Merge branch 'linus' into timers/nohz

18 files changed, 76 insertions, 27 deletions

diff --git a/arch/um/Makefile b/arch/um/Makefile
index dbeab15e7bb7..ca40397017b9 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -77,7 +77,6 @@ include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
 KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
 			 -Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
 KBUILD_CFLAGS += $(KERNEL_DEFINES)
-KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
 
 PHONY += linux
 
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 561e373bd850..302cbe504543 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -32,4 +32,11 @@ cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
 # an unresolved reference.
 cflags-y += -ffreestanding
 
+# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
+# a lot more stack due to the lack of sharing of stacklots.  Also, gcc
+# 4.3.0 needs -funit-at-a-time for extern inline functions.
+KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
+			echo $(call cc-option,-fno-unit-at-a-time); \
+			else echo $(call cc-option,-funit-at-a-time); fi ;)
+
 KBUILD_CFLAGS += $(cflags-y)
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 8ed362f93582..a9cd7e77a7ab 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -21,3 +21,6 @@ HEADER_ARCH := x86
 
 LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib64
 LINK-y += -m64
+
+# Do unit-at-a-time unconditionally on x86_64, following the host
+KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index a9ad4bd6d953..d332503fa1be 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -66,6 +66,7 @@ static int harddog_open(struct inode *inode, struct file *file)
 	int err = -EBUSY;
 	char *sock = NULL;
 
+	lock_kernel();
 	spin_lock(&lock);
 	if(timer_alive)
 		goto err;
@@ -82,9 +83,11 @@ static int harddog_open(struct inode *inode, struct file *file)
 
 	timer_alive = 1;
 	spin_unlock(&lock);
+	unlock_kernel();
 	return nonseekable_open(inode, file);
 err:
 	spin_unlock(&lock);
+	unlock_kernel();
 	return err;
 }
 
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index 67b2f55a602f..eb240323c40a 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/arch/um/drivers/mmapper_kern.c
@@ -16,6 +16,7 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include "mem_user.h"
 
@@ -77,6 +78,7 @@ out:
 
 static int mmapper_open(struct inode *inode, struct file *file)
 {
+	cycle_kernel_lock();
 	return 0;
 }
 
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 4949044773ba..6eabb7022a2d 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -7,6 +7,7 @@
  * of the GNU General Public License, incorporated herein by reference.
  */
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/interrupt.h>
@@ -33,6 +34,8 @@ static DECLARE_WAIT_QUEUE_HEAD(host_read_wait);
 
 static int rng_dev_open (struct inode *inode, struct file *filp)
 {
+	cycle_kernel_lock();
+
 	/* enforce read-only access to this chrdev */
 	if ((filp->f_mode & FMODE_READ) == 0)
 		return -EINVAL;
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 44ad1607be2d..b58fb8941d8d 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -49,7 +49,6 @@
 #include "irq_user.h"
 #include "irq_kern.h"
 #include "ubd_user.h"
-#include "kern_util.h"
 #include "os.h"
 #include "mem.h"
 #include "mem_kern.h"
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index e2716ac8889a..db5be46e3e18 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -299,6 +299,6 @@ extern int os_arch_prctl(int pid, int code, unsigned long *addr);
 extern int get_pty(void);
 
 /* sys-$ARCH/task_size.c */
-extern unsigned long os_get_task_size(void);
+extern unsigned long os_get_top_address(void);
 
 #endif
diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index e1062ec36d40..be2d50c3aa95 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -214,8 +214,7 @@ void smp_call_function_slave(int cpu)
 	atomic_inc(&scf_finished);
 }
 
-int smp_call_function(void (*_func)(void *info), void *_info, int nonatomic,
-		      int wait)
+int smp_call_function(void (*_func)(void *info), void *_info, int wait)
 {
 	int cpus = num_online_cpus() - 1;
 	int i;
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 9db85b2ce698..8d84250324b3 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -274,7 +274,7 @@ int __init linux_main(int argc, char **argv)
 	if (have_root == 0)
 		add_arg(DEFAULT_COMMAND_LINE);
 
-	host_task_size = os_get_task_size();
+	host_task_size = os_get_top_address();
 	/*
 	 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
 	 * out
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 74ca7aabf4e1..30860b89ec58 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -7,6 +7,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <sched.h>
+#include <linux/limits.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
 #include "kern_constants.h"
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 6be028ca1817..172ad8f72e12 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -55,7 +55,7 @@ static int ptrace_dump_regs(int pid)
  * Signals that are OK to receive in the stub - we'll just continue it.
  * SIGWINCH will happen when UML is inside a detached screen.
  */
-#define STUB_SIG_MASK (1 << SIGVTALRM)
+#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH))
 
 /* Signals that the stub will finish with - anything else is an error */
 #define STUB_DONE_MASK (1 << SIGTRAP)
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index b4b36e0f2e89..183db26d01bf 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -121,8 +121,10 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit)
 {
 	int status, n, ret = 0;
 
-	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		fatal_perror("stop_ptraced_child : ptrace failed");
+	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
+		perror("stop_ptraced_child : ptrace failed");
+		return -1;
+	}
 	CATCH_EINTR(n = waitpid(pid, &status, 0));
 	if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
 		int exit_with = WEXITSTATUS(status);
@@ -212,7 +214,7 @@ static void __init check_sysemu(void)
 	if (n < 0)
 		fatal_perror("check_sysemu : wait failed");
 	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-		fatal("check_sysemu : expected SIGTRAP, got status = %d",
+		fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
 		      status);
 
 	if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
@@ -254,9 +256,11 @@ static void __init check_sysemu(void)
 
 		if (WIFSTOPPED(status) &&
 		    (WSTOPSIG(status) == (SIGTRAP|0x80))) {
-			if (!count)
-				fatal("check_ptrace : SYSEMU_SINGLESTEP "
-				      "doesn't singlestep");
+			if (!count) {
+				non_fatal("check_ptrace : SYSEMU_SINGLESTEP "
+					  "doesn't singlestep");
+				goto fail;
+			}
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 				   os_getpid());
 			if (n < 0)
@@ -266,9 +270,12 @@ static void __init check_sysemu(void)
 		}
 		else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
 			count++;
-		else
-			fatal("check_ptrace : expected SIGTRAP or "
-			      "(SIGTRAP | 0x80), got status = %d", status);
+		else {
+			non_fatal("check_ptrace : expected SIGTRAP or "
+				  "(SIGTRAP | 0x80), got status = %d\n",
+				  status);
+			goto fail;
+		}
 	}
 	if (stop_ptraced_child(pid, 0, 0) < 0)
 		goto fail_stopped;
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index b487cbead1bd..229f7a53d8da 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -6,7 +6,7 @@
 
 #include <errno.h>
 #include <sys/ptrace.h>
-#include <asm/user.h>
+#include <sys/user.h>
 #include "kern_constants.h"
 #include "longjmp.h"
 #include "user.h"
@@ -76,7 +76,7 @@ int put_fp_registers(int pid, unsigned long *regs)
 
 void arch_init_registers(int pid)
 {
-	struct user_fxsr_struct fpx_regs;
+	struct user_fpxregs_struct fpx_regs;
 	int err;
 
 	err = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpx_regs);
diff --git a/arch/um/os-Linux/sys-i386/task_size.c b/arch/um/os-Linux/sys-i386/task_size.c
index ccb49b0aff59..be04c1e183bf 100644
--- a/arch/um/os-Linux/sys-i386/task_size.c
+++ b/arch/um/os-Linux/sys-i386/task_size.c
@@ -63,7 +63,7 @@ static int page_ok(unsigned long page)
 	return ok;
 }
 
-unsigned long os_get_task_size(void)
+unsigned long os_get_top_address(void)
 {
 	struct sigaction sa, old;
 	unsigned long bottom = 0;
@@ -76,9 +76,9 @@ unsigned long os_get_task_size(void)
 	 * hosts, but shouldn't hurt otherwise.
 	 */
 	unsigned long top = 0xffffd000 >> UM_KERN_PAGE_SHIFT;
-	unsigned long test;
+	unsigned long test, original;
 
-	printf("Locating the top of the address space ... ");
+	printf("Locating the bottom of the address space ... ");
 	fflush(stdout);
 
 	/*
@@ -89,16 +89,31 @@ unsigned long os_get_task_size(void)
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_NODEFER;
 	if (sigaction(SIGSEGV, &sa, &old)) {
-		perror("os_get_task_size");
+		perror("os_get_top_address");
 		exit(1);
 	}
 
-	if (!page_ok(bottom)) {
-		fprintf(stderr, "Address 0x%x no good?\n",
-			bottom << UM_KERN_PAGE_SHIFT);
+	/* Manually scan the address space, bottom-up, until we find
+	 * the first valid page (or run out of them).
+	 */
+	for (bottom = 0; bottom < top; bottom++) {
+		if (page_ok(bottom))
+			break;
+	}
+
+	/* If we've got this far, we ran out of pages. */
+	if (bottom == top) {
+		fprintf(stderr, "Unable to determine bottom of address "
+			"space.\n");
 		exit(1);
 	}
 
+	printf("0x%x\n", bottom << UM_KERN_PAGE_SHIFT);
+	printf("Locating the top of the address space ... ");
+	fflush(stdout);
+
+	original = bottom;
+
 	/* This could happen with a 4G/4G split */
 	if (page_ok(top))
 		goto out;
@@ -114,7 +129,7 @@ unsigned long os_get_task_size(void)
 out:
 	/* Restore the old SIGSEGV handling */
 	if (sigaction(SIGSEGV, &old, NULL)) {
-		perror("os_get_task_size");
+		perror("os_get_top_address");
 		exit(1);
 	}
 	top <<= UM_KERN_PAGE_SHIFT;
diff --git a/arch/um/os-Linux/sys-x86_64/task_size.c b/arch/um/os-Linux/sys-x86_64/task_size.c
index fad6f57f8ee3..26a0dd1f349c 100644
--- a/arch/um/os-Linux/sys-x86_64/task_size.c
+++ b/arch/um/os-Linux/sys-x86_64/task_size.c
@@ -1,4 +1,4 @@
-unsigned long os_get_task_size(unsigned long shift)
+unsigned long os_get_top_address(unsigned long shift)
 {
 	/* The old value of CONFIG_TOP_ADDR */
 	return 0x7fc0000000;
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index bee98f466d66..dec5678fc17f 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -106,6 +106,10 @@ static void deliver_alarm(void)
 	unsigned long long this_tick = os_nsecs();
 	int one_tick = UM_NSEC_PER_SEC / UM_HZ;
 
+	/* Protection against the host's time going backwards */
+	if ((last_tick != 0) && (this_tick < last_tick))
+		this_tick = last_tick;
+
 	if (last_tick == 0)
 		last_tick = this_tick - one_tick;
 
@@ -148,6 +152,9 @@ static int after_sleep_interval(struct timespec *ts)
 		start_usecs = usec;
 
 	start_usecs -= skew / UM_NSEC_PER_USEC;
+	if (start_usecs < 0)
+		start_usecs = 0;
+
 	tv = ((struct timeval) { .tv_sec  = start_usecs / UM_USEC_PER_SEC,
 				 .tv_usec = start_usecs % UM_USEC_PER_SEC });
 	interval = ((struct itimerval) { { 0, usec }, tv });
diff --git a/arch/um/sys-x86_64/ksyms.c b/arch/um/sys-x86_64/ksyms.c
index 6604673a849d..1db2fce00948 100644
--- a/arch/um/sys-x86_64/ksyms.c
+++ b/arch/um/sys-x86_64/ksyms.c
@@ -3,5 +3,9 @@
 #include <asm/checksum.h>
 
 /*XXX: we need them because they would be exported by x86_64 */
+#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
+EXPORT_SYMBOL(memcpy);
+#else
 EXPORT_SYMBOL(__memcpy);
+#endif
 EXPORT_SYMBOL(csum_partial);