On Thu, Nov 16, 2017 at 12:05 PM, Geert Uytterhoeven <[email protected]> wrote: > Hi Arnd, > > On Thu, Nov 16, 2017 at 11:50 AM, Arnd Bergmann <[email protected]> wrote: >> On Thu, Nov 16, 2017 at 11:26 AM, Geert Uytterhoeven >> <[email protected]> wrote: >>> With gcc-4.1.2: >>> >>> drivers/infiniband/core/iwpm_util.c: In function ‘iwpm_send_mapinfo’: >>> drivers/infiniband/core/iwpm_util.c:647: warning: ‘ret’ may be used >>> uninitialized in this function >>> >>> Indeed, if nl_client is not found in any of the scanned has buckets, ret >>> will be used uninitialized. >>> >>> Preinitialize ret to zero to fix this. >>> >>> Fixes: 30dc5e63d6a5ad24 ("RDMA/core: Add support for iWARP Port Mapper user >>> space service") >>> Signed-off-by: Geert Uytterhoeven <[email protected]> >>> --- >>> RFC as I have no idea if this can ever happen, and if yes, what's the >>> correct behavior to handle it: >>> - return 0, >>> - return an error code, >>> - don't send anything, >>> - anything else? >> >> This looks like a reasonable warning. I don't see on my box with any compiler >> version. Do you have a configuration I can use to reproduce it, I'd just like >> to see out of curiosity which other compilers report it. > > m68k/allmodconfig
I see my problem now, my randconfig test series has a patch I never sent out, see https://pastebin.com/ZJDHP7g4 ;-) With plan linux-next, I see the warning on x86 with gcc-4.3 and older, but not on newer gcc versions or clang (I tried them all). I also see that x86 builds broke again in recent kernels with gcc-4.2 and older unless you revert ec1e1b610917 ("objtool: Prevent GCC from merging annotate_unreachable(), take 2"). Arnd
