bcc/tools/fileslower: Attach to vfs_read after failing to attach __vf…

…s_read

__vfs_read has been removed since kernel v5.8-rc5
775802c0571f ("fs: remove __vfs_read"). Then try vfs_read instead.

Signed-off-by: He Zhe <[email protected]>

tools/fileslower.py

@@ -199,13 +199,18 @@
 # do_sync_read/do_sync_write), but those became static. So trace these from
 # the parent functions, at the cost of more overhead, instead.
 # Ultimately, we should be using [V]FS tracepoints.
-b.attach_kprobe(event="__vfs_read", fn_name="trace_read_entry")
-b.attach_kretprobe(event="__vfs_read", fn_name="trace_read_return")
+try:
+ b.attach_kprobe(event="__vfs_read", fn_name="trace_read_entry")
+ b.attach_kretprobe(event="__vfs_read", fn_name="trace_read_return")
+except Exception:
+ print('Current kernel does not have __vfs_read, try vfs_read instead')
+ b.attach_kprobe(event="vfs_read", fn_name="trace_read_entry")
+ b.attach_kretprobe(event="vfs_read", fn_name="trace_read_return")
 try:
  b.attach_kprobe(event="__vfs_write", fn_name="trace_write_entry")
  b.attach_kretprobe(event="__vfs_write", fn_name="trace_write_return")
 except Exception:
- # older kernels don't have __vfs_write so try vfs_write instead
+ print('Current kernel does not have __vfs_write, try vfs_write instead')
  b.attach_kprobe(event="vfs_write", fn_name="trace_write_entry")
  b.attach_kretprobe(event="vfs_write", fn_name="trace_write_return")