[Bug 1317136] Re: useful Yama EPERM error message missing (regression)

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** Branch linked: lp:ubuntu/utopic-proposed/gdb

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https://bugs.launchpad.net/bugs/1317136

Title:
  useful Yama EPERM error message missing (regression)

Status in “gdb” package in Ubuntu:
  Confirmed
Status in “ltrace” package in Ubuntu:
  Fix Released
Status in “gdb” source package in Trusty:
  Confirmed
Status in “ltrace” source package in Trusty:
  Confirmed
Status in “gdb” source package in Utopic:
  Confirmed
Status in “ltrace” source package in Utopic:
  Fix Released

Bug description:
  Trusty's gdb and ltrace have lost the helpful error details when
  ptrace attach fails. Compare to strace:

  $ strace -p 1
  strace: attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted
  Could not attach to process.  If your uid matches the uid of the target
  process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try
  again as the root user.  For more details, see /etc/sysctl.d/10-ptrace.conf

  $ gdb -p 1
  GNU gdb (Ubuntu 7.7-0ubuntu3) 7.7
  ...
  Attaching to process 1
  ptrace: Operation not permitted.

  $ ltrace -p 1
  Cannot attach to pid 1: Operation not permitted

  
  In Precise ltrace has the correct error (though gdb is still missing it -- this was lost quite some time ago it seems):

  $ ltrace -p 1
  Could not attach to process.  If your uid matches the uid of the target
  process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try
  again as the root user.  For more details, see /etc/sysctl.d/10-ptrace.conf
  Cannot attach to pid 1: Operation not permitted

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