tools/nvmeblk.bt: force nvme_core module BTF to be loaded

bpftrace list_modules() does not yet support loading BTFs for modules on ProbeType::kprobe and it is not clear if it will. To load the BTF for modules so we can get structures for it which might be private (and could conflict with other modules own structures) one has to use a probe type which does load the BTF for the corresponding module. Since we already are adding a kprobe on nvme_setup_cmd() just use the kretfunc probe on the same routine and have it do nothing. This fixes the use case of nvmeblk.bt when we nvme_core is a module. Signed-off-by: Luis Chamberlain <[email protected]>
dkruces · Nov 15, 2023 · d1d7262 · d1d7262
1 parent a72ad75
commit d1d7262
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/tools/nvmeblk.bt b/tools/nvmeblk.bt
@@ -55,6 +55,11 @@ BEGIN
 	printf("%-9s %-10s %-8s %-6s %-16s %-16s\n", "DISK", "LBA", "LEN", "OP", "COMM", "ALIGN");
 }
 
+kretfunc:nvme_core:nvme_setup_cmd
+{
+	/* we add an empty kretfuncs probe to load module BTF */
+}
+
 kprobe:nvme_setup_cmd
 {
 	$req = (struct request *)arg1;