On Fri, 12 Aug 2016 16:24:44 -0400 David Long <dave.l...@linaro.org> wrote:
> From: "David A. Long" <dave.l...@linaro.org> > > Some architectures (i.e.: sparc64 and arm64) make reasonable partial stack > duplication for jprobes problematic. Document this. > > Signed-off-by: David A. Long <dave.l...@linaro.org> Looks good to me. Acked-by: Masami Hiramatsu <mhira...@kernel.org> Thanks! > --- > Documentation/kprobes.txt | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt > index 1f9b3e2..1f6d45a 100644 > --- a/Documentation/kprobes.txt > +++ b/Documentation/kprobes.txt > @@ -103,6 +103,16 @@ Note that the probed function's args may be passed on > the stack > or in registers. The jprobe will work in either case, so long as the > handler's prototype matches that of the probed function. > > +Note that in some architectures (e.g.: arm64 and sparc64) the stack > +copy is not done, as the actual location of stacked parameters may be > +outside of a reasonable MAX_STACK_SIZE value and because that location > +cannot be determined by the jprobes code. In this case the jprobes > +user must be careful to make certain the calling signature of the > +function does not cause parameters to be passed on the stack (e.g.: > +more than eight function arguments, an argument of more than sixteen > +bytes, or more than 64 bytes of argument data, depending on > +architecture). > + > 1.3 Return Probes > > 1.3.1 How Does a Return Probe Work? > -- > 2.5.0 > -- Masami Hiramatsu <mhira...@kernel.org>
