[Crash-utility] [ANNOUNCE] crash 7.0.4 is available

[Dave Anderson]

Download from: http://people.redhat.com/anderson

Changelog:

 - Fix for the "ps" command's display of per-task RSS and %MEM values 
   in Linux 2.6.34 and later kernels in which SPLIT_RSS_COUNTING is
   enabled.  Without the patch, the values are only taken from each 
   task's mm_struct.rss_stat structure, which may contain stale values
   because they may not be synchronized with the RSS values stored
   in each per-thread task_struct.rss_stat structure; this may lead
   to invalid or slightly low RSS values, and worst-case, the %MEM
   value may show garbage percentage values.
   (vinayakm.list at gmail.com)

 - Addressed a few (harmless) Coverity Scan complaints in diskdump.c:
     1579:dead_error_line – Execution cannot reach this expression ""|""
          inside statement "fprintf(fp, "%sDUMP_DH_COMP...".
     1574:dead_error_line – Execution cannot reach this expression ""|""
          inside statement "fprintf(fp, "%sDUMP_HEADER_...".
     1571:dead_error_line – Execution cannot reach this expression ""|""
          inside statement "fprintf(fp, "%sDUMP_HEADER_...".
   (anderson at redhat.com)

 - Addressed two warnings when compiling diskdump.c on 32-bit architectures
   when the snappy library is built in:
     diskdump.c:1046: warning: passing argument 3 of 
       'snappy_uncompressed_length' from incompatible pointer type
       /usr/include/snappy-c.h:120: note: expected ‘size_t *’ but argument
       is of type ‘ulong *’
     diskdump.c:1056: warning: passing argument 4 of ‘snappy_uncompress’ 
       from incompatible pointer type
       /usr/include/snappy-c.h:103: note: expected ‘size_t *’ but argument
       is of type ‘ulong *’
   (anderson at redhat.com)

 - Created a simpler interface with the internal do_list() function.
   Currently, if a caller wants to gather the contents of a list into
   an array, it must do the following:

    (1) call hq_open() so that the list contents will be verified and
        saved in the hash queue
    (2) call do_list() to store the list in the hash queue and return
        the number of entries in the list
    (3) allocate a buffer to store the array of entries in the list
    (4) pass the allocated buffer to retrieve_list() to be populated 
        from the hash queue
    (5) call hq_close()

   With this patch, if the passed-in list_data.flags field has a new  
   LIST_ALLOCATE bit set, then do_list() will perform steps (1), (3), 
   (4) and (5) above.  The caller can access the allocated array via
   a new list_data.list_ptr member, and, when done parsing the list,
   the allocated buffer should be returned via FREEBUF().  The only 
   restriction is that the hash queue cannot be currently in use, or
   the do_list() call will fail.  It should also be noted that there
   are circumstances where it still makes sense that steps (1), (3), 
   (4) and (5) are performed by the do_list() caller.
   (anderson at redhat.com)

 - Modified the internal parent_list() function, used by "ps -p", to 
   utilize the simpler new do_list() functionality described above.
   (anderson at redhat.com)

 - Modified the internal dump_vmap_area() function, used by the 
   "kmem -v", "kmem <address>" and "search" commands, to utilize
   the simpler new do_list() functionality.
   (anderson at redhat.com)

 - Modified the internal nr_blockdev_pages() function, used by the 
   "kmem -i", to utilize the simpler new do_list() functionality.
   (anderson at redhat.com)

 - Modified the internal get_mount_list() function, used by the 
   "mount" and "files -d" commands, to utilize the simpler new 
   do_list() functionality.
   (anderson at redhat.com)

 - Modified the internal get_kmem_cache_list() function, used by the 
   "kmem -[sS]", "kmem <address>", "rd -S" and "bf -F" commands,
   to utilize the simpler new do_list() functionality.
   (anderson at redhat.com)

 - Modified the internal show_net_devices_v2() and show_net_devices_v3()
   functions, used by the "net" command, to utilize the simpler new 
   do_list() functionality.
   (anderson at redhat.com)

 - The "help -r" option has been extended to dump the X86 and X86_64 
   registers stored in the NT_PRSTATUS notes in netdump ELF, kdump ELF,
   and compressed kdump dumpfiles.  Without the patch, the option only 
   supports ELF dumpfiles created by the "virsh dump --memory-only"
   facility.
   (anderson at redhat.com)

 - Modified the "runq -g" display to show the CFS task_group and cfs_rq 
   addresses; also the current task is also displayed in its CFS or RT
   queue with with the notation "[CURRENT]" appended to the task data. 
   (Anthony.Chen at Teradata.com)

 - Additional modification to the "runq -g" to display the task_group
   and rt_rq addresses for the RT queues, similar in nature to the CFS
   queue changes are done by the patch above.  In addition, the CFS 
   rb_root and RT prio_array addresses are no longer shown given that 
   they can be determined by looking at the cfs_rq and rt_rq structures
   whose addresses are now displayed. 
   (anderson at redhat.com)

 - Modified the behavior of the "mod -t" option when running against
   Linux 2.6.18 and earlier kernels such that the hexadecimal value of
   the module->license_gplok member is always displayed.  Without the
   patch, if a module's license_gplok boolean or bitmask value is 0,
   it would only be displayed if the module was unsigned.
   (anderson at redhat.com, atomlin at redhat.com)

 - Modified the internal dump_tasks_in_task_group_rt_rq() and 
   dump_RT_prio_array() functions, used by the "runq" command,
   to utilize the simpler new do_list() functionality.
   (anderson at redhat.com)

 - Resurrection of the remote analysis capability for use with the
   "xen-crashd" daemon running on a Xen Dom0 host, which communicates
   with a paused or shutdown DomU guest kernel.  The daemon can be 
   accessed like so:

     $ crash localhost:5001,/dev/xenmem vmlinux

   (dslutz at verizon.com)

 - Prevent the X86_64 "bt" command from using starting RSP and RIP 
   values taken from the NT_PRSTATUS notes of kdump dumpfiles if the
   RSP address is not in the task's kernel stack, or in any of the 
   relevant per-cpu exception stacks.  This can happen when the number
   of NT_PRSTATUS notes does not match the number of online cpus.  
   Without the patch, the command may generate a segmentation violation,
   fail with the error message "bt: cannot determine starting stack 
   pointer", or fail with an error message indicating that the command 
   "cannot transition" from an exception stack to the previous stack.
   (anderson at redhat.com)

 - Fix for the X86_64 "bt" command for displaying the backtraces of 
   active tasks running on the non-crashing cpus in kdump dumpfiles
   in which the "crash_nmi_callback" function frame does not appear
   in the per-cpu NMI exception stacks.  That function frame is 
   normally used as the starting point for the backtraces of those 
   tasks, but if it does not exist, the "notify_die" frame will be 
   used instead.  Without the patch, the backtraces of the active 
   non-crashing tasks are incorrect or incomplete.
   (anderson at redhat.com)
  
 - Increment the X86_64 NR_CPUS maximum value from 5120 to 8192
   to be able to account for Linux 3.13-rc1 and later kernels 
   in which CONFIG_MAXSMP has been configured.  If that is true, 
   the CONFIG_NR_CPUS value is overridden, and the kernel NR_CPUS 
   value will be set to 8192.  This will cause the crash session to
   fail with the messages "WARNING: kernel-configured NR_CPUS (8192) 
   greater than compiled-in NR_CPUS (5120)" and "crash: recompile crash
   with larger NR_CPUS".
   (anderson at redhat.com)

 - A crash-7.0.3 fix for the proper determination of the kernel NR_CPUS
   configurable for Linux 3.8 and later kernels introduced a regression
   in Linux 3.8 and later kernels if:
     (1) the kernel is configured with CONFIG_SLAB, and
     (2) the sum of the kernel's NR_CPUS and MAX_NUMNODES values exceed 
         the NR_CPUS value compiled into the crash utility.
   Without the patch, the crash session generates a segmentation fault
   while it indicates "please wait: gathering kmem slab cache data".
   (anderson at redhat.com)

 - Update for the extensions/trace.c extension module to support the 
   ftrace data structure changes introduced in Linux 3.10 kernels.  
   Without the patch, loading the module with the "extend" command fails
   with the error message "extend: trace.so: no commands registered: 
   shared object unloaded".
   (d.hatayama at jp.fujitsu.com)

 - Increment the S390 and S390X NR_CPUS maximum value from 64 to 512.
   (holzheu at linux.vnet.ibm.com)

 - Implemented support for the redesigned per-slab object bookkeeping 
   that was introduced in Linux 3.13-rc1 for kernels configured with 
   CONFIG_SLAB.  In those kernels, the head page structure associated 
   with each slab is overloaded to serve as the (now removed) slab data
   structure, and the array of kmem_bufctl_t data structures that used 
   to be appended to each slab data structure for object management has
   been replaced by a new freelist stack mechanism.  Without the patch,
   the crash session would fail during initialization with the error 
   message "crash: invalid structure member offset: kmem_cache_s_c_num".
   It should be noted that this patch has only been tested on 3.13-rc1
   kernels, which do not have the modified freelist_idx_t in place as
   of yet, so the replacement of integer-sized indexes with byte or 
   short sized indexes had not been checked in.  Furthermore, if this 
   proposed patch set gets accepted:
     [RFC][PATCH 0/3] re-shrink 'struct page' when SLUB is on.
     https://lkml.org/lkml/2013/12/11/589
   then both CONFIG_SLAB and CONFIG_SLUB support in the crash utility
   will be broken yet again.
   (anderson at redhat.com)

 - In order to facilitate the building of the crash binary with either
   or both of the optional LZO or SNAPPY compression libraries, two new
   Makefile targets have been added:
     $ make lzo
     $ make snappy
   Without the patch, the CFLAGS.extra and LDFLAGS.extra files must be
   created or modified as described in these changelog entries:
     http://people.redhat.com/anderson/crash.changelog.html#LZO
     http://people.redhat.com/anderson/crash.changelog.html#SNAPPY
   This patch simply does the work automatically.  After having done it
   one time, there is no need to use the targets for subsequent builds.          
   The relevant libraries must pre-exist on the build machine.
   (anderson at redhat.com)

 - Long overdue update of the README file.
   (anderson at redhat.com)