How to translate from user space symbol name to address?

How to translate from user space symbol name to address?

[Yibin Zhao]

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Hi,


usymname can be used to translate address to symbol name, but I can't find
an easy way to translate symbol name to address.

I can get the ubacktrace and translate the addresses to symbols one by one,
and try to find the relationship between the symbol and the address, but
it's a bit tricky I think.


In systemtap source code, tapset.cxx do get address for probed symbols, is
it possible to get symbol address during runtime?


The reason why I want to translate a symbol to an address is , I want to
strip part of the stack for readability.

Any clue is appreciated


Thanks

Yibin

Re: How to translate from user space symbol name to address?

[Frank Ch. Eigler]

Yibin Zhao via Systemtap <systemtap@sourceware.org> writes:

> I can get the ubacktrace and translate the addresses to symbols one by
> one, and try to find the relationship between the symbol and the
> address, but it's a bit tricky I think.

We don't have a runtime tapset function for that direction of mapping,
but a new one could be written, whether slowish/linear, or sorted/binary
like the address-to-symbol table.

- FChE

Re: How to translate from user space symbol name to address?

[Yibin Zhao]

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Understood. I'm not sure if this kind of usage is common.
Finally I translated those addresses to symbols and stripped them by a post
processing script, the performance is acceptable.

Thanks
Yibin
On Fri, Nov 18, 2022 at 11:41 PM Frank Ch. Eigler <fche@redhat.com> wrote:

> Yibin Zhao via Systemtap <systemtap@sourceware.org> writes:
>
> > I can get the ubacktrace and translate the addresses to symbols one by
> > one, and try to find the relationship between the symbol and the
> > address, but it's a bit tricky I think.
>
> We don't have a runtime tapset function for that direction of mapping,
> but a new one could be written, whether slowish/linear, or sorted/binary
> like the address-to-symbol table.
>
> - FChE
>
>