[Crash-utility] [ANNOUNCE] crash 7.0.6 is available

Download from: http://people.redhat.com/anderson or https://github.com/crash-utility/crash/releases Note that the github "crash-crash-..." tar/zip file naming issue has been fixed with this release. 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 It should also be noted that although the initial ARM64 support was put in place back in the crash-7.0.1 timeframe, this is the first release that has been developed/tested on actual ARM64 hardware. As a result, almost half of the following crash-7.0.6 patches are ARM64-related. Changelog: - Fix for custom X86_64 kernels that change the declaration of the context_switch() function so that it is not an inline function. Without the patch, the message "crash: cannot determine thread return address" is displayed during invocation, and backtraces of blocked tasks may have missing or invalid frames. (ahonig(a)google.com) - Fix to prevent a possible invocation-time error on Linux 3.7 and later kernels configured with CONFIG_SLAB, running against vmcore files filtered with the makedumpfile(8) facility. Without the patch, the message "crash: page excluded: kernel virtual address: <address> type: kmem_cache buffer" is immediately followed by the message "crash: unable to initialize kmem slab cache subsystem". Because of a kernel data structure name change from "cache_cache" to "kmem_cache_boot", the crash utility failed to properly downsize the stored size of the kernel's kmem_cache data structure from the size indicated by the vmlinux debuginfo data. This in turn could lead to reading beyond the end of a kmem_cache data structure into a page of memory that had been excluded from the vmcore. The fix was also applied to kernels configured with CONFIG_SLUB. (anderson(a)redhat.com) - Added a new "--kaslr <offset>" command line option for X86_64 kernels that are configured with CONFIG_RANDOMIZE_BASE. The offset value must be equal to the difference between the symbol values compiled into the vmlinux file and their relocated KASLR values. (ahonig(a)google.com, anderson(a)redhat.com) - Added a new "--kaslr=auto" command line option for X86_64 kernels that that are configured with CONFIG_RANDOMIZE_BASE. When set to "auto", the KASLR relocation value will be determined automatically by comparing the "_stext" symbol value compiled into the vmlinux file with the _stext symbol value stored in kdump vmcoreinfo data; on live systems the comparison will be made with the "_stext" symbol value that is found in /proc/kallsyms. (ahonig(a)google.com, anderson(a)redhat.com) - Enable kernel text line number capability for the "dis -l", "bt -l", "sys -c", and "sym" commands for kernels that are configured with CONFIG_RANDOMIZE_BASE. (anderson(a)redhat.com) - Fix for the "crash --log vmcore" command to account for the kernel data structure and VMCOREINFO string name changes from "log" to "printk_log" in Linux 3.11-rc4 and later kernels. Without the patch, the command fails with the error message "crash: VMCOREINFO: no log buffer data". (anderson(a)redhat.com) - Adjustment to the internal symbol-handling to prevent the usage of kernel system call alias/wrapper names, for examples, "SyS_read" and "compat_SyS_futex" instead of "sys_read" and "compat_sys_futex". Without the patch, commands such as "dis", "sym <address>", and "sys -c" display the alias/wrapper name instead of the real system call name in Linux 3.10 and later kernels. (anderson(a)redhat.com) - Increase the internal hash queue head count from 128 to 32768. The hash queue is used for gathering and verifying lists, and the original count of 128 may be overwhelmed if a list is extremely large. For example, on a 256GB system with 192GB of free pages, the "kmem -f" command takes hours to complete; with this patch, the time is reduced to a few minutes. In addition, a new command line option "--hash <count>" has been added to allow a user to override the default hash queue head count of 32768. (anderson(a)redhat.com) - Fix for the "kmem -F" display and the "kmem -f <address>" or "kmem <address>" options. Without the patch, "kmem -F" does not display the first page in a list of free page blocks on its own line, but rather at the end of the previous line that shows the area number, block size, and free_area struct address that the page is linked to. Due to this error, both "kmem -f <address>" and "kmem -f address>" would not find the associated page or page block if it happened to be the first page or page block in the list. (anderson(a)redhat.com) - Created a new feature for the internal do_list() function if it is necessary to immediately perform a function for each entry in a list while the list is being traversed. A callback function, and an option callback data pointer, can be registered in the list_data structure. The address of each entry in the list along with the optional callback data pointer will be passed to the callback function. If desired, the callback function may also dictate that do_list() should stop the list traversal and return immediately to its caller. (anderson(a)redhat.com) - Made the "kmem -f <address>" and "kmem <address>" options more efficient by using the new do_list() callback function feature above as well as restricting the search to only the NUMA node that contains the address. (anderson(a)redhat.com) - If the first assembly language instruction in an X86_64 function is "nopl 0x0(%rax,%rax,1)" or "data32 data32 data32 xchg %ax,%ax", which are generated when the ftrace facility is configured, the X86_64 "dis" command will append "[FTRACE NOP]" to the line. (anderson(a)redhat.com) - Correction for the "crash -h" and crash.8 man page documentation of the "--machdep phys_base=<physical-address>" command line option. In both places the parameter mistakenly indicated "physbase". (ptesarik(a)suse.cz) - If a host build system does not have /usr/bin/wget installed, and the crash package is built from a directory that was git-cloned from github.com/crash-utility/crash.git, the error message has been clarified to indicate "/usr/bin/wget is required to download gdb-7.6.tar.gz". Without the patch, the message indicates "tar (child): gdb-7.6.tar.gz: Cannot open: No such file or directory". (anderson(a)redhat.com) - Updated the ARM64 implementation to support Linux 3.13 and later kernels that expand to a 42-bit address space when 64K pages are configured. This is also the first crash version that has been tested on a live ARM64 system with 4K pages, where it cleanly make it to the "crash>" prompt. However, it should be noted that some commands (most notably "bt") still do not work as of yet. (anderson(a)redhat.com) - Document the "--machdep phys_offset=<physical-address>" command line option for the ARM64 architecture in the crash.8 man page and the "crash -h" output. (anderson(a)redhat.com) - Fix for KVM dumpfiles created with "virsh dump --memory-only" if an X86_64 kernel was loaded with a non-zero "phys_base". Without the patch, the crash session fails 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) - Initial working implementation of the basic ARM64 "bt" command, with several command options still under development. In-kernel exception frames are only dumped if the exception handler function is contained within the symbol boundaries from "__exception_text_start" to "__exception_text_end"; when ARM64 kdump is eventually implemented, further exception-related work will be resumed. (anderson(a)redhat.com) - Cleaned up the exception frame displays of 64-bit in-kernel and both 32-bit and 64-bit user-mode exceptions. (anderson(a)redhat.com) - Implemented support for the ARM64 "bt -e" option. (anderson(a)redhat.com) - Implemented support for the ARM64 "bt -l" option. (anderson(a)redhat.com) - Update for the X86_64 "bt -l" option such that it also displays the available file and line number information for functions indicated as the "exception RIP" in kernel exception frames. The line number information will follow the exception frame register dump. (anderson(a)redhat.com) - Fix for the ARM64 virtual-to-physical translation of vmemmap page structure addresses for kernels configured with 4K pages. Without the patch, any command that required the contents of a page structure would fail with a readmem error. (cldu(a)marvell.com, anderson(a)redhat.com) - Added support for the ARM64 architecture in the extensions/snap.c extension module. Also fixed the progress percentage display to correct for systems which have non-zero starting physical addresses. (anderson(a)redhat.com) - Implemented support for the ARM64 "bt -f" and "bt -F[F]" options. (anderson(a)redhat.com) - Increase the ARM64 PTRS_PER_PGD_L2_64K from 1024 to 9182 to account for the Linux 3.13 increase of the ARM64 virtual address space size from 39 to 42 bits when 64K pages are configured. Without the patch, the warning message "WARNING: cannot access vmalloc'd module memory" is displayed during session initialization. (anderson(a)redhat.com) - Fix for the "vm -p" option on ARM64 so that file-backed pages are properly translated to the filename and offset. Without the patch, file-backed pages are erroneously shown as being backed on a swap device. (anderson(a)redhat.com) - Increment maximum ARM64 physical address from 40 to 48 bits to match upstream kernel commit 87366d8cf7b3f6dc34633938aa8766e5a390ce33. (anderson(a)redhat.com) - Fix for a segmentation violation generated by the "crash -g vmlinux" command on ARM64. (anderson(a)redhat.com) - Fix for the ARM64 "vtop <address>" command on kernels configured with 64K pages if the address argument is located in the kernel logical memory map region, which uses 512MB hugepage mappings. Without the patch, the verbose page table walk mistakenly continues to the PTE level. (anderson(a)redhat.com) - Fix for ARM64 /proc/kcore support. Without the patch, the crash session fails with the warning message "WARNING: cannot read linux_banner string" followed by the fatal error message "crash: vmlinux and <dumpfile name> do not match!". At this point in time, the kernel requires a patch to the ARM64 kern_addr_valid() function to properly allow memory to be read from the kernel logical memory map region. (anderson(a)redhat.com)