On Fri 2022-06-03 18:01 -0700, Saravana Kannan wrote:
> 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: Saravana Kannan <saravanak@xxxxxxxxxx>
> ---
> v1->v2:
> - Updated the documentation to capture all the details/changes.
>
> Documentation/admin-guide/kernel-parameters.txt | 17 +++++++++++++++--
> kernel/module/main.c | 11 ++++++++++-
> 2 files changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 710b52d87bdd..5174a08e20b0 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1147,8 +1147,12 @@
> 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
> @@ -3201,6 +3205,15 @@
> log everything. Information is printed at KERN_DEBUG
> so loglevel=8 may also need to be specified.
>
> + 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.
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index fed58d30725d..47085795f037 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -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.
> *
> @@ -2630,7 +2636,8 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname,
> int ret;
>
> if (strcmp(param, "async_probe") == 0) {
> - mod->async_probe_requested = true;
> + 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,
> --
> 2.36.1.255.ge46751e96f-goog
Reviewed-by: Aaron Tomlin <atomlin@xxxxxxxxxx>
--
Aaron Tomlin
