Messages in this thread | | | Date | Mon, 26 Aug 2019 16:38:29 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH] rdma/siw: Use proper enumerated type in map_cqe_status |
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On Mon, Aug 26, 2019 at 12:42:28PM -0300, Jason Gunthorpe wrote: > On Mon, Aug 26, 2019 at 08:38:00AM -0700, Nathan Chancellor wrote: > > On Fri, Aug 23, 2019 at 11:24:27AM -0300, Jason Gunthorpe wrote: > > > The latest clang-9 packages from apt.llvm.org do seem to build the > > > kernel, I get one puzzling warning under RDMA: > > > > > > drivers/infiniband/hw/hfi1/platform.o: warning: objtool: tune_serdes()+0x1f4: can't find jump dest instruction at .text+0x118a > > > > Any particular config that I should use to easily reproduce this? > > Sure, attached. With the clang-9 build for Bionic
This is reproducible with the kernel config attached and a tip of tree build of LLVM.
$ make -j$(nproc) CC=clang O=out clean olddefconfig drivers/infiniband/hw/hfi1/platform.o ... CC drivers/infiniband/hw/hfi1/platform.o drivers/infiniband/hw/hfi1/platform.o: warning: objtool: tune_serdes()+0x1f4: can't find jump dest instruction at .text+0x117a
I ran creduce on that file and it spits out:
a() { char *b = a; switch (b[7] & 240 >> 4) { case 10 ... 11: c(); case 0 ... 9: case 12: case 14: d(); case 13: case 15:; } }
to simply reproduce the warning. The original preprocessed file + interestingness test are available here:
https://github.com/nathanchance/creduce-files/tree/4e252c0ca19742c90be1445e6c722a43ae561144/rdma-objtool
Looks like that comes from tune_qsfp, which gets inlined into tune_serdes but I am far from an objtool expert so I am not really sure what kind of issues I am looking for. Adding Josh and Peter for a little more visibility.
Here is the original .o file as well:
https://github.com/nathanchance/creduce-files/raw/4e252c0ca19742c90be1445e6c722a43ae561144/rdma-objtool/platform.o.orig
Cheers, Nathan
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