bcc/tools: Introduce bpf_probe_read_user to the tools.

This is essential for architecture which do have overlapping address space.
- bpf_probe_read_kernel() shall be used for reading data from kernel space
to the bpf vm.
- bpf_probe_read_user() shall be used for reading data from user space
  to the bpf vm.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
diff --git a/tools/sslsniff.py b/tools/sslsniff.py
index e48fbb4..8c027fe 100755
--- a/tools/sslsniff.py
+++ b/tools/sslsniff.py
@@ -72,7 +72,7 @@
         bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
 
         if ( buf != 0) {
-                bpf_probe_read(&__data.v0, sizeof(__data.v0), buf);
+                bpf_probe_read_user(&__data.v0, sizeof(__data.v0), buf);
         }
 
         perf_SSL_write.perf_submit(ctx, &__data, sizeof(__data));
@@ -108,7 +108,7 @@
         bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
 
         if (bufp != 0) {
-                bpf_probe_read(&__data.v0, sizeof(__data.v0), (char *)*bufp);
+                bpf_probe_read_user(&__data.v0, sizeof(__data.v0), (char *)*bufp);
         }
 
         bufs.delete(&pid);