raw_tracepoints are an eBPF alternative to standard tracepoints which
attach to a tracepoint without the perf layer being executed, making
them faster.
Since xdp_monitor is supposed to have as little impact on the system as
possible it is switched to using them by append raw_ to the SEC names.
There was also a small issues with 'samples/bpf/bpf_load' - it was
loading the raw_tracepoints with the tracing subsystem name still
attached, which the bpf syscall rejects with a No such file or directory
error. This is now fixed.
Signed-off-by: Eric Sage <e...@sage.org>
---
samples/bpf/bpf_load.c | 5 +++--
samples/bpf/xdp_monitor_kern.c | 26 +++++++++++++-------------
2 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index 4574b1939e49..6f57eee8e913 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -156,9 +156,10 @@ static int load_and_attach(const char *event, struct
bpf_insn *prog, int size)
}
if (is_raw_tracepoint) {
- efd = bpf_raw_tracepoint_open(event + 15, fd);
+ efd = bpf_raw_tracepoint_open(event + 19, fd);
if (efd < 0) {
- printf("tracepoint %s %s\n", event + 15,
strerror(errno));
+ printf("tracepoint %s %s\n", event + 19,
+ strerror(errno));
return -1;
}
event_fd[prog_cnt - 1] = efd;
diff --git a/samples/bpf/xdp_monitor_kern.c b/samples/bpf/xdp_monitor_kern.c
index ad10fe700d7d..6f67c38468b9 100644
--- a/samples/bpf/xdp_monitor_kern.c
+++ b/samples/bpf/xdp_monitor_kern.c
@@ -23,10 +23,10 @@ struct bpf_map_def SEC("maps") exception_cnt = {
};
/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_redirect/format
+ * Notice: For raw_tracepoints first 8 bytes are not part of 'format' struct
* Code in: kernel/include/trace/events/xdp.h
*/
struct xdp_redirect_ctx {
- u64 __pad; // First 8 bytes are not accessible by bpf code
int prog_id; // offset:8; size:4; signed:1;
u32 act; // offset:12 size:4; signed:0;
int ifindex; // offset:16 size:4; signed:1;
@@ -65,44 +65,44 @@ int xdp_redirect_collect_stat(struct xdp_redirect_ctx *ctx)
*/
}
-SEC("tracepoint/xdp/xdp_redirect_err")
+SEC("raw_tracepoint/xdp/xdp_redirect_err")
int trace_xdp_redirect_err(struct xdp_redirect_ctx *ctx)
{
return xdp_redirect_collect_stat(ctx);
}
-SEC("tracepoint/xdp/xdp_redirect_map_err")
+SEC("raw_tracepoint/xdp/xdp_redirect_map_err")
int trace_xdp_redirect_map_err(struct xdp_redirect_ctx *ctx)
{
return xdp_redirect_collect_stat(ctx);
}
/* Likely unloaded when prog starts */
-SEC("tracepoint/xdp/xdp_redirect")
+SEC("raw_tracepoint/xdp/xdp_redirect")
int trace_xdp_redirect(struct xdp_redirect_ctx *ctx)
{
return xdp_redirect_collect_stat(ctx);
}
/* Likely unloaded when prog starts */
-SEC("tracepoint/xdp/xdp_redirect_map")
+SEC("raw_tracepoint/xdp/xdp_redirect_map")
int trace_xdp_redirect_map(struct xdp_redirect_ctx *ctx)
{
return xdp_redirect_collect_stat(ctx);
}
/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_exception/format
+ * Notice: For raw_tracepoints first 8 bytes are not part of 'format' struct
* Code in: kernel/include/trace/events/xdp.h
*/
struct xdp_exception_ctx {
- u64 __pad; // First 8 bytes are not accessible by bpf code
int prog_id; // offset:8; size:4; signed:1;
u32 act; // offset:12; size:4; signed:0;
int ifindex; // offset:16; size:4; signed:1;
};
-SEC("tracepoint/xdp/xdp_exception")
+SEC("raw_tracepoint/xdp/xdp_exception")
int trace_xdp_exception(struct xdp_exception_ctx *ctx)
{
u64 *cnt;
@@ -144,10 +144,10 @@ struct bpf_map_def SEC("maps") cpumap_kthread_cnt = {
};
/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_enqueue/format
+ * Notice: For raw_tracepoints first 8 bytes are not part of 'format' struct
* Code in: kernel/include/trace/events/xdp.h
*/
struct cpumap_enqueue_ctx {
- u64 __pad; // First 8 bytes are not accessible by bpf code
int map_id; // offset:8; size:4; signed:1;
u32 act; // offset:12; size:4; signed:0;
int cpu; // offset:16; size:4; signed:1;
@@ -156,7 +156,7 @@ struct cpumap_enqueue_ctx {
int to_cpu; // offset:28; size:4; signed:1;
};
-SEC("tracepoint/xdp/xdp_cpumap_enqueue")
+SEC("raw_tracepoint/xdp/xdp_cpumap_enqueue")
int trace_xdp_cpumap_enqueue(struct cpumap_enqueue_ctx *ctx)
{
u32 to_cpu = ctx->to_cpu;
@@ -179,10 +179,10 @@ int trace_xdp_cpumap_enqueue(struct cpumap_enqueue_ctx
*ctx)
}
/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_kthread/format
+ * Notice: For raw_tracepoints first 8 bytes are not part of 'format' struct
* Code in: kernel/include/trace/events/xdp.h
*/
struct cpumap_kthread_ctx {
- u64 __pad; // First 8 bytes are not accessible by bpf code
int map_id; // offset:8; size:4; signed:1;
u32 act; // offset:12; size:4; signed:0;
int cpu; // offset:16; size:4; signed:1;
@@ -191,7 +191,7 @@ struct cpumap_kthread_ctx {
int sched; // offset:28; size:4; signed:1;
};
-SEC("tracepoint/xdp/xdp_cpumap_kthread")
+SEC("raw_tracepoint/xdp/xdp_cpumap_kthread")
int trace_xdp_cpumap_kthread(struct cpumap_kthread_ctx *ctx)
{
struct datarec *rec;
@@ -218,10 +218,10 @@ struct bpf_map_def SEC("maps") devmap_xmit_cnt = {
};
/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_devmap_xmit/format
+ * Notice: For raw_tracepoints first 8 bytes are not part of 'format' struct
* Code in: kernel/include/trace/events/xdp.h
*/
struct devmap_xmit_ctx {
- u64 __pad; // First 8 bytes are not accessible by bpf code
int map_id; // offset:8; size:4; signed:1;
u32 act; // offset:12; size:4; signed:0;
u32 map_index; // offset:16; size:4; signed:0;
@@ -232,7 +232,7 @@ struct devmap_xmit_ctx {
int err; // offset:36; size:4; signed:1;
};
-SEC("tracepoint/xdp/xdp_devmap_xmit")
+SEC("raw_tracepoint/xdp/xdp_devmap_xmit")
int trace_xdp_devmap_xmit(struct devmap_xmit_ctx *ctx)
{
struct datarec *rec;
--
2.18.1
