[Bug 555130] Re: perf doesn't work on -pae-kernels [patch proposal]

[Andy Whitcroft]

** Description changed:

+ SRU Justification
+ 
+ Justification: by default the perf command will not work correctly on
+ any flavour which contains a - in its name
+ 
+ Impact: unable to use the perf command to debug applications when using
+ generic-paeetc
+ 
+ Fix Description: change flavour removal to work with all flavours
+ through use of the known shape version number
+ 
+ Patch: http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-
+ lucid.git;a=commit;h=6ec3efb32496eafa8be998507d26f7ffbe0747c4
+ 
+ Risks: low, this only changes the perf wrapper which has been tested
+ with all known flavours
+ 
+ TEST CASE: attempt to use perf on a generic-pae install note it fails,
+ install patch, note it now works as expected
+ 
+ ===
+ 
  Binary package hint: linux-tools-common
  
  linux-tools-common contains a small redirection-script (/usr/bin/perf),
  for dispatching to the perf-version corresponding to the running kernel.
  
  This script uses basically ${`uname -r`%-*} to figure the running kernel
  version, where %-* strips the last dash-delimited component of the
  kernel name. This breaks for -generic-pae.
  
  Examples of uname "-r":
  2.6.32-19-generic  # Works today
  2.6.32-19-generic-pae  # Breaks, since the TWO last components needs to be stripped.
  
  A proposed solution could be to instead use "%%-[a-z-]*", which would
  remove ALL trailing letters, and dashes, up to the last digit in the
  string (the package-release-number).
  
  However, since I don't know kernel-release names for other
  architectures, it needs to be verified first.
  
  Suggested new perf, change only on line 3
  ----------------
  #!/bin/bash
  version=`uname -r`
  version=${version%%-[a-z-]*}
  exec "perf_$version" "$@"

-- 
perf doesn't work on -pae-kernels [patch proposal]
https://bugs.launchpad.net/bugs/555130
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