diff mbox series

[5.4,05/18] nfp: bpf: silence bitwise vs. logical OR warning

Message ID 20220513142229.310212274@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman May 13, 2022, 2:23 p.m. UTC 
From: Nathan Chancellor <nathan@kernel.org>

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>
---
 drivers/net/ethernet/netronome/nfp/nfp_asm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- 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, swr
 	}
 
 	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
 	}
 
 	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;
 }