diff options
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 335696d3360d..39c95c0e13d3 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -446,6 +446,27 @@ Notes:
successful IPC object allocation. If an IPC object allocation syscall
fails, it is undefined if the value remains unmodified or is reset to -1.
+The path to the usermode helper for autoloading kernel modules, by
+default "/sbin/modprobe". This binary is executed when the kernel
+requests a module. For example, if userspace passes an unknown
+filesystem type to mount(), then the kernel will automatically request
+the corresponding filesystem module by executing this usermode helper.
+This usermode helper should insert the needed module into the kernel.
+This sysctl only affects module autoloading. It has no effect on the
+ability to explicitly insert modules.
+If this sysctl is set to the empty string, then module autoloading is
+completely disabled. The kernel will not try to execute a usermode
+helper at all, nor will it call the kernel_module_request LSM hook.
+If CONFIG_STATIC_USERMODEHELPER=y is set in the kernel configuration,
+then the configured static usermode helper overrides this sysctl,
+except that the empty string is still accepted to completely disable
+module autoloading as described above.