An updated crash package that fixes various bugs and adds several enhancements is now available for Red Hat Enterprise Linux 6.
The crash package provides a self-contained tool that can be used to investigate live systems, and kernel core dumps created from the netdump, diskdump, kdump, and Xen/KVM "virsh dump" facilities from Red Hat Enterprise Linux.
The crash package has been upgraded to upstream version 5.1.8, which provides a number of enhancements and bug fixes over the previous version.
Previously, compressed kdump dump files were handled incorrectly on AMD64 and Intel 64 architectures if a system contained more than 454 CPUs. In such a case, the crash session terminated during initialization with the "crash: compressed kdump: invalid nr_cpus value: [cpus]" error message. A patch has been provided to address this issue, and the compressed dump files are now handled properly, thus fixing this bug.
When the first chunk of physical memory on a system was assigned to NUMA (Non-Uniform Memory Architecture) node 1 (typically it is assigned to NUMA node 0), the "kmem -s" or "kmem -S" command incorrectly showed all cache blocks allocated by the slab allocator as empty. This bug has been fixed, and the kmem command now shows populated kmem_cache slab data correctly.
In a rare scenario, a non-crashing CPU received a shutdown NMI (non-maskable interrupt) immediately after receiving an interrupt from another source. Because the IRQ entry-point symbols "IRQ0x00_interrupt" through "IRQ0x##_interrupt" no longer existed, the bt command terminated with the "bt: cannot transition from exception stack to current process stack" error message on AMD64 and Intel 64 architectures. This bug has been fixed, and backtrace now properly transitions from the NMI stack back to the interrupted process stack.
The crash.8 man page and the associated built-in "crash -h" output have been re-written. The crash.8 man page now clarifies the required invocation options, adds all of the rarely-used command line options that have proliferated over the years, and updates the ENVIRONMENT variables section. The "crash -h" output now closely mimics the relevant parts of the crash.8 man page.
With this update, the new "--osrelease [dump_file]" command line option that displays the OSRELEASE vmcoreinfo string from a kdump dump file has been added.
Users of crash are advised to upgrade to this updated package which fixes these bugs and adds these enhancements.