63e36597ff07f9c12e4d6 mm: make compound_head()
robust
The commit above removes the PG_tail and PG_compound page.flags bits and the
page.first_page member, and introduces a page.compound_head member, which is
a pointer to the head page and whose bit 0 acts as the tail flag. Without
the patch, a SLAB or SLUB warning message that indicates "cannot determine
how compound pages are linked" is displayed during initialization, and any
command that tracks compound pages will be affected.
* Fix for the handling of dynamically-sized task_struct structures in Linux
4.2 and later kernels, which contain these commits:
commit 5aaeb5c01c5b6c0be7b7aadbf3ace9f3a4458c3d x86/fpu, sched: Introduce
CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86 commit
0c8c0f03e3a292e031596484275c14cf39c0ab7a x86/fpu, sched: Dynamically
allocate 'struct fpu'
Without the patch, when running on a filtered kdump dumpfile, it is possible
that error messages like this will be seen when gathering the tasks running
on a system: "crash: page excluded: kernel virtual address: <task_struct
address> type: "fill_task_struct".
* Fix for the "kmem -s <address>" command in Linux 3.13 and later kernels
configured with CONFIG_SLAB. Without the patch, if the address argument
is contained within an object in a tail page of a multi-page slab, the
command fails with the message "kmem: address is not allocated in slab
subsystem: <address>". Furthermore, in Linux 4.4 and later kernels
configured with CONFIG_SLAB, addresses that are contained within an object
in a tail page of a multi-page slab will not be marked by their slab cache
name by the "rd -S" and "bt -F" commands.
* Fix for a segmentation violation when attempting to run live on a a system
without the crash.ko memory driver, and whose kernel was configured with
CONFIG_STRICT_DEVMEM. Without the patch, if any -d<value> is entered on
the command line, the crash session fails during initialization.
* Update for the determination of the ARM64 page size for kernels containing
this Linux 4.4 commit:
commit 9d372c9fab34cd8803141871195141995f85c7f7 arm64: Add page size to
the kernel image header
Without the patch, the kernel page size is calculated by looking at the size
of the "swapper_pg_dir" page directory. With this update, the page size can
be determined by checking a flag built into the kernel image header,
available in the "_kernel_flags_le" absolute symbol.
* Fix for the handling of ARM and ARM64 QEMU-generated ELF dumpfiles and
compressed kdump clones. The patch utilizes the NT_PRSTATUS notes in the
dumpfile headers instead of reading them from the kernel's "crash_notes",
which are not initialized when QEMU generates a dumpfile. Without the
patch, these warning messages are displayed during session initialization:
WARNING: invalid note (n_type != NT_PRSTATUS) WARNING: cannot retrieve
registers for active tasks
and running "bt" on an active task causes a segmentation violation.
* Update to the previous QEMU-specific patch to handle kdump dumpfiles which
have offline cpus, and therefore will not contain associated NT_PRSTATUS
notes in the dumpfile header. Without the patch, if there are any offline
cpus, a segmentation violation is generated during session initialization.
* The s390 stand-alone dump tools may write the kernel memory directly to a
block device. When running the crash utility against such a block device,
a misleading warning message such as this is displayed:
WARNING: /dev/sda1: may be truncated or incomplete PT_LOAD p_offset: 16384
p_filesz: 5497558138880 bytes required: 5497558155264 dumpfile size: 0
With the patch, the warning message above will be replaced by a note using
this format:
NOTE: /dev/sda1: No dump complete check for block devices
* Map CTRL-l to clear the screen while in vi insertion mode. Without the
patch, it displays "^L".
* Introduced a general-purpose handler to register data structures that the
kernel has dynamically downsized from the size indicated by the debuginfo
data. At this time, only "kmem_cache" and "task_struct" structures that
have been downsized are registered, but others may be added in the future.
If a downsized data structure is passed to gdb for display, gdb will
request a read of the "full" data structure, which may flow into a memory
region that was either filtered by makedumpfile(8), or perhaps into
non-existent memory, thereby killing the generating command immediately
due to a partial read. With this patch, commands such as "struct" and
"task" that reference downsized data structures will have their reads
flagged to return successfully if partial read error occurs.
* Fix for Linux 3.18 and later 32-bit ARM kernels that are configured with
CONFIG_SLAB which contain percpu array_cache structures that were
allocated with vmalloc(). Without the patch, during session
initialization there will be error messages that indicate "crash:
kmem_cache: <vaddr>: invalid array_cache pointer: <vaddr>", and during
runtime, the "kmem -[sS]" commands will show kmem_cache lines that marked
as "[INVALID/CORRUPTED]".
* Added a new "list -l <offset>" option that can only be used in conjunction
with "-s", and requires that the "start" address is the address of a
list_head, or other similar list linkage structure whose first member
points to the next linkage structure. The "-l <offset>" argument is the
offset of the embedded list linkage structure in the specified "-s" data
structure; it can be either a number of bytes or expressed in
"struct.member" format.
* Enhanced the debug-only display of the first kernel data items read during
session initialization. This includes the system's cpu maps, xtime, and
utsname data. These require at least "-d1" as a command line option
value, and are primarily useful as an aide for debugging suspect dumpfiles
that fail during session initialization.
* Added "print_array" as a new internal variable that may be turned on/off
with the "set" command. When set to "on", gdb's printing of arrays will
be set to "pretty", so that the display of each array element will consume
one line.
* Introduction of the "sys -i" option, which displays the kernel's DMI
identification string data if available.
* Fix for "crash --osrelease" on Xen kernels that have both VMCOREINFO and
VMCOREINFO_XEN ELF notes. Without the patch, the command returns
"(unknown)".
-- Troy Heber <email address hidden> Fri, 15 Jan 2016 09:40:34 -0700
