From: luoliang __COMPAT_read_enum() and __COMPAT_struct_has_field() open-code the vlen lookup via the raw BTF_INFO_VLEN(t->info) UAPI macro. libbpf exposes btf_vlen() for exactly this purpose; use it in the three call sites, matching the pattern in kernel/bpf/inode.c and tools/bpf/bpftool. btf_vlen() returns __u32 (since commit cacd6729c0923, "libbpf: Adjust btf_vlen() to return a __u32", which expanded the BTF vlen field from 16 to 24 bits). Declare the loop counters as __u32 to match the return type, keeping the comparison as a plain '__u32 < __u32' and silencing the -Wsign-compare warnings. No functional change. Suggested-by: Andrea Righi Signed-off-by: Liang Luo --- Changes in v2: - Correct the commit message: btf_vlen() returns __u32 (not __u16) on mainline since cacd6729c0923. The v1 description was accurate only on a v7.1 baseline. (Thanks to Sashiko AI review and Andrea Righi for catching this.) - Declare the loop counters as __u32 to match btf_vlen()'s return type, as suggested by Andrea Righi. This properly silences -Wsign-compare on mainline. --- tools/sched_ext/include/scx/compat.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/sched_ext/include/scx/compat.h b/tools/sched_ext/include/scx/compat.h index 602f07061ee3..23d9ef3e4c9d 100644 --- a/tools/sched_ext/include/scx/compat.h +++ b/tools/sched_ext/include/scx/compat.h @@ -28,7 +28,7 @@ static inline bool __COMPAT_read_enum(const char *type, const char *name, u64 *v const struct btf_type *t; const char *n; s32 tid; - int i; + __u32 i; __COMPAT_load_vmlinux_btf(); @@ -42,7 +42,7 @@ static inline bool __COMPAT_read_enum(const char *type, const char *name, u64 *v if (btf_is_enum(t)) { struct btf_enum *e = btf_enum(t); - for (i = 0; i < BTF_INFO_VLEN(t->info); i++) { + for (i = 0; i < btf_vlen(t); i++) { n = btf__name_by_offset(__COMPAT_vmlinux_btf, e[i].name_off); SCX_BUG_ON(!n, "btf__name_by_offset()"); if (!strcmp(n, name)) { @@ -53,7 +53,7 @@ static inline bool __COMPAT_read_enum(const char *type, const char *name, u64 *v } else if (btf_is_enum64(t)) { struct btf_enum64 *e = btf_enum64(t); - for (i = 0; i < BTF_INFO_VLEN(t->info); i++) { + for (i = 0; i < btf_vlen(t); i++) { n = btf__name_by_offset(__COMPAT_vmlinux_btf, e[i].name_off); SCX_BUG_ON(!n, "btf__name_by_offset()"); if (!strcmp(n, name)) { @@ -85,7 +85,7 @@ static inline bool __COMPAT_struct_has_field(const char *type, const char *field const struct btf_member *m; const char *n; s32 tid; - int i; + __u32 i; __COMPAT_load_vmlinux_btf(); tid = btf__find_by_name_kind(__COMPAT_vmlinux_btf, type, BTF_KIND_STRUCT); @@ -97,7 +97,7 @@ static inline bool __COMPAT_struct_has_field(const char *type, const char *field m = btf_members(t); - for (i = 0; i < BTF_INFO_VLEN(t->info); i++) { + for (i = 0; i < btf_vlen(t); i++) { n = btf__name_by_offset(__COMPAT_vmlinux_btf, m[i].name_off); SCX_BUG_ON(!n, "btf__name_by_offset()"); if (!strcmp(n, field)) -- 2.43.0