Re: [BUG] Systemtap git master HEAD fails on Fedora 17 x86_64 (kernel 3.6.7)

[Josh Stone <jistone at redhat dot com>]

On 11/26/2012 03:05 PM, agentzh wrote:
> Hello!
> 
> On Mon, Nov 26, 2012 at 2:54 PM, agentzh wrote:
>>     open("/lib/modules/3.6.7-4.fc17.x86_64/build/System.map",
>> O_RDONLY) = -1 ENOENT (No such file or directory)
>>     open("/boot/System.map-3.6.7-4.fc17.x86_64", O_RDONLY) = -1 EACCES
>> (Permission denied)
> 
> Okay...from the strace output given by myself, it seems that it was
> just because stap failed to read the file
> /boot/System.map-3.6.7-4.fc17.x86_64:

The /boot/System.map is used as a fallback, but I'm actually more
surprised at the ENOENT for the /lib/modules/ path.  That ought to be
present as part of the kernel-devel package.  In fact, the strace read()
lines you pasted before look like they're showing good data from
Module.symvers, also part of kernel-devel.

Any idea why your kernel-devel would seem incomplete?  I have the same
kernel-devel-3.6.7-4.fc17.x86_64 installed, and for me it contains both
Module.symvers and System.map.

> Maybe stap should give an error message here instead of just crashing silently?

There actually is an error message, guarded by verbose>3, which is way
too quiet.  This is moved code that used to live in a non-critical path.
 (and perhaps it shouldn't be treated as critical here either, but we
can consider that separately.)  So yes, we should always print a message
when something errors out, and I'll make this do so.

Josh