From: Yonghong Song <yonghong.song@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
kernel-team@fb.com, Martin KaFai Lau <martin.lau@kernel.org>,
kernel test robot <lkp@intel.com>
Subject: [PATCH bpf-next 1/2] bpf: Fix compilation warning with -Wparentheses
Date: Thu, 27 Jul 2023 22:57:40 -0700 [thread overview]
Message-ID: <20230728055740.2284534-1-yonghong.song@linux.dev> (raw)
The kernel test robot reported compilation warnings when -Wparentheses is
added to KBUILD_CFLAGS with gcc compiler. The following is the error message:
.../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_reg_to_size_sx’:
.../bpf-next/kernel/bpf/verifier.c:5901:14:
error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses]
if (s64_max >= 0 == s64_min >= 0) {
~~~~~~~~^~~~
.../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_subreg_to_size_sx’:
.../bpf-next/kernel/bpf/verifier.c:5965:14:
error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses]
if (s32_min >= 0 == s32_max >= 0) {
~~~~~~~~^~~~
To fix the issue, add proper parentheses for the above '>=' condition
to silence the warning/error.
I tried a few clang compilers like clang16 and clang18 and they do not emit
such warnings with -Wparentheses.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307281133.wi0c4SqG-lkp@intel.com/
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
kernel/bpf/core.c | 4 ++--
kernel/bpf/verifier.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index db0b631908c2..baccdec22f19 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1877,7 +1877,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
case 1:
AX = abs((s32)DST);
do_div(AX, abs((s32)SRC));
- if ((s32)DST < 0 == (s32)SRC < 0)
+ if (((s32)DST < 0) == ((s32)SRC < 0))
DST = (u32)AX;
else
DST = (u32)-AX;
@@ -1904,7 +1904,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
case 1:
AX = abs((s32)DST);
do_div(AX, abs((s32)IMM));
- if ((s32)DST < 0 == (s32)IMM < 0)
+ if (((s32)DST < 0) == ((s32)IMM < 0))
DST = (u32)AX;
else
DST = (u32)-AX;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 0b1ada93582b..e7b1af016841 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5898,7 +5898,7 @@ static void coerce_reg_to_size_sx(struct bpf_reg_state *reg, int size)
s64_min = min(init_s64_max, init_s64_min);
/* both of s64_max/s64_min positive or negative */
- if (s64_max >= 0 == s64_min >= 0) {
+ if ((s64_max >= 0) == (s64_min >= 0)) {
reg->smin_value = reg->s32_min_value = s64_min;
reg->smax_value = reg->s32_max_value = s64_max;
reg->umin_value = reg->u32_min_value = s64_min;
@@ -5962,7 +5962,7 @@ static void coerce_subreg_to_size_sx(struct bpf_reg_state *reg, int size)
s32_max = max(init_s32_max, init_s32_min);
s32_min = min(init_s32_max, init_s32_min);
- if (s32_min >= 0 == s32_max >= 0) {
+ if ((s32_min >= 0) == (s32_max >= 0)) {
reg->s32_min_value = s32_min;
reg->s32_max_value = s32_max;
reg->u32_min_value = (u32)s32_min;
--
2.34.1
next reply other threads:[~2023-07-28 5:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 5:57 Yonghong Song [this message]
2023-07-28 5:57 ` [PATCH bpf-next 2/2] selftests/bpf: Enable test test_progs-cpuv4 for gcc build kernel Yonghong Song
2023-07-28 10:25 ` [PATCH bpf-next 1/2] bpf: Fix compilation warning with -Wparentheses Jiri Olsa
2023-07-28 16:00 ` patchwork-bot+netdevbpf
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