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: - Fix for the "snap.so" extension module to pass the KASLR relocation offset value in the ELF header for x86_64 kernels that are compiled with CONFIG_RANDOMIZE_BASE. Without the patch, it is necessary to use the "--kaslr=<offset>" command line option, or the session fails with the message "WARNING: cannot read linux_banner string", followed by "crash: vmlinux and vmcore do not match!". (anderson(a)redhat.com) - The native gdb "disassemble" command fails if the kernel has been compiled with CONFIG_RANDOMIZE_BASE because the embedded gdb module still operates under the assumption that the (non-relocated) text locations in the vmlinux file are correct. The error message that is issued is somewhat confusing, indicating "No function contains specified address". This patch simply clarifies the error message to indicate "crash: the gdb "disassemble" command is prohibited because the kernel text was relocated by KASLR; use the crash "dis" command instead." (anderson(a)redhat.com) - Fix for the "mach -m" command in Linux 4.9 and later kernels that contain commit 475339684ef19e46f4702e2d185a869a5c454688, titled "x86/e820: Prepare e280 code for switch to dynamic storage", in which the "e820" symbol was changed from a static e820map structure to a pointer to an e820map structure. Without the patch, the command either displays just the header, or the header with several nonsensical entries. (anderson(a)redhat.com) - Fix for Linux 4.10 and later kdump dumpfiles, or kernels that have backported commit 401721ecd1dcb0a428aa5d6832ee05ffbdbffbbe, titled "kexec: export the value of phys_base instead of symbol address". Without the patch, if the x86_64 "phys_base" value in the VMCOREINFO note is a negative decimal number, the crash session fails during session intialization with a "page excluded" or "seek error" when reading "page_offset_base". (anderson(a)redhat.com) - Fix for the PPC64 "pte" command. Without the patch, if the target PTE references a present page, the physical address is incorrect. (anderson(a)redhat.com) - Fix for a 32-bit MIPS compilation error if glibc-2.25 or later has been installed on the host build machine. Without the patch, the build fails with the error message "mips-linux-nat.c:157:1: error: conflicting types for 'ps_get_thread_area'". (dengke.du(a)windriver.com) - Fix for the validity check of S390X virtual addresses for 5-level page tables where user space memory is mapped above 8 Petabytes. Without the patch, "rd -u" fails and indicates "invalid user virtual address", and "vtop -u" indicates that the address is "(not mapped)". (zaslonko(a)linux.vnet.ibm.com) - Crash 7.1.5 commit c3413456599161cabc4e910a0ae91dfe5eec3c21 (xen: Add support for dom0 with Linux kernel 3.19 and newer) from Daniel Kiper implemented support for Xen dom0 vmcores after Linux 3.19 kernel commit 054954eb051f35e74b75a566a96fe756015352c8 (xen: switch to linear virtual mapped sparse p2m list). This patch can be deemed subsequent to Daniel's patch, and implements support Xen PV domU dumpfiles for Linux 3.19 and later kernels. (honglei.wang@oracle com) - Fix for the "dis" command to detect duplicate symbols in the case of a "symbol+offset" argument where the duplicates are not contiguous in the symbol list. Without the patch, the first of multiple symbol instances is used in the address evaluation. With the patch, the command will fail with the error message "dis: <symbol+offset>: duplicate text symbols found:", followed by a list of the duplicate symbols, and their file and line numbers if available. (anderson(a)redhat.com) - Enhancement to the error reporting mechanism for the "kmem -[sS]" options. When a fatal error is encountered while gathering basic CONFIG_SLUB statistics, it is possible that the slab cache name is not displayed in the error message, and the line containing the slab cache name, address, etc., is not displayed at all. With this patch, an extra error message indicating "kmem: <cache-name>: cannot gather relevant slab data" will be displayed under the fatal error message; and under that, the CACHE address, cache NAME, OBJSIZE, and SSIZE columns will be displayed, but with "?" under the ALLOCATED, TOTAL, and SLABS columns. (anderson(a)redhat.com) - Fix to prevent the "tree -t radix" option from failing when it encounters duplicate entries in a radix_tree_node[slots] array. Without the patch, if a duplicate slot entry is found, the command fails with the message "tree: duplicate tree entry: radix_tree_node: <node address> slots[<index>]: <entry>\n". (The error can be prevented if the command is preceded by "set hash off".) However, certain radix trees contain duplicate entries by design, such as the "pgmap_radix" radix tree, in which a radix_tree_node may contain multiple instances of the same page_map structure. With the patch, checks will only be made for duplicate radix_tree_node structures. (anderson(a)redhat.com) - First phase of future support for x86_64 5-level page tables. New sets of virtual memory offsets have been #define'd and helper macros and placeholder functions for the p4d page tables have been added. The only functional changes with this patchset are dynamically-set PGDIR_SHIFT and PHYSICAL_MASK_SHIFT values that are based upon the kernel configuration. (anderson(a)redhat.com) - Fix for a build failure. Without the patch, if the build is done by a user whose username cannot be determined from the user ID number, the build fails immediately with a segmentation fault. (sargun(a)sargun.me, anderson(a)redhat.com) - Fix for Linux 4.13-rc0 commit 7fd8329ba502ef76dd91db561c7aed696b2c7720 "x86/boot/64: Rename init_level4_pgt and early_level4_pgt". Without the patch, the crash session fails during initialization with the error message "crash: cannot resolve "init_level4_pgt". (anderson(a)redhat.com) - The internal "build_data" string contains the compile-time date, the user id of the builder, and the build machine hostname, and is viewable by the "crash --buildinfo" command line option or by the "help -B" option during runtime. This patch replaces that string data with "reproducible build" if the SOURCE_DATE_EPOCH environment variable contains a value string when the crash binary is compiled. (bwiedemann(a)suse.de) - Fix for Linux 4.13-rc1 commit 2d070eab2e8270c8a84d480bb91e4f739315f03d "mm: consider zone which is not fully populated to have holes". Without the patch, SPARSEMEM page struct addresses are incorrectly calculated because a new section state, and an associated flag bit, has been added to the low bits of the mem_section.section_mem_map address; the extra bit is erroneously passed back as part of the section_mem_map and resultant page struct address, leading to errors in commands such as "kmem -p", "kmem -s", "kmem -n", and any other command that translates a physical address to its page struct address. (anderson(a)redhat.com) - Enhancement to the S390X "vtop" command to display page table walk information, adding output showing the following page table contents: "Region-First-Table Entry" (RFTE) "Region-Second-Table Entry" (RSTE) "Region-Third-Table Entry" (RTTE) "Segment Table Entry" (STE) "Page Table Entry" (PTE) "Read address of page" (PAGE) Depending on the size of the address space, the page tables can start at different levels. For example: crash> vtop 3ff8000c000 VIRTUAL PHYSICAL 3ff8000c000 2e3832000 PAGE DIRECTORY: 0000000000aaa000 RTTE: 0000000000aadff8 => 00000002e3c00007 STE: 00000002e3c00000 => 00000002e3df7000 PTE: 00000002e3df7060 => 00000002e383203d PAGE: 00000002e3832000 PAGE PHYSICAL MAPPING INDEX CNT FLAGS 3d10b8e0c80 2e3832000 0 0 1 7fffc0000000000 (holzheu(a)linux.vnet.ibm.com) - Fix the s390dbf time stamps for S390X kernel versions 4.11 and 4.14. With kernel commit ea417aa8a38bc7db ("s390/debug: make debug event time stamps relative to the boot TOD clock") for s390dbf time is stored relative to the kernel boot time. In order to still show absolute time since 1970 we have to detect those kernels and re-add the boot time before printing the records. We can use the tod_to_timeval() symbol to check for those kernels because the patch has removed the symbol. With kernel commit 6e2ef5e4f6cc5734 ("s390/time: add support for the TOD clock epoch extension") the symbol name for storing the boot time has changed from "sched_clock_base_cc" to "tod_clock_base". This commit is currently on the s390 features branch and will be integrated in Linux 4.14. (holzheu(a)linux.vnet.ibm.com) - Further enhancement to the S390X "vtop" command to translate the binary values of the hardware flags for region, segment and page table entries. For example: crash> vtop -u 0x60000000000000 VIRTUAL PHYSICAL 60000000000000 5b50a000 PAGE DIRECTORY: 000000005cea0000 RFTE: 000000005cea0018 => 000000006612400f (flags = 00f) flags in binary : P=0; TF=00; I=0; TT=11; TL=11 RSTE: 0000000066124000 => 000000005d91800b (flags = 00b) flags in binary : P=0; TF=00; I=0; TT=10; TL=11 RTTE: 000000005d918000 => 000000006615c007 (flags = 007) flags in binary : FC=0; P=0; TF=00; I=0; CR=0; TT=01; TL=11 STE: 000000006615c000 => 000000005ce48800 (flags = 800) flags in binary : FC=0; P=0; I=0; CS=0; TT=00 PTE: 000000005ce48800 => 000000005b50a03f (flags = 03f) flags in binary : I=0; P=0 PAGE: 000000005b50a000 or for large pages: crash> vtop -k 0x3d100000000 VIRTUAL PHYSICAL 3d100000000 77c00000 PAGE DIRECTORY: 0000000001210000 RTTE: 0000000001213d10 => 0000000077dc4007 (flags = 007) flags in binary : FC=0; P=0; TF=00; I=0; CR=0; TT=01; TL=11 STE: 0000000077dc4000 => 0000000077c03403 (flags = 03403) flags in binary : AV=0, ACC=0011; F=0; FC=1; P=0; I=0; CS=0; TT=00 (zaslonko(a)linux.vnet.ibm.com) - PPC64 kernel commit 2f18d533757da3899f4bedab0b2c051b080079dc lowered the max real address to 53 bits. Without this patch, the warning message "WARNING: cannot access vmalloc'd module memory" appears during initialization, and any command that attempts to read a vmalloc'd kernel virtual address will fail and display "read error" messages. (hbathini(a)linux.vnet.ibm.com) - Display the KASLR relocation value warning message whenever it is in use. Without the patch, the message may not get displayed if the --kaslr option is used, or if the dumpfile is a vmcore generated by the current snap.so extension module, which now exports the relocation value in the header. (anderson(a)redhat.com) - Fix to prevent an initialization-time failure when running a live session on a host system that does not have a "/usr/src" directory. Without the patch, the session fails with the message "*** Error in 'crash': free(): invalid pointer: <address> ***". (Lei Chen) - Fix for the ARM64 "bt" command's display of the user mode exception frame at the top of the stack in Linux 4.7 and later kernels. Without the patch, the contents of the user mode exception frame are invalid due to the miscalculation of the starting address of the pt_regs structure on the kernel stack. (anderson(a)redhat.com) - Integrated support for usage of the Linux 4.14 ORC unwinder by the x86_64 "bt" command. Kernels configured with CONFIG_ORC_UNWINDER contain .orc_unwind and .orc_unwind_ip sections that can be queried to determine the stack frame size of any text address within a kernel function. For kernels not configured with CONFIG_FRAME_POINTER, the crash utility does frame size calculation by disassembling a function from its beginning to the specified text address, counting the push, pop, and add/sub rsp instructions, accounting for retq instructions that occur in the middle of a function. With this patch, access to the new ORC sections has been plugged into the existing frame size calculator, resulting in a more efficient and accurate manner of determining frame sizes, and as a result, more accurate backtraces. (anderson(a)redhat.com) - Fix for the ARM64 "bt" command when run against Linux 4.14-rc1. Without the patch, a message indicating "crash: builtin stackframe.sp offset incorrect!" is issued during session initialization, and the "bt" command fails with the error message "bt: invalid structure member offset: task_struct_thread_context_sp". (anderson(a)redhat.com) - For for the "task -R <member>" option on Linux 4.13 and later kernels where the task_struct contains a "randomized_struct_fields_start" to "randomized_struct_fields_end" section. Without the patch, a member argument that is inside the randomized section is not found. (anderson(a)redhat.com) - Fix for the "snap.so" extension module to pass the value of the ARM64 "kimage_voffset" value in the ELF header. Without the patch, it is necessary to use the "--machdep kvimage_offset=<value>" command line option, or the session fails with the message "crash: vmlinux and vmcore do not match!". (anderson(a)redhat.com)