13 files changed, 131 insertions, 106 deletions

diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 1d18e4e46989..1c2d4b29a3d4 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -16,11 +16,13 @@ extra-y := vmlinux.lds
 
 obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \
 	physmem.o process.o ptrace.o reboot.o sigio.o \
-	signal.o syscall.o sysrq.o time.o tlb.o trap.o \
+	signal.o sysrq.o time.o tlb.o trap.o \
 	um_arch.o umid.o maccess.o kmsg_dump.o capflags.o skas/
+obj-y += load_file.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
+obj-$(CONFIG_OF) += dtb.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-$(CONFIG_GENERIC_PCI_IOMAP) += ioport.o
diff --git a/arch/um/kernel/dtb.c b/arch/um/kernel/dtb.c
new file mode 100644
index 000000000000..ca69d72025f3
--- /dev/null
+++ b/arch/um/kernel/dtb.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/init.h>
+#include <linux/of_fdt.h>
+#include <linux/printk.h>
+#include <linux/memblock.h>
+#include <init.h>
+
+#include "um_arch.h"
+
+static char *dtb __initdata;
+
+void uml_dtb_init(void)
+{
+	long long size;
+	void *area;
+
+	area = uml_load_file(dtb, &size);
+	if (!area)
+		return;
+
+	if (!early_init_dt_scan(area)) {
+		pr_err("invalid DTB %s\n", dtb);
+		memblock_free(area, size);
+		return;
+	}
+
+	unflatten_device_tree();
+	early_init_fdt_scan_reserved_mem();
+}
+
+static int __init uml_dtb_setup(char *line, int *add)
+{
+	dtb = line;
+	return 0;
+}
+
+__uml_setup("dtb=", uml_dtb_setup,
+"dtb=<file>\n"
+"    Boot the kernel with the devicetree blob from the specified file.\n"
+);
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 4d8498100341..c85e40c72779 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -16,6 +16,7 @@
 #include <linux/uaccess.h>
 #include <as-layout.h>
 #include <mem_user.h>
+#include <registers.h>
 #include <skas.h>
 #include <os.h>
 
diff --git a/arch/um/kernel/initrd.c b/arch/um/kernel/initrd.c
index c1981ffb7179..47b8cb1a1156 100644
--- a/arch/um/kernel/initrd.c
+++ b/arch/um/kernel/initrd.c
@@ -10,37 +10,21 @@
 #include <init.h>
 #include <os.h>
 
+#include "um_arch.h"
+
 /* Changed by uml_initrd_setup, which is a setup */
 static char *initrd __initdata = NULL;
-static int load_initrd(char *filename, void *buf, int size);
 
 int __init read_initrd(void)
 {
+	unsigned long long size;
 	void *area;
-	long long size;
-	int err;
-
-	if (initrd == NULL)
-		return 0;
 
-	err = os_file_size(initrd, &size);
-	if (err)
+	if (!initrd)
 		return 0;
 
-	/*
-	 * This is necessary because alloc_bootmem craps out if you
-	 * ask for no memory.
-	 */
-	if (size == 0) {
-		printk(KERN_ERR "\"%s\" is a zero-size initrd\n", initrd);
-		return 0;
-	}
-
-	area = memblock_alloc(size, SMP_CACHE_BYTES);
+	area = uml_load_file(initrd, &size);
 	if (!area)
-		panic("%s: Failed to allocate %llu bytes\n", __func__, size);
-
-	if (load_initrd(initrd, area, size) == -1)
 		return 0;
 
 	initrd_start = (unsigned long) area;
@@ -59,25 +43,3 @@ __uml_setup("initrd=", uml_initrd_setup,
 "    This is used to boot UML from an initrd image.  The argument is the\n"
 "    name of the file containing the image.\n\n"
 );
-
-static int load_initrd(char *filename, void *buf, int size)
-{
-	int fd, n;
-
-	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
-	if (fd < 0) {
-		printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,
-		       -fd);
-		return -1;
-	}
-	n = os_read_file(fd, buf, size);
-	if (n != size) {
-		printk(KERN_ERR "Read of %d bytes from '%s' failed, "
-		       "err = %d\n", size,
-		       filename, -n);
-		return -1;
-	}
-
-	os_close_file(fd);
-	return 0;
-}
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index b1e5634398d0..3a85bde3e173 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -6,7 +6,7 @@
 #include <linux/module.h>
 #include <os.h>
 
-EXPORT_SYMBOL(set_signals);
+EXPORT_SYMBOL(um_set_signals);
 EXPORT_SYMBOL(signals_enabled);
 
 EXPORT_SYMBOL(os_stat_fd);
diff --git a/arch/um/kernel/load_file.c b/arch/um/kernel/load_file.c
new file mode 100644
index 000000000000..5cecd0e291fb
--- /dev/null
+++ b/arch/um/kernel/load_file.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+#include <linux/memblock.h>
+#include <os.h>
+
+#include "um_arch.h"
+
+static int __init __uml_load_file(const char *filename, void *buf, int size)
+{
+	int fd, n;
+
+	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
+	if (fd < 0) {
+		printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,
+		       -fd);
+		return -1;
+	}
+	n = os_read_file(fd, buf, size);
+	if (n != size) {
+		printk(KERN_ERR "Read of %d bytes from '%s' failed, "
+		       "err = %d\n", size,
+		       filename, -n);
+		return -1;
+	}
+
+	os_close_file(fd);
+	return 0;
+}
+
+void *uml_load_file(const char *filename, unsigned long long *size)
+{
+	void *area;
+	int err;
+
+	*size = 0;
+
+	if (!filename)
+		return NULL;
+
+	err = os_file_size(filename, size);
+	if (err)
+		return NULL;
+
+	if (*size == 0) {
+		printk(KERN_ERR "\"%s\" is empty\n", filename);
+		return NULL;
+	}
+
+	area = memblock_alloc(*size, SMP_CACHE_BYTES);
+	if (!area)
+		panic("%s: Failed to allocate %llu bytes\n", __func__, *size);
+
+	if (__uml_load_file(filename, area, *size)) {
+		memblock_free(area, *size);
+		return NULL;
+	}
+
+	return area;
+}
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 0039771eb01c..15295c3237a0 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -85,8 +85,7 @@ static void __init one_md_table_init(pud_t *pud)
 		      __func__, PAGE_SIZE, PAGE_SIZE);
 
 	set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
-	if (pmd_table != pmd_offset(pud, 0))
-		BUG();
+	BUG_ON(pmd_table != pmd_offset(pud, 0));
 #endif
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 82107373ac7e..4a420778ed87 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -31,6 +31,7 @@
 #include <kern_util.h>
 #include <os.h>
 #include <skas.h>
+#include <registers.h>
 #include <linux/time-internal.h>
 
 /*
@@ -263,11 +264,6 @@ int clear_user_proc(void __user *buf, int size)
 	return clear_user(buf, size);
 }
 
-int cpu(void)
-{
-	return current_thread_info()->cpu;
-}
-
 static atomic_t using_sysemu = ATOMIC_INIT(0);
 int sysemu_supported;
 
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index a509be911026..23775d01a2a6 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -146,11 +146,6 @@ static int copy_chunk_from_user(unsigned long from, int len, void *arg)
 
 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (uaccess_kernel()) {
-		memcpy(to, (__force void*)from, n);
-		return 0;
-	}
-
 	return buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to);
 }
 EXPORT_SYMBOL(raw_copy_from_user);
@@ -166,11 +161,6 @@ static int copy_chunk_to_user(unsigned long to, int len, void *arg)
 
 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	if (uaccess_kernel()) {
-		memcpy((__force void *) to, from, n);
-		return 0;
-	}
-
 	return buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from);
 }
 EXPORT_SYMBOL(raw_copy_to_user);
@@ -196,12 +186,6 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
 
 	if (!access_ok(src, 1))
 		return -EFAULT;
-
-	if (uaccess_kernel()) {
-		strncpy(dst, (__force void *) src, count);
-		return strnlen(dst, count);
-	}
-
 	n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
 		      &ptr);
 	if (n != 0)
@@ -218,11 +202,6 @@ static int clear_chunk(unsigned long addr, int len, void *unused)
 
 unsigned long __clear_user(void __user *mem, unsigned long len)
 {
-	if (uaccess_kernel()) {
-		memset((__force void*)mem, 0, len);
-		return 0;
-	}
-
 	return buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL);
 }
 EXPORT_SYMBOL(__clear_user);
@@ -245,10 +224,6 @@ long strnlen_user(const char __user *str, long len)
 
 	if (!access_ok(str, 1))
 		return -EFAULT;
-
-	if (uaccess_kernel())
-		return strnlen((__force char*)str, len) + 1;
-
 	n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
 	if (n == 0)
 		return count + 1;
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
deleted file mode 100644
index eed54c53fbbb..000000000000
--- a/arch/um/kernel/syscall.c
+++ /dev/null
@@ -1,28 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#include <linux/file.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/sched.h>
-#include <linux/utsname.h>
-#include <linux/syscalls.h>
-#include <asm/current.h>
-#include <asm/mman.h>
-#include <linux/uaccess.h>
-#include <asm/unistd.h>
-
-long old_mmap(unsigned long addr, unsigned long len,
-	      unsigned long prot, unsigned long flags,
-	      unsigned long fd, unsigned long offset)
-{
-	long err = -EINVAL;
-	if (offset & ~PAGE_MASK)
-		goto out;
-
-	err = ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
- out:
-	return err;
-}
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index c32efb09db21..561a2b03c3cf 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -127,7 +127,6 @@ out_of_memory:
 	pagefault_out_of_memory();
 	return 0;
 }
-EXPORT_SYMBOL(handle_page_fault);
 
 static void show_segv_info(struct uml_pt_regs *regs)
 {
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 54447690de11..abceeabe29b9 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -29,6 +29,8 @@
 #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=tty"
 
@@ -407,6 +409,7 @@ void __init setup_arch(char **cmdline_p)
 	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();
diff --git a/arch/um/kernel/um_arch.h b/arch/um/kernel/um_arch.h
new file mode 100644
index 000000000000..1e07fb7ee35e
--- /dev/null
+++ b/arch/um/kernel/um_arch.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __UML_ARCH_H__
+#define __UML_ARCH_H__
+
+extern void * __init uml_load_file(const char *filename, unsigned long long *size);
+
+#ifdef CONFIG_OF
+extern void __init uml_dtb_init(void);
+#else
+static inline void uml_dtb_init(void) { }
+#endif
+
+#endif