The eBPF is using target specific macros, please provide -target

[evanzhang87]

It's my error:

evan@ubuntu:~/golang/gopath/src/ebpf/examples/offcpu$ go generate -x
go run github.com/cilium/ebpf/cmd/bpf2go -target bpfel -cc clang-14 -cflags -O2 -g -Wall -Werror bpf offcpu.c -- -I../headers -D__TARGET_ARCH_X86
/home/evan/golang/gopath/src/ebpf/examples/offcpu/offcpu.c:33:41: error: The eBPF is using target specific macros, please provide -target
    struct task_struct *prev = (void *) PT_REGS_PARM1(ctx);
                                        ^
../headers/bpf_tracing.h:341:29: note: expanded from macro 'PT_REGS_PARM1'
#define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
                            ^
<scratch space>:32:6: note: expanded from here
 GCC error "The eBPF is using target specific macros, please provide -target"
     ^
1 error generated.
Error: clang-14: exit status 1
exit status 1
main.go:23: running "go": exit status 1

It's my C code:

...

int do_finish_task_switch(struct pt_regs *ctx) {
    ...

    struct task_struct *prev = (void *) PT_REGS_PARM1(ctx);
    pid = _(prev->pid);
    tgid = _(prev->tgid);

    ...
}

PT_REGS_PARM1

#define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })

Anyone can help?

[lmb]

You need to provide an architecture specific target like amd64 or arm64. PT_REGS_PARM1, etc. are not compatible with bpfel or bpfeb.

[evanzhang87]

It works, thank you very much！

[harisudarsan1]

Can you please explain how to apply target in go genrate

[loheagn]

@harisudarsan1 Hi, you can add the target argument to the go generate comment, just like this:

//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -target amd64 -type event bpf kprobe.c

[harisudarsan1]

@loheagn 😊 tysm