Hi Kernel test robot,
CC linux-sparse
On Thu, Jan 2, 2025 at 10:40 PM kernel test robot <lkp@xxxxxxxxx> wrote:
First bad commit (maybe != root cause):
tree: https://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k.git master
head: 17810b1de0e9e5c1000cf8f5b4787ad930b0353e
commit: e96424b86d5098f44279399b85551e0f84a1c9e9 [2/2] m68k: Use kernel's generic muldi3 libgcc function
config: m68k-randconfig-r122-20250101 (https://download.01.org/0day-ci/archive/20250103/202501030516.uZrwnuQQ-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 14.2.0
reproduce: (https://download.01.org/0day-ci/archive/20250103/202501030516.uZrwnuQQ-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501030516.uZrwnuQQ-lkp@xxxxxxxxx/
sparse warnings: (new ones prefixed by >>)
lib/muldi3.c:53:28: sparse: sparse: asm output is not an lvalue
lib/muldi3.c:53:28: sparse: sparse: asm output is not an lvalue
lib/muldi3.c:53:28: sparse: sparse: not addressable
lib/muldi3.c:53:28: sparse: sparse: generating address of non-lvalue (11)
lib/muldi3.c:53:28: sparse: sparse: generating address of non-lvalue (11)
vim +53 lib/muldi3.c
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 48
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 49 long long notrace __muldi3(long long u, long long v)
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 50 {
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 51 const DWunion uu = {.ll = u};
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 52 const DWunion vv = {.ll = v};
b35cd9884fa5d81 Palmer Dabbelt 2017-05-23 @53 DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
:::::: The code at line 53 was first introduced by commit
:::::: b35cd9884fa5d81c9d5e7f57c9d03264ae2bd835 lib: Add shared copies of some GCC library routines
Thanks for the report!
Comparing m68k to the other two architectures that use
GENERIC_LIB_MULDI3 (csky and xtensa), and to microblaze (which has
its own arch/microblaze/lib/muldi3.c), that don't trigger this error,
the difference is that m68k uses inline assembler in its umul_ppmm()
implementation. I don't see anything that's wrong with it, though.
Perhaps this is an issue with sparse?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
