clang does not support variable length array for structure member. It has the following error during compilation:
kernel/trace/trace_syscalls.c:568:17: error: fields must have a constant size: 'variable length array in structure' extension will never be supported unsigned long args[sys_data->nb_args]; ^ The fix is to use a fixed array length instead. Reported-by: Nick Desaulniers <ndesaulni...@google.com> Signed-off-by: Yonghong Song <y...@fb.com> --- include/linux/syscalls.h | 2 ++ kernel/trace/trace_syscalls.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 88951b7..95606a2 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -200,6 +200,8 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) #define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__) #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) +#define SYSCALL_DEFINE_MAXARGS 6 + #define SYSCALL_DEFINEx(x, sname, ...) \ SYSCALL_METADATA(sname, x, __VA_ARGS__) \ __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 9c4eef2..696afe7 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -565,7 +565,7 @@ static int perf_call_bpf_enter(struct bpf_prog *prog, struct pt_regs *regs, struct syscall_tp_t { unsigned long long regs; unsigned long syscall_nr; - unsigned long args[sys_data->nb_args]; + unsigned long args[SYSCALL_DEFINE_MAXARGS]; } param; int i; -- 2.9.5