Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a bit more MM

 - procfs updates

 - dynamic-debug fixes

 - lib/ updates

 - checkpatch

 - epoll

 - nilfs2

 - signals

 - rapidio

 - PID management cleanup and optimization

 - kcov updates

 - sysvipc updates

 - quite a few misc things all over the place

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
  EXPERT Kconfig menu: fix broken EXPERT menu
  include/asm-generic/topology.h: remove unused parent_node() macro
  arch/tile/include/asm/topology.h: remove unused parent_node() macro
  arch/sparc/include/asm/topology_64.h: remove unused parent_node() macro
  arch/sh/include/asm/topology.h: remove unused parent_node() macro
  arch/ia64/include/asm/topology.h: remove unused parent_node() macro
  drivers/pcmcia/sa1111_badge4.c: avoid unused function warning
  mm: add infrastructure for get_user_pages_fast() benchmarking
  sysvipc: make get_maxid O(1) again
  sysvipc: properly name ipc_addid() limit parameter
  sysvipc: duplicate lock comments wrt ipc_addid()
  sysvipc: unteach ids->next_id for !CHECKPOINT_RESTORE
  initramfs: use time64_t timestamps
  drivers/watchdog: make use of devm_register_reboot_notifier()
  kernel/reboot.c: add devm_register_reboot_notifier()
  kcov: update documentation
  Makefile: support flag -fsanitizer-coverage=trace-cmp
  kcov: support comparison operands collection
  kcov: remove pointless current != NULL check
  kernel/panic.c: add TAINT_AUX
  ...

Documentation/admin-guide/dynamic-debug-howto.rst

@@ -18,7 +18,7 @@ shortcut for ``print_hex_dump(KERN_DEBUG)``.
 
 For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
 its ``prefix_str`` argument, if it is constant string; or ``hexdump``
-in case ``prefix_str`` is build dynamically.
+in case ``prefix_str`` is built dynamically.
 
 Dynamic debug has even more useful features:
 
@@ -197,8 +197,8 @@ line
     line number matches the callsite line number exactly.  A
     range of line numbers matches any callsite between the first
     and last line number inclusive.  An empty first number means
-    the first line in the file, an empty line number means the
-    last number in the file.  Examples::
+    the first line in the file, an empty last line number means the
+    last line number in the file.  Examples::
 
 	line 1603           // exactly line 1603
 	line 1600-1605      // the six lines from line 1600 to line 1605

Documentation/clearing-warn-once.txt

@@ -0,0 +1,7 @@
+
+WARN_ONCE / WARN_ON_ONCE only print a warning once.
+
+echo 1 > /sys/kernel/debug/clear_warn_once
+
+clears the state and allows the warnings to print once again.
+This can be useful after test suite runs to reproduce problems.

Documentation/dev-tools/kcov.rst

@@ -12,19 +12,30 @@ To achieve this goal it does not collect coverage in soft/hard interrupts
 and instrumentation of some inherently non-deterministic parts of kernel is
 disabled (e.g. scheduler, locking).
 
-Usage
------
+kcov is also able to collect comparison operands from the instrumented code
+(this feature currently requires that the kernel is compiled with clang).
+
+Prerequisites
+-------------
 
 Configure the kernel with::
 
         CONFIG_KCOV=y
 
 CONFIG_KCOV requires gcc built on revision 231296 or later.
+
+If the comparison operands need to be collected, set::
+
+	CONFIG_KCOV_ENABLE_COMPARISONS=y
+
 Profiling data will only become accessible once debugfs has been mounted::
 
         mount -t debugfs none /sys/kernel/debug
 
-The following program demonstrates kcov usage from within a test program:
+Coverage collection
+-------------------
+The following program demonstrates coverage collection from within a test
+program using kcov:
 
 .. code-block:: c
 
@@ -44,6 +55,9 @@ The following program demonstrates kcov usage from within a test program:
     #define KCOV_DISABLE			_IO('c', 101)
     #define COVER_SIZE			(64<<10)
 
+    #define KCOV_TRACE_PC  0
+    #define KCOV_TRACE_CMP 1
+
     int main(int argc, char **argv)
     {
 	int fd;
@@ -64,7 +78,7 @@ The following program demonstrates kcov usage from within a test program:
 	if ((void*)cover == MAP_FAILED)
 		perror("mmap"), exit(1);
 	/* Enable coverage collection on the current thread. */
-	if (ioctl(fd, KCOV_ENABLE, 0))
+	if (ioctl(fd, KCOV_ENABLE, KCOV_TRACE_PC))
 		perror("ioctl"), exit(1);
 	/* Reset coverage from the tail of the ioctl() call. */
 	__atomic_store_n(&cover[0], 0, __ATOMIC_RELAXED);
@@ -111,3 +125,80 @@ The interface is fine-grained to allow efficient forking of test processes.
 That is, a parent process opens /sys/kernel/debug/kcov, enables trace mode,
 mmaps coverage buffer and then forks child processes in a loop. Child processes
 only need to enable coverage (disable happens automatically on thread end).
+
+Comparison operands collection
+------------------------------
+Comparison operands collection is similar to coverage collection:
+
+.. code-block:: c
+
+    /* Same includes and defines as above. */
+
+    /* Number of 64-bit words per record. */
+    #define KCOV_WORDS_PER_CMP 4
+
+    /*
+     * The format for the types of collected comparisons.
+     *
+     * Bit 0 shows whether one of the arguments is a compile-time constant.
+     * Bits 1 & 2 contain log2 of the argument size, up to 8 bytes.
+     */
+
+    #define KCOV_CMP_CONST          (1 << 0)
+    #define KCOV_CMP_SIZE(n)        ((n) << 1)
+    #define KCOV_CMP_MASK           KCOV_CMP_SIZE(3)
+
+    int main(int argc, char **argv)
+    {
+	int fd;
+	uint64_t *cover, type, arg1, arg2, is_const, size;
+	unsigned long n, i;
+
+	fd = open("/sys/kernel/debug/kcov", O_RDWR);
+	if (fd == -1)
+		perror("open"), exit(1);
+	if (ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE))
+		perror("ioctl"), exit(1);
+	/*
+	* Note that the buffer pointer is of type uint64_t*, because all
+	* the comparison operands are promoted to uint64_t.
+	*/
+	cover = (uint64_t *)mmap(NULL, COVER_SIZE * sizeof(unsigned long),
+				     PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if ((void*)cover == MAP_FAILED)
+		perror("mmap"), exit(1);
+	/* Note KCOV_TRACE_CMP instead of KCOV_TRACE_PC. */
+	if (ioctl(fd, KCOV_ENABLE, KCOV_TRACE_CMP))
+		perror("ioctl"), exit(1);
+	__atomic_store_n(&cover[0], 0, __ATOMIC_RELAXED);
+	read(-1, NULL, 0);
+	/* Read number of comparisons collected. */
+	n = __atomic_load_n(&cover[0], __ATOMIC_RELAXED);
+	for (i = 0; i < n; i++) {
+		type = cover[i * KCOV_WORDS_PER_CMP + 1];
+		/* arg1 and arg2 - operands of the comparison. */
+		arg1 = cover[i * KCOV_WORDS_PER_CMP + 2];
+		arg2 = cover[i * KCOV_WORDS_PER_CMP + 3];
+		/* ip - caller address. */
+		ip = cover[i * KCOV_WORDS_PER_CMP + 4];
+		/* size of the operands. */
+		size = 1 << ((type & KCOV_CMP_MASK) >> 1);
+		/* is_const - true if either operand is a compile-time constant.*/
+		is_const = type & KCOV_CMP_CONST;
+		printf("ip: 0x%lx type: 0x%lx, arg1: 0x%lx, arg2: 0x%lx, "
+			"size: %lu, %s\n",
+			ip, type, arg1, arg2, size,
+		is_const ? "const" : "non-const");
+	}
+	if (ioctl(fd, KCOV_DISABLE, 0))
+		perror("ioctl"), exit(1);
+	/* Free resources. */
+	if (munmap(cover, COVER_SIZE * sizeof(unsigned long)))
+		perror("munmap"), exit(1);
+	if (close(fd))
+		perror("close"), exit(1);
+	return 0;
+    }
+
+Note that the kcov modes (coverage collection or comparison operands) are
+mutually exclusive.

Documentation/filesystems/proc.txt

@@ -181,6 +181,7 @@ read the file /proc/PID/status:
   VmPTE:        20 kb
   VmSwap:        0 kB
   HugetlbPages:          0 kB
+  CoreDumping:    0
   Threads:        1
   SigQ:   0/28578
   SigPnd: 0000000000000000
@@ -253,6 +254,8 @@ Table 1-2: Contents of the status files (as of 4.8)
  VmSwap                      amount of swap used by anonymous private data
                              (shmem swap usage is not included)
  HugetlbPages                size of hugetlb memory portions
+ CoreDumping                 process's memory is currently being dumped
+                             (killing the process may lead to a corrupted core)
  Threads                     number of threads
  SigQ                        number of signals queued/max. number for queue
  SigPnd                      bitmap of pending signals for the thread

Documentation/sysctl/vm.txt

@@ -818,7 +818,7 @@ tooling to work, you can do:
 swappiness
 
 This control is used to define how aggressive the kernel will swap
-memory pages.  Higher values will increase agressiveness, lower values
+memory pages.  Higher values will increase aggressiveness, lower values
 decrease the amount of swap.  A value of 0 instructs the kernel not to
 initiate swap until the amount of free and file-backed pages is less
 than the high water mark in a zone.

Makefile

@@ -375,8 +375,6 @@ CFLAGS_KERNEL	=
 AFLAGS_KERNEL	=
 LDFLAGS_vmlinux =
 CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
-CFLAGS_KCOV	:= $(call cc-option,-fsanitize-coverage=trace-pc,)
-
 
 # Use USERINCLUDE when you must reference the UAPI directories only.
 USERINCLUDE    := \
@@ -659,6 +657,7 @@ ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLA
 	KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
 endif
 
+include scripts/Makefile.kcov
 include scripts/Makefile.gcc-plugins
 
 ifdef CONFIG_READABLE_ASM

arch/ia64/include/asm/topology.h

@@ -33,13 +33,6 @@
 			       cpu_all_mask :				\
 			       &node_to_cpu_mask[node])
 
-/*
- * Returns the number of the node containing Node 'nid'.
- * Not implemented here. Multi-level hierarchies detected with
- * the help of node_distance().
- */
-#define parent_node(nid) (nid)
-
 /*
  * Determines the node for a given pci bus
  */

arch/ia64/kernel/asm-offsets.c

@@ -31,8 +31,8 @@ void foo(void)
 	DEFINE(SIGFRAME_SIZE, sizeof (struct sigframe));
 	DEFINE(UNW_FRAME_INFO_SIZE, sizeof (struct unw_frame_info));
 
-	BUILD_BUG_ON(sizeof(struct upid) != 32);
-	DEFINE(IA64_UPID_SHIFT, 5);
+	BUILD_BUG_ON(sizeof(struct upid) != 16);
+	DEFINE(IA64_UPID_SHIFT, 4);
 
 	BLANK();
 

arch/mn10300/mm/fault.c

@@ -60,7 +60,7 @@ void bust_spinlocks(int yes)
 void do_BUG(const char *file, int line)
 {
 	bust_spinlocks(1);
-	printk(KERN_EMERG "------------[ cut here ]------------\n");
+	printk(KERN_EMERG CUT_HERE);
 	printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
 }
 

arch/powerpc/platforms/cell/spufs/sched.c

@@ -1093,7 +1093,7 @@ static int show_spu_loadavg(struct seq_file *s, void *private)
 		LOAD_INT(c), LOAD_FRAC(c),
 		count_active_contexts(),
 		atomic_read(&nr_spu_contexts),
-		task_active_pid_ns(current)->last_pid);
+		idr_get_cursor(&task_active_pid_ns(current)->idr));
 	return 0;
 }
 

arch/sh/boot/compressed/misc.c

@@ -104,6 +104,18 @@ static void error(char *x)
 	while(1);	/* Halt */
 }
 
+unsigned long __stack_chk_guard;
+
+void __stack_chk_guard_setup(void)
+{
+	__stack_chk_guard = 0x000a0dff;
+}
+
+void __stack_chk_fail(void)
+{
+	error("stack-protector: Kernel stack is corrupted\n");
+}
+
 #ifdef CONFIG_SUPERH64
 #define stackalign	8
 #else
@@ -118,6 +130,8 @@ void decompress_kernel(void)
 {
 	unsigned long output_addr;
 
+	__stack_chk_guard_setup();
+
 #ifdef CONFIG_SUPERH64
 	output_addr = (CONFIG_MEMORY_START + 0x2000);
 #else

arch/sh/include/asm/topology.h

@@ -5,7 +5,6 @@
 #ifdef CONFIG_NUMA
 
 #define cpu_to_node(cpu)	((void)(cpu),0)
-#define parent_node(node)	((void)(node),0)
 
 #define cpumask_of_node(node)	((void)node, cpu_online_mask)
 

arch/sparc/include/asm/topology_64.h

@@ -11,8 +11,6 @@ static inline int cpu_to_node(int cpu)
 	return numa_cpu_lookup_table[cpu];
 }
 
-#define parent_node(node)	(node)
-
 #define cpumask_of_node(node) ((node) == -1 ?				\
 			       cpu_all_mask :				\
 			       &numa_cpumask_lookup_table[node])

arch/tile/include/asm/topology.h

@@ -29,12 +29,6 @@ static inline int cpu_to_node(int cpu)
 	return cpu_2_node[cpu];
 }
 
-/*
- * Returns the number of the node containing Node 'node'.
- * This architecture is flat, so it is a pretty simple function!
- */
-#define parent_node(node) (node)
-
 /* Returns a bitmask of CPUs on Node 'node'. */
 static inline const struct cpumask *cpumask_of_node(int node)
 {

drivers/misc/lkdtm_bugs.c

@@ -63,9 +63,11 @@ void lkdtm_BUG(void)
 	BUG();
 }
 
+static int warn_counter;
+
 void lkdtm_WARNING(void)
 {
-	WARN_ON(1);
+	WARN(1, "Warning message trigger count: %d\n", warn_counter++);
 }
 
 void lkdtm_EXCEPTION(void)

drivers/pcmcia/sa1111_badge4.c

@@ -144,6 +144,7 @@ int pcmcia_badge4_init(struct sa1111_dev *dev)
 				 sa11xx_drv_pcmcia_add_one);
 }
 
+#ifndef MODULE
 static int __init pcmv_setup(char *s)
 {
 	int v[4];
@@ -158,3 +159,4 @@ static int __init pcmv_setup(char *s)
 }
 
 __setup("pcmv=", pcmv_setup);
+#endif

drivers/rapidio/devices/rio_mport_cdev.c

@@ -959,9 +959,10 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 
 	nents = dma_map_sg(chan->device->dev,
 			   req->sgt.sgl, req->sgt.nents, dir);
-	if (nents == -EFAULT) {
+	if (nents == 0) {
 		rmcd_error("Failed to map SG list");
-		return -EFAULT;
+		ret = -EFAULT;
+		goto err_pg;
 	}
 
 	ret = do_dma_request(req, xfer, sync, nents);

drivers/rapidio/switches/idt_gen2.c

@@ -458,7 +458,7 @@ static void idtg2_remove(struct rio_dev *rdev)
 	idtg2_sysfs(rdev, false);
 }
 
-static struct rio_device_id idtg2_id_table[] = {
+static const struct rio_device_id idtg2_id_table[] = {
 	{RIO_DEVICE(RIO_DID_IDTCPS1848, RIO_VID_IDT)},
 	{RIO_DEVICE(RIO_DID_IDTCPS1616, RIO_VID_IDT)},
 	{RIO_DEVICE(RIO_DID_IDTVPS1616, RIO_VID_IDT)},

drivers/rapidio/switches/idt_gen3.c

@@ -348,7 +348,7 @@ static void idtg3_shutdown(struct rio_dev *rdev)
 	}
 }
 
-static struct rio_device_id idtg3_id_table[] = {
+static const struct rio_device_id idtg3_id_table[] = {
 	{RIO_DEVICE(RIO_DID_IDTRXS1632, RIO_VID_IDT)},
 	{RIO_DEVICE(RIO_DID_IDTRXS2448, RIO_VID_IDT)},
 	{ 0, }	/* terminate list */

drivers/rapidio/switches/idtcps.c

@@ -168,7 +168,7 @@ static void idtcps_remove(struct rio_dev *rdev)
 	spin_unlock(&rdev->rswitch->lock);
 }
 
-static struct rio_device_id idtcps_id_table[] = {
+static const struct rio_device_id idtcps_id_table[] = {
 	{RIO_DEVICE(RIO_DID_IDTCPS6Q, RIO_VID_IDT)},
 	{RIO_DEVICE(RIO_DID_IDTCPS8, RIO_VID_IDT)},
 	{RIO_DEVICE(RIO_DID_IDTCPS10Q, RIO_VID_IDT)},