From: Arnd Bergmann <arnd@xxxxxxxx>
Building with -Wextra shows lots of warnings in the bpf
code such as
kernel/bpf/verifier.c: In function ‘jit_subprogs’:
include/linux/filter.h:345:4: warning: cast between incompatible function types from ‘unsigned int (*)(const void *, const struct bpf_insn *)’ to ‘u64 (*)(u64, u64, u64, u64, u64)’ {aka ‘long long unsigned int (*)(long long unsigned int, long long unsigned int, long long unsigned int, long long unsigned int, long long unsigned int)’} [-Wcast-function-type]
345 | ((u64 (*)(u64, u64, u64, u64, u64))(x))
| ^
kernel/bpf/verifier.c:10706:16: note: in expansion of macro ‘BPF_CAST_CALL’
10706 | insn->imm = BPF_CAST_CALL(func[subprog]->bpf_func) -
| ^~~~~~~~~~~~~
This appears to be intentional, so change the cast in a way that
suppresses the warning.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
include/linux/filter.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 1b62397bd124..20ba04583eaa 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -342,7 +342,7 @@ static inline bool insn_is_zext(const struct bpf_insn *insn)
/* Function call */
#define BPF_CAST_CALL(x) \
- ((u64 (*)(u64, u64, u64, u64, u64))(x))
+ ((u64 (*)(u64, u64, u64, u64, u64))(uintptr_t)(x))
#define BPF_EMIT_CALL(FUNC) \
((struct bpf_insn) { \
--
2.27.0
