MAX_SNPRINTF_VARARGS and MAX_SEQ_PRINTF_VARARGS are used by bpf helpers
bpf_snprintf and bpf_seq_printf to limit their varargs. Both call into
bpf_bprintf_prepare for print formatting logic and have convenience
macros in libbpf (BPF_SNPRINTF, BPF_SEQ_PRINTF) which use the same
helper macros to convert varargs to a byte array.
Changing shared functionality to support more varargs for either bpf
helper would affect the other as well, so let's combine the _VARARGS
macros to make this more obvious.
Signed-off-by: Dave Marchevsky <davemarchevsky@xxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
include/linux/bpf.h | 2 ++
kernel/bpf/helpers.c | 4 +---
kernel/trace/bpf_trace.c | 4 +---
3 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f4c16f19f83e..be8d57e6e78a 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2216,6 +2216,8 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
struct btf_id_set;
bool btf_id_set_contains(const struct btf_id_set *set, u32 id);
+#define MAX_BPRINTF_VARARGS 12
+
int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
u32 **bin_buf, u32 num_args);
void bpf_bprintf_cleanup(void);
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 9aabf84afd4b..8f9f392c1322 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -979,15 +979,13 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
return err;
}
-#define MAX_SNPRINTF_VARARGS 12
-
BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
const void *, data, u32, data_len)
{
int err, num_args;
u32 *bin_args;
- if (data_len % 8 || data_len > MAX_SNPRINTF_VARARGS * 8 ||
+ if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
(data_len && !data))
return -EINVAL;
num_args = data_len / 8;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 8e2eb950aa82..10672ebc63b7 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -414,15 +414,13 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
return &bpf_trace_printk_proto;
}
-#define MAX_SEQ_PRINTF_VARARGS 12
-
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
const void *, data, u32, data_len)
{
int err, num_args;
u32 *bin_args;
- if (data_len & 7 || data_len > MAX_SEQ_PRINTF_VARARGS * 8 ||
+ if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
(data_len && !data))
return -EINVAL;
num_args = data_len / 8;
--
2.30.2
