Commit ae39e9ed authored by Saravana Kannan's avatar Saravana Kannan Committed by Luis Chamberlain
Browse files

module: Add support for default value for module async_probe 



Add a module.async_probe kernel command line option that allows enabling
async probing for all modules. When this command line option is used,
there might still be some modules for which we want to explicitly force
synchronous probing, so extend <modulename>.async_probe to take an
optional bool input so that async probing can be disabled for a specific
module.

Signed-off-by: default avatarSaravana Kannan <saravanak@google.com>
Reviewed-by: default avatarAaron Tomlin <atomlin@redhat.com>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent e69a6614

Documentation/admin-guide/kernel-parameters.txt

+15 −2
Original line number Diff line number Diff line
@@ -1152,8 +1152,12 @@ 
	nopku		[X86] Disable Memory Protection Keys CPU feature found

			in some Intel CPUs.



	<module>.async_probe [KNL]

			Enable asynchronous probe on this module.

	<module>.async_probe[=<bool>] [KNL]

			If no <bool> value is specified or if the value

			specified is not a valid <bool>, enable asynchronous

			probe on this module.  Otherwise, enable/disable

			asynchronous probe on this module as indicated by the

			<bool> value. See also: module.async_probe



	early_ioremap_debug [KNL]

			Enable debug messages in early_ioremap support. This
@@ -3241,6 +3245,15 @@ 
			For details see:

			Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst



	module.async_probe=<bool>

			[KNL] When set to true, modules will use async probing

			by default. To enable/disable async probing for a

			specific module, use the module specific control that

			is documented under <module>.async_probe. When both

			module.async_probe and <module>.async_probe are

			specified, <module>.async_probe takes precedence for

			the specific module.



	module.sig_enforce

			[KNL] When CONFIG_MODULE_SIG is set, this means that

			modules without (valid) signatures will fail to load.

kernel/module/main.c

+10 −1
Original line number Diff line number Diff line
@@ -2410,6 +2410,12 @@ static void do_free_init(struct work_struct *w) 
	}

}



#undef MODULE_PARAM_PREFIX

#define MODULE_PARAM_PREFIX "module."

/* Default value for module->async_probe_requested */

static bool async_probe;

module_param(async_probe, bool, 0644);



/*

 * This is where the real work happens.

 *
@@ -2630,6 +2636,7 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname, 
	int ret;



	if (strcmp(param, "async_probe") == 0) {

		if (strtobool(val, &mod->async_probe_requested))

			mod->async_probe_requested = true;

		return 0;

	}
@@ -2797,6 +2804,8 @@ static int load_module(struct load_info *info, const char __user *uargs, 
	if (err)

		goto bug_cleanup;



	mod->async_probe_requested = async_probe;



	/* Module is ready to execute: parsing args may do that. */

	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,

				  -32768, 32767, mod,