[BUG] syscall.unlink no longer works after upgrading kernel to 3.7.3

[Josh Stone]

On 05/28/2013 12:56 PM, Zheng Da wrote:
> Sorry, I forgot to mention the version of systemtap I'm using.
> I'm using v2.2.1. I checked its source code and the patch you
> mentioned has been applied.
> Does the patch only work with gcc 4.7?

I'm not sure if the -mfentry bug afflicted earlier gcc, but if so that
patch should work just as well.

But there are other reasons for "not accessible" errors, as described in
"man error::dwarf".  Just optimization or inlining can be enough to make
variables unavailable from certain addresses.

Are you able to look at the DWARF dump to see where that variable can be
reached?  The specific symptom of -mfentry is that the locations don't
start until exactly 5 bytes after the start of the function.

It would also help if you gave us your script code snippet that led to
the error.  By $sdev, I'm guessing this is a scsi probe - but I can't
find that exact line in our scsi tapset, so I guess this is your code.


Josh