Merge branch 'akpm' (incoming from Andrew)

Merge third batch of fixes from Andrew Morton:
 "Most of the rest.  I still have two large patchsets against AIO and
  IPC, but they're a bit stuck behind other trees and I'm about to
  vanish for six days.

   - random fixlets
   - inotify
   - more of the MM queue
   - show_stack() cleanups
   - DMI update
   - kthread/workqueue things
   - compat cleanups
   - epoll udpates
   - binfmt updates
   - nilfs2
   - hfs
   - hfsplus
   - ptrace
   - kmod
   - coredump
   - kexec
   - rbtree
   - pids
   - pidns
   - pps
   - semaphore tweaks
   - some w1 patches
   - relay updates
   - core Kconfig changes
   - sysrq tweaks"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  Documentation/sysrq: fix inconstistent help message of sysrq key
  ethernet/emac/sysrq: fix inconstistent help message of sysrq key
  sparc/sysrq: fix inconstistent help message of sysrq key
  powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
  ARM/etm/sysrq: fix inconstistent help message of sysrq key
  power/sysrq: fix inconstistent help message of sysrq key
  kgdb/sysrq: fix inconstistent help message of sysrq key
  lib/decompress.c: fix initconst
  notifier-error-inject: fix module names in Kconfig
  kernel/sys.c: make prctl(PR_SET_MM) generally available
  UAPI: remove empty Kbuild files
  menuconfig: print more info for symbol without prompts
  init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
  kconfig menu: move Virtualization drivers near other virtualization options
  Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
  relay: use macro PAGE_ALIGN instead of FIX_SIZE
  kernel/relay.c: move FIX_SIZE macro into relay.c
  kernel/relay.c: remove unused function argument actor
  drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
  drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
  ...

9 files changed, 291 insertions, 54 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 28be08c09bab..566cf2bc08ea 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1192,7 +1192,7 @@ config MEMORY_NOTIFIER_ERROR_INJECT
           bash: echo: write error: Cannot allocate memory
 
           To compile this code as a module, choose M here: the module will
-          be called pSeries-reconfig-notifier-error-inject.
+          be called memory-notifier-error-inject.
 
           If unsure, say N.
 
@@ -1209,7 +1209,7 @@ config OF_RECONFIG_NOTIFIER_ERROR_INJECT
           notified, write the error code to "actions/<notifier event>/error".
 
           To compile this code as a module, choose M here: the module will
-          be called memory-notifier-error-inject.
+          be called of-reconfig-notifier-error-inject.
 
           If unsure, say N.
 
@@ -1292,6 +1292,24 @@ config LATENCYTOP
           Enable this option if you want to use the LatencyTOP tool
           to find out which userspace is blocking on what kernel operations.
 
+config ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+        bool
+
+config DEBUG_STRICT_USER_COPY_CHECKS
+        bool "Strict user copy size checks"
+        depends on ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+        depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
+        help
+          Enabling this option turns a certain set of sanity checks for user
+          copy operations into compile time failures.
+
+          The copy_from_user() etc checks are there to help test if there
+          are sufficient security checks on the length argument of
+          the copy operation, by having gcc prove that the argument is
+          within bounds.
+
+          If unsure, say N.
+
 source mm/Kconfig.debug
 source kernel/trace/Kconfig
 
@@ -1463,5 +1481,8 @@ source "lib/Kconfig.kgdb"
 
 source "lib/Kconfig.kmemcheck"
 
+config TEST_STRING_HELPERS
+        tristate "Test functions located in the string_helpers module at runtime"
+
 config TEST_KSTRTOX
         tristate "Test kstrto*() family of functions at runtime"
diff --git a/lib/Makefile b/lib/Makefile
index 6e2cc561f761..e9c52e1b853a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,6 +15,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
          is_single_threaded.o plist.o decompress.o kobject_uevent.o \
          earlycpio.o
 
+obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 
@@ -22,8 +23,10 @@ lib-y	+= kobject.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
          bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
-         string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \
+         gcd.o lcm.o list_sort.o uuid.o flex_array.o \
          bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o
+obj-y += string_helpers.o
+obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
 obj-y += kstrtox.o
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 
diff --git a/lib/decompress.c b/lib/decompress.c
index 31a804277282..f8fdedaf7b3d 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -38,7 +38,7 @@ struct compress_format {
         decompress_fn decompressor;
 };
 
-static const struct compress_format compressed_formats[] __initdata = {
+static const struct compress_format compressed_formats[] __initconst = {
         { {037, 0213}, "gzip", gunzip },
         { {037, 0236}, "gzip", gunzip },
         { {0x42, 0x5a}, "bzip2", bunzip2 },
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 42f4f55c9458..53bad099ebd6 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -5,11 +5,16 @@
 
 #include <linux/kernel.h>
 #include <linux/export.h>
+#include <linux/sched.h>
 
+/**
+ * dump_stack - dump the current task information and its stack trace
+ *
+ * Architectures can override this implementation by implementing its own.
+ */
 void dump_stack(void)
 {
-        printk(KERN_NOTICE
-                "This architecture does not implement dump_stack()\n");
+        dump_stack_print_info(KERN_DEFAULT);
+        show_stack(NULL, NULL);
 }
-
 EXPORT_SYMBOL(dump_stack);
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 46032453abd5..99fec3ae405a 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -24,6 +24,7 @@
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
 #include <linux/string.h>
+#include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 #include <linux/dynamic_debug.h>
 #include <linux/debugfs.h>
@@ -276,47 +277,6 @@ static inline int parse_lineno(const char *str, unsigned int *val)
         return 0;
 }
 
-/*
- * Undo octal escaping in a string, inplace.  This is useful to
- * allow the user to express a query which matches a format
- * containing embedded spaces.
- */
-static char *unescape(char *str)
-{
-        char *in = str;
-        char *out = str;
-
-        while (*in) {
-                if (*in == '\\') {
-                        if (in[1] == '\\') {
-                                *out++ = '\\';
-                                in += 2;
-                                continue;
-                        } else if (in[1] == 't') {
-                                *out++ = '\t';
-                                in += 2;
-                                continue;
-                        } else if (in[1] == 'n') {
-                                *out++ = '\n';
-                                in += 2;
-                                continue;
-                        } else if (isodigit(in[1]) &&
-                                   isodigit(in[2]) &&
-                                   isodigit(in[3])) {
-                                *out++ = (((in[1] - '0') << 6) |
-                                          ((in[2] - '0') << 3) |
-                                          (in[3] - '0'));
-                                in += 4;
-                                continue;
-                        }
-                }
-                *out++ = *in++;
-        }
-        *out = '\0';
-
-        return str;
-}
-
 static int check_set(const char **dest, char *src, char *name)
 {
         int rc = 0;
@@ -370,8 +330,10 @@ static int ddebug_parse_query(char *words[], int nwords,
                 } else if (!strcmp(words[i], "module")) {
                         rc = check_set(&query->module, words[i+1], "module");
                 } else if (!strcmp(words[i], "format")) {
-                        rc = check_set(&query->format, unescape(words[i+1]),
-                                       "format");
+                        string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
+                                                            UNESCAPE_OCTAL |
+                                                            UNESCAPE_SPECIAL);
+                        rc = check_set(&query->format, words[i+1], "format");
                 } else if (!strcmp(words[i], "line")) {
                         char *first = words[i+1];
                         char *last = strchr(first, '-');
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index af38aedbd874..122f02f9941b 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -117,8 +117,7 @@ static int black_path_count(struct rb_node *rb)
 static void check(int nr_nodes)
 {
         struct rb_node *rb;
-        int count = 0;
-        int blacks = 0;
+        int count = 0, blacks = 0;
         u32 prev_key = 0;
 
         for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
@@ -134,7 +133,9 @@ static void check(int nr_nodes)
                 prev_key = node->key;
                 count++;
         }
+
         WARN_ON_ONCE(count != nr_nodes);
+        WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root))) - 1);
 }
 
 static void check_augmented(int nr_nodes)
@@ -148,7 +149,7 @@ static void check_augmented(int nr_nodes)
         }
 }
 
-static int rbtree_test_init(void)
+static int __init rbtree_test_init(void)
 {
         int i, j;
         cycles_t time1, time2, time;
@@ -221,7 +222,7 @@ static int rbtree_test_init(void)
         return -EAGAIN; /* Fail will directly unload the module */
 }
 
-static void rbtree_test_exit(void)
+static void __exit rbtree_test_exit(void)
 {
         printk(KERN_ALERT "test exit\n");
 }
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 1cffc223bff5..ed5c1454dd62 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -2,10 +2,12 @@
  * Helpers for formatting and printing strings
  *
  * Copyright 31 August 2008 James Bottomley
+ * Copyright (C) 2013, Intel Corporation
  */
 #include <linux/kernel.h>
 #include <linux/math64.h>
 #include <linux/export.h>
+#include <linux/ctype.h>
 #include <linux/string_helpers.h>
 
 /**
@@ -66,3 +68,134 @@ int string_get_size(u64 size, const enum string_size_units units,
         return 0;
 }
 EXPORT_SYMBOL(string_get_size);
+
+static bool unescape_space(char **src, char **dst)
+{
+        char *p = *dst, *q = *src;
+
+        switch (*q) {
+        case 'n':
+                *p = '\n';
+                break;
+        case 'r':
+                *p = '\r';
+                break;
+        case 't':
+                *p = '\t';
+                break;
+        case 'v':
+                *p = '\v';
+                break;
+        case 'f':
+                *p = '\f';
+                break;
+        default:
+                return false;
+        }
+        *dst += 1;
+        *src += 1;
+        return true;
+}
+
+static bool unescape_octal(char **src, char **dst)
+{
+        char *p = *dst, *q = *src;
+        u8 num;
+
+        if (isodigit(*q) == 0)
+                return false;
+
+        num = (*q++) & 7;
+        while (num < 32 && isodigit(*q) && (q - *src < 3)) {
+                num <<= 3;
+                num += (*q++) & 7;
+        }
+        *p = num;
+        *dst += 1;
+        *src = q;
+        return true;
+}
+
+static bool unescape_hex(char **src, char **dst)
+{
+        char *p = *dst, *q = *src;
+        int digit;
+        u8 num;
+
+        if (*q++ != 'x')
+                return false;
+
+        num = digit = hex_to_bin(*q++);
+        if (digit < 0)
+                return false;
+
+        digit = hex_to_bin(*q);
+        if (digit >= 0) {
+                q++;
+                num = (num << 4) | digit;
+        }
+        *p = num;
+        *dst += 1;
+        *src = q;
+        return true;
+}
+
+static bool unescape_special(char **src, char **dst)
+{
+        char *p = *dst, *q = *src;
+
+        switch (*q) {
+        case '\"':
+                *p = '\"';
+                break;
+        case '\\':
+                *p = '\\';
+                break;
+        case 'a':
+                *p = '\a';
+                break;
+        case 'e':
+                *p = '\e';
+                break;
+        default:
+                return false;
+        }
+        *dst += 1;
+        *src += 1;
+        return true;
+}
+
+int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
+{
+        char *out = dst;
+
+        while (*src && --size) {
+                if (src[0] == '\\' && src[1] != '\0' && size > 1) {
+                        src++;
+                        size--;
+
+                        if (flags & UNESCAPE_SPACE &&
+                                        unescape_space(&src, &out))
+                                continue;
+
+                        if (flags & UNESCAPE_OCTAL &&
+                                        unescape_octal(&src, &out))
+                                continue;
+
+                        if (flags & UNESCAPE_HEX &&
+                                        unescape_hex(&src, &out))
+                                continue;
+
+                        if (flags & UNESCAPE_SPECIAL &&
+                                        unescape_special(&src, &out))
+                                continue;
+
+                        *out++ = '\\';
+                }
+                *out++ = *src++;
+        }
+        *out = '\0';
+
+        return out - dst;
+}
+EXPORT_SYMBOL(string_unescape);
diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
new file mode 100644
index 000000000000..6ac48de04c0e
--- /dev/null
+++ b/lib/test-string_helpers.c
@@ -0,0 +1,103 @@
+/*
+ * Test cases for lib/string_helpers.c module.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/string.h>
+#include <linux/string_helpers.h>
+
+struct test_string {
+        const char *in;
+        const char *out;
+        unsigned int flags;
+};
+
+static const struct test_string strings[] __initconst = {
+        {
+                .in = "\\f\\ \\n\\r\\t\\v",
+                .out = "\f\\ \n\r\t\v",
+                .flags = UNESCAPE_SPACE,
+        },
+        {
+                .in = "\\40\\1\\387\\0064\\05\\040\\8a\\110\\777",
+                .out = " \001\00387\0064\005 \\8aH?7",
+                .flags = UNESCAPE_OCTAL,
+        },
+        {
+                .in = "\\xv\\xa\\x2c\\xD\\x6f2",
+                .out = "\\xv\n,\ro2",
+                .flags = UNESCAPE_HEX,
+        },
+        {
+                .in = "\\h\\\\\\\"\\a\\e\\",
+                .out = "\\h\\\"\a\e\\",
+                .flags = UNESCAPE_SPECIAL,
+        },
+};
+
+static void __init test_string_unescape(unsigned int flags, bool inplace)
+{
+        char in[256];
+        char out_test[256];
+        char out_real[256];
+        int i, p = 0, q_test = 0, q_real = sizeof(out_real);
+
+        for (i = 0; i < ARRAY_SIZE(strings); i++) {
+                const char *s = strings[i].in;
+                int len = strlen(strings[i].in);
+
+                /* Copy string to in buffer */
+                memcpy(&in[p], s, len);
+                p += len;
+
+                /* Copy expected result for given flags */
+                if (flags & strings[i].flags) {
+                        s = strings[i].out;
+                        len = strlen(strings[i].out);
+                }
+                memcpy(&out_test[q_test], s, len);
+                q_test += len;
+        }
+        in[p++] = '\0';
+
+        /* Call string_unescape and compare result */
+        if (inplace) {
+                memcpy(out_real, in, p);
+                if (flags == UNESCAPE_ANY)
+                        q_real = string_unescape_any_inplace(out_real);
+                else
+                        q_real = string_unescape_inplace(out_real, flags);
+        } else if (flags == UNESCAPE_ANY) {
+                q_real = string_unescape_any(in, out_real, q_real);
+        } else {
+                q_real = string_unescape(in, out_real, q_real, flags);
+        }
+
+        if (q_real != q_test || memcmp(out_test, out_real, q_test)) {
+                pr_warn("Test failed: flags = %u\n", flags);
+                print_hex_dump(KERN_WARNING, "Input: ",
+                               DUMP_PREFIX_NONE, 16, 1, in, p - 1, true);
+                print_hex_dump(KERN_WARNING, "Expected: ",
+                               DUMP_PREFIX_NONE, 16, 1, out_test, q_test, true);
+                print_hex_dump(KERN_WARNING, "Got: ",
+                               DUMP_PREFIX_NONE, 16, 1, out_real, q_real, true);
+        }
+}
+
+static int __init test_string_helpers_init(void)
+{
+        unsigned int i;
+
+        pr_info("Running tests...\n");
+        for (i = 0; i < UNESCAPE_ANY + 1; i++)
+                test_string_unescape(i, false);
+        test_string_unescape(get_random_int() % (UNESCAPE_ANY + 1), true);
+
+        return -EINVAL;
+}
+module_init(test_string_helpers_init);
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/lib/usercopy.c b/lib/usercopy.c
new file mode 100644
index 000000000000..4f5b1ddbcd25
--- /dev/null
+++ b/lib/usercopy.c
@@ -0,0 +1,9 @@
+#include <linux/export.h>
+#include <linux/bug.h>
+#include <linux/uaccess.h>
+
+void copy_from_user_overflow(void)
+{
+        WARN(1, "Buffer overflow detected!\n");
+}
+EXPORT_SYMBOL(copy_from_user_overflow);