Re: [PATCH 19/20] drivers/net/ethernet/marvell/skge.c: fix errorreturn code

[Julia Lawall]

On Fri, 5 Oct 2012, Joe Perches wrote:

> On Fri, 2012-10-05 at 07:22 +0200, Julia Lawall wrote:
> > A tool was used to find a potential problem, and then Peter
> > studied the code to see what fix was appropriate.
>
> Hi Julia.
>
> Was it true that a static analysis tool found the original
> potential issue?  If so, what tool was it?

In the very beginning, I think that I found the problem in a patch when 
looking at patches that contain oopses.

> From that I wrote a Coccinelle rule.  As Peter showed, the rule just 
produces a list of line numbers.  The fix cannot easily be automated, 
because there are many cases where 0 is a valid error value.  Some 
functions, for example, have their error value as a nonpositive integer.

> But wasn't the scripted fix applied to the rest of the tree
> robotically?

No.  Peter studied each case and considered what should be done, and then 
did that.  I guess a potentially bad fix could have been applied 
automatically and then cleaned up manually, but considering the number of 
cases where the fix would be wrong, that seem like a bad idea.  Also one 
might want to adapt a bit to local conventions about where the 
initialization should be added.

julia
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