crash 7.2.0-1 source package in Ubuntu

Changelog

crash (7.2.0-1) unstable; urgency=medium

  * New upstream (closes: #884464)

  * Fix for the "snap.so" extension module to pass the KASLR relocation offset
    value in the ELF header for x86_64 kernels that are compiled with
    CONFIG_RANDOMIZE_BASE.  Without the patch, it is necessary to use the
    "--kaslr=<offset>" command line option, or the session fails with the
    message "WARNING: cannot read linux_banner string", followed by "crash:
    vmlinux and vmcore do not match!".

  * The native gdb "disassemble" command fails if the kernel has been compiled
    with CONFIG_RANDOMIZE_BASE because the embedded gdb module still operates
    under the assumption that the (non-relocated) text locations in the
    vmlinux file are correct.  The error message that is issued is somewhat
    confusing, indicating "No function contains specified address".  This
    patch simply clarifies the error message to indicate "crash: the gdb
    "disassemble" command is prohibited because the kernel text was relocated
    by KASLR; use the crash "dis" command instead."

  * Fix for the "mach -m" command in Linux 4.9 and later kernels that contain
    commit 475339684ef19e46f4702e2d185a869a5c454688, titled "x86/e820: Prepare
    e280 code for switch to dynamic storage", in which the "e820" symbol was
    changed from a static e820map structure to a pointer to an e820map
    structure.  Without the patch, the command either displays just the
    header, or the header with several nonsensical entries.

  * Fix for Linux 4.10 and later kdump dumpfiles, or kernels that have
    backported commit 401721ecd1dcb0a428aa5d6832ee05ffbdbffbbe, titled "kexec:
    export the value of phys_base instead of symbol address".  Without the
    patch, if the x86_64 "phys_base" value in the VMCOREINFO note is a
    negative decimal number, the crash session fails during session
    intialization with a "page excluded" or "seek error" when reading
    "page_offset_base".

  * Fix for the PPC64 "pte" command.  Without the patch, if the target PTE
    references a present page, the physical address is incorrect.

  * Fix for a 32-bit MIPS compilation error if glibc-2.25 or later has been
    installed on the host build machine.  Without the patch, the build fails
    with the error message "mips-linux-nat.c:157:1: error: conflicting types
    for 'ps_get_thread_area'".

  * Fix for the validity check of S390X virtual addresses for 5-level page
    tables where user space memory is mapped above 8 Petabytes.  Without the
    patch, "rd -u" fails and indicates "invalid user virtual address", and
    "vtop -u" indicates that the address is "(not mapped)".

  * Crash 7.1.5 commit c3413456599161cabc4e910a0ae91dfe5eec3c21 (xen: Add
    support for dom0 with Linux kernel 3.19 and newer) from Daniel Kiper
    implemented support for Xen dom0 vmcores after Linux 3.19 kernel commit
    054954eb051f35e74b75a566a96fe756015352c8 (xen: switch to linear virtual
    mapped sparse p2m list).  This patch can be deemed subsequent to Daniel's
    patch, and implements support Xen PV domU dumpfiles for Linux 3.19 and
    later kernels.

  * Fix for the "dis" command to detect duplicate symbols in the case of a
    "symbol+offset" argument where the duplicates are not contiguous in the
    symbol list.  Without the patch, the first of multiple symbol instances is
    used in the address evaluation.  With the patch, the command will fail
    with the error message "dis: <symbol+offset>: duplicate text symbols
    found:", followed by a list of the duplicate symbols, and their file and
    line numbers if available.

  * Enhancement to the error reporting mechanism for the "kmem -[sS]" options.
    When a fatal error is encountered while gathering basic CONFIG_SLUB
    statistics, it is possible that the slab cache name is not displayed in
    the error message, and the line containing the slab cache name, address,
    etc., is not displayed at all.  With this patch, an extra error message
    indicating "kmem: <cache-name>: cannot gather relevant slab data" will be
    displayed under the fatal error message; and under that, the CACHE
    address, cache NAME, OBJSIZE, and SSIZE columns will be displayed, but
    with "?" under the ALLOCATED, TOTAL, and SLABS columns.

  * Fix to prevent the "tree -t radix" option from failing when it encounters
    duplicate entries in a radix_tree_node[slots] array.  Without the patch,
    if a duplicate slot entry is found, the command fails with the message
    "tree: duplicate tree entry: radix_tree_node: <node address>
    slots[<index>]: <entry>\n".  (The error can be prevented if the command is
    preceded by "set hash off".)  However, certain radix trees contain
    duplicate entries by design, such as the "pgmap_radix" radix tree, in
    which a radix_tree_node may contain multiple instances of the same
    page_map structure.  With the patch, checks will only be made for
    duplicate radix_tree_node structures.

  * First phase of future support for x86_64 5-level page tables.  New sets of
    virtual memory offsets have been #define'd and helper macros and
    placeholder functions for the p4d page tables have been added.  The only
    functional changes with this patchset are dynamically-set PGDIR_SHIFT and
    PHYSICAL_MASK_SHIFT values that are based upon the kernel configuration.

  * Fix for a build failure.  Without the patch, if the build is done by a
    user whose username cannot be determined from the user ID number, the
    build fails immediately with a segmentation fault.

  * Fix for Linux 4.13-rc0 commit 7fd8329ba502ef76dd91db561c7aed696b2c7720
    "x86/boot/64: Rename init_level4_pgt and early_level4_pgt".  Without the
    patch, the crash session fails during initialization with the error
    message "crash: cannot resolve "init_level4_pgt".

  * The internal "build_data" string contains the compile-time date, the user
    id of the builder, and the build machine hostname, and is viewable by the
    "crash --buildinfo" command line option or by the "help -B" option during
    runtime.  This patch replaces that string data with "reproducible build"
    if the SOURCE_DATE_EPOCH environment variable contains a value string when
    the crash binary is compiled.

  * Fix for Linux 4.13-rc1 commit 2d070eab2e8270c8a84d480bb91e4f739315f03d
    "mm: consider zone which is not fully populated to have holes".  Without
    the patch, SPARSEMEM page struct addresses are incorrectly calculated
    because a new section state, and an associated flag bit, has been added to
    the low bits of the mem_section.section_mem_map address; the extra bit is
    erroneously passed back as part of the section_mem_map and resultant page
    struct address, leading to errors in commands such as "kmem -p", "kmem
    -s", "kmem -n", and any other command that translates a physical address
    to its page struct address.

  * Enhancement to the S390X "vtop" command to display page table walk
    information, adding output showing the following page table contents:

       "Region-First-Table Entry" (RFTE)
       "Region-Second-Table Entry" (RSTE)
       "Region-Third-Table Entry" (RTTE)
       "Segment Table Entry" (STE)
       "Page Table Entry" (PTE)
       "Read address of page" (PAGE)

    Depending on the size of the address space, the page tables can start at
    different levels.  For example:

      crash> vtop 3ff8000c000
      VIRTUAL           PHYSICAL
      3ff8000c000       2e3832000

      PAGE DIRECTORY: 0000000000aaa000
       RTTE: 0000000000aadff8 => 00000002e3c00007
        STE: 00000002e3c00000 => 00000002e3df7000
        PTE: 00000002e3df7060 => 00000002e383203d
       PAGE: 00000002e3832000

            PAGE      PHYSICAL     MAPPING      INDEX CNT FLAGS
      3d10b8e0c80    2e3832000               0       0  1 7fffc0000000000


  * Fix the s390dbf time stamps for S390X kernel versions 4.11 and 4.14.  With
    kernel commit ea417aa8a38bc7db ("s390/debug: make debug event time stamps
    relative to the boot TOD clock") for s390dbf time is stored relative to
    the kernel boot time.  In order to still show absolute time since 1970 we
    have to detect those kernels and re-add the boot time before printing the
    records.  We can use the tod_to_timeval() symbol to check for those
    kernels because the patch has removed the symbol.  With kernel commit
    6e2ef5e4f6cc5734 ("s390/time: add support for the TOD clock epoch
    extension") the symbol name for storing the boot time has changed from
    "sched_clock_base_cc" to "tod_clock_base".  This commit is currently on
    the s390 features branch and will be integrated in Linux 4.14.

  * Further enhancement to the S390X "vtop" command to translate the binary
    values of the hardware flags for region, segment and page table entries.
    For example:

      crash> vtop -u 0x60000000000000 VIRTUAL           PHYSICAL
      60000000000000    5b50a000

      PAGE DIRECTORY: 000000005cea0000 RFTE: 000000005cea0018 =>
      000000006612400f (flags = 00f) flags in binary : P=0; TF=00; I=0; TT=11;
      TL=11 RSTE: 0000000066124000 => 000000005d91800b (flags = 00b) flags in
      binary : P=0; TF=00; I=0; TT=10; TL=11 RTTE: 000000005d918000 =>
      000000006615c007 (flags = 007) flags in binary : FC=0; P=0; TF=00; I=0;
      CR=0; TT=01; TL=11 STE: 000000006615c000 => 000000005ce48800 (flags =
      800) flags in binary : FC=0; P=0; I=0; CS=0; TT=00 PTE: 000000005ce48800
      => 000000005b50a03f (flags = 03f) flags in binary : I=0; P=0 PAGE:
      000000005b50a000

    or for large pages:

      crash> vtop -k 0x3d100000000 VIRTUAL           PHYSICAL 3d100000000
      77c00000

      PAGE DIRECTORY: 0000000001210000 RTTE: 0000000001213d10 =>
      0000000077dc4007 (flags = 007) flags in binary : FC=0; P=0; TF=00; I=0;
      CR=0; TT=01; TL=11 STE: 0000000077dc4000 => 0000000077c03403 (flags =
      03403) flags in binary : AV=0, ACC=0011; F=0; FC=1; P=0; I=0; CS=0;
      TT=00


  * PPC64 kernel commit 2f18d533757da3899f4bedab0b2c051b080079dc lowered the
    max real address to 53 bits.  Without this patch, the warning message
    "WARNING: cannot access vmalloc'd module memory" appears during
    initialization, and any command that attempts to read a vmalloc'd kernel
    virtual address will fail and display "read error" messages.

  * Display the KASLR relocation value warning message whenever it is in use.
    Without the patch, the message may not get displayed if the --kaslr option
    is used, or if the dumpfile is a vmcore generated by the current snap.so
    extension module, which now exports the relocation value in the header.

  * Fix to prevent an initialization-time failure when running a live session
    on a host system that does not have a "/usr/src" directory.  Without the
    patch, the session fails with the message "*** Error in 'crash': free():
    invalid pointer: <address> ***".  (Lei Chen)

  * Fix for the ARM64 "bt" command's display of the user mode exception frame
    at the top of the stack in Linux 4.7 and later kernels.  Without the
    patch, the contents of the user mode exception frame are invalid due to
    the miscalculation of the starting address of the pt_regs structure on the
    kernel stack.

  * Integrated support for usage of the Linux 4.14 ORC unwinder by the x86_64
    "bt" command.  Kernels configured with CONFIG_ORC_UNWINDER contain
    .orc_unwind and .orc_unwind_ip sections that can be queried to determine
    the stack frame size of any text address within a kernel function.  For
    kernels not configured with CONFIG_FRAME_POINTER, the crash utility does
    frame size calculation by disassembling a function from its beginning to
    the specified text address, counting the push, pop, and add/sub rsp
    instructions, accounting for retq instructions that occur in the middle of
    a function.  With this patch, access to the new ORC sections has been
    plugged into the existing frame size calculator, resulting in a more
    efficient and accurate manner of determining frame sizes, and as a result,
    more accurate backtraces.

  * Fix for the ARM64 "bt" command when run against Linux 4.14-rc1.  Without
    the patch, a message indicating "crash: builtin stackframe.sp offset
    incorrect!" is issued during session initialization, and the "bt" command
    fails with the error message "bt: invalid structure member offset:
    task_struct_thread_context_sp".

  * For for the "task -R <member>" option on Linux 4.13 and later kernels
    where the task_struct contains a "randomized_struct_fields_start" to
    "randomized_struct_fields_end" section.  Without the patch, a member
    argument that is inside the randomized section is not found.

  * Fix for the "snap.so" extension module to pass the value of the ARM64
    "kimage_voffset" value in the ELF header.  Without the patch, it is
    necessary to use the "--machdep kvimage_offset=<value>" command line
    option, or the session fails with the message "crash: vmlinux and vmcore
    do not match!".

 -- Troy Heber <email address hidden>  Sun, 17 Dec 2017 08:25:06 -0700