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Description of problem: There is a possibility of crashing the kernel when creating a backtrace in a stap script. This is caused by a kernel backport of the dump_stack code that now takes a new argument which wasn't filled in by the systemtap runtime code. Version-Release number of selected component (if applicable): systemtap-1.2-3.el6.x86_64 How reproducible: 50%. It depends on the normal systemtap unwinder failing (for example because it cannot access some memory needed), then the fallback kernel dump_stack code might be called with a not fully filled in stacktrace_ops struct (since the backport introduced a new stack_walk field we don't expect in kernel version < 2.6.33), which might lead to the kernel jumping to a random address. Steps to Reproduce: 1. Run context.exp testcase (make installcheck RUNTESTFLAGS=context.exp) Actual results: Kernel crash with OOPs. Expected results: No crashing kernel, but passing testcase. Additional info: Fixed upstream commit c265cd259a82542abf290a6aeb058056d6c18b73 Author: Mark Wielaard <mjw@redhat.com> Date: Thu Jun 3 11:26:17 2010 +0200 Replace walk_stack field version guard with autoconf test. The test for whether or not to assign print_context_stack to the walk_stack stacktrace_ops field depended on the kernel version. Replace with a proper runtime/autoconf test to make sure the field always gets assigned when available. * buildrun.cxx (compile_pass): Add output for STAP_CONF_WALK_STACK. * runtime/autoconf-walk-stack.c: New test. * runtime/stack.c (print_stack_ops): Assign walk_stack field print_context_stack depending on STAP_CONF_WALK_STACK.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux major release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Major release. This request is not yet committed for inclusion.
*** Bug 602560 has been marked as a duplicate of this bug. ***
*** Bug 612322 has been marked as a duplicate of this bug. ***
Event posted on 07-13-2010 07:11am EDT by Glen Johnson ------- Comment From 2010-07-13 07:09 EDT------- Ported and tested the RHEL 6 Beta2 systemtap packages with commit posted in https://bugzilla.redhat.com/show_bug.cgi?id=599498#c0, it fixes the bug. This event sent from IssueTracker by jkachuck issue 1092833
I've been running the testcase in a loop for about a day, and no box is dead. I suppose thats a PASS. There are still FAILs, but that's different story. Moving to VERIFIED.
Red Hat Enterprise Linux 6.0 is now available and should resolve the problem described in this bug report. This report is therefore being closed with a resolution of CURRENTRELEASE. You may reopen this bug report if the solution does not work for you.