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 Linux 4.6 commit b03a017bebc403d40aa53a092e79b3020786537d, which introduced the new slab management type OBJFREELIST_SLAB. In this mode, the freelist can be an object, and if the slab is full, there is no freelist. On the next free, an object is recycled to be used as the freelist but not cleaned-up. This patch will go through only known freed objects, and will prevent "kmem -S" errors that indicate "invalid/corrupt freelist entry" on kernels configured with CONFIG_SLAB. (thgarnie(a)google.com) - Fix for the initialization-time loading of kernel module symbols if the kernel crashed while running a module's initcall. Without the patch, the crash session fails during initialation with a message similar to "crash: store_module_symbols_v2: total: 7 mcnt: 8". (rabinv(a)axis.com) - Fix for a segmentation violation during session inialization when running against a 32-bit MIPS ELF kdump or compressed kdump if a per-cpu NT_PRSTATUS note cannot be be gathered from the dumpfile header. Without the the patch, a segmentation violation occurs after the message "WARNING: cannot find NT_PRSTATUS note for cpu: <number>" is displayed. (rabinv(a)axis.com) - The 32-bit MIPS PGD_ORDER() macro expects __PGD_ORDER to be signed, which it isn't now since the internal machdep->pagesize is unsigned. Without this patch, module loading fails during initialization on a kernel that has a page size of 16KB, with messages that indicate "please wait... (gathering module symbol data)" followed by "crash: invalid size request: 0 type: pgd page". (rabinv(a)axis.com) - For ARM64 dumpfiles with VMCOREINFO, verify the new "VA_BITS" number against the calculated number. (anderson(a)redhat.com) - Fix for the ARM64 "bt" command in Linux 4.10 and later kernels that are configured with CONFIG_THREAD_INFO_IN_TASK. Without the patch, the "bt" command will fail for active tasks in dumpfiles that were generated by the kdump facility. (takahiro.akashi(a)linaro.org) - Fix for Linux 4.10 commit 7fd8329ba502ef76dd91db561c7aed696b2c7720 "taint/module: Clean up global and module taint flags handling". Without the patch, when running against Linux 4.10-rc1 and later kernels, the crash utility fails during session initialization with the message "crash: invalid structure size: tnt". (panand(a)redhat.com) - Fix for support of /proc/kcore as the live memory source in Linux 4.8 and later x86_64 kernels configured with CONFIG_RANDOMIZE_BASE, which randomizes the unity-mapping PAGE_OFFSET value. Without the patch, the crash session fails during session initialization with the error message "crash: seek error: kernel virtual address: <address> type: page_offset_base". (anderson(a)redhat.com) - Update to the module taint flags handling patch above to account for the change in size of the module.taints flag from an int to a long, while allowing for a kernel backport that keeps it as an int. (anderson(a)redhat.com) - Prepare for the kernel's "taint_flag.true" and "taint_flag.false" member names to be changed to "c_true" and "c_false", which fixes build problems when an out-of-tree module defines "true" or "false". (anderson(a)redhat.com) - Prevent the livepatch taint flag check during the system banner display from generating a fatal session-killing error if relevant kernel symbol names or data structures change in the future (again). (anderson(a)redhat.com) - Fix for the PPC64 "bt" command for non-panicking active tasks in FADUMP-generated dumpfiles (Firmware Assisted Dump facility). Without the patch, backtraces of those tasks may be of the form "#0 [c0000000700b3a90] (null) at c0000000700b3b50 (unreliable)". This patch uses and displays the ptregs register set saved in the dumpfile header for the non-panicking active tasks. (hbathini(a)linux.vnet.ibm.com) - Fix for a possible segmentation violation when analyzing Linux 4.6 and earlier x86_64 kernels configured with CONFIG_RANDOMIZE_BASE. A segmentation violation may occur during session initialization, just after the patching of the gdb minimal_symbol values message, depending upon the value of KERNEL_IMAGE_SIZE, which was variable in the earlier KASLR kernels. This patch sets the KERNEL_IMAGE_SIZE default value to 1GB for those earlier kernels, and also adds a new "--machdep kernel_image_size=<value>" option that can be used to override the default KERNEL_IMAGE_SIZE value if necessary. (anderson(a)redhat.com) - Fix the bracketing of the x86_64 FILL_PML4() macro. (anderson(a)redhat.com) - Fix for the "tree -t radix", "irq", and "files -p" command options in Linux 4.6 and later kernels due to upstream changes in the radix tree facility. Without the patch, the commands will fail with the message "radix trees do not exist or have changed their format". (hirofumi(a)mail.parknet.co.jp) - Fix for the "trace.c" extension module. The kernel buffer referenced by "max_tr_ring_buffer" is not available in all configurations of the kernel so the unitialized max_tr_ring_buffer variable should not be used. A similar check existed previously before the recent rework of the trace extension module to support multiple buffers. (rabinv(a)axix.com) - Clarification in the display of CONFIG_SLUB object addresses that are displayed by the "kmem" command when SLAB_RED_ZONE has been enabled. By default, CONFIG_SLUB object addresses that are displayed by the "kmem" command will point to the SLAB_RED_ZONE padding inserted at the beginning of the object. As an alternative, a new "redzone" environment variable has been addedd that can be toggled on or off. If "set redzone off" is entered, the object addresses will point to the address that gets returned to the allocator. (hirofumi(a)mail.parknet.co.jp, anderson(a)redhat.com) - Fix for the "CURRENT" value displayed by the "timer -r" command. Without the patch, if the target machine has been up for a long enough time, an arithmetic overflow will occur and the time value displayed will be incorrect. (shane.seymour(a)hpe.com) - Fix for 32-bit X86 kernels configured with CONFIG_RANDOMIZE_BASE. Without the patch, an invalid kernel PAGE_OFFSET value is calculated and as a result the session fails during session initialization just after the patching of the gdb minimal_symbol values message, showing the warning message "WARNING: cannot read linux_banner string", followed by "crash: /vmlinux and /dev/crash do not match!". This patch also adds a new "--machdep page_offset=<value>" option that can be used if the CONFIG_PAGE_OFFSET value is not the default address of 0xc0000000. (anderson(a)redhat.com) - Introduction of a new PPC64-only "mach -o" option that dumps the OPAL "Open Power Abstraction Layer" console buffer. (ankit(a)linux.vnet.ibm.com) - Fix for the "bt" command on Linux 4.9 and later 32-bit X86 kernels containing kernel commit 0100301bfdf56a2a370c7157b5ab0fbf9313e1cd, subject "sched/x86: Rewrite the switch_to() code". Without the patch, backtraces for inactive (sleeping) tasks fail with the message "bt: invalid structure member offset: task_struct_thread_eip". (anderson(a)redhat.com) - Fix for a "[-Wmisleading-indentation]" compiler warning and the associated bug that is generated by lkcd_x86_trace.c when building 32-bit X86 with "make warn" with gcc-6.3.1. (anderson(a)redhat.com) - Fix for an invalid "bt" warning on a 32-bit X86 idle/swapper task. Without the patch, the backtrace displays the "cannot resolve stack trace" warning, dumps the backtrace, and then the text symbols: crash> bt PID: 0 TASK: f0962180 CPU: 6 COMMAND: "swapper/6" bt: cannot resolve stack trace: #0 [f095ff1c] __schedule at c0b6ef8d #1 [f095ff58] schedule at c0b6f4a9 #2 [f095ff64] schedule_preempt_disabled at c0b6f728 #3 [f095ff6c] cpu_startup_entry at c04b0310 #4 [f095ff94] start_secondary at c04468c0 bt: text symbols on stack: [f095ff1c] __schedule at c0b6ef8d [f095ff58] schedule at c0b6f4ae [f095ff64] schedule_preempt_disabled at c0b6f72d [f095ff6c] cpu_startup_entry at c04b0315 [f095ff94] start_secondary at c04468c5 crash> The backtrace shown is actually correct. (anderson(a)redhat.com) - Another fix for a similar "bt: cannot resolve stack trace" warning on a 32-bit X86 idle/swapper task, but when running on cpu 0. (anderson(a)redhat.com) - Remove two one-time warning messages that are displayed when running the "bt" command on Linux 4.2 and later 32-bit X86 kernels. Without the patch, the first "bt" command that is executed will be preceded by "bt: WARNING: "system_call" symbol does not exist", followed by "bt: WARNING: neither "ret_from_sys_call" nor "syscall_badsys" symbols exist". (anderson(a)redhat.com) - Fix for Linux 3.15 and later 32-bit X86 kernels containing kernel commit 198d208df4371734ac4728f69cb585c284d20a15, titled "x86: Keep thread_info on thread stack in x86_32". Without the patch, incorrect addresses of each per-cpu hardirq_stack and softirq_stack were saved for usage by the "bt" command. (hirofumi(a)mail.parknet.co.jp, anderson(a)redhat.com) - Additional fix for Linux 3.15 and later 32-bit X86 kernels containing kernel commit 198d208df4371734ac4728f69cb585c284d20a15, titled "x86: Keep thread_info on thread stack in x86_32". The patch fixes the stack transition symbol from "handle_IRQ" to "handle_irq" for usage by the "bt" command. (anderson(a)redhat.com) - Fix for 32-bit X86 kernels to determine the active task in a dumpfile in the situation where the task was running on its soft IRQ stack, took a hard IRQ, and then the system crashed while it was running on its hard IRQ stack. (hirofumi(a)mail.parknet.co.jp) - Allow the "--kaslr=<offset>" and/or "--kaslr=auto" command line options to be used with the 32-bit X86 architecture. (anderson(a)redhat.com) - Removed -Werror from the bfd and opcode library builds. (anderson(a)redhat.com)