Fix integration trace expectations and fd/open event handling

3 files changed, 47 insertions, 0 deletions

diff --git a/internal/generate/bpfhandler.go b/internal/generate/bpfhandler.go
index 1ce6d3e..eb9c4c4 100644
--- a/internal/generate/bpfhandler.go
+++ b/internal/generate/bpfhandler.go
@@ -59,6 +59,10 @@ func generateExtra(tp GeneratedTracepoint, isEnter bool) string {
 
 	switch tp.Classification.Kind {
 	case KindFd:
+		fdIdx := f.FieldNumber("fd")
+		if fdIdx >= 0 {
+			return fmt.Sprintf("    ev->fd = (__s32)ctx->args[%d];\n", fdIdx)
+		}
 		return "    ev->fd = (__s32)ctx->args[0];\n"
 
 	case KindDup3:
diff --git a/internal/generate/codegen_test.go b/internal/generate/codegen_test.go
index 6402214..3e48c79 100644
--- a/internal/generate/codegen_test.go
+++ b/internal/generate/codegen_test.go
@@ -149,6 +149,16 @@ func TestGenerateIoUringRegisterHandler(t *testing.T) {
 	requireContains(t, output, "ev->fd = (__s32)ctx->args[0];")
 }
 
+func TestGenerateMmapHandlerUsesFdArgumentIndex(t *testing.T) {
+	output := generateFromPair(t, FormatMmap, FormatExitMmap)
+
+	requireContains(t, output, `SEC("tracepoint/syscalls/sys_enter_mmap")`)
+	requireContains(t, output, "struct fd_event *ev")
+	requireContains(t, output, "ev->event_type = ENTER_FD_EVENT;")
+	requireContains(t, output, "ev->trace_id = SYS_ENTER_MMAP;")
+	requireContains(t, output, "ev->fd = (__s32)ctx->args[4];")
+}
+
 func TestGenerateDup3Handler(t *testing.T) {
 	output := generateFromPair(t, FormatDup3, FormatExitDup3)
 
diff --git a/internal/generate/testdata.go b/internal/generate/testdata.go
index 76228a3..fb68dfb 100644
--- a/internal/generate/testdata.go
+++ b/internal/generate/testdata.go
@@ -168,6 +168,39 @@ format:
 print fmt: "start: 0x%08lx, len: 0x%08lx, flags: 0x%08lx", ((unsigned long)(REC->start)), ((unsigned long)(REC->len)), ((unsigned long)(REC->flags))
 `
 
+const FormatMmap = `name: sys_enter_mmap
+ID: 100
+format:
+	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
+	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
+	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
+	field:int common_pid;	offset:4;	size:4;	signed:1;
+
+	field:int __syscall_nr;	offset:8;	size:4;	signed:1;
+	field:unsigned long addr;	offset:16;	size:8;	signed:0;
+	field:unsigned long len;	offset:24;	size:8;	signed:0;
+	field:unsigned long prot;	offset:32;	size:8;	signed:0;
+	field:unsigned long flags;	offset:40;	size:8;	signed:0;
+	field:unsigned long fd;	offset:48;	size:8;	signed:0;
+	field:unsigned long off;	offset:56;	size:8;	signed:0;
+
+print fmt: "addr: 0x%08lx, len: 0x%08lx, prot: 0x%08lx, flags: 0x%08lx, fd: 0x%08lx, off: 0x%08lx", ((unsigned long)(REC->addr)), ((unsigned long)(REC->len)), ((unsigned long)(REC->prot)), ((unsigned long)(REC->flags)), ((unsigned long)(REC->fd)), ((unsigned long)(REC->off))
+`
+
+const FormatExitMmap = `name: sys_exit_mmap
+ID: 99
+format:
+	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
+	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
+	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
+	field:int common_pid;	offset:4;	size:4;	signed:1;
+
+	field:int __syscall_nr;	offset:8;	size:4;	signed:1;
+	field:long ret;	offset:16;	size:8;	signed:1;
+
+print fmt: "0x%lx", REC->ret
+`
+
 const FormatExitMsync = `name: sys_exit_msync
 ID: 1028
 format: