Bug 2685 – need to skip probes on insufficient stack

Bug 2685 - need to skip probes on insufficient stack


Summary:	need to skip probes on insufficient stack

Status:	RESOLVED FIXED

Product:	systemtap
Classification:	Unclassified
Component:	translator
Version:	unspecified

Importance:	P2 normal
Target Milestone:	---
Assigned To:	Frank Ch. Eigler

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Reported:	2006-05-22 18:19 UTC by Frank Ch. Eigler
Modified:	2006-11-26 23:28 UTC (History)
CC List:	0 users

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Description Frank Ch. Eigler 2006-05-22 18:19:41 UTC

Similarly to bug #2185, because we don't have a separate stack for kprobe
handling (bug #931), we may have stack exhaustion problems in ordinary usage
without reentrancy.  We go out of our way to minimize stack usage, but we need to
- estimate or measure stack usage of a worst-case scenario (kprobes handler,
deeply nested systemtap expression, calling into the most complex runtime routine)
- add code to the probe entry functions to check for available stack space, and
punt (skip probe) if it's not sufficient

Comment 1 Frank Ch. Eigler 2006-11-26 23:28:56 UTC

patch committed.  The default MINSTACKSPACE may need to be tuned in the future.