This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
[Bug runtime/4633] New: backtracing broken
- From: "fche at redhat dot com" <sourceware-bugzilla at sourceware dot org>
- To: systemtap at sources dot redhat dot com
- Date: 12 Jun 2007 19:57:09 -0000
- Subject: [Bug runtime/4633] New: backtracing broken
- Reply-to: sourceware-bugzilla at sourceware dot org
Bug #3050 may have been closed but the bug did not stay dead. The same code on
current fc7 kernels gives the usual single line of backtrace info.
The kernel backtracer always seems to do a better job than the code in the runtime.
There are several problems with the code. It uses unprotected dereference code
like "*stack++", even though the stack values are not completely reliable. It
does not know how to distinguish between alternative stacks such as the trap stack,
the normal kernel stack, or whatever happens to come in pt_regs. This is key
because backtrace() should from both kprobes and from ordinary hook calls
such as timers, begin/end, and markers. The backtrace() function should not
include the "Inexact backtrace:" string, as this breaks subsequent tokenizing
with print_stack().
--
Summary: backtracing broken
Product: systemtap
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: runtime
AssignedTo: systemtap at sources dot redhat dot com
ReportedBy: fche at redhat dot com
GCC host triplet: x86-64
http://sourceware.org/bugzilla/show_bug.cgi?id=4633
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.