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 for the handling of 32-bit ELF xendump dumpfiles if the guest was configured with more than 4GB of memory. Without the patch, the crash session may fail during initialization with the error message "crash: vmlinux and <dumpfile> do not match!". (dslutz(a)verizon.com) - Fix for file-handling errors when a compressed vmlinux.debug file is followed by a vmlinux file on the crash command line. When the crash session ends, two errors will occur: (1) the vmlinux file will be deleted (2) the temporary uncompressed version of the vmlinux.debug file will remain in /var/tmp This problem also occurs in the highly unlikely case where a compressed vmlinux file is followed by a vmlinux.debug file on the command line, and the uncompressed temporary version of the vmlinux file is larger than the vmlinux.debug file. In that case: (1) the vmlinux.debug file will be deleted (2) the temporary uncompressed version of the vmlinux file will remain in /var/tmp (dmair(a)suse.com) - Fix for the "search -t" option if the system has 2064 or more tasks. Without the patch, the command fails with a dump of the crash utility memory allocation statistics, ending with "search: cannot allocate any more memory!". (anderson(a)redhat.com) - Fix for the "mod -S" command to find the debuginfo data for Red Hat "kpatch" modules. Without the patch, the command would display "mod: cannot find or load object file for <kpatch-module> module". (anderson(a)redhat.com) - Deprecated the "mount -f" option for Linux 3.13 and later kernels containing commit eee5cc2702929fd41cce28058dc6d6717f723f87, which removed the super_block.s_files list_head member and the open files list that it contained. Without the patch, the command option fails with the error message "mount: invalid structure member offset: super_block_s_files" (anderson(a)redhat.com) - If a compressed kdump is damaged/truncated such that the bitmap data in the dumpfile header is not contained within the file, attempts to analyze it with a vmlinux file, or using the "crash --osrelease" or "crash --log" options with just the vmcore, will result in the crash utility spinning forever, endlessly performing reads of 0 bytes from the file without recognizing the EOF condition. (dwysocha(a)redhat.com) - Fix for an ARM64 compilation failure of the embedded gdb file "aarch-linux-nat.c" in the Fedora fc21 rawhide environment, which uses glibc-headers-2.19.90-24.fc21. (anderson(a)redhat.com) - Document the reason behind the deprecation of the "mount -f" option for Linux 3.13 and later kernels if the option is attempted, and in the "help mount" output, similar to the deprecated "mount -d" option. (anderson(a)redhat.com) - During initialization, reject useless ARM64 "(A)" absolute symbols that begin with "__crc_". Without the patch, several thousand of them may be displayed by "sym -l" prior to the first kernel virtual address symbol. (anderson(a)redhat.com) - When running against an ARM64 dumpfile created with the "snap.so" extension module, do not attempt to read the crash_notes. Since the dumpfile was taken while running on a live system, the crash_notes, if configured into the kernel, would not contain valid data. Without the patch, the message "WARNING: could not retrieve crash_notes" is displayed during session initialization. (anderson(a)redhat.com) - Determine the various ARM64 kernel virtual address ranges using the kernel's VA_BITS value. It currently is hardwired in the kernel to one of two values depending upon whether 4K or 64K pages are configured. However, there are plans to support 16K paqes, to make VA_BITS a configurable value, and to make the number of page-table levels configurable. Towards that end, the crash utility has been changed to determine the VA_BITS value based upon known kernel virtual addresses, and to then calculate the relevant kernel virtual address ranges on that value instead of hardwiring them based upon the page size. (anderson(a)redhat.com) - Enhancement to the "kmem -S" option for Linux 3.2 and later kernels configured with CONFIG_SLUB to display the address of each per-cpu kmem_cache_cpu address and the contents of its per-cpu partial list. (qiaonuohan(a)cn.fujitsu.com) - If an ARM or ARM64 dumpfile does not contain the register sets of the active tasks in the kernel's per-cpu crash_notes, there is an initialization-time warning message indicating "could not retrieve crash_notes". It has been changed to a more meaningful warning message indicating "cannot retrieve registers for active tasks". (anderson(a)redhat.com) - Implement support for ARM and ARM64 raw RAM dumpfiles. One or more "ramdump" files may be entered on the crash command line in an ordered pair format consisting of the RAM dump filename and the starting physical address expressed in hexadecimal, connected with an ampersand: $ crash vmlinux ramdump@address [ramdump@address] A temporary ELF header will be created in /var/tmp, and the combination of the header and the ramdump file(s) will be handled like a normal ELF vmcore. The ELF header will only exist during the crash session. If desired, an optional "-o <filename>" may be entered to create a permanent ELF vmcore file from the ramdump file(s). (vinayakm.list(a)gmail.com, paawan1982(a)yahoo.com, anderson(a)redhat.com) - Fix for the "help -[nD]" ELF header translation to recognize the EM_ARM and EM_AARCH values as "e_machine" types, and ELFOSABI_LINUX as an "e_ident[EI_OSABI]" type. Without the patch, the e_machine translation would show "40 (unsupported)" for 32-bit ARM, or "183 (unsupported)" on ARM64; and the ELFOSABI_LINUX type would be translated as "3 (?)". (anderson(a)redhat.com) - Re-run a command in the history list by entering an "!" followed by the number identifying the command. However, unlike the similar "r" pseudo-command, if the number is a command name in the user's PATH, maintain the current behavior and execute that command. (anderson(a)redhat.com) - Fix to recognize that the live system "crash.ko" memory driver may be compressed and named "crash.ko.xz". Without the patch, the driver is not recognized and loaded, and as a result the /dev/mem driver and/or /proc/kcore will be tried as the live memory source. (anderson(a)redhat.com) - On a live system during session initialization, delay the first read error message (typically when reading the "cpu_possible_mask") until it is confirmed that all of the following are true: (1) /dev/crash does not exist, and (2) /dev/mem is restricted via CONFIG_STRICT_DEVMEM, and (3) /proc/kcore cannot be read/accessed. The "kernel may be configured with CONFIG_STRICT_DEVMEM" and the "trying /proc/kcore as an alternative" messages will still be displayed when appropriate. The read error message be displayed only if all three live memory read options fail. (anderson(a)redhat.com) - Fortify the validity verification of the data structures traversed by the "kmem [-sS]" options for kernels configured with CONFIG_SLUB. Without the patch, the contents of several structure members are not validated, and may generate bogus or never-ending output, typically seen when running the commands on a "live dump" where the dumpfile was taken while the kernel was still running. The patch aborts the relevant parts of per-kmem_cache output when invalid data is encountered or if an object list contains duplicate entries, and error messages have been enhanced to more accurately describe the issues encountered. (anderson(a)redhat.com) - Implement support for the ppc64le PPC64 little-endian architecture. Since this required a large number of patches to be applied to architecture-neutral files in the gdb-7.6 tree, the changes are only applied if the host build system is a ppc64le. (ptesarik(a)suse.cz, normand(a)linux.vnet.ibm.com) - Fix for SMP active task register-gathering from "kvmdump" dumpfiles that were created with a cpu version id of 12 or greater that contain additional XSAVE related fields in their cpu device headers. Without the patch, active tasks running on cpus above 0 may have truncated backtraces. (uobergfe(a)redhat.com) - Maintain backwards-compatibility for "kvmdump" dumpfiles that were created by older development versions of KVM tools in which the cpu version id was 12, but the cpu device headers did not contain the additional XSAVE related fields. (uobergfe(a)redhat.com) - Address a "ps" command performance degradation that was introduced by a crash-7.0.4 patch which added per-thread task_struct.rss_stat page counts to the task's mm_struct.rss_stat page counts in order to show an accurate/synchronized RSS value. Without the patch, the "ps" command performance would degrade as the number of tasks increased, most notably when there were thousands of tasks. (panfy.fnst(a)cn.fujitsu.com, anderson(a)redhat.com)