[PATCH v5 02/23] perf trace: Include the augmented arg header in nanosleep's payload length

[Ian Rogers]

sys_enter_nanosleep() sizes the record it outputs as

	unsigned int len = sizeof(augmented_args->args);

where every other augmenter that appends a payload uses

	unsigned int len = sizeof(u64) + sizeof(augmented_args->args);

the extra u64 being the size and err fields of the struct augmented_arg
that the payload follows.

The payload is copied to augmented_args->arg.value, which starts 8 bytes
after the tracepoint arguments, but only len + size bytes are output. So
the record stops 8 bytes short of the end of the timespec, and userspace
reads the tail of tv_nsec from whatever follows in the ring buffer.

Count the header, as the other augmenters do.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
index dd3aa5bd910b..18904bebf672 100644
--- a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
+++ b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c
@@ -426,7 +426,8 @@ int sys_enter_nanosleep(struct syscall_enter_args *args)
 {
 	struct augmented_args_payload *augmented_args = augmented_args_payload();
 	const void *req_arg = (const void *)args->args[0];
-	unsigned int len = sizeof(augmented_args->args);
+	// the size + err in all 'augmented_arg' structs
+	unsigned int len = sizeof(u64) + sizeof(augmented_args->args);
 	__u32 size = sizeof(struct timespec64);
 	int err;
 
-- 
2.56.0.rc1.315.gc6ed9934b7-goog