Re: [PATCH bpf-next 1/5] bpf: merge printk and seq_printf VARARG max macros
From: Andrii Nakryiko <hidden>
Date: 2021-08-24 04:38:55
Also in:
bpf, linux-kselftest
On Fri, Aug 20, 2021 at 7:59 PM Dave Marchevsky [off-list ref] wrote:
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 <redacted> ---
Acked-by: Andrii Nakryiko <andrii@kernel.org>
quoted hunk ↗ jump to hunk
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 4e8540716187..5ce19b376ef7 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c@@ -969,15 +969,13 @@ 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 cbc73c08c4a4..2cf4bfa1ab7b 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