Re: kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared; did you mean 'UCOUNT_COUNTS'?

[Steven Rostedt]

On Thu, 2 Jan 2020 02:09:22 +0800
kbuild test robot <lkp@xxxxxxxxx> wrote:

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   738d2902773e30939a982c8df7a7f94293659810
> commit: ff205766dbbee024a4a716638868d98ffb17748a ftrace: Fix function_graph tracer interaction with BPF trampoline
> date:   3 weeks ago
> config: riscv-randconfig-a001-20200102 (attached as .config)
> compiler: riscv64-linux-gcc (GCC) 7.5.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         git checkout ff205766dbbee024a4a716638868d98ffb17748a
>         # save the attached .config to linux build tree
>         GCC_VERSION=7.5.0 make.cross ARCH=riscv 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> 
> All errors (new ones prefixed by >>):
> 
>    kernel//trace/fgraph.c: In function 'function_graph_enter':
> >> kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared (first use in this function); did you mean 'UCOUNT_COUNTS'?  
>          ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
>                                       ^~~~~~~~~~~~~~~~
>                                       UCOUNT_COUNTS
>    kernel//trace/fgraph.c:111:35: note: each undeclared identifier is reported only once for each function it appears in
> 
>

The next two patches should fix this. The second patch fixes a
different location with the same problem. It appears that without
DYNAMIC_FTRACE (which x86 always has now) that this isn't defined.

-- Steve