[RFC updated PATCH 1/2] Bug Translator 3016 : Error accessing members of anonymous structs / unions

[Masami Hiramatsu]

Hi Prerna,

Prerna Saxena wrote:
> Agree, but making "die_mem" as the 6th arg will disturb the call flow.
> This is because in each recursive call, the 6th arg is overwritten by a 
> die which is pointed to by DW_AT_type attribute of the original 
> attr_mem. If die_mem is re-used as 6th arg instead of a new variable, 
> the old contents of die (in the parent recursive call) will also be lost 
> as both die & die_mem point to the same location, (whose contents would 
> be overwritten). This is not a problem if search in a branch  has 
> succeeded-- but in case a search path fails and a new branch needs to be 
> tried, this will deem it impossible.
> 
> I agree with your concern about "temp_die_2" being local memory on the 
> stack which may be reused, so I've fixed it by copying the contents of 
> "temp_die_2" to "die_mem" in case of a successful match. This should 
> take care of memory errors.

Hmm, you seems right, but the below command still cause SEGV.

$ stap -e 'probe module("libsas").function("sas_ex_revalidate_domain"){print($port_dev->ex_dev->children)}' -vp2
Pass 1: parsed user script and 45 library script(s) in 370usr/30sys/404real ms.
Segmentation fault

Would you run above command for testing & debugging?

Thank you,

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com