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tracing: Add -mcount-nop option support
authorVasily Gorbik <gor@linux.ibm.com>
Mon, 6 Aug 2018 13:17:46 +0000 (15:17 +0200)
committerSteven Rostedt (VMware) <rostedt@goodmis.org>
Thu, 16 Aug 2018 02:38:38 +0000 (22:38 -0400)
commit2f4df0017baedd535254d987c6b10f855f1fb11f
treec035a8d2357ee4c54b584a3ba4153d4673fa057f
parent07d0408120216b60625c9a5b8012d1c3a907984d
tracing: Add -mcount-nop option support

-mcount-nop gcc option generates the calls to the profiling functions
as nops which allows to avoid patching mcount jump with NOP instructions
initially.

-mcount-nop gcc option will be activated if platform selects
HAVE_NOP_MCOUNT and gcc actually supports it.
In addition to that CC_USING_NOP_MCOUNT is defined and could be used by
architectures to adapt ftrace patching behavior.

Link: http://lkml.kernel.org/r/patch-3.thread-aa7b8d.git-e02ed2dc082b.your-ad-here.call-01533557518-ext-9465@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Makefile
kernel/trace/Kconfig
kernel/trace/ftrace.c