On Mon, 2020-12-07 at 20:55 +0100, Florent Revest wrote:
> This avoids
> ld: kernel/trace/bpf_trace.o: in function `bpf_sock_from_file':
> bpf_trace.c:(.text+0xe23): undefined reference to `sock_from_file'
> When compiling a kernel with BPF and without NET.
>
> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 0cf0a6331482..877123bae71f 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1272,7 +1272,11 @@ const struct bpf_func_proto
> bpf_snprintf_btf_proto = {
>
> BPF_CALL_1(bpf_sock_from_file, struct file *, file)
> {
> +#ifdef CONFIG_NET
> return (unsigned long) sock_from_file(file);
> +#else
> + return NULL;
Ugh, and of course I messed up my fix... :) Now this causes a:
./include/linux/stddef.h:8:14: warning: returning ‘void *’ from a
function with return type ‘u64’ {aka ‘long long unsigned int’} makes
integer from pointer without a cast [-Wint-conversion]
8 | #define NULL ((void *)0)
| ^
kernel/trace/bpf_trace.c:1278:9: note: in expansion of macro ‘NULL’
1278 | return NULL;
So I'm sending a v2!
