[RFC, PATCH] UBUNTU: fix perf kernel version detection for multiple-flavour strings

[Jeremy Kerr]

Currently, the perf tool doesn't work for the generic-pae flavour:

 $ bash -x /usr/bin/perf
 ++ uname -r
 + version=2.6.32-21-generic-pae
 + version=2.6.32-21-generic
 + exec perf_2.6.32-21-generic
 /usr/bin/perf: line 4: exec: perf_2.6.32-21-generic: not found

- the PAE flavour has a version string ending in -generic-pae, but the
version cleaning in the perf script doesn't handle the multiple flavour
strings correctly. The perf tool is named perf_2.6.32-21, not
perf_2.6.32-21-generic.

This change fixes the perf wrapper script to throw away version data
after a 'dash, non-digit' sequence instead of just the last dash. This
fixes the problem on the PAE kernel. We need to do a special pass for
the -386 flavour, as it's virtually indisinguishable from a normal
version number. Testing this parsing against the possible flavours
gives:

        2.6.32-21-generic -> 2.6.32-21
         2.6.32-21-server -> 2.6.32-21
        2.6.32-21-preempt -> 2.6.32-21
      2.6.32-21-versatile -> 2.6.32-21
        2.6.32-21-generic -> 2.6.32-21
    2.6.32-21-generic-pae -> 2.6.32-21
            2.6.32-21-386 -> 2.6.32-21
           2.6.32-21-ia64 -> 2.6.32-21
           2.6.32-21-lpia -> 2.6.32-21
        2.6.32-21-powerpc -> 2.6.32-21
    2.6.32-21-powerpc-smp -> 2.6.32-21
  2.6.32-21-powerpc64-smp -> 2.6.32-21
        2.6.32-21-sparc64 -> 2.6.32-21
    2.6.32-21-sparc64-smp -> 2.6.32-21

Signed-off-by: Jeremy Kerr <jeremy.kerr at canonical.com>

---
 debian/tools/perf |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/debian/tools/perf b/debian/tools/perf
index 1a9915f..33df59d 100644
--- a/debian/tools/perf
+++ b/debian/tools/perf
@@ -1,4 +1,5 @@
 #!/bin/bash
 version=`uname -r`
-version=${version%-*}
+version=${version/-[^0-9]*}
+version=${version%-386}
 exec "perf_$version" "$@"