SETFL

3 files changed, 13 insertions, 5 deletions

diff --git a/README.md b/README.md
index 598e5ec..5a2abc2 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# I/O Riot NG
+# I/O Riot NG (aka ior)
 
 <img src=assets/ior-small.png />
 
@@ -8,6 +8,8 @@ I/O Riot NG is an experiments with BPF. This program traces for I/O syscalls and
 
 Maybe this is a spiritual successor of one of my previous projects, I/O Riot https://codeberg.org/snonux/ioriot, the latter was based on SystemTap and C. The NG is based on Go, C and BPF (via libbpfgo).
 
+This works only on Linux!
+
 ## Fedora
 
 To get this running on Fedora 39, run:
diff --git a/cmd/ior/main.go b/cmd/ior/main.go
index 025abbb..2d8584a 100644
--- a/cmd/ior/main.go
+++ b/cmd/ior/main.go
@@ -3,8 +3,12 @@ package main
 import (
 	"ior/internal"
 	"ior/internal/flags"
+	"runtime"
 )
 
 func main() {
+	if runtime.GOOS != "linux" {
+		panic("Unsupported OS")
+	}
 	internal.Run(flags.New())
 }
diff --git a/internal/eventloop.go b/internal/eventloop.go
index 01ba90c..b451b69 100644
--- a/internal/eventloop.go
+++ b/internal/eventloop.go
@@ -249,16 +249,18 @@ func (e *eventLoop) syscallExit(exitEv event.Event, ch chan<- *event.Pair) {
 			ev.File = file.NewFdWithPid(fd, v.Pid)
 		}
 		switch v.Cmd {
-		case syscall.F_SETFD:
+		case syscall.F_SETFL:
 			fdFile, ok := ev.File.(file.FdFile)
 			if !ok {
 				panic("expected a file.FdFile")
 			}
-			fdFile.Flags = int32(v.Arg)
+			fmt.Println("DEBUG BEFORE", fdFile.FlagsString())
+			// fcntl(2)
+			canChange := syscall.O_APPEND | syscall.O_ASYNC | syscall.O_DIRECT | syscall.O_NOATIME | syscall.O_NONBLOCK
+			fdFile.Flags |= (int32(v.Arg) & int32(canChange))
 			ev.File = fdFile
 			e.files[fd] = fdFile
-		case syscall.F_SETFL:
-			fmt.Println("TODO: F_SETFL with fcntl not yet implememented")
+			fmt.Println("DEBUG AFTER", fdFile.FlagsString())
 		case syscall.F_DUPFD:
 			fmt.Println("TODO: F_DUPFD with fcntl not yet implememented")
 		case syscall.F_DUPFD_CLOEXEC: