Re: [PATCH] MIPS: lib: Mark intrinsics notrace

[Ralf Baechle]

On Wed, May 25, 2016 at 11:06:35AM +0100, Harvey Hunt wrote:

> On certain MIPS32 devices, the ftrace tracer "function_graph" uses
> __lshrdi3() during the capturing of trace data. ftrace then attempts to
> trace __lshrdi3() which leads to infinite recursion and a stack overflow.
> Fix this by marking __lshrdi3() as notrace. Mark the other compiler
> intrinsics as notrace in case the compiler decides to use them in the
> ftrace path.

Makes perfect sense - but I'm wondering how you triggered it.  Was this
a build with the GCC option -Os that is CONFIG_CC_OPTIMIZE_FOR_SIZE?
Usually people build with CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE that is -O2
which results in intrinsics being inlined.

  Ralf