nfp: bpf: silence bitwise vs. logical OR warning

commit 8a64ef042eab8a6cec04a6c79d44d1af79b628ca upstream.

A new warning in clang points out two places in this driver where
boolean expressions are being used with a bitwise OR instead of a
logical one:

drivers/net/ethernet/netronome/nfp/nfp_asm.c:199:20: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
        reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                             ||
drivers/net/ethernet/netronome/nfp/nfp_asm.c:199:20: note: cast one or both operands to int to silence this warning
drivers/net/ethernet/netronome/nfp/nfp_asm.c:280:20: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
        reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                             ||
drivers/net/ethernet/netronome/nfp/nfp_asm.c:280:20: note: cast one or both operands to int to silence this warning
2 errors generated.

The motivation for the warning is that logical operations short circuit
while bitwise operations do not. In this case, it does not seem like
short circuiting is harmful so implement the suggested fix of changing
to a logical operation to fix the warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/1479
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20211018193101.2340261-1-nathan@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.c b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
index b04b83687fe219d98b8a9e1c2b21d1970ac409e0..488615434e4ae7784f9338d612f9c6f27243567b 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
@@ -196,7 +196,7 @@ int swreg_to_unrestricted(swreg dst, swreg lreg, swreg rreg,
        }
 
        reg->dst_lmextn = swreg_lmextn(dst);
-       reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
+       reg->src_lmextn = swreg_lmextn(lreg) || swreg_lmextn(rreg);
 
        return 0;
 }
@@ -277,7 +277,7 @@ int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg,
        }
 
        reg->dst_lmextn = swreg_lmextn(dst);
-       reg->src_lmextn = swreg_lmextn(lreg) | swreg_lmextn(rreg);
+       reg->src_lmextn = swreg_lmextn(lreg) || swreg_lmextn(rreg);
 
        return 0;
 }