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Re: no match while resolving probe point kernel.function("printk")
- From: fche at redhat dot com (Frank Ch. Eigler)
- To: Om <om dot turyx at gmail dot com>
- Cc: systemtap at sourceware dot org
- Date: Tue, 26 Aug 2008 20:20:02 -0400
- Subject: Re: no match while resolving probe point kernel.function("printk")
- References: <48B46A96.8090906@gmail.com>
Om <om.turyx@gmail.com> writes:
> I am trying to execute this script.
> [...]
> # stap -v -u printk-time-toggle.stp 1
> [...]
> semantic error: write to target variable not permitted: identifier
> '$printk_time' at printk-time-toggle.stp:8:4
> [...]
That's the key message there. Since this script attempts to modify
a kernel variable, it needs to be run under guru mode ("stap -g ...").
> When I comment out the statement $printk_time = 1 - $printk_time, it
> compiles without complaining any semantic error. [...]
Right, because then the script does not attempt anything privileged.
- FChE