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| author |   Alexei Starovoitov <ast@kernel.org> | 2023-12-26 11:11:43 -0800 |
|---|---|---|
| committer |   Andrii Nakryiko <andrii@kernel.org> | 2024-01-03 10:41:22 -0800 |
| commit | 495d2d8133fd1407519170a5238f455abbd9ec9b (patch) | |
| tree | 12f60945f5c43cbd7daaaf7be7e3594612a477c4 /tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c | |
| parent | Merge branch 'bpf-simplify-checking-size-of-helper-accesses' (diff) | |
| download | linux-495d2d8133fd1407519170a5238f455abbd9ec9b.tar.xz linux-495d2d8133fd1407519170a5238f455abbd9ec9b.zip | |
selftests/bpf: Attempt to build BPF programs with -Wsign-compare
GCC's -Wall includes -Wsign-compare while clang does not.
Since BPF programs are built with clang we need to add this flag explicitly
to catch problematic comparisons like:
int i = -1;
unsigned int j = 1;
if (i < j) // this is false.
long i = -1;
unsigned int j = 1;
if (i < j) // this is true.
C standard for reference:
- If either operand is unsigned long the other shall be converted to unsigned long.
- Otherwise, if one operand is a long int and the other unsigned int, then if a
long int can represent all the values of an unsigned int, the unsigned int
shall be converted to a long int; otherwise both operands shall be converted to
unsigned long int.
- Otherwise, if either operand is long, the other shall be converted to long.
- Otherwise, if either operand is unsigned, the other shall be converted to unsigned.
Unfortunately clang's -Wsign-compare is very noisy.
It complains about (s32)a == (u32)b which is safe and doen't have surprising behavior.
This patch fixes some of the issues. It needs a follow up to fix the rest.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20231226191148.48536-2-alexei.starovoitov@gmail.com
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c index a17dd83eae67..ee4a601dcb06 100644 --- a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c +++ b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c @@ -53,7 +53,7 @@ int test_core_kernel(void *ctx) struct task_struct *task = (void *)bpf_get_current_task(); struct core_reloc_kernel_output *out = (void *)&data.out; uint64_t pid_tgid = bpf_get_current_pid_tgid(); - uint32_t real_tgid = (uint32_t)pid_tgid; + int32_t real_tgid = (int32_t)pid_tgid; int pid, tgid; if (data.my_pid_tgid != pid_tgid) |