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
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
+ acpi_force_table_verification [HW,ACPI]
+ Enable table checksum verification during early stage.
+ By default, this is disabled due to x86 early mapping
+ size limitation.
+
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
This feature is enabled by default.
This option allows to turn off the feature.
- acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+ acpi_no_static_ssdt [HW,ACPI]
+ Disable installation of static SSDTs at early boot time
+ By default, SSDTs contained in the RSDT/XSDT will be
+ installed automatically and they will appear under
+ /sys/firmware/acpi/tables.
+ This option turns off this feature.
+ Note that specifying this option does not affect
+ dynamic table installation which will install SSDT
+ tables to /sys/firmware/acpi/tables/dynamic.
acpica_no_return_repair [HW, ACPI]
Disable AML predefined validation mechanism
Also note the kernel might malfunction if you disable
some critical bits.
- cma=nn[MG] [ARM,KNL]
- Sets the size of kernel global memory area for contiguous
+ cma=nn[MG]@[start[MG][-end[MG]]]
+ [ARM,X86,KNL]
+ Sets the size of kernel global memory area for
+ contiguous memory allocations and optionally the
+ placement constraint by the physical address range of
memory allocations. For more information, see
include/linux/dma-contiguous.h
which are not unmapped.
earlycon= [KNL] Output early console device and options.
+
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
(mmio) or 32-bit (mmio32).
The options are the same as for ttyS, above.
- earlyprintk= [X86,SH,BLACKFIN,ARM]
+ pl011,<addr>
+ Start an early, polled-mode console on a pl011 serial
+ port at the specified address. The pl011 serial port
+ must already be setup and configured. Options are not
+ yet supported.
+
+ smh Use ARM semihosting calls for early console.
+
+ earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
earlyprintk=vga
earlyprintk=efi
earlyprintk=xen
for working out where the kernel is dying during
startup.
+ initcall_blacklist= [KNL] Do not execute a comma-separated list of
+ initcall functions. Useful for debugging built-in
+ modules and initcalls.
+
initrd= [BOOT] Specify the location of the initial ramdisk
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
- nordrand [X86] Disable the direct use of the RDRAND
- instruction even if it is supported by the
- processor. RDRAND is still available to user
- space applications.
+ nordrand [X86] Disable kernel use of the RDRAND and
+ RDSEED instructions even if they are supported
+ by the processor. RDRAND and RDSEED are still
+ available to user space applications.
noresume [SWSUSP] Disables resume and restores original swap
space.
timeout < 0: reboot immediately
Format: <timeout>
+ crash_kexec_post_notifiers
+ Run kdump after running panic-notifiers and dumping
+ kmsg. This only for the users who doubt kdump always
+ succeeds in any situation.
+ Note that this also increases risks of kdump failure,
+ because some panic notifiers can make the crashed
+ kernel more unstable.
+
parkbd.port= [HW] Parallel port number the keyboard adapter is
connected to, default is 0.
Format: <parport#>
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/cgroups/cpusets.txt.
+ relative_sleep_states=
+ [SUSPEND] Use sleep state labeling where the deepest
+ state available other than hibernation is always "mem".
+ Format: { "0" | "1" }
+ 0 -- Traditional sleep state labels.
+ 1 -- Relative sleep state labels.
+
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
reservetop= [X86-32]
the allocated input device; If set to 0, video driver
will only send out the event without touching backlight
brightness level.
- default: 1
+ default: 0
virtio_mmio.device=
[VMMIO] Memory mapped virtio (platform) device.
payload.offset = 0;
payload.length = 4096;
payload.func_specific = kzalloc(4096, GFP_KERNEL);
+ if (!payload.func_specific)
+ return -ENOMEM;
PM8001_CHIP_DISP->get_nvmd_req(pm8001_ha, &payload);
wait_for_completion(&completion);
virt_addr = pm8001_ha->memoryMap.region[NVMD].virt_ptr;
bios_index++)
str += sprintf(str, "%c",
*((u8 *)((u8 *)virt_addr+bios_index)));
+ kfree(payload.func_specific);
return str - buf;
}
static DEVICE_ATTR(bios_version, S_IRUGO, pm8001_ctl_bios_version_show, NULL);
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,
#include <linux/sched_clock.h>
#include <linux/context_tracking.h>
#include <linux/random.h>
+#include <linux/list.h>
#include <asm/io.h>
#include <asm/bugs.h>
static int __init debug_kernel(char *str)
{
- console_loglevel = 10;
+ console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
return 0;
}
static int __init quiet_kernel(char *str)
{
- console_loglevel = 4;
+ console_loglevel = CONSOLE_LOGLEVEL_QUIET;
return 0;
}
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).
* the init task will end up wanting to create kthreads, which, if
* we schedule it before we create kthreadd, will OOPS.
*/
- kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
+ kernel_thread(kernel_init, NULL, CLONE_FS);
numa_default_policy();
pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
rcu_read_lock();
vmalloc_init();
}
-asmlinkage void __init start_kernel(void)
+asmlinkage __visible void __init start_kernel(void)
{
- char * command_line;
+ char * command_line, *after_dashes;
extern const struct kernel_param __start___param[], __stop___param[];
/*
page_address_init();
pr_notice("%s", linux_banner);
setup_arch(&command_line);
- mm_init_owner(&init_mm, &init_task);
mm_init_cpumask(&init_mm);
setup_command_line(command_line);
setup_nr_cpu_ids();
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();
#ifdef CONFIG_X86
if (efi_enabled(EFI_RUNTIME_SERVICES))
efi_enter_virtual_mode();
+#endif
+#ifdef CONFIG_X86_ESPFIX64
+ /* Should be run before the first non-init thread is created */
+ init_espfix_bsp();
#endif
thread_info_cache_init();
cred_init();
signals_init();
/* rootfs populating might need page-writeback */
page_writeback_init();
-#ifdef CONFIG_PROC_FS
proc_root_init();
-#endif
cgroup_init();
cpuset_init();
taskstats_init_early();
bool initcall_debug;
core_param(initcall_debug, initcall_debug, bool, 0644);
+#ifdef CONFIG_KALLSYMS
+struct blacklist_entry {
+ struct list_head next;
+ char *buf;
+};
+
+static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
+
+static int __init initcall_blacklist(char *str)
+{
+ char *str_entry;
+ struct blacklist_entry *entry;
+
+ /* str argument is a comma-separated list of functions */
+ do {
+ str_entry = strsep(&str, ",");
+ if (str_entry) {
+ pr_debug("blacklisting initcall %s\n", str_entry);
+ entry = alloc_bootmem(sizeof(*entry));
+ entry->buf = alloc_bootmem(strlen(str_entry) + 1);
+ strcpy(entry->buf, str_entry);
+ list_add(&entry->next, &blacklisted_initcalls);
+ }
+ } while (str_entry);
+
+ return 0;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+ struct list_head *tmp;
+ struct blacklist_entry *entry;
+ char *fn_name;
+
+ fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
+ if (!fn_name)
+ return false;
+
+ list_for_each(tmp, &blacklisted_initcalls) {
+ entry = list_entry(tmp, struct blacklist_entry, next);
+ if (!strcmp(fn_name, entry->buf)) {
+ pr_debug("initcall %s blacklisted\n", fn_name);
+ kfree(fn_name);
+ return true;
+ }
+ }
+
+ kfree(fn_name);
+ return false;
+}
+#else
+static int __init initcall_blacklist(char *str)
+{
+ pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
+ return 0;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+ return false;
+}
+#endif
+__setup("initcall_blacklist=", initcall_blacklist);
+
static int __init_or_module do_one_initcall_debug(initcall_t fn)
{
ktime_t calltime, delta, rettime;
unsigned long long duration;
int ret;
- pr_debug("calling %pF @ %i\n", fn, task_pid_nr(current));
+ printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
calltime = ktime_get();
ret = fn();
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
duration = (unsigned long long) ktime_to_ns(delta) >> 10;
- pr_debug("initcall %pF returned %d after %lld usecs\n",
+ printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
fn, ret, duration);
return ret;
int ret;
char msgbuf[64];
+ if (initcall_blacklisted(fn))
+ return -EPERM;
+
if (initcall_debug)
ret = do_one_initcall_debug(fn);
else
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
- if (!(flags & O_NONBLOCK))
- pr_warn("waiting module removal not supported: please upgrade\n");
-
if (mutex_lock_interruptible(&module_mutex) != 0)
return -EINTR;
*/
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)
dynamic_debug_setup(info->debug, info->num_debug);
+ /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
+ ftrace_module_init(mod);
+
/* Finally it's fully formed, ready to start executing. */
err = complete_formation(mod, 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);
s->module->name,
is_vmlinux(s->module->name) ?"":".ko");
} else {
- /* In case Modules.symvers was out of date */
+ /* In case Module.symvers was out of date */
s->module = mod;
}
}
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