WSL2-Linux-Kernel/arch/um/kernel/um_arch.c

518 строки
12 KiB
C

/*
* Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/sched.h"
#include "linux/notifier.h"
#include "linux/mm.h"
#include "linux/types.h"
#include "linux/tty.h"
#include "linux/init.h"
#include "linux/bootmem.h"
#include "linux/spinlock.h"
#include "linux/utsname.h"
#include "linux/sysrq.h"
#include "linux/seq_file.h"
#include "linux/delay.h"
#include "linux/module.h"
#include "linux/utsname.h"
#include "asm/page.h"
#include "asm/pgtable.h"
#include "asm/ptrace.h"
#include "asm/elf.h"
#include "asm/user.h"
#include "asm/setup.h"
#include "ubd_user.h"
#include "asm/current.h"
#include "kern_util.h"
#include "as-layout.h"
#include "arch.h"
#include "kern.h"
#include "mem_user.h"
#include "mem.h"
#include "initrd.h"
#include "init.h"
#include "os.h"
#include "choose-mode.h"
#include "mode_kern.h"
#include "mode.h"
#ifdef UML_CONFIG_MODE_SKAS
#include "skas.h"
#endif
#define DEFAULT_COMMAND_LINE "root=98:0"
/* Changed in add_arg and setup_arch, which run before SMP is started */
static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
static void __init add_arg(char *arg)
{
if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
printf("add_arg: Too many command line arguments!\n");
exit(1);
}
if(strlen(command_line) > 0)
strcat(command_line, " ");
strcat(command_line, arg);
}
/*
* These fields are initialized at boot time and not changed.
* XXX This structure is used only in the non-SMP case. Maybe this
* should be moved to smp.c.
*/
struct cpuinfo_um boot_cpu_data = {
.loops_per_jiffy = 0,
.ipi_pipe = { -1, -1 }
};
unsigned long thread_saved_pc(struct task_struct *task)
{
return os_process_pc(CHOOSE_MODE_PROC(thread_pid_tt, thread_pid_skas,
task));
}
/* Changed in setup_arch, which is called in early boot */
static char host_info[(__NEW_UTS_LEN + 1) * 5];
static int show_cpuinfo(struct seq_file *m, void *v)
{
int index = 0;
#ifdef CONFIG_SMP
index = (struct cpuinfo_um *) v - cpu_data;
if (!cpu_online(index))
return 0;
#endif
seq_printf(m, "processor\t: %d\n", index);
seq_printf(m, "vendor_id\t: User Mode Linux\n");
seq_printf(m, "model name\t: UML\n");
seq_printf(m, "mode\t\t: %s\n", CHOOSE_MODE("tt", "skas"));
seq_printf(m, "host\t\t: %s\n", host_info);
seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
loops_per_jiffy/(500000/HZ),
(loops_per_jiffy/(5000/HZ)) % 100);
return 0;
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
return *pos < NR_CPUS ? cpu_data + *pos : NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo,
};
/* Set in linux_main */
unsigned long host_task_size;
unsigned long task_size;
unsigned long uml_physmem;
unsigned long uml_reserved; /* Also modified in mem_init */
unsigned long start_vm;
unsigned long end_vm;
/* Set in uml_ncpus_setup */
int ncpus = 1;
#ifdef CONFIG_CMDLINE_ON_HOST
/* Pointer set in linux_main, the array itself is private to each thread,
* and changed at address space creation time so this poses no concurrency
* problems.
*/
static char *argv1_begin = NULL;
static char *argv1_end = NULL;
#endif
/* Set in early boot */
static int have_root __initdata = 0;
/* Set in uml_mem_setup and modified in linux_main */
long long physmem_size = 32 * 1024 * 1024;
void set_cmdline(char *cmd)
{
#ifdef CONFIG_CMDLINE_ON_HOST
char *umid, *ptr;
if(CHOOSE_MODE(honeypot, 0)) return;
umid = get_umid();
if(*umid != '\0'){
snprintf(argv1_begin,
(argv1_end - argv1_begin) * sizeof(*ptr),
"(%s) ", umid);
ptr = &argv1_begin[strlen(argv1_begin)];
}
else ptr = argv1_begin;
snprintf(ptr, (argv1_end - ptr) * sizeof(*ptr), "[%s]", cmd);
memset(argv1_begin + strlen(argv1_begin), '\0',
argv1_end - argv1_begin - strlen(argv1_begin));
#endif
}
static char *usage_string =
"User Mode Linux v%s\n"
" available at http://user-mode-linux.sourceforge.net/\n\n";
static int __init uml_version_setup(char *line, int *add)
{
printf("%s\n", init_utsname()->release);
exit(0);
return 0;
}
__uml_setup("--version", uml_version_setup,
"--version\n"
" Prints the version number of the kernel.\n\n"
);
static int __init uml_root_setup(char *line, int *add)
{
have_root = 1;
return 0;
}
__uml_setup("root=", uml_root_setup,
"root=<file containing the root fs>\n"
" This is actually used by the generic kernel in exactly the same\n"
" way as in any other kernel. If you configure a number of block\n"
" devices and want to boot off something other than ubd0, you \n"
" would use something like:\n"
" root=/dev/ubd5\n\n"
);
#ifndef CONFIG_MODE_TT
static int __init no_skas_debug_setup(char *line, int *add)
{
printf("'debug' is not necessary to gdb UML in skas mode - run \n");
printf("'gdb linux' and disable CONFIG_CMDLINE_ON_HOST if gdb \n");
printf("doesn't work as expected\n");
return 0;
}
__uml_setup("debug", no_skas_debug_setup,
"debug\n"
" this flag is not needed to run gdb on UML in skas mode\n\n"
);
#endif
#ifdef CONFIG_SMP
static int __init uml_ncpus_setup(char *line, int *add)
{
if (!sscanf(line, "%d", &ncpus)) {
printf("Couldn't parse [%s]\n", line);
return -1;
}
return 0;
}
__uml_setup("ncpus=", uml_ncpus_setup,
"ncpus=<# of desired CPUs>\n"
" This tells an SMP kernel how many virtual processors to start.\n\n"
);
#endif
static int force_tt = 0;
#if defined(CONFIG_MODE_TT) && defined(CONFIG_MODE_SKAS)
#define DEFAULT_TT 0
static int __init mode_tt_setup(char *line, int *add)
{
force_tt = 1;
return 0;
}
#else
#ifdef CONFIG_MODE_SKAS
#define DEFAULT_TT 0
static int __init mode_tt_setup(char *line, int *add)
{
printf("CONFIG_MODE_TT disabled - 'mode=tt' ignored\n");
return 0;
}
#else
#ifdef CONFIG_MODE_TT
#define DEFAULT_TT 1
static int __init mode_tt_setup(char *line, int *add)
{
printf("CONFIG_MODE_SKAS disabled - 'mode=tt' redundant\n");
return 0;
}
#endif
#endif
#endif
__uml_setup("mode=tt", mode_tt_setup,
"mode=tt\n"
" When both CONFIG_MODE_TT and CONFIG_MODE_SKAS are enabled, this option\n"
" forces UML to run in tt (tracing thread) mode. It is not the default\n"
" because it's slower and less secure than skas mode.\n\n"
);
int mode_tt = DEFAULT_TT;
static int __init Usage(char *line, int *add)
{
const char **p;
printf(usage_string, init_utsname()->release);
p = &__uml_help_start;
while (p < &__uml_help_end) {
printf("%s", *p);
p++;
}
exit(0);
return 0;
}
__uml_setup("--help", Usage,
"--help\n"
" Prints this message.\n\n"
);
static int __init uml_checksetup(char *line, int *add)
{
struct uml_param *p;
p = &__uml_setup_start;
while(p < &__uml_setup_end) {
int n;
n = strlen(p->str);
if(!strncmp(line, p->str, n)){
if (p->setup_func(line + n, add)) return 1;
}
p++;
}
return 0;
}
static void __init uml_postsetup(void)
{
initcall_t *p;
p = &__uml_postsetup_start;
while(p < &__uml_postsetup_end){
(*p)();
p++;
}
return;
}
/* Set during early boot */
unsigned long brk_start;
unsigned long end_iomem;
EXPORT_SYMBOL(end_iomem);
#define MIN_VMALLOC (32 * 1024 * 1024)
extern char __binary_start;
int __init linux_main(int argc, char **argv)
{
unsigned long avail, diff;
unsigned long virtmem_size, max_physmem;
unsigned int i, add;
char * mode;
for (i = 1; i < argc; i++){
if((i == 1) && (argv[i][0] == ' ')) continue;
add = 1;
uml_checksetup(argv[i], &add);
if (add)
add_arg(argv[i]);
}
if(have_root == 0)
add_arg(DEFAULT_COMMAND_LINE);
os_early_checks();
if (force_tt)
clear_can_do_skas();
mode_tt = force_tt ? 1 : !can_do_skas();
#ifndef CONFIG_MODE_TT
if (mode_tt) {
/*Since CONFIG_MODE_TT is #undef'ed, force_tt cannot be 1. So,
* can_do_skas() returned 0, and the message is correct. */
printf("Support for TT mode is disabled, and no SKAS support is present on the host.\n");
exit(1);
}
#endif
#ifndef CONFIG_MODE_SKAS
mode = "TT";
#else
/* Show to the user the result of selection */
if (mode_tt)
mode = "TT";
else if (proc_mm && ptrace_faultinfo)
mode = "SKAS3";
else
mode = "SKAS0";
#endif
printf("UML running in %s mode\n", mode);
host_task_size = CHOOSE_MODE_PROC(set_task_sizes_tt,
set_task_sizes_skas, &task_size);
/*
* Setting up handlers to 'sig_info' struct
*/
os_fill_handlinfo(handlinfo_kern);
brk_start = (unsigned long) sbrk(0);
CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
/* Increase physical memory size for exec-shield users
so they actually get what they asked for. This should
add zero for non-exec shield users */
diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
if(diff > 1024 * 1024){
printf("Adding %ld bytes to physical memory to account for "
"exec-shield gap\n", diff);
physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
}
uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
/* Reserve up to 4M after the current brk */
uml_reserved = ROUND_4M(brk_start) + (1 << 22);
setup_machinename(init_utsname()->machine);
#ifdef CONFIG_CMDLINE_ON_HOST
argv1_begin = argv[1];
argv1_end = &argv[1][strlen(argv[1])];
#endif
highmem = 0;
iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
/* Zones have to begin on a 1 << MAX_ORDER page boundary,
* so this makes sure that's true for highmem
*/
max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
if(physmem_size + iomem_size > max_physmem){
highmem = physmem_size + iomem_size - max_physmem;
physmem_size -= highmem;
#ifndef CONFIG_HIGHMEM
highmem = 0;
printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
"to %Lu bytes\n", physmem_size);
#endif
}
high_physmem = uml_physmem + physmem_size;
end_iomem = high_physmem + iomem_size;
high_memory = (void *) end_iomem;
start_vm = VMALLOC_START;
setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
if(init_maps(physmem_size, iomem_size, highmem)){
printf("Failed to allocate mem_map for %Lu bytes of physical "
"memory and %Lu bytes of highmem\n", physmem_size,
highmem);
exit(1);
}
virtmem_size = physmem_size;
avail = get_kmem_end() - start_vm;
if(physmem_size > avail) virtmem_size = avail;
end_vm = start_vm + virtmem_size;
if(virtmem_size < physmem_size)
printf("Kernel virtual memory size shrunk to %lu bytes\n",
virtmem_size);
uml_postsetup();
stack_protections((unsigned long) &init_thread_info);
os_flush_stdout();
return CHOOSE_MODE(start_uml_tt(), start_uml_skas());
}
extern int uml_exitcode;
static int panic_exit(struct notifier_block *self, unsigned long unused1,
void *unused2)
{
bust_spinlocks(1);
show_regs(&(current->thread.regs));
bust_spinlocks(0);
uml_exitcode = 1;
os_dump_core();
return 0;
}
static struct notifier_block panic_exit_notifier = {
.notifier_call = panic_exit,
.next = NULL,
.priority = 0
};
void __init setup_arch(char **cmdline_p)
{
atomic_notifier_chain_register(&panic_notifier_list,
&panic_exit_notifier);
paging_init();
strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
setup_hostinfo(host_info, sizeof host_info);
}
void __init check_bugs(void)
{
arch_check_bugs();
os_check_bugs();
}
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
}
#ifdef CONFIG_SMP
void alternatives_smp_module_add(struct module *mod, char *name,
void *locks, void *locks_end,
void *text, void *text_end)
{
}
void alternatives_smp_module_del(struct module *mod)
{
}
#endif