Re: vmlinux search path

[Ritesh Raj Sarraf <rrs at debian dot org>]

Hello Srikar,


On Monday 24 May 2010 19:27:28 Srikar Dronamraju wrote:
> From my experience stap looks for debuginfo files in this order.
> As soon as it finds a vmlinux file, it stops searching even if that
> vmlinux file is not debug file.
> 
> The directory containing vmlinux can also specified by using 
> SYSTEMTAP_DEBUGINFO_PATH environmental variable.
>

I tried the environment trick but that does not help. I think the 
DEBUGINFO_PATH is for the kernel modules.

21:21:13 rrs@champaran:/var/tmp/Debian/Result $ export 
SYSTEMTAP_DEBUGINFO_PATH="/usr/lib/debug/"
21:21:39 rrs@champaran:/var/tmp/Debian/Result $ stap -v -e 'probe vfs.read 
{printf("read performed\n"); exit()}' 
Pass 1: parsed user script and 68 library script(s) using 
49924virt/20852res/1740shr kb, in 380usr/30sys/418real ms.
semantic error: missing x86_64 kernel/module debuginfo under 
'/lib/modules/2.6.34-1-amd64/build' while resolving probe point 
kernel.function("vfs_read")
semantic error: no match while resolving probe point vfs.read
Pass 2: analyzed script: 0 probe(s), 0 function(s), 0 embed(s), 0 global(s) 
using 50532virt/21776res/2008shr kb, in 30usr/110sys/142real ms.
Pass 2: analysis failed.  Try again with another '--vp 01' option.
 
> /boot/vmlinux-`uname
> -r`                                                                       
>                                    /boot/.debug/vmlinux-`uname -r`
> /usr/lib/debug/boot/vmlinux-`uname -r` /boot/vmlinux-`uname -r`.debug
> /boot/.debug/vmlinux-`uname -r`.debug /usr/lib/debug/boot/`uname
> -r`5.1snap2.debug /lib/modules/`uname -r`/vmlinux /lib/modules/`uname
> -r`/vmlinux.debug /lib/modules/`uname -r`/.debug/vmlinux.debug
> /usr/lib/debug/lib/modules/`uname -r`/vmlinux.debug

Debian is shipping the vmlinux file as /usr/lib/debug/vmlinux-`uname -r`
which unfortunately does not match the list you have mentioned.
(See Debian BTS: #582810)

Is this something that can be patched (upstream) to include 
/usr/lib/debug/`uname -r` also in the list?

Regards,
Ritesh
-- 
Ritesh Raj Sarraf | http://people.debian.org/~rrs
"Necessity is the mother of invention."

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