From 9df1c28bb75217b244257152ab7d788bb2a386d0 Mon Sep 17 00:00:00 2001 From: Matt Mullins Date: Fri, 26 Apr 2019 11:49:47 -0700 Subject: bpf: add writable context for raw tracepoints This is an opt-in interface that allows a tracepoint to provide a safe buffer that can be written from a BPF_PROG_TYPE_RAW_TRACEPOINT program. The size of the buffer must be a compile-time constant, and is checked before allowing a BPF program to attach to a tracepoint that uses this feature. The pointer to this buffer will be the first argument of tracepoints that opt in; the pointer is valid and can be bpf_probe_read() by both BPF_PROG_TYPE_RAW_TRACEPOINT and BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE programs that attach to such a tracepoint, but the buffer to which it points may only be written by the latter. Signed-off-by: Matt Mullins Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 2 ++ include/linux/bpf_types.h | 1 + include/linux/tracepoint-defs.h | 1 + 3 files changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f15432d90728..cd6341eabd74 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -272,6 +272,7 @@ enum bpf_reg_type { PTR_TO_SOCK_COMMON_OR_NULL, /* reg points to sock_common or NULL */ PTR_TO_TCP_SOCK, /* reg points to struct tcp_sock */ PTR_TO_TCP_SOCK_OR_NULL, /* reg points to struct tcp_sock or NULL */ + PTR_TO_TP_BUFFER, /* reg points to a writable raw tp's buffer */ }; /* The information passed from prog-specific *_is_valid_access @@ -361,6 +362,7 @@ struct bpf_prog_aux { u32 used_map_cnt; u32 max_ctx_offset; u32 max_pkt_offset; + u32 max_tp_access; u32 stack_depth; u32 id; u32 func_cnt; /* used by non-func prog as the number of func progs */ diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index d26991a16894..a10d37bce364 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -25,6 +25,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe) BPF_PROG_TYPE(BPF_PROG_TYPE_TRACEPOINT, tracepoint) BPF_PROG_TYPE(BPF_PROG_TYPE_PERF_EVENT, perf_event) BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint) +BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, raw_tracepoint_writable) #endif #ifdef CONFIG_CGROUP_BPF BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev) diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h index 49ba9cde7e4b..b29950a19205 100644 --- a/include/linux/tracepoint-defs.h +++ b/include/linux/tracepoint-defs.h @@ -45,6 +45,7 @@ struct bpf_raw_event_map { struct tracepoint *tp; void *bpf_func; u32 num_args; + u32 writable_size; } __aligned(32); #endif -- cgit v1.2.3