[Crash-utility] [ANNOUNCE] crash version 7.2.6 is available

Download from: http://people.redhat.com/anderson or https://github.com/crash-utility/crash/releases The github 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: - Two fixes for the Xen hypervisor; the first fixes a bug seen with Xen 4.11.0 during initialization, which fails with the error message "crash: invalid kernel virtual address: <address> type: fill_pcpu_struct", followed by "WARNING: cannot fill pcpu_struct" and "crash: cannot read cpu_info". The second fix prevents a segmentation violation associated with a crash-7.1.1 commit that addressed the Xen 4.5.0 hypervisor symbol name change from "dom0" to "hardware_domain". (dietmar.hahn(a)ts.fujitsu.com) - Fix for Linux 4.20 and later x86_64 kernels which are NOT configured with CONFIG_RANDOMIZE_BASE. Linux 4.20 introduced kernel commit d52888aa2753e3063a9d3a0c9f72f94aa9809c15, titled "x86/mm: Move LDT remap out of KASLR region on 5-level paging", which modified the 4-level and 5-level paging PAGE_OFFSET values. Without this patch, the crash session fails during initialization with the error message "crash: read error: kernel virtual address: <address> type: tss_struct ist array". For kernels prior to Linux 4.20.0 which have backports of the kernel commit, the kernel's PAGE_OFFSET value must be manually specified via the command line option "--machdep page_offset=ffff888000000000" for kernels with 4-level page tables, or "--machdep page_offset=ff11000000000000" for kernels with 5-level paging. (or alternatively the shorter version "-m page_offset=<address>" may be used). The command line option requirement may be revisited in the future. (anderson(a)redhat.com) - Fix for the "p" command if the expression contains more than one opening parenthesis character and a minus/dash sign. Without the patch, the minus/dash sign will get dropped from the command prior to it being passed on to gdb for evaluation, and the command will fail with the message "p: gdb request failed: <expression>", where the <expression> string will not contain the minus/dash sign. (anderson(a)redhat.com) - Fix for the internal parse_line() utility function to account for embedded sets of parentheses, which may be used for expressions that are passed to gdb by the "p" command. Without the patch, expressions containing embedded sets of parentheses are broken up into multiple argument tokens instead of just one. The previous commit has been reverted by this one. (anderson(a)redhat.com) - First phase of support for ARM64 kernels that are configured with CONFIG_ARM64_USER_VA_BITS_52, which causes the PTRS_PER_PGD count to increase from 64 to 1024. Without the patch, "WARNING: cannot access vmalloc'd module memory" will be displayed during session initialization, and the translation of any mapped kernel virtual address that requires a page table walk will fail, leading to a myriad of other errors. (anderson(a)redhat.com) - Support for configurable CONFIG_ARM64_PA_BITS values introduced in kernel commit 982aa7c5f0861bf56b2412ca341a13f44c238ba4, titled "arm64: add kconfig symbol to configure physical address size". Without the patch, it is impossible to determine the value of CONFIG_ARM64_PA_BITS is, and will require a new MAX_PHYSMEM_BITS vmcoreinfo entry to be exported. This patch reads that entry during intitialization. (anderson(a)redhat.com) - For live system analysis where there is no vmcoreinfo ELF note attached to /proc/kcore, or for dumpfile analysis where there is no vmcoreinfo ELF note attached to the dumpfile, this patch sets the internal pc->read_vmcoreinfo() function to a new plugin function that reads the data directly from the live kernel or dumpfile. Because the function is set much later during initialization than if the ELF note is attached to /proc/kcore or the dumpfile, it may not be available during very early session initialization. (anderson(a)redhat.com) - Fix for Linux 4.14.84 and later 4.14-based x86_64 kernels which are NOT configured with CONFIG_RANDOMIZE_BASE and have backported kernel commit d52888aa2753e3063a9d3a0c9f72f94aa9809c15, titled "x86/mm: Move LDT remap out of KASLR region on 5-level paging", which modified the 4-level and 5-level paging PAGE_OFFSET values. Without this patch, the crash session fails during initialization with the error message "crash: read error: kernel virtual address: <address> type: tss_struct ist array". (anderson(a)redhat.com) - Fix for determining the x86_64 "phys_base" value in dumpfiles created by the KVM "virsh dump" facility if the kernel is KASLR-enabled and does not have the phys_base value stored in vmcoreinfo data. Without the patch, the message "WARNING: cannot determine physical base address: defaulting to 0" is displayed, and the crash session fails to initialize. (jiangran.jr(a)alibaba-inc.com) - 32-bit ARM kernels built with the Thumb-2 instruction set utilize the R7 register instead of FP for unwinding stacks using the DWARF unwinder. On those kernels, without the patch, the "bt" command only shows the task header. (vincent.whitchurch(a)axis.com) - Fix for the "kmem -z" option on Linux 5.0 and later kernels that contain commit a921444382b49cc7fdeca3fba3e278bc09484a27, titled "mm: move zone watermark accesses behind an accessor". Without the patch, the command fails with the error message "kmem: invalid (optional) structure member offsets: zone_pages_min or zone_struct_pages_min". (k-hagio(a)ab.jp.nec.com) - Fix for the "kmem -i" option on Linux 5.0 and later kernels that contain commit ca79b0c211af63fa3276f0e3fd7dd9ada2439839 titled "mm: convert totalram_pages and totalhigh_pages variables to atomic". Without the patch, the command prints some incorrect values, and besides does not print high/low memory information on kernels which are configured with CONFIG_HIGHMEM. (k-hagio(a)ab.jp.nec.com) - Fix for the display of kernel module symbol types by the "sym" command in Linux 5.0 and later kernels if the module debuginfo data has not been loaded into the crash session. The st_info member of the Elf32_Sym or Elf64_Sym structures has changed so as to not contain ASCII symbol type characters, and as a result the "sym" command will show unprintable data as the symbol type. With the patch, only text types ("t" or "T") will be displayed, and the symbols others will show "?". (anderson(a)redhat.com) - First phase of support of the upcoming ARM64 kernel memory map changes to support 52-bit kernel virtual addressing, which allows the configuration of CONFIG_ARM64_VA_BITS to be 52, but where the actual number of VA bits may be downgraded during boot depending upon the hardware capability. This phase is only applicable for live system analysis. (anderson(a)redhat.com) - Fix for the "dis <function>" option with kernel module text symbols on Linux 5.0 and later kernels. Without the patch, the disassembly may stop prematurely or extend into the next function because the st_size member of the Elf32_Sym or Elf64_Sym text symbol structures can no longer be used as the function size. (anderson(a)redhat.com) - Commit dd12805ed1db7 in the linux-next kernel repository, titled "XArray: Remove radix tree compatibility", changes the definition of "radix_tree_root" back to be a struct. However, the content of the new structure differs from the original structure, so without the patch, current linux-next kernels fail during initialization with the error message "radix trees do not exist or have changed their format". Because the new "radix_tree_root" and "xarray" structures have nearly the same layout, the existing functionality for XArrays can be reused. (prudo(a)linux.ibm.com) - Fixes for the "trace.so" extension module: (1) The reader_page can be empty if it was never read, do not record it if it is empty. Better yet, do not record any page that is empty. The struct buffer_page "real_end" is not available in older kernels, so it needs to be tested if it exists before we can use it. (2) In newer kernels, the sp->type of kernel module symbols does not contain the symbol type character unless the module's debuginfo data has been loaded into the crash session. Writing a garbage type to the kallsyms file for trace-cmd to read causes it to crash, so just always write an 'm'. (3) Add the "trace dump -t <trace.dat>" option to the SYNOPSIS line of the help page. (rostedt(a)goodmis.org) - Fix to find the kernel configuration data in Linux 5.1 kernels containing commit 13610aa908dcfce77135bb799c0a10d0172da6ba, titled "kernel/configs: use .incbin directive to embed config_data.gz". Without the patch, new kernels configured with CONFIG_IKCONFIG_PROC will display "WARNING: could not find MAGIC_START!" during session initialization, and also when running "sys config" during runtime. (anderson(a)redhat.com) - Fix for the PPC64 "bt" command running against kernels that are configured with CONFIG_THREAD_INFO_IN_TASK. Without the patch, the "bt" command fails with the message "bt: invalid/stale stack pointer for this task: <address>". (anderson(a)redhat.com) - Fix for the "files -d <dentry>" option if the dentry.d_inode pointer is NULL. Without the patch, the command output does not display the super_block pointer or the file's pathname. (martin.moore(a)hpe.com) - When the is_s390_dump() function is called to determine whether a file is an s390 dumpfile, it currently presumes that the fopen() call always works, and then tries to read it with using a NULL file pointer. Change it to verify that the fopen() was successful, and if not, print an error message as is done with the other dumpfile type verifier functions. (ramin.blackhat(a)gmail.com) - Implement support for ARM64 kernels that are configured with: CONFIG_ARM64_PA_BITS=52 CONFIG_ARM64_64K_PAGES CONFIG_PGTABLE_LEVELS=3 and that run on a host containing physical memory that utilizes any bit in the uppermost 4 bits of the 52-bit physical address range. (anderson(a)redhat.com) - Extension of the "snap.so" extension module to pass a second architecture-specific value in the ELF header; its initial use is for support of the upcoming ARM64 52-bit kernel virtual address space by passing both the VA_BITS and VA_BITS_ACTUAL values. (anderson(a)redhat.com) - Apply initial changes to support kernel address space layout randomization (KASLR) for s390X. This is the minimal patch-set required to process s390x dumps for the kernels configured with CONFIG_RANDOMIZE_BASE, and to accept the "--kaslr" command line option. Only dumpfiles whose headers contain kernel VMCOREINFO data are supported. (zaslonko(a)linux.ibm.com) - Fix for the "dev -[dD]" options on Linux 5.1-rc1 and later kernels that contain commit 570d0200123fb4f809aa2f6226e93a458d664d70, titled "driver core: move device->knode_class to device_private". Without the patch, the command options fail with the error message "dev: invalid structure member offset: device_knode_class". (k-hagio(a)ab.jp.nec.com) - Linux 4.18 kernels introduced a new CONFIG_PROC_VMCORE_DEVICE_DUMP configuration in commit 2724273e8fd00b512596a77ee063f49b25f36507, titled "vmcore: add API to collect hardware dump in second kernel", in which device drivers may collect a device specific snapshot of the hardware/firmware state of their underlying devices, and export the data as a kdump ELF note with type NT_VMCOREDD. This patch recognizes the new ELF note(s) in both ELF and compressed kdump vmcore dumpfiles. The "help -[nD]" option shows basic information about each note, and two new "dev" command options have been introduced. The "dev -V" option displays an indexed list of each note, showing the device name, the dumpfile offset, and the size of each note. The "dev -v index [file]" option either dumps the contents of a note to the display screen in a human-readable format, or copies the note data directly to a specified file. (surendra(a)chelsio.com) - If the kernel's "vmap_area_list" doubly-linked list is corrupt such that it does not link back to the global list_head, commands that require information regarding the range of virtually-mapped kernel addresses will display a generic list-handling error message such as "kmem: invalid list entry: 0", and the command will typically fail to fully complete. However, without the patch, there will also be "WARNING: malloc/free mismatch (29/30)" messages that get displayed after every subsequent command. This patch prevents the mismatch messages, and also adds an additional error message indicating "WARNING: invalid/corrupt vmap_area_list" to further clarify the generic list-handling error message. (dwysocha(a)redhat.com, anderson(a)redhat.com) - Fix for the "dev" help page to remove the unused -r option letter. (surendra(a)chelsio.com) - If a duplicate list entry is encountered when using the "list -B" Brent algorithm, change the list loop length value from hexadecimal to decimal. (dwysocha(a)redhat.com) - Update the README file to indicate the capability of building an x86_64 crash binary with "make target=PPC64", which can be used to analyze ppc64le dumpfiles on an x86_64 host. (anderson(a)redhat.com) - Fix for hybrid kernels that have backported support for the Xarray facility while allowing subsystems to continue to use radix trees. Without the patch, the crash session fails during initialization with the message "crash: xarray facility does not exist or has changed its format". (anderson(a)redhat.com)