Merge tag 'for-linus-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML fixes from Richard Weinberger:

 - Make sure to set a default console, otherwise ttynull is selected

 - Revert initial ARCH_HAS_SET_MEMORY support, this needs more work

 - Fix a regression due to ubd refactoring

 - Various small fixes

* tag 'for-linus-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: time: fix initialization in time-travel mode
  um: fix os_idle_sleep() to not hang
  Revert "um: support some of ARCH_HAS_SET_MEMORY"
  Revert "um: allocate a guard page to helper threads"
  um: virtio: free vu_dev only with the contained struct device
  um: kmsg_dumper: always dump when not tty console
  um: stdio_console: Make preferred console
  um: return error from ioremap()
  um: ubd: fix command line handling of ubd

arch/um/Kconfig

@@ -15,7 +15,6 @@ config UML
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_BUGVERBOSE
 	select NO_DMA
-	select ARCH_HAS_SET_MEMORY
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select HAVE_GCC_PLUGINS

arch/um/drivers/ubd_kern.c

@@ -375,11 +375,11 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out)
 		file = NULL;
 
 	backing_file = strsep(&str, ",:");
-	if (*backing_file == '\0')
+	if (backing_file && *backing_file == '\0')
 		backing_file = NULL;
 
 	serial = strsep(&str, ",:");
-	if (*serial == '\0')
+	if (serial && *serial == '\0')
 		serial = NULL;
 
 	if (backing_file && ubd_dev->no_cow) {
@@ -1241,7 +1241,7 @@ static int __init ubd_driver_init(void){
 		/* Letting ubd=sync be like using ubd#s= instead of ubd#= is
 		 * enough. So use anyway the io thread. */
 	}
-	stack = alloc_stack(0);
+	stack = alloc_stack(0, 0);
 	io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
 				 &thread_fd);
 	if(io_pid < 0){

arch/um/drivers/virtio_uml.c

@@ -1084,6 +1084,7 @@ static void virtio_uml_release_dev(struct device *d)
 	}
 
 	os_close_file(vu_dev->sock);
+	kfree(vu_dev);
 }
 
 /* Platform device */
@@ -1097,7 +1098,7 @@ static int virtio_uml_probe(struct platform_device *pdev)
 	if (!pdata)
 		return -EINVAL;
 
-	vu_dev = devm_kzalloc(&pdev->dev, sizeof(*vu_dev), GFP_KERNEL);
+	vu_dev = kzalloc(sizeof(*vu_dev), GFP_KERNEL);
 	if (!vu_dev)
 		return -ENOMEM;
 

arch/um/include/asm/io.h

@@ -5,7 +5,7 @@
 #define ioremap ioremap
 static inline void __iomem *ioremap(phys_addr_t offset, size_t size)
 {
-	return (void __iomem *)(unsigned long)offset;
+	return NULL;
 }
 
 #define iounmap iounmap

arch/um/include/asm/pgtable.h

@@ -55,15 +55,12 @@ extern unsigned long end_iomem;
 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define __PAGE_KERNEL_EXEC                                              \
 	 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
-#define __PAGE_KERNEL_RO						\
-	 (_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED)
 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
 #define PAGE_KERNEL_EXEC	__pgprot(__PAGE_KERNEL_EXEC)
-#define PAGE_KERNEL_RO		__pgprot(__PAGE_KERNEL_RO)
 
 /*
  * The i386 can't do page protection for execute, and considers that the same

arch/um/include/asm/set_memory.h

-#include <asm-generic/set_memory.h>

arch/um/include/shared/kern_util.h

@@ -19,7 +19,7 @@ extern int kmalloc_ok;
 #define UML_ROUND_UP(addr) \
 	((((unsigned long) addr) + PAGE_SIZE - 1) & PAGE_MASK)
 
-extern unsigned long alloc_stack(int atomic);
+extern unsigned long alloc_stack(int order, int atomic);
 extern void free_stack(unsigned long stack, int order);
 
 struct pt_regs;

arch/um/kernel/kmsg_dump.c

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/kmsg_dump.h>
 #include <linux/console.h>
+#include <linux/string.h>
 #include <shared/init.h>
 #include <shared/kern.h>
 #include <os.h>
@@ -16,8 +17,12 @@ static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
 	if (!console_trylock())
 		return;
 
-	for_each_console(con)
-		break;
+	for_each_console(con) {
+		if(strcmp(con->name, "tty") == 0 &&
+		   (con->flags & (CON_ENABLED | CON_CONSDEV)) != 0) {
+			break;
+		}
+	}
 
 	console_unlock();
 

arch/um/kernel/process.c

@@ -32,7 +32,6 @@
 #include <os.h>
 #include <skas.h>
 #include <linux/time-internal.h>
-#include <asm/set_memory.h>
 
 /*
  * This is a per-cpu array.  A processor only modifies its entry and it only
@@ -63,18 +62,16 @@ void free_stack(unsigned long stack, int order)
 	free_pages(stack, order);
 }
 
-unsigned long alloc_stack(int atomic)
+unsigned long alloc_stack(int order, int atomic)
 {
-	unsigned long addr;
+	unsigned long page;
 	gfp_t flags = GFP_KERNEL;
 
 	if (atomic)
 		flags = GFP_ATOMIC;
-	addr = __get_free_pages(flags, 1);
+	page = __get_free_pages(flags, order);
 
-	set_memory_ro(addr, 1);
-
-	return addr + PAGE_SIZE;
+	return page;
 }
 
 static inline void set_current(struct task_struct *task)

arch/um/kernel/time.c

@@ -535,6 +535,31 @@ static int time_travel_connect_external(const char *socket)
 
 	return 1;
 }
+
+static void time_travel_set_start(void)
+{
+	if (time_travel_start_set)
+		return;
+
+	switch (time_travel_mode) {
+	case TT_MODE_EXTERNAL:
+		time_travel_start = time_travel_ext_req(UM_TIMETRAVEL_GET_TOD, -1);
+		/* controller gave us the *current* time, so adjust by that */
+		time_travel_ext_get_time();
+		time_travel_start -= time_travel_time;
+		break;
+	case TT_MODE_INFCPU:
+	case TT_MODE_BASIC:
+		if (!time_travel_start_set)
+			time_travel_start = os_persistent_clock_emulation();
+		break;
+	case TT_MODE_OFF:
+		/* we just read the host clock with os_persistent_clock_emulation() */
+		break;
+	}
+
+	time_travel_start_set = true;
+}
 #else /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
 #define time_travel_start_set 0
 #define time_travel_start 0
@@ -553,6 +578,10 @@ static void time_travel_set_interval(unsigned long long interval)
 {
 }
 
+static inline void time_travel_set_start(void)
+{
+}
+
 /* fail link if this actually gets used */
 extern u64 time_travel_ext_req(u32 op, u64 time);
 
@@ -731,6 +760,8 @@ void read_persistent_clock64(struct timespec64 *ts)
 {
 	long long nsecs;
 
+	time_travel_set_start();
+
 	if (time_travel_mode != TT_MODE_OFF)
 		nsecs = time_travel_start + time_travel_time;
 	else
@@ -742,25 +773,6 @@ void read_persistent_clock64(struct timespec64 *ts)
 
 void __init time_init(void)
 {
-#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
-	switch (time_travel_mode) {
-	case TT_MODE_EXTERNAL:
-		time_travel_start = time_travel_ext_req(UM_TIMETRAVEL_GET_TOD, -1);
-		/* controller gave us the *current* time, so adjust by that */
-		time_travel_ext_get_time();
-		time_travel_start -= time_travel_time;
-		break;
-	case TT_MODE_INFCPU:
-	case TT_MODE_BASIC:
-		if (!time_travel_start_set)
-			time_travel_start = os_persistent_clock_emulation();
-		break;
-	case TT_MODE_OFF:
-		/* we just read the host clock with os_persistent_clock_emulation() */
-		break;
-	}
-#endif
-
 	timer_set_signal_handler();
 	late_time_init = um_timer_setup;
 }

arch/um/kernel/tlb.c

@@ -608,57 +608,3 @@ void force_flush_all(void)
 		vma = vma->vm_next;
 	}
 }
-
-struct page_change_data {
-	unsigned int set_mask, clear_mask;
-};
-
-static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
-{
-	struct page_change_data *cdata = data;
-	pte_t pte = READ_ONCE(*ptep);
-
-	pte_clear_bits(pte, cdata->clear_mask);
-	pte_set_bits(pte, cdata->set_mask);
-
-	set_pte(ptep, pte);
-	return 0;
-}
-
-static int change_memory(unsigned long start, unsigned long pages,
-			 unsigned int set_mask, unsigned int clear_mask)
-{
-	unsigned long size = pages * PAGE_SIZE;
-	struct page_change_data data;
-	int ret;
-
-	data.set_mask = set_mask;
-	data.clear_mask = clear_mask;
-
-	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
-				  &data);
-
-	flush_tlb_kernel_range(start, start + size);
-
-	return ret;
-}
-
-int set_memory_ro(unsigned long addr, int numpages)
-{
-	return change_memory(addr, numpages, 0, _PAGE_RW);
-}
-
-int set_memory_rw(unsigned long addr, int numpages)
-{
-	return change_memory(addr, numpages, _PAGE_RW, 0);
-}
-
-int set_memory_nx(unsigned long addr, int numpages)
-{
-	return -EOPNOTSUPP;
-}
-
-int set_memory_x(unsigned long addr, int numpages)
-{
-	return -EOPNOTSUPP;
-}

arch/um/kernel/um_arch.c

@@ -26,7 +26,8 @@
 #include <mem_user.h>
 #include <os.h>
 
-#define DEFAULT_COMMAND_LINE "root=98:0"
+#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
+#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty"
 
 /* Changed in add_arg and setup_arch, which run before SMP is started */
 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
@@ -109,7 +110,8 @@ unsigned long end_vm;
 int ncpus = 1;
 
 /* Set in early boot */
-static int have_root __initdata = 0;
+static int have_root __initdata;
+static int have_console __initdata;
 
 /* Set in uml_mem_setup and modified in linux_main */
 long long physmem_size = 32 * 1024 * 1024;
@@ -161,6 +163,17 @@ __uml_setup("debug", no_skas_debug_setup,
 "    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;
@@ -264,7 +277,10 @@ int __init linux_main(int argc, char **argv)
 			add_arg(argv[i]);
 	}
 	if (have_root == 0)
-		add_arg(DEFAULT_COMMAND_LINE);
+		add_arg(DEFAULT_COMMAND_LINE_ROOT);
+
+	if (have_console == 0)
+		add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
 
 	host_task_size = os_get_top_address();
 	/*

arch/um/os-Linux/helper.c

@@ -45,7 +45,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 	unsigned long stack, sp;
 	int pid, fds[2], ret, n;
 
-	stack = alloc_stack(__cant_sleep());
+	stack = alloc_stack(0, __cant_sleep());
 	if (stack == 0)
 		return -ENOMEM;
 
@@ -116,7 +116,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
 	unsigned long stack, sp;
 	int pid, status, err;
 
-	stack = alloc_stack(__cant_sleep());
+	stack = alloc_stack(0, __cant_sleep());
 	if (stack == 0)
 		return -ENOMEM;
 

arch/um/os-Linux/time.c

@@ -104,5 +104,18 @@ long long os_nsecs(void)
  */
 void os_idle_sleep(void)
 {
-	pause();
+	struct itimerspec its;
+	sigset_t set, old;
+
+	/* block SIGALRM while we analyze the timer state */
+	sigemptyset(&set);
+	sigaddset(&set, SIGALRM);
+	sigprocmask(SIG_BLOCK, &set, &old);
+
+	/* check the timer, and if it'll fire then wait for it */
+	timer_gettime(event_high_res_timer, &its);
+	if (its.it_value.tv_sec || its.it_value.tv_nsec)
+		sigsuspend(&old);
+	/* either way, restore the signal mask */
+	sigprocmask(SIG_UNBLOCK, &set, NULL);
 }