Missing inode/filename when tracing a process

[Paolo Pisati]

[Impact]

Sysdig doesn't print filename when tracing a process - this, among other things, breaks the qa kernel team ubuntu_sysdig_smoke test.

[How to reproduce]

$ sudo ~/bin/sysdig -p%evt.info proc.name=dd &
$ dd if=/dev/zero bs=1024 count=5 > /dev/null

This is actual output:

...
fd=0 size=1024
res=1024 data=
fd=1 size=1024
fd=0 size=1024
fd=1 size=1024
fd=0 size=1024
fd=1 size=1024
fd=0 size=1024
fd=1 size=1024
fd=0 size=1024
fd=1 size=1024
fd=0
...

while this is the expected/correct output:

...
fd=0(<f>/dev/zero) size=1024
res=1024 data=................................................................................
fd=1(<f>/dev/null) size=1024
res=1024 data=................................................................................
fd=0(<f>/dev/zero) size=1024
res=1024 data=................................................................................
fd=1(<f>/dev/null) size=1024
res=1024 data=................................................................................
fd=0(<f>/dev/zero) size=1024
res=1024 data=................................................................................
fd=1(<f>/dev/null) size=1024
res=1024 data=................................................................................
fd=0(<f>/dev/zero) size=1024
res=1024 data=................................................................................
fd=1(<f>/dev/null) size=1024
res=1024 data=................................................................................
fd=0(<f>/dev/zero) size=1024
res=1024 data=................................................................................
fd=1(<f>/dev/null) size=1024
res=1024 data=................................................................................
fd=0(<f>/dev/zero)
...

[Fix]

Cherry-pick an upstream commit that entered the 0.26.5 dev cycle:

https://github.com/draios/sysdig/commit/bbed8dab66157c0be0275040510ef189764582dd

[Regression potential]

Low, it's a clean upstream cherry pick.