1 files changed, 541 insertions, 0 deletions
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
new file mode 100644
index 0000000000..b1bfed0c85
--- /dev/null
+++ b/arch/um/kernel/um_arch.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/panic_notifier.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/utsname.h>
+#include <linux/sched.h>
+#include <linux/sched/task.h>
+#include <linux/kmsg_dump.h>
+#include <linux/suspend.h>
+#include <linux/random.h>
+
+#include <asm/processor.h>
+#include <asm/cpufeature.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <as-layout.h>
+#include <arch.h>
+#include <init.h>
+#include <kern.h>
+#include <kern_util.h>
+#include <mem_user.h>
+#include <os.h>
+
+#include "um_arch.h"
+
+#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
+#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
+
+/* 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) {
+		os_warn("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 },
+	.cache_alignment	= L1_CACHE_BYTES,
+	.x86_capability		= { 0 }
+};
+
+EXPORT_SYMBOL(boot_cpu_data);
+
+union thread_union cpu0_irqstack
+	__section(".data..init_irqstack") =
+		{ .thread_info = INIT_THREAD_INFO(init_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 i = 0;
+
+	seq_printf(m, "processor\t: %d\n", i);
+	seq_printf(m, "vendor_id\t: User Mode Linux\n");
+	seq_printf(m, "model name\t: UML\n");
+	seq_printf(m, "mode\t\t: skas\n");
+	seq_printf(m, "host\t\t: %s\n", host_info);
+	seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
+	seq_printf(m, "flags\t\t:");
+	for (i = 0; i < 32*NCAPINTS; i++)
+		if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
+			seq_printf(m, " %s", x86_cap_flags[i]);
+	seq_printf(m, "\n");
+	seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
+	seq_printf(m, "bogomips\t: %lu.%02lu\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_cpu_ids ? &boot_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 uml_physmem;
+EXPORT_SYMBOL(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;
+
+/* Set in early boot */
+static int have_root __initdata;
+static int have_console __initdata;
+
+/* Set in uml_mem_setup and modified in linux_main */
+long long physmem_size = 64 * 1024 * 1024;
+EXPORT_SYMBOL(physmem_size);
+
+static const 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)
+{
+	/* Explicitly use printf() to show version in stdout */
+	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"
+);
+
+static int __init no_skas_debug_setup(char *line, int *add)
+{
+	os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
+	os_warn("'gdb linux'\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"
+);
+
+static int __init uml_console_setup(char *line, int *add)
+{
+	have_console = 1;
+	return 0;
+}
+
+__uml_setup("console=", uml_console_setup,
+"console=<preferred console>\n"
+"    Specify the preferred console output driver\n\n"
+);
+
+static int __init Usage(char *line, int *add)
+{
+	const char **p;
+
+	printf(usage_string, init_utsname()->release);
+	p = &__uml_help_start;
+	/* Explicitly use printf() to show help in stdout */
+	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 void __init uml_checksetup(char *line, int *add)
+{
+	struct uml_param *p;
+
+	p = &__uml_setup_start;
+	while (p < &__uml_setup_end) {
+		size_t n;
+
+		n = strlen(p->str);
+		if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
+			return;
+		p++;
+	}
+}
+
+static void __init uml_postsetup(void)
+{
+	initcall_t *p;
+
+	p = &__uml_postsetup_start;
+	while (p < &__uml_postsetup_end) {
+		(*p)();
+		p++;
+	}
+	return;
+}
+
+static int panic_exit(struct notifier_block *self, unsigned long unused1,
+		      void *unused2)
+{
+	kmsg_dump(KMSG_DUMP_PANIC);
+	bust_spinlocks(1);
+	bust_spinlocks(0);
+	uml_exitcode = 1;
+	os_dump_core();
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block panic_exit_notifier = {
+	.notifier_call	= panic_exit,
+	.priority	= INT_MAX - 1, /* run as 2nd notifier, won't return */
+};
+
+void uml_finishsetup(void)
+{
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &panic_exit_notifier);
+
+	uml_postsetup();
+
+	new_thread_handler();
+}
+
+/* Set during early boot */
+unsigned long stub_start;
+unsigned long task_size;
+EXPORT_SYMBOL(task_size);
+
+unsigned long host_task_size;
+
+unsigned long brk_start;
+unsigned long end_iomem;
+EXPORT_SYMBOL(end_iomem);
+
+#define MIN_VMALLOC (32 * 1024 * 1024)
+
+static void parse_host_cpu_flags(char *line)
+{
+	int i;
+	for (i = 0; i < 32*NCAPINTS; i++) {
+		if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
+			set_cpu_cap(&boot_cpu_data, i);
+	}
+}
+static void parse_cache_line(char *line)
+{
+	long res;
+	char *to_parse = strstr(line, ":");
+	if (to_parse) {
+		to_parse++;
+		while (*to_parse != 0 && isspace(*to_parse)) {
+			to_parse++;
+		}
+		if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
+			boot_cpu_data.cache_alignment = res;
+		else
+			boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
+	}
+}
+
+int __init linux_main(int argc, char **argv)
+{
+	unsigned long avail, diff;
+	unsigned long virtmem_size, max_physmem;
+	unsigned long stack;
+	unsigned int i;
+	int add;
+
+	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_ROOT);
+
+	if (have_console == 0)
+		add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
+
+	host_task_size = os_get_top_address();
+	/* reserve a few pages for the stubs (taking care of data alignment) */
+	/* align the data portion */
+	BUILD_BUG_ON(!is_power_of_2(STUB_DATA_PAGES));
+	stub_start = (host_task_size - 1) & ~(STUB_DATA_PAGES * PAGE_SIZE - 1);
+	/* another page for the code portion */
+	stub_start -= PAGE_SIZE;
+	host_task_size = stub_start;
+
+	/*
+	 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
+	 * out
+	 */
+	task_size = host_task_size & PGDIR_MASK;
+
+	/* OS sanity checks that need to happen before the kernel runs */
+	os_early_checks();
+
+	get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
+
+	brk_start = (unsigned long) sbrk(0);
+
+	/*
+	 * 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) {
+		os_info("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);
+
+	highmem = 0;
+	iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
+	max_physmem = TASK_SIZE - 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;
+	}
+
+	high_physmem = uml_physmem + physmem_size;
+	end_iomem = high_physmem + iomem_size;
+	high_memory = (void *) end_iomem;
+
+	start_vm = VMALLOC_START;
+
+	virtmem_size = physmem_size;
+	stack = (unsigned long) argv;
+	stack &= ~(1024 * 1024 - 1);
+	avail = stack - start_vm;
+	if (physmem_size > avail)
+		virtmem_size = avail;
+	end_vm = start_vm + virtmem_size;
+
+	if (virtmem_size < physmem_size)
+		os_info("Kernel virtual memory size shrunk to %lu bytes\n",
+			virtmem_size);
+
+	os_flush_stdout();
+
+	return start_uml();
+}
+
+int __init __weak read_initrd(void)
+{
+	return 0;
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+	u8 rng_seed[32];
+
+	stack_protections((unsigned long) &init_thread_info);
+	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
+	mem_total_pages(physmem_size, iomem_size, highmem);
+	uml_dtb_init();
+	read_initrd();
+
+	paging_init();
+	strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
+	*cmdline_p = command_line;
+	setup_hostinfo(host_info, sizeof host_info);
+
+	if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
+		add_bootloader_randomness(rng_seed, sizeof(rng_seed));
+		memzero_explicit(rng_seed, sizeof(rng_seed));
+	}
+}
+
+void __init arch_cpu_finalize_init(void)
+{
+	arch_check_bugs();
+	os_check_bugs();
+}
+
+void apply_seal_endbr(s32 *start, s32 *end)
+{
+}
+
+void apply_retpolines(s32 *start, s32 *end)
+{
+}
+
+void apply_returns(s32 *start, s32 *end)
+{
+}
+
+void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
+		   s32 *start_cfi, s32 *end_cfi)
+{
+}
+
+void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
+{
+}
+
+void *text_poke(void *addr, const void *opcode, size_t len)
+{
+	/*
+	 * In UML, the only reference to this function is in
+	 * apply_relocate_add(), which shouldn't ever actually call this
+	 * because UML doesn't have live patching.
+	 */
+	WARN_ON(1);
+
+	return memcpy(addr, opcode, len);
+}
+
+void text_poke_sync(void)
+{
+}
+
+void uml_pm_wake(void)
+{
+	pm_system_wakeup();
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int um_suspend_valid(suspend_state_t state)
+{
+	return state == PM_SUSPEND_MEM;
+}
+
+static int um_suspend_prepare(void)
+{
+	um_irqs_suspend();
+	return 0;
+}
+
+static int um_suspend_enter(suspend_state_t state)
+{
+	if (WARN_ON(state != PM_SUSPEND_MEM))
+		return -EINVAL;
+
+	/*
+	 * This is identical to the idle sleep, but we've just
+	 * (during suspend) turned off all interrupt sources
+	 * except for the ones we want, so now we can only wake
+	 * up on something we actually want to wake up on. All
+	 * timing has also been suspended.
+	 */
+	um_idle_sleep();
+	return 0;
+}
+
+static void um_suspend_finish(void)
+{
+	um_irqs_resume();
+}
+
+const struct platform_suspend_ops um_suspend_ops = {
+	.valid = um_suspend_valid,
+	.prepare = um_suspend_prepare,
+	.enter = um_suspend_enter,
+	.finish = um_suspend_finish,
+};
+
+static int init_pm_wake_signal(void)
+{
+	/*
+	 * In external time-travel mode we can't use signals to wake up
+	 * since that would mess with the scheduling. We'll have to do
+	 * some additional work to support wakeup on virtio devices or
+	 * similar, perhaps implementing a fake RTC controller that can
+	 * trigger wakeup (and request the appropriate scheduling from
+	 * the external scheduler when going to suspend.)
+	 */
+	if (time_travel_mode != TT_MODE_EXTERNAL)
+		register_pm_wake_signal();
+
+	suspend_set_ops(&um_suspend_ops);
+
+	return 0;
+}
+
+late_initcall(init_pm_wake_signal);
+#endif