3:41 p.m.
Download from: http://people.redhat.com/anderson
or
https://github.com/crash-utility/crash/releases
The master branch serves as a development branch that will contain all
patches that are queued for the next release:
$ git clone git://github.com/crash-utility/crash.git
Changelog:
- Fix the CPU timer and clock comparator output for the "bt -a" command
on S390X machines. The output of CPU timer and clock comparator has
always been incorrect because:
- We added S390X_WORD_SIZE (8) instead of 4 to get the second word
- We did not left shift the clock comparator by 8
The fix gets the complete 64 bit values and by shifting the clock
comparator correctly.
(holzheu(a)linux.vnet.ibm.com)
- Add "/lib/modules/<version>/build" to the list of directories that
are searched for the currently-running kernel on live systems. This
will automatically locate the vmlinux namelist for kernels that were
locally installed with "make modules_install install".
(lrintel(a)redhat.com)
- Addressed 3 Coverity Scan issues:
(1) task.c: initialize the "curr" and "curr_my_q" variables in
the
dump_tasks_in_task_group_cfs_rq() function.
(2) ramdump.c: make the "rd" and "len" return values from read()
and write() calls in write_elf() to be ssize_t types.
(3) cmdline.c: make the parsed PATH string buffer equal to the size
of the PATH string + 1 to prevent a possible buffer overflow
when a command line starts with a "!".
(anderson(a)redhat.com)
- Fix for the one-time (dumpfile), or as-required (live system),
gathering of tasks from the kernel pid_hash[] in 2.6.24 and later
kernels. Without the patch, if an entry in a pid_hash[] chain is
not related to the "init_pid_ns" pid_namespace structure, any
remaining entries in the hlist chain are skipped.
(vvs(a)parallels.com)
- Update the "extensions/snap.mk" file to allow the "snap.so"
extension
module to be built outside of a crash source tree on a ppc64le PPC64
little-endian host. Without the patch, "make -f snap.mk" would fail
to compile, indicating "gcc: error: macro name missing after '-D'"
(anderson(a)redhat.com)
- Improve the method for determining whether a 32-bit ARM vmlinux is
an LPAE enabled kernel by first checking whether CONFIG_ARM_LPAE
exists in the vmcoreinfo data, and if it does not, by then checking
whether the next higher symbol above "swapper_pg_dir" is 0x5000 bytes
higher in value.
(sdu.liu(a)huawei.com)
- Fix "defs.h" for building extension modules outside of the crash
utility source tree on PPC and PPC64 machines. Without the patch,
both PPC and PPC64 will get #define'd if the extension module build
procedure does not #define one or the other, which in turn causes
multiple conflicting declarations.
(anderson(a)redhat.com)
- Fix for the "ps" command performance degradation patch the was
introduced in crash-7.0.8. Without this patch, it is possible that
the "ps" command may fail prematurely with the error message
"ps: bsearch for tgid failed: task: <address> tgid: <number>"
when running on a live system or against a "live" dumpfile.
(panfy.fnst(a)cn.fujitsu.com)
- Set the 32-bit ARM HZ value to a default value of 100 if the kernel
was not configured with CONFIG_IKCONFIG. Without the patch, the
initial system banner and the "sys" command show "UPTIME: (cannot
calculate: unknown HZ value)", the "ps -t" option shows "RUN TIME:
(cannot calculate: unknown HZ value)", and the "timer -r" option
kills the crash session with a floating point exception.
(hukeping(a)huawei.com)
- Fix the error message displayed if the vmlinux or vmcore file is
not the same endian as the crash utility binary. Without the patch
the filename is shown with the incorrect/opposite endian type.
(hukeping(a)huawei.com)
- Update the "ps" command's "ST" task state display to recognize
the
TASK_PARKED state in Linux 3.9 and later kernels. Without the patch,
the command's "ST" column entry for parked tasks shows "??".
The
state column will now show "PA", and the foreach command will accept
"PA" as a "state" argument.
(anderson(a)redhat.com)
- Fortify the protection against the use of an invalid/corrupted
CONFIG_SLAB kmem_cache per-cpu array_cache.limit value during
session initialization. In a recently seen vmcore, several of the
array_cache.limit values were corrupted such that they were stored
as negative values, which in turn caused the "kmem -[sS]" options
to fail immediately with a dump of the internal memory buffer
allocation statistics and the error message "kmem: cannot allocate
any more memory!".
(anderson(a)redhat.com)
- Implement a new "offline" internal crash variable that can be set to
either "show" (the default) or "hide". When set to
"hide", certain
command output associated with offline cpus will be hidden from view,
and the output will indicate that the cpu is "[OFFLINE]". The new
variable can be set during invocation on the crash command line via
the option "--offline [show|hide]". During runtime, or in a .crashrc
or other crash input file, the variable can be set by entering
"set offline [show|hide]". The commands or options that are affected
when the variable is set to "hide" are as follows:
o On X86_64 machines, the "bt -E" option will not search exception
stacks associated with offline cpus.
o On X86_64 machines, the "mach" command will append
"[OFFLINE]"
to the addresses of IRQ and exception stacks associated with
offline cpus.
o On X86_64 machines, the "mach -c" command will not display the
cpuinfo_x86 data structure associated with offline cpus.
o The "help -r" option has been fixed so as to not attempt to
display register sets of offline cpus from ELF kdump vmcores,
compressed kdump vmcores, and ELF kdump clones created by
"virsh dump --memory-only".
o The "bt -c" option will not accept an offline cpu number.
o The "set -c" option will not accept an offline cpu number.
o The "irq -s" option will not display statistics associated with
offline cpus.
o The "timer" command will not display hrtimer data associated
with offline cpus.
o The "timer -r" option will not display hrtimer data associated
with offline cpus.
o The "ptov" command will append "[OFFLINE]" when translating a
per-cpu address offset to a virtal address of an offline cpu.
o The "kmem -o" option will append "[OFFLINE]" to the base
per-cpu
virtual address of an offline cpu.
o The "kmem -S" option in CONFIG_SLUB kernels will not display
per-cpu data associated with offline cpus.
o When a per-cpu address reference is passed to the "struct"
command, the data structure will not be displayed for offline
cpus.
o When a per-cpu symbol and cpu reference is passed to the "p"
command, the data will not be displayed for offline cpus.
o When the "ps -[l|m]" option is passed the optional "-C [cpus]"
option, the tasks queued on offline cpus are not shown.
o The "runq" command and the "runq [-t/-m/-g/-d]" options will
not
display runqueue data for offline cpus.
o The "ps" command will replace the ">" active task indicator
to
a "-" for offline cpus.
The initial system information banner and the "sys" command will
display the total number of cpus as before, but will append the count
of offline cpus. Lastly, a fix has been made for the initialization
time determination of the maximum number of per-cpu objects queued
in a CONFIG_SLAB kmem_cache so as to continue checking all cpus
higher than the first offline cpu. These changes in behavior are not
dependent upon the setting of the crash "offline" variable.
(qiaonuohan(a)cn.fujitsu.com)
- Adjustment to the "offline" patch-set to make the initial system
banner, the "sys" command, and the X86_64 "mach" command, to only
show the "OFFLINE" cpu count if there are actually offline cpus.
(anderson(a)redhat.com)
- Make the "bt -E" option conform to a "-c cpu(s)" specification when
the the two options are used together. Without the patch, "bt -E"
ignores a cpu specifier.
(anderson(a)redhat.com)
- Fix for the determination of the cpu count on 32-bit ARM machines.
Without the patch, if certain patterns of cpus are offline, the count
may be too small, causing cpu-dependent commands to not recognize
online cpus.
(Jan.Karlsson(a)sonymobile.com, anderson(a)redhat.com)
- Fix for a missing exception frame dump by the X86_64 "bt" command
when an IRQ is received while a task is running on its per-cpu
interrupt stack with interrupts enabled.
(anderson(a)redhat.com)
- Fix for the determination of the cpu count on ARM64 machines.
Without the patch, if certain patterns of cpus are offline, the count
may be too small, causing cpu-dependent commands to not recognize
online cpus.
(Jan.Karlsson(a)sonymobile.com, anderson(a)redhat.com)
- Fix for a possible SIGSEGV generated during session initialization
while "please wait... (determining panic task)" is being displayed.
This was caused by a patch introduced in crash-7.0.8, and can only
happen when analyzing dumpfiles whose header does not contain the
requisite information to determine the panic task and the active
tasks do not have any crash-related traces in their kernel stacks.
It should be noted that the SIGSEGV can be avoided by entering
"--no_panic" on the crash command line.
(anderson(a)redhat.com)
- Fix for a SIGSEGV generated by the "bt -a" or "help -r" commands
if the NT_PRSTATUS notes in a compressed kdump are invalid/corrupt.
If all cpus are online but the dumpfile initialization that cycles
through the NT_PRSTATUS notes does not find exactly one note per
cpu, then the register contents in those notes should not be used.
(anderson(a)redhat.com)
- Fix for data access from "split" compressed kdump dumpfiles. Without
the patch, if a dumpfile read targets physical memory in the first
memory page stored in the second or later sequential split dumpfile,
incorrect data will be returned.
(qiaonuohan(a)cn.fujitsu.com)
- Correction of the copyright and authorship of ramdump.c.
(oza(a)broadcom.com)
- Added recognition of the new DUMP_DH_COMPRESSED_INCOMPLETE flag in
the header of compressed kdumps, and the new DUMP_ELF_INCOMPLETE flag
in the header of ELF kdumps. If the makedumpfile(8) facility fails
to complete the creation of compressed or ELF kdump vmcore files
due to ENOSPC or other error, it will mark the vmcore as incomplete.
If either flag is set, the crash utility will issue a warning that
the dumpfile is known to be incomplete during initialization, just
prior to the system banner display. When reads are attempted on
missing data, a read error will be returned. As an alternative,
zero-filled data will be returned if the "--zero_excluded" command
line flag is used, or the "zero_excluded" runtime variable is set
to "on". In either case, the read errors or zero-filled memory
may cause the crash session to fail entirely, cause commands to
fail, or may result in other unpredictable runtime behavior.
(anderson(a)redhat.com, zhouwj-fnst(a)cn.fujitsu.com)
- If a kernel has been configured with CONFIG_DEBUG_INFO_REDUCED, then
the crash utility will fail to initialize, typically with a message
indicating "no debugging data available". However, it has been
reported (on a 32-bit ARM system) that the initialization sequence
continued on beyond that message point, and the session failed later
on with the message "neither runqueue nor rq structures exist". As
an aid to understanding why the session failed, if the target kernel
is configured with CONFIG_IKCONFIG, and CONFIG_DEBUG_INFO_REDUCED has
been set to "y", a relevant warning message will be displayed.
(anderson(a)redhat.com)
- Implemented support for this Linux 3.18 commit for kernels that are
configured with CONFIG_SLAB:
commit bf0dea23a9c094ae869a88bb694fbe966671bf6d
mm/slab: use percpu allocator for cpu cache
The commit above redesigned the kmem_cache.array_cache[] from a
hardwired array to a per-cpu pointer referencing external array_cache
structures. Without the patch, the crash session would fail during
initialization with the message "crash: cannot resolve cache_cache".
Note that it could be worked around by using the "--no_kmem_cache"
command line option, with a resulting loss of functionality for
commands requiring slab-related data.
(anderson(a)redhat.com)
- Implemented a new "sys -t" option that displays kernel taint
information. If the "tainted_mask" symbol exists, the option will
show its hexadecimal value and translate each bit set to the symbolic
letter of the taint type. On kernels prior to 2.6.28 which had the
"tainted" symbol, only its hexadecimal value is shown. The relevant
kernel sources should be consulted for the meaning of the letter(s)
or hexadecimal bit value(s).
(anderson(a)redhat.com)
- Cosmetic fix for the "help -[n|D]" translation of the bitmap contents
of the kdump_sub_header.dump_level flag in compressed kdump dumpfiles.
(anderson(a)redhat.com)
- Fix for the support of compressed kdump clones created with the KVM
"virsh dump --memory-only --format <compression-type>" command,
where the compression-type is either "kdump-zlib", "kdump-lzo" or
"kdump-snappy". Without the patch, if an x86_64 guest kernel was loaded
with a non-zero "phys_base", the "--machdep
phys_base=<offset>" command
line option was required as a workaround or the crash session would fail
with the warning message "WARNING: cannot read linux_banner string"
followed by the fatal error message "crash: vmlinux and <dumpfile name>
do not match!".
(anderson(a)redhat.com)