From: Arnd Bergmann <[email protected]>
Some internal functions in bpf produce a warning when -Wsuggest-attribute=format
is passed to the compiler, e.g. in 'make W=1':
kernel/trace/bpf_trace.c: In function '____bpf_trace_printk':
kernel/trace/bpf_trace.c:377:9: error: function '____bpf_trace_printk' might be
a candidate for 'gnu_printf' format attribute [-Werror=suggest-attribute=format]
377 | ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt,
data.bin_args);
| ^~~
The attribute here is useless since there are no callers from C code,
but it helps to shut up the output anyway so we can eventually turn
the warning option on by default.
Signed-off-by: Arnd Bergmann <[email protected]>
---
kernel/bpf/helpers.c | 1 +
kernel/bpf/stream.c | 1 +
kernel/trace/bpf_trace.c | 3 +++
3 files changed, 5 insertions(+)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index b54ec0e945aa..45d026fc4e8a 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1046,6 +1046,7 @@ int bpf_bprintf_prepare(const char *fmt, u32 fmt_size,
const u64 *raw_args,
return err;
}
+__printf(3, 0)
BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
const void *, args, u32, data_len)
{
diff --git a/kernel/bpf/stream.c b/kernel/bpf/stream.c
index 24730df55e69..816fd7fba3d2 100644
--- a/kernel/bpf/stream.c
+++ b/kernel/bpf/stream.c
@@ -212,6 +212,7 @@ __bpf_kfunc_start_defs();
* Avoid using enum bpf_stream_id so that kfunc users don't have to pull in the
* enum in headers.
*/
+__printf(2, 0)
__bpf_kfunc int bpf_stream_vprintk(int stream_id, const char *fmt__str, const
void *args,
u32 len__sz, struct bpf_prog_aux *aux)
{
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index eadaef8592a3..2d3de71ab86a 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -359,6 +359,7 @@ static const struct bpf_func_proto
bpf_probe_write_user_proto = {
#define MAX_TRACE_PRINTK_VARARGS 3
#define BPF_TRACE_PRINTK_SIZE 1024
+__printf(1, 0)
BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
u64, arg2, u64, arg3)
{
@@ -412,6 +413,7 @@ const struct bpf_func_proto
*bpf_get_trace_printk_proto(void)
return &bpf_trace_printk_proto;
}
+__printf(1, 0)
BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
u32, data_len)
{
@@ -455,6 +457,7 @@ const struct bpf_func_proto
*bpf_get_trace_vprintk_proto(void)
return &bpf_trace_vprintk_proto;
}
+__printf(2, 0)
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
const void *, args, u32, data_len)
{
--
2.39.5
