Kernel Parameters
~~~~~~~~~~~~~~~~~
-The following is a consolidated list of the kernel parameters as implemented
-(mostly) by the __setup() macro and sorted into English Dictionary order
-(defined as ignoring all punctuation and sorting digits before letters in a
-case insensitive manner), and with descriptions where known.
-
-Module parameters for loadable modules are specified only as the
-parameter name with optional '=' and value as appropriate, such as:
-
- modprobe usbcore blinkenlights=1
-
-Module parameters for modules that are built into the kernel image
-are specified on the kernel command line with the module name plus
-'.' plus parameter name, with '=' and value if appropriate, such as:
-
- usbcore.blinkenlights=1
+The following is a consolidated list of the kernel parameters as
+implemented by the __setup(), core_param() and module_param() macros
+and sorted into English Dictionary order (defined as ignoring all
+punctuation and sorting digits before letters in a case insensitive
+manner), and with descriptions where known.
+
+The kernel parses parameters from the kernel command line up to "--";
+if it doesn't recognize a parameter and it doesn't contain a '.', the
+parameter gets passed to init: parameters with '=' go into init's
+environment, others are passed as command line arguments to init.
+Everything after "--" is passed as an argument to init.
+
+Module parameters can be specified in two ways: via the kernel command
+line with a module name prefix, or via modprobe, e.g.:
+
+ (kernel command line) usbcore.blinkenlights=1
+ (modprobe command line) modprobe usbcore blinkenlights=1
+
+Parameters for modules which are built into the kernel need to be
+specified on the kernel command line. modprobe looks through the
+kernel command line (/proc/cmdline) and collects module parameters
+when it loads a module, so the kernel command line can be used for
+loadable modules too.
Hyphens (dashes) and underscores are equivalent in parameter names, so
log_buf_len=1M print-fatal-signals=1
can also be entered as
log-buf-len=1M print_fatal_signals=1
+Double-quotes can be used to protect spaces in values, e.g.:
+ param="spaces in here"
This document may not be entirely up to date and comprehensive. The command
"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf);
static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
-static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IRWXO, lg4ff_range_show, lg4ff_range_store);
+static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IROTH, lg4ff_range_show, lg4ff_range_store);
struct lg4ff_device_entry {
__u32 product_id;
return count;
}
-static DEVICE_ATTR(fb_update_rate, 0666, picolcd_fb_update_rate_show,
+static DEVICE_ATTR(fb_update_rate, 0664, picolcd_fb_update_rate_show,
picolcd_fb_update_rate_store);
/* initialize Framebuffer device */
#define FLOOR_SYSFS(id) { \
__ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
__ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
- __ATTR(f##id##_dps0_protection_key, S_IWUGO, NULL, dps0_insert_key), \
- __ATTR(f##id##_dps1_protection_key, S_IWUGO, NULL, dps1_insert_key), \
+ __ATTR(f##id##_dps0_protection_key, S_IWUSR|S_IWGRP, NULL, dps0_insert_key), \
+ __ATTR(f##id##_dps1_protection_key, S_IWUSR|S_IWGRP, NULL, dps1_insert_key), \
}
static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
return count;
}
-static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
-static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
-static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
-static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
-static DEVICE_ATTR(mode, 0666, show_mode, set_mode);
+static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
+static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
+static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
+static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
+static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
static struct attribute *regulator_virtual_attributes[] = {
&dev_attr_min_microvolts.attr,
flash_error_table[i].reason);
}
-static DEVICE_ATTR(update_fw, S_IRUGO|S_IWUGO,
+static DEVICE_ATTR(update_fw, S_IRUGO|S_IWUSR|S_IWGRP,
pm8001_show_update_fw, pm8001_store_update_fw);
struct device_attribute *pm8001_host_attrs[] = {
&dev_attr_interface_rev,
}
/* Prepare the device_attr for registration with sysfs later */
-static DEVICE_ATTR(crt_src, 0666, sm501fb_crtsrc_show, sm501fb_crtsrc_store);
+static DEVICE_ATTR(crt_src, 0664, sm501fb_crtsrc_show, sm501fb_crtsrc_store);
/* sm501fb_show_regs
*
static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
{
char *nl = strchr(buf, '\n');
- int len = nl ? nl - buf : strlen(buf);
+ unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
}
extern bool parameqn(const char *name1, const char *name2, size_t n);
/* Called on module insert or kernel boot */
-extern int parse_args(const char *name,
+extern char *parse_args(const char *name,
char *args,
const struct kernel_param *params,
unsigned num,
return 0;
}
+/* Anything after -- gets handed straight to init. */
+static int __init set_init_arg(char *param, char *val, const char *unused)
+{
+ unsigned int i;
+
+ if (panic_later)
+ return 0;
+
+ repair_env_string(param, val, unused);
+
+ for (i = 0; argv_init[i]; i++) {
+ if (i == MAX_INIT_ARGS) {
+ panic_later = "init";
+ panic_param = param;
+ return 0;
+ }
+ }
+ argv_init[i] = param;
+ return 0;
+}
+
/*
* Unknown boot options get handed to init, unless they look like
* unused parameters (modprobe will find them in /proc/cmdline).
asmlinkage __visible void __init start_kernel(void)
{
- char * command_line;
+ char * command_line, *after_dashes;
extern const struct kernel_param __start___param[], __stop___param[];
/*
pr_notice("Kernel command line: %s\n", boot_command_line);
parse_early_param();
- parse_args("Booting kernel", static_command_line, __start___param,
- __stop___param - __start___param,
- -1, -1, &unknown_bootoption);
+ after_dashes = parse_args("Booting kernel",
+ static_command_line, __start___param,
+ __stop___param - __start___param,
+ -1, -1, &unknown_bootoption);
+ if (after_dashes)
+ parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
+ set_init_arg);
jump_label_init();
*/
current->flags &= ~PF_USED_ASYNC;
- blocking_notifier_call_chain(&module_notify_list,
- MODULE_STATE_COMING, mod);
-
- /* Set RO and NX regions for core */
- set_section_ro_nx(mod->module_core,
- mod->core_text_size,
- mod->core_ro_size,
- mod->core_size);
-
- /* Set RO and NX regions for init */
- set_section_ro_nx(mod->module_init,
- mod->init_text_size,
- mod->init_ro_size,
- mod->init_size);
-
do_mod_ctors(mod);
/* Start the module */
if (mod->init != NULL)
/* This relies on module_mutex for list integrity. */
module_bug_finalize(info->hdr, info->sechdrs, mod);
+ /* Set RO and NX regions for core */
+ set_section_ro_nx(mod->module_core,
+ mod->core_text_size,
+ mod->core_ro_size,
+ mod->core_size);
+
+ /* Set RO and NX regions for init */
+ set_section_ro_nx(mod->module_init,
+ mod->init_text_size,
+ mod->init_ro_size,
+ mod->init_size);
+
/* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */
mod->state = MODULE_STATE_COMING;
+ mutex_unlock(&module_mutex);
+
+ blocking_notifier_call_chain(&module_notify_list,
+ MODULE_STATE_COMING, mod);
+ return 0;
out:
mutex_unlock(&module_mutex);
{
struct module *mod;
long err;
+ char *after_dashes;
err = module_sig_check(info);
if (err)
goto ddebug_cleanup;
/* Module is ready to execute: parsing args may do that. */
- err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
- -32768, 32767, unknown_module_param_cb);
- if (err < 0)
+ after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
+ -32768, 32767, unknown_module_param_cb);
+ if (IS_ERR(after_dashes)) {
+ err = PTR_ERR(after_dashes);
goto bug_cleanup;
+ } else if (after_dashes) {
+ pr_warn("%s: parameters '%s' after `--' ignored\n",
+ mod->name, after_dashes);
+ }
/* Link in to syfs. */
err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
}
/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
-int parse_args(const char *doing,
- char *args,
- const struct kernel_param *params,
- unsigned num,
- s16 min_level,
- s16 max_level,
- int (*unknown)(char *param, char *val, const char *doing))
+char *parse_args(const char *doing,
+ char *args,
+ const struct kernel_param *params,
+ unsigned num,
+ s16 min_level,
+ s16 max_level,
+ int (*unknown)(char *param, char *val, const char *doing))
{
char *param, *val;
int irq_was_disabled;
args = next_arg(args, ¶m, &val);
+ /* Stop at -- */
+ if (!val && strcmp(param, "--") == 0)
+ return args;
irq_was_disabled = irqs_disabled();
ret = parse_one(param, val, doing, params, num,
min_level, max_level, unknown);
switch (ret) {
case -ENOENT:
pr_err("%s: Unknown parameter `%s'\n", doing, param);
- return ret;
+ return ERR_PTR(ret);
case -ENOSPC:
pr_err("%s: `%s' too large for parameter `%s'\n",
doing, val ?: "", param);
- return ret;
+ return ERR_PTR(ret);
case 0:
break;
default:
pr_err("%s: `%s' invalid for parameter `%s'\n",
doing, val ?: "", param);
- return ret;
+ return ERR_PTR(ret);
}
}
/* All parsed OK. */
- return 0;
+ return NULL;
}
/* Lazy bastard, eh? */
return count;
}
+/* Sysfs attributes cannot be world-writable. */
static struct kobj_attribute foo_attribute =
- __ATTR(foo, 0666, foo_show, foo_store);
+ __ATTR(foo, 0664, foo_show, foo_store);
/*
* More complex function where we determine which variable is being accessed by
}
static struct kobj_attribute baz_attribute =
- __ATTR(baz, 0666, b_show, b_store);
+ __ATTR(baz, 0664, b_show, b_store);
static struct kobj_attribute bar_attribute =
- __ATTR(bar, 0666, b_show, b_store);
+ __ATTR(bar, 0664, b_show, b_store);
/*
return count;
}
+/* Sysfs attributes cannot be world-writable. */
static struct foo_attribute foo_attribute =
- __ATTR(foo, 0666, foo_show, foo_store);
+ __ATTR(foo, 0664, foo_show, foo_store);
/*
* More complex function where we determine which variable is being accessed by
}
static struct foo_attribute baz_attribute =
- __ATTR(baz, 0666, b_show, b_store);
+ __ATTR(baz, 0664, b_show, b_store);
static struct foo_attribute bar_attribute =
- __ATTR(bar, 0666, b_show, b_store);
+ __ATTR(bar, 0664, b_show, b_store);
/*
* Create a group of attributes so that we can create and destroy them all
s->preloaded = 1;
sym_update_crc(symname, mod, crc, export_no(export));
}
+ release_file(file, size);
return;
fail:
+ release_file(file, size);
fatal("parse error in symbol dump file\n");
}
projects / firefly-linux-kernel-4.4.55.git / commitdiff