tree 71d6d128a9a54940d707a9534ff733e2c560d6f3
parent 87c7662bea584d5e495e97a59c20b9abaac4eee8
parent a949ae560a511fe4e3adf48fa44fefded93e5c2b
author Linus Torvalds <torvalds@linux-foundation.org> 1398729471 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1398729471 -0700
mergetag object a949ae560a511fe4e3adf48fa44fefded93e5c2b
 type commit
 tag trace-fixes-v3.15-rc2
 tagger Steven Rostedt <rostedt@rostedt.homelinux.com> 1398727143 -0400
 
 Takao Indoh reported that he was able to cause a ftrace bug while
 loading a module and enabling function tracing at the same time.
 
 He uncovered a race where the module when loaded will convert the
 calls to mcount into nops, and expects the module's text to be RW.
 But when function tracing is enabled, it will convert all kernel
 text (core and module) from RO to RW to convert the nops to calls
 to ftrace to record the function. After the convertion, it will
 convert all the text back from RW to RO.
 
 The issue is, it will also convert the module's text that is loading.
 If it converts it to RO before ftrace does its conversion, it will
 cause ftrace to fail and require a reboot to fix it again.
 
 This patch moves the ftrace module update that converts calls to mcount
 into nops to be done when the module state is still MODULE_STATE_UNFORMED.
 This will ignore the module when the text is being converted from
 RW back to RO.
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Merge tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace bugfix from Steven Rostedt:
 "Takao Indoh reported that he was able to cause a ftrace bug while
  loading a module and enabling function tracing at the same time.

  He uncovered a race where the module when loaded will convert the
  calls to mcount into nops, and expects the module's text to be RW.
  But when function tracing is enabled, it will convert all kernel text
  (core and module) from RO to RW to convert the nops to calls to ftrace
  to record the function.  After the convertion, it will convert all the
  text back from RW to RO.

  The issue is, it will also convert the module's text that is loading.
  If it converts it to RO before ftrace does its conversion, it will
  cause ftrace to fail and require a reboot to fix it again.

  This patch moves the ftrace module update that converts calls to
  mcount into nops to be done when the module state is still
  MODULE_STATE_UNFORMED.  This will ignore the module when the text is
  being converted from RW back to RO"

* tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/module: Hardcode ftrace_module_init() call into load_module()