samples: bpf: fix: broken sample regarding removed function

Currently, running sample "task_fd_query" and "tracex3" occurs the
following error. On kernel v5.0-rc* this sample will be unavailable
due to the removal of function 'blk_start_request' at commit "a1ce35f".
(function removed, as "Single Queue IO scheduler" no longer exists)

$ sudo ./task_fd_query
failed to create kprobe 'blk_start_request' error 'No such file or
directory'

This commit will change the function 'blk_start_request' to
'blk_mq_start_request' to fix the broken sample.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

3 files changed, 3 insertions, 3 deletions

diff --git a/samples/bpf/task_fd_query_kern.c b/samples/bpf/task_fd_query_kern.c
index f4b0a9ea674d..fb56fc2a3e5d 100644
--- a/samples/bpf/task_fd_query_kern.c
+++ b/samples/bpf/task_fd_query_kern.c
@@ -4,7 +4,7 @@
 #include <uapi/linux/bpf.h>
 #include "bpf_helpers.h"
 
-SEC("kprobe/blk_start_request")
+SEC("kprobe/blk_mq_start_request")
 int bpf_prog1(struct pt_regs *ctx)
 {
         return 0;
diff --git a/samples/bpf/task_fd_query_user.c b/samples/bpf/task_fd_query_user.c
index 8381d792f138..aff2b4ae914e 100644
--- a/samples/bpf/task_fd_query_user.c
+++ b/samples/bpf/task_fd_query_user.c
@@ -311,7 +311,7 @@ int main(int argc, char **argv)
         }
 
         /* test two functions in the corresponding *_kern.c file */
-        CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_start_request",
+        CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
                                            BPF_FD_TYPE_KPROBE));
         CHECK_AND_RET(test_debug_fs_kprobe(1, "blk_account_io_completion",
                                            BPF_FD_TYPE_KRETPROBE));
diff --git a/samples/bpf/tracex3_kern.c b/samples/bpf/tracex3_kern.c
index 9974c3d7c18b..ea1d4c19c132 100644
--- a/samples/bpf/tracex3_kern.c
+++ b/samples/bpf/tracex3_kern.c
@@ -20,7 +20,7 @@ struct bpf_map_def SEC("maps") my_map = {
 /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
  * example will no longer be meaningful
  */
-SEC("kprobe/blk_start_request")
+SEC("kprobe/blk_mq_start_request")
 int bpf_prog1(struct pt_regs *ctx)
 {
         long rq = PT_REGS_PARM1(ctx);