Merge branch 'linus' into cpus4096

Conflicts:

	arch/x86/xen/smp.c
	kernel/sched_rt.c
	net/iucv/iucv.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

lib/Kconfig.debug

@@ -419,7 +419,6 @@ config DEBUG_LOCKING_API_SELFTESTS
 
 config STACKTRACE
 	bool
-	depends on DEBUG_KERNEL
 	depends on STACKTRACE_SUPPORT
 
 config DEBUG_KOBJECT
@@ -531,16 +530,34 @@ config BOOT_PRINTK_DELAY
 config RCU_TORTURE_TEST
 	tristate "torture tests for RCU"
 	depends on DEBUG_KERNEL
-	depends on m
 	default n
 	help
 	  This option provides a kernel module that runs torture tests
 	  on the RCU infrastructure.  The kernel module may be built
 	  after the fact on the running kernel to be tested, if desired.
 
+	  Say Y here if you want RCU torture tests to be built into
+	  the kernel.
 	  Say M if you want the RCU torture tests to build as a module.
 	  Say N if you are unsure.
 
+config RCU_TORTURE_TEST_RUNNABLE
+	bool "torture tests for RCU runnable by default"
+	depends on RCU_TORTURE_TEST = y
+	default n
+	help
+	  This option provides a way to build the RCU torture tests
+	  directly into the kernel without them starting up at boot
+	  time.  You can use /proc/sys/kernel/rcutorture_runnable
+	  to manually override this setting.  This /proc file is
+	  available only when the RCU torture tests have been built
+	  into the kernel.
+
+	  Say Y here if you want the RCU torture tests to start during
+	  boot (you probably don't).
+	  Say N here if you want the RCU torture tests to start only
+	  after being manually enabled via /proc.
+
 config KPROBES_SANITY_TEST
 	bool "Kprobes sanity tests"
 	depends on DEBUG_KERNEL
@@ -563,6 +580,9 @@ config BACKTRACE_SELF_TEST
 	  for distributions or general kernels, but only for kernel
 	  developers working on architecture code.
 
+	  Note that if you want to also test saved backtraces, you will
+	  have to enable STACKTRACE as well.
+
 	  Say N if you are unsure.
 
 config LKDTM
@@ -634,6 +654,8 @@ config LATENCYTOP
 	  Enable this option if you want to use the LatencyTOP tool
 	  to find out which userspace is blocking on what kernel operations.
 
+source kernel/trace/Kconfig
+
 config PROVIDE_OHCI1394_DMA_INIT
 	bool "Remote debugging over FireWire early on boot"
 	depends on PCI && X86

lib/Makefile

@@ -8,6 +8,15 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 sha1.o irq_regs.o reciprocal_div.o argv_split.o \
 	 proportions.o prio_heap.o ratelimit.o
 
+ifdef CONFIG_FTRACE
+# Do not profile string.o, since it may be used in early boot or vdso
+CFLAGS_REMOVE_string.o = -pg
+# Also do not profile any debug utilities
+CFLAGS_REMOVE_spinlock_debug.o = -pg
+CFLAGS_REMOVE_list_debug.o = -pg
+CFLAGS_REMOVE_debugobjects.o = -pg
+endif
+
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 

lib/percpu_counter.c

@@ -52,7 +52,7 @@ EXPORT_SYMBOL(__percpu_counter_add);
  * Add up all the per-cpu counts, return the result.  This is a more accurate
  * but much slower version of percpu_counter_read_positive()
  */
-s64 __percpu_counter_sum(struct percpu_counter *fbc)
+s64 __percpu_counter_sum(struct percpu_counter *fbc, int set)
 {
 	s64 ret;
 	int cpu;
@@ -62,7 +62,12 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
 	for_each_online_cpu(cpu) {
 		s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
 		ret += *pcount;
+		if (set)
+			*pcount = 0;
 	}
+	if (set)
+		fbc->count = ret;
+
 	spin_unlock(&fbc->lock);
 	return ret;
 }

lib/smp_processor_id.c

@@ -7,7 +7,7 @@
 #include <linux/kallsyms.h>
 #include <linux/sched.h>
 
-unsigned int debug_smp_processor_id(void)
+notrace unsigned int debug_smp_processor_id(void)
 {
 	unsigned long preempt_count = preempt_count();
 	int this_cpu = raw_smp_processor_id();
@@ -37,7 +37,7 @@ unsigned int debug_smp_processor_id(void)
 	/*
 	 * Avoid recursion:
 	 */
-	preempt_disable();
+	preempt_disable_notrace();
 
 	if (!printk_ratelimit())
 		goto out_enable;
@@ -49,7 +49,7 @@ unsigned int debug_smp_processor_id(void)
 	dump_stack();
 
 out_enable:
-	preempt_enable_no_resched();
+	preempt_enable_no_resched_notrace();
 out:
 	return this_cpu;
 }

lib/textsearch.c

@@ -97,6 +97,7 @@
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/init.h>
+#include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/err.h>
 #include <linux/textsearch.h>

lib/vsprintf.c

@@ -22,6 +22,8 @@
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/kernel.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
 
 #include <asm/page.h>		/* for PAGE_SIZE */
 #include <asm/div64.h>
@@ -482,6 +484,89 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
 	return buf;
 }
 
+static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
+{
+	int len, i;
+
+	if ((unsigned long)s < PAGE_SIZE)
+		s = "<NULL>";
+
+	len = strnlen(s, precision);
+
+	if (!(flags & LEFT)) {
+		while (len < field_width--) {
+			if (buf < end)
+				*buf = ' ';
+			++buf;
+		}
+	}
+	for (i = 0; i < len; ++i) {
+		if (buf < end)
+			*buf = *s;
+		++buf; ++s;
+	}
+	while (len < field_width--) {
+		if (buf < end)
+			*buf = ' ';
+		++buf;
+	}
+	return buf;
+}
+
+static inline void *dereference_function_descriptor(void *ptr)
+{
+#if defined(CONFIG_IA64) || defined(CONFIG_PPC64)
+	void *p;
+	if (!probe_kernel_address(ptr, p))
+		ptr = p;
+#endif
+	return ptr;
+}
+
+static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
+{
+	unsigned long value = (unsigned long) ptr;
+#ifdef CONFIG_KALLSYMS
+	char sym[KSYM_SYMBOL_LEN];
+	sprint_symbol(sym, value);
+	return string(buf, end, sym, field_width, precision, flags);
+#else
+	field_width = 2*sizeof(void *);
+	flags |= SPECIAL | SMALL | ZEROPAD;
+	return number(buf, end, value, 16, field_width, precision, flags);
+#endif
+}
+
+/*
+ * Show a '%p' thing.  A kernel extension is that the '%p' is followed
+ * by an extra set of alphanumeric characters that are extended format
+ * specifiers.
+ *
+ * Right now we just handle 'F' (for symbolic Function descriptor pointers)
+ * and 'S' (for Symbolic direct pointers), but this can easily be
+ * extended in the future (network address types etc).
+ *
+ * The difference between 'S' and 'F' is that on ia64 and ppc64 function
+ * pointers are really function descriptors, which contain a pointer the
+ * real address. 
+ */
+static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
+{
+	switch (*fmt) {
+	case 'F':
+		ptr = dereference_function_descriptor(ptr);
+		/* Fallthrough */
+	case 'S':
+		return symbol_string(buf, end, ptr, field_width, precision, flags);
+	}
+	flags |= SMALL;
+	if (field_width == -1) {
+		field_width = 2*sizeof(void *);
+		flags |= ZEROPAD;
+	}
+	return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
+}
+
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
@@ -502,11 +587,9 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
  */
 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 {
-	int len;
 	unsigned long long num;
-	int i, base;
+	int base;
 	char *str, *end, c;
-	const char *s;
 
 	int flags;		/* flags to number() */
 
@@ -622,43 +705,18 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 				continue;
 
 			case 's':
-				s = va_arg(args, char *);
-				if ((unsigned long)s < PAGE_SIZE)
-					s = "<NULL>";
-
-				len = strnlen(s, precision);
-
-				if (!(flags & LEFT)) {
-					while (len < field_width--) {
-						if (str < end)
-							*str = ' ';
-						++str;
-					}
-				}
-				for (i = 0; i < len; ++i) {
-					if (str < end)
-						*str = *s;
-					++str; ++s;
-				}
-				while (len < field_width--) {
-					if (str < end)
-						*str = ' ';
-					++str;
-				}
+				str = string(str, end, va_arg(args, char *), field_width, precision, flags);
 				continue;
 
 			case 'p':
-				flags |= SMALL;
-				if (field_width == -1) {
-					field_width = 2*sizeof(void *);
-					flags |= ZEROPAD;
-				}
-				str = number(str, end,
-						(unsigned long) va_arg(args, void *),
-						16, field_width, precision, flags);
+				str = pointer(fmt+1, str, end,
+						va_arg(args, void *),
+						field_width, precision, flags);
+				/* Skip all alphanumeric pointer suffixes */
+				while (isalnum(fmt[1]))
+					fmt++;
 				continue;
 
-
 			case 'n':
 				/* FIXME:
 				* What does C99 say about the overflow case here? */