19 files changed, 546 insertions, 75 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1d1521c26302..8c15b29d5adc 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -312,6 +312,15 @@ config DEBUG_SECTION_MISMATCH
           - Enable verbose reporting from modpost in order to help resolve
             the section mismatches that are reported.
 
+config SECTION_MISMATCH_WARN_ONLY
+        bool "Make section mismatch errors non-fatal"
+        default y
+        help
+          If you say N here, the build process will fail if there are any
+          section mismatch, instead of just throwing warnings.
+
+          If unsure, say Y.
+
 #
 # Select this config option from the architecture Kconfig, if it
 # is preferred to always offer frame pointers as a config
@@ -1686,6 +1695,9 @@ config TEST_STRING_HELPERS
 config TEST_KSTRTOX
         tristate "Test kstrto*() family of functions at runtime"
 
+config TEST_PRINTF
+        tristate "Test printf() family of functions at runtime"
+
 config TEST_RHASHTABLE
         tristate "Perform selftest on resizable hash table"
         default n
diff --git a/lib/Makefile b/lib/Makefile
index 8de3b012eac7..7f1de26613d2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
+obj-$(CONFIG_TEST_PRINTF) += test_printf.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/div64.c b/lib/div64.c
index 19ea7ed4b948..62a698a432bc 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -162,7 +162,7 @@ s64 div64_s64(s64 dividend, s64 divisor)
 {
         s64 quot, t;
 
-        quot = div64_u64(abs64(dividend), abs64(divisor));
+        quot = div64_u64(abs(dividend), abs(divisor));
         t = (dividend ^ divisor) >> 63;
 
         return (quot ^ t) - t;
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index fcb65d2a0b94..8855f019ebe8 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1249,6 +1249,14 @@ static void check_sync(struct device *dev,
                                 dir2name[entry->direction],
                                 dir2name[ref->direction]);
 
+        if (ref->sg_call_ents && ref->type == dma_debug_sg &&
+            ref->sg_call_ents != entry->sg_call_ents) {
+                err_printk(ref->dev, entry, "DMA-API: device driver syncs "
+                           "DMA sg list with different entry count "
+                           "[map count=%d] [sync count=%d]\n",
+                           entry->sg_call_ents, ref->sg_call_ents);
+        }
+
 out:
         put_hash_bucket(bucket, &flags);
 }
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e491e02eff54..e3952e9c8ec0 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -42,7 +42,7 @@ extern struct _ddebug __stop___verbose[];
 
 struct ddebug_table {
         struct list_head link;
-        char *mod_name;
+        const char *mod_name;
         unsigned int num_ddebugs;
         struct _ddebug *ddebugs;
 };
@@ -841,12 +841,12 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
                              const char *name)
 {
         struct ddebug_table *dt;
-        char *new_name;
+        const char *new_name;
 
         dt = kzalloc(sizeof(*dt), GFP_KERNEL);
         if (dt == NULL)
                 return -ENOMEM;
-        new_name = kstrdup(name, GFP_KERNEL);
+        new_name = kstrdup_const(name, GFP_KERNEL);
         if (new_name == NULL) {
                 kfree(dt);
                 return -ENOMEM;
@@ -907,7 +907,7 @@ int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module)
 static void ddebug_table_free(struct ddebug_table *dt)
 {
         list_del_init(&dt->link);
-        kfree(dt->mod_name);
+        kfree_const(dt->mod_name);
         kfree(dt);
 }
 
diff --git a/lib/halfmd4.c b/lib/halfmd4.c
index a8fe6274a13c..137e861d9690 100644
--- a/lib/halfmd4.c
+++ b/lib/halfmd4.c
@@ -1,6 +1,7 @@
 #include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/cryptohash.h>
+#include <linux/bitops.h>
 
 /* F, G and H are basic MD4 functions: selection, majority, parity */
 #define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
@@ -14,7 +15,7 @@
  * Rotation is separate from addition to prevent recomputation
  */
 #define ROUND(f, a, b, c, d, x, s)      \
-        (a += f(b, c, d) + x, a = (a << s) | (a >> (32 - s)))
+        (a += f(b, c, d) + x, a = rol32(a, s))
 #define K1 0
 #define K2 013240474631UL
 #define K3 015666365641UL
diff --git a/lib/hexdump.c b/lib/hexdump.c
index 8d74c20d8595..992457b1284c 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -169,11 +169,15 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
                 }
         } else {
                 for (j = 0; j < len; j++) {
-                        if (linebuflen < lx + 3)
+                        if (linebuflen < lx + 2)
                                 goto overflow2;
                         ch = ptr[j];
                         linebuf[lx++] = hex_asc_hi(ch);
+                        if (linebuflen < lx + 2)
+                                goto overflow2;
                         linebuf[lx++] = hex_asc_lo(ch);
+                        if (linebuflen < lx + 2)
+                                goto overflow2;
                         linebuf[lx++] = ' ';
                 }
                 if (j)
diff --git a/lib/idr.c b/lib/idr.c
index 5335c43adf46..6098336df267 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -399,7 +399,7 @@ void idr_preload(gfp_t gfp_mask)
          * allocation guarantee.  Disallow usage from those contexts.
          */
         WARN_ON_ONCE(in_interrupt());
-        might_sleep_if(gfp_mask & __GFP_WAIT);
+        might_sleep_if(gfpflags_allow_blocking(gfp_mask));
 
         preempt_disable();
 
@@ -453,7 +453,7 @@ int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask)
         struct idr_layer *pa[MAX_IDR_LEVEL + 1];
         int id;
 
-        might_sleep_if(gfp_mask & __GFP_WAIT);
+        might_sleep_if(gfpflags_allow_blocking(gfp_mask));
 
         /* sanity checks */
         if (WARN_ON_ONCE(start < 0))
diff --git a/lib/is_single_threaded.c b/lib/is_single_threaded.c
index bd2bea963364..391fd23976a2 100644
--- a/lib/is_single_threaded.c
+++ b/lib/is_single_threaded.c
@@ -36,8 +36,7 @@ bool current_is_single_threaded(void)
                 if (unlikely(p == task->group_leader))
                         continue;
 
-                t = p;
-                do {
+                for_each_thread(p, t) {
                         if (unlikely(t->mm == mm))
                                 goto found;
                         if (likely(t->mm))
@@ -48,7 +47,7 @@ bool current_is_single_threaded(void)
                          * forked before exiting.
                          */
                         smp_rmb();
-                } while_each_thread(p, t);
+                }
         }
         ret = true;
 found:
diff --git a/lib/kasprintf.c b/lib/kasprintf.c
index 32f12150fc4f..f194e6e593e1 100644
--- a/lib/kasprintf.c
+++ b/lib/kasprintf.c
@@ -31,6 +31,22 @@ char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
 }
 EXPORT_SYMBOL(kvasprintf);
 
+/*
+ * If fmt contains no % (or is exactly %s), use kstrdup_const. If fmt
+ * (or the sole vararg) points to rodata, we will then save a memory
+ * allocation and string copy. In any case, the return value should be
+ * freed using kfree_const().
+ */
+const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list ap)
+{
+        if (!strchr(fmt, '%'))
+                return kstrdup_const(fmt, gfp);
+        if (!strcmp(fmt, "%s"))
+                return kstrdup_const(va_arg(ap, const char*), gfp);
+        return kvasprintf(gfp, fmt, ap);
+}
+EXPORT_SYMBOL(kvasprintf_const);
+
 char *kasprintf(gfp_t gfp, const char *fmt, ...)
 {
         va_list ap;
diff --git a/lib/kobject.c b/lib/kobject.c
index 055407746266..7cbccd2b4c72 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -257,18 +257,32 @@ static int kobject_add_internal(struct kobject *kobj)
 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
                                   va_list vargs)
 {
-        char *s;
+        const char *s;
 
         if (kobj->name && !fmt)
                 return 0;
 
-        s = kvasprintf(GFP_KERNEL, fmt, vargs);
+        s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
         if (!s)
                 return -ENOMEM;
 
-        /* ewww... some of these buggers have '/' in the name ... */
-        strreplace(s, '/', '!');
-        kfree(kobj->name);
+        /*
+         * ewww... some of these buggers have '/' in the name ... If
+         * that's the case, we need to make sure we have an actual
+         * allocated copy to modify, since kvasprintf_const may have
+         * returned something from .rodata.
+         */
+        if (strchr(s, '/')) {
+                char *t;
+
+                t = kstrdup(s, GFP_KERNEL);
+                kfree_const(s);
+                if (!t)
+                        return -ENOMEM;
+                strreplace(t, '/', '!');
+                s = t;
+        }
+        kfree_const(kobj->name);
         kobj->name = s;
 
         return 0;
@@ -466,7 +480,7 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
         envp[0] = devpath_string;
         envp[1] = NULL;
 
-        name = dup_name = kstrdup(new_name, GFP_KERNEL);
+        name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
         if (!name) {
                 error = -ENOMEM;
                 goto out;
@@ -486,7 +500,7 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
         kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 
 out:
-        kfree(dup_name);
+        kfree_const(dup_name);
         kfree(devpath_string);
         kfree(devpath);
         kobject_put(kobj);
@@ -634,7 +648,7 @@ static void kobject_cleanup(struct kobject *kobj)
         /* free name if we allocated it */
         if (name) {
                 pr_debug("kobject: '%s': free name\n", name);
-                kfree(name);
+                kfree_const(name);
         }
 }
 
diff --git a/lib/llist.c b/lib/llist.c
index 0b0e9779d675..ae5872b1df0c 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -66,12 +66,12 @@ struct llist_node *llist_del_first(struct llist_head *head)
 {
         struct llist_node *entry, *old_entry, *next;
 
-        entry = head->first;
+        entry = smp_load_acquire(&head->first);
         for (;;) {
                 if (entry == NULL)
                         return NULL;
                 old_entry = entry;
-                next = entry->next;
+                next = READ_ONCE(entry->next);
                 entry = cmpxchg(&head->first, old_entry, next);
                 if (entry == old_entry)
                         break;
diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index f75715131f20..6d40944960de 100644
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -135,7 +135,7 @@ static inline unsigned alloc_local_tag(struct percpu_ida_cpu *tags)
  * TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, of course).
  *
  * @gfp indicates whether or not to wait until a free id is available (it's not
- * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep
+ * used for internal memory allocations); thus if passed __GFP_RECLAIM we may sleep
  * however long it takes until another thread frees an id (same semantics as a
  * mempool).
  *
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index f9ebe1c82060..fcf5d98574ce 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -188,7 +188,7 @@ radix_tree_node_alloc(struct radix_tree_root *root)
          * preloading in the interrupt anyway as all the allocations have to
          * be atomic. So just do normal allocation when in interrupt.
          */
-        if (!(gfp_mask & __GFP_WAIT) && !in_interrupt()) {
+        if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) {
                 struct radix_tree_preload *rtp;
 
                 /*
@@ -249,7 +249,7 @@ radix_tree_node_free(struct radix_tree_node *node)
  * with preemption not disabled.
  *
  * To make use of this facility, the radix tree must be initialised without
- * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
  */
 static int __radix_tree_preload(gfp_t gfp_mask)
 {
@@ -286,12 +286,12 @@ out:
  * with preemption not disabled.
  *
  * To make use of this facility, the radix tree must be initialised without
- * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
  */
 int radix_tree_preload(gfp_t gfp_mask)
 {
         /* Warn on non-sensical use... */
-        WARN_ON_ONCE(!(gfp_mask & __GFP_WAIT));
+        WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
         return __radix_tree_preload(gfp_mask);
 }
 EXPORT_SYMBOL(radix_tree_preload);
@@ -303,7 +303,7 @@ EXPORT_SYMBOL(radix_tree_preload);
  */
 int radix_tree_maybe_preload(gfp_t gfp_mask)
 {
-        if (gfp_mask & __GFP_WAIT)
+        if (gfpflags_allow_blocking(gfp_mask))
                 return __radix_tree_preload(gfp_mask);
         /* Preloading doesn't help anything with this gfp mask, skip it */
         preempt_disable();
diff --git a/lib/string.c b/lib/string.c
index 84775ba873b9..0323c0d5629a 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -904,7 +904,7 @@ void *memchr_inv(const void *start, int c, size_t bytes)
 
         value64 = value;
 #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64
-        value64 *= 0x0101010101010101;
+        value64 *= 0x0101010101010101ULL;
 #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER)
         value64 *= 0x01010101;
         value64 |= value64 << 32;
diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index 8e376efd88a4..98866a770770 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -326,6 +326,39 @@ out:
         kfree(out_test);
 }
 
+#define string_get_size_maxbuf 16
+#define test_string_get_size_one(size, blk_size, units, exp_result)            \
+        do {                                                                   \
+                BUILD_BUG_ON(sizeof(exp_result) >= string_get_size_maxbuf);    \
+                __test_string_get_size((size), (blk_size), (units),            \
+                                       (exp_result));                          \
+        } while (0)
+
+
+static __init void __test_string_get_size(const u64 size, const u64 blk_size,
+                                          const enum string_size_units units,
+                                          const char *exp_result)
+{
+        char buf[string_get_size_maxbuf];
+
+        string_get_size(size, blk_size, units, buf, sizeof(buf));
+        if (!memcmp(buf, exp_result, strlen(exp_result) + 1))
+                return;
+
+        buf[sizeof(buf) - 1] = '\0';
+        pr_warn("Test 'test_string_get_size_one' failed!\n");
+        pr_warn("string_get_size(size = %llu, blk_size = %llu, units = %d\n",
+                size, blk_size, units);
+        pr_warn("expected: '%s', got '%s'\n", exp_result, buf);
+}
+
+static __init void test_string_get_size(void)
+{
+        test_string_get_size_one(16384, 512, STRING_UNITS_2, "8.00 MiB");
+        test_string_get_size_one(8192, 4096, STRING_UNITS_10, "32.7 MB");
+        test_string_get_size_one(1, 512, STRING_UNITS_10, "512 B");
+}
+
 static int __init test_string_helpers_init(void)
 {
         unsigned int i;
@@ -344,6 +377,9 @@ static int __init test_string_helpers_init(void)
         for (i = 0; i < (ESCAPE_ANY_NP | ESCAPE_HEX) + 1; i++)
                 test_string_escape("escape 1", escape1, i, TEST_STRING_2_DICT_1);
 
+        /* Test string_get_size() */
+        test_string_get_size();
+
         return -EINVAL;
 }
 module_init(test_string_helpers_init);
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index d1377390b3ad..10cd1860e5b0 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -5056,6 +5056,36 @@ static struct bpf_test tests[] = {
                 { {0x1, 0x0 } },
         },
         {
+                "MOD default X",
+                .u.insns = {
+                        /*
+                         * A = 0x42
+                         * A = A mod X ; this halt the filter execution if X is 0
+                         * ret 0x42
+                         */
+                        BPF_STMT(BPF_LD | BPF_IMM, 0x42),
+                        BPF_STMT(BPF_ALU | BPF_MOD | BPF_X, 0),
+                        BPF_STMT(BPF_RET | BPF_K, 0x42),
+                },
+                CLASSIC | FLAG_NO_DATA,
+                {},
+                { {0x1, 0x0 } },
+        },
+        {
+                "MOD default A",
+                .u.insns = {
+                        /*
+                         * A = A mod 1
+                         * ret A
+                         */
+                        BPF_STMT(BPF_ALU | BPF_MOD | BPF_K, 0x1),
+                        BPF_STMT(BPF_RET | BPF_A, 0x0),
+                },
+                CLASSIC | FLAG_NO_DATA,
+                {},
+                { {0x1, 0x0 } },
+        },
+        {
                 "JMP EQ default A",
                 .u.insns = {
                         /*
diff --git a/lib/test_printf.c b/lib/test_printf.c
new file mode 100644
index 000000000000..c5a666af9ba5
--- /dev/null
+++ b/lib/test_printf.c
@@ -0,0 +1,362 @@
+/*
+ * Test cases for printf facility.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <linux/socket.h>
+#include <linux/in.h>
+
+#define BUF_SIZE 256
+#define FILL_CHAR '$'
+
+#define PTR1 ((void*)0x01234567)
+#define PTR2 ((void*)(long)(int)0xfedcba98)
+
+#if BITS_PER_LONG == 64
+#define PTR1_ZEROES "000000000"
+#define PTR1_SPACES "         "
+#define PTR1_STR "1234567"
+#define PTR2_STR "fffffffffedcba98"
+#define PTR_WIDTH 16
+#else
+#define PTR1_ZEROES "0"
+#define PTR1_SPACES " "
+#define PTR1_STR "1234567"
+#define PTR2_STR "fedcba98"
+#define PTR_WIDTH 8
+#endif
+#define PTR_WIDTH_STR stringify(PTR_WIDTH)
+
+static unsigned total_tests __initdata;
+static unsigned failed_tests __initdata;
+static char *test_buffer __initdata;
+
+static int __printf(4, 0) __init
+do_test(int bufsize, const char *expect, int elen,
+        const char *fmt, va_list ap)
+{
+        va_list aq;
+        int ret, written;
+
+        total_tests++;
+
+        memset(test_buffer, FILL_CHAR, BUF_SIZE);
+        va_copy(aq, ap);
+        ret = vsnprintf(test_buffer, bufsize, fmt, aq);
+        va_end(aq);
+
+        if (ret != elen) {
+                pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
+                        bufsize, fmt, ret, elen);
+                return 1;
+        }
+
+        if (!bufsize) {
+                if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE)) {
+                        pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
+                                fmt);
+                        return 1;
+                }
+                return 0;
+        }
+
+        written = min(bufsize-1, elen);
+        if (test_buffer[written]) {
+                pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
+                        bufsize, fmt);
+                return 1;
+        }
+
+        if (memcmp(test_buffer, expect, written)) {
+                pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
+                        bufsize, fmt, test_buffer, written, expect);
+                return 1;
+        }
+        return 0;
+}
+
+static void __printf(3, 4) __init
+__test(const char *expect, int elen, const char *fmt, ...)
+{
+        va_list ap;
+        int rand;
+        char *p;
+
+        BUG_ON(elen >= BUF_SIZE);
+
+        va_start(ap, fmt);
+
+        /*
+         * Every fmt+args is subjected to four tests: Three where we
+         * tell vsnprintf varying buffer sizes (plenty, not quite
+         * enough and 0), and then we also test that kvasprintf would
+         * be able to print it as expected.
+         */
+        failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
+        rand = 1 + prandom_u32_max(elen+1);
+        /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
+        failed_tests += do_test(rand, expect, elen, fmt, ap);
+        failed_tests += do_test(0, expect, elen, fmt, ap);
+
+        p = kvasprintf(GFP_KERNEL, fmt, ap);
+        if (p) {
+                if (memcmp(p, expect, elen+1)) {
+                        pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
+                                fmt, p, expect);
+                        failed_tests++;
+                }
+                kfree(p);
+        }
+        va_end(ap);
+}
+
+#define test(expect, fmt, ...)                                  \
+        __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
+
+static void __init
+test_basic(void)
+{
+        /* Work around annoying "warning: zero-length gnu_printf format string". */
+        char nul = '\0';
+
+        test("", &nul);
+        test("100%", "100%%");
+        test("xxx%yyy", "xxx%cyyy", '%');
+        __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
+}
+
+static void __init
+test_number(void)
+{
+        test("0x1234abcd  ", "%#-12x", 0x1234abcd);
+        test("  0x1234abcd", "%#12x", 0x1234abcd);
+        test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
+}
+
+static void __init
+test_string(void)
+{
+        test("", "%s%.0s", "", "123");
+        test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
+        test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
+        /*
+         * POSIX and C99 say that a missing precision should be
+         * treated as a precision of 0. However, the kernel's printf
+         * implementation treats this case as if the . wasn't
+         * present. Let's add a test case documenting the current
+         * behaviour; should anyone ever feel the need to follow the
+         * standards more closely, this can be revisited.
+         */
+        test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
+        test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
+}
+
+static void __init
+plain(void)
+{
+        test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
+        /*
+         * The field width is overloaded for some %p extensions to
+         * pass another piece of information. For plain pointers, the
+         * behaviour is slightly odd: One cannot pass either the 0
+         * flag nor a precision to %p without gcc complaining, and if
+         * one explicitly gives a field width, the number is no longer
+         * zero-padded.
+         */
+        test("|" PTR1_STR PTR1_SPACES "  |  " PTR1_SPACES PTR1_STR "|",
+             "|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
+        test("|" PTR2_STR "  |  " PTR2_STR "|",
+             "|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
+
+        /*
+         * Unrecognized %p extensions are treated as plain %p, but the
+         * alphanumeric suffix is ignored (that is, does not occur in
+         * the output.)
+         */
+        test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
+        test("|"PTR2_STR"|", "|%p0y|", PTR2);
+}
+
+static void __init
+symbol_ptr(void)
+{
+}
+
+static void __init
+kernel_ptr(void)
+{
+}
+
+static void __init
+struct_resource(void)
+{
+}
+
+static void __init
+addr(void)
+{
+}
+
+static void __init
+escaped_str(void)
+{
+}
+
+static void __init
+hex_string(void)
+{
+        const char buf[3] = {0xc0, 0xff, 0xee};
+
+        test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
+             "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
+        test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
+             "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
+}
+
+static void __init
+mac(void)
+{
+        const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
+
+        test("2d:48:d6:fc:7a:05", "%pM", addr);
+        test("05:7a:fc:d6:48:2d", "%pMR", addr);
+        test("2d-48-d6-fc-7a-05", "%pMF", addr);
+        test("2d48d6fc7a05", "%pm", addr);
+        test("057afcd6482d", "%pmR", addr);
+}
+
+static void __init
+ip4(void)
+{
+        struct sockaddr_in sa;
+
+        sa.sin_family = AF_INET;
+        sa.sin_port = cpu_to_be16(12345);
+        sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
+
+        test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
+        test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
+        sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
+        test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
+}
+
+static void __init
+ip6(void)
+{
+}
+
+static void __init
+ip(void)
+{
+        ip4();
+        ip6();
+}
+
+static void __init
+uuid(void)
+{
+        const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
+                               0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
+
+        test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
+        test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
+        test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
+        test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
+}
+
+static void __init
+dentry(void)
+{
+}
+
+static void __init
+struct_va_format(void)
+{
+}
+
+static void __init
+struct_clk(void)
+{
+}
+
+static void __init
+bitmap(void)
+{
+        DECLARE_BITMAP(bits, 20);
+        const int primes[] = {2,3,5,7,11,13,17,19};
+        int i;
+
+        bitmap_zero(bits, 20);
+        test("00000|00000", "%20pb|%*pb", bits, 20, bits);
+        test("|", "%20pbl|%*pbl", bits, 20, bits);
+
+        for (i = 0; i < ARRAY_SIZE(primes); ++i)
+                set_bit(primes[i], bits);
+        test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
+        test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
+
+        bitmap_fill(bits, 20);
+        test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
+        test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
+}
+
+static void __init
+netdev_features(void)
+{
+}
+
+static void __init
+test_pointer(void)
+{
+        plain();
+        symbol_ptr();
+        kernel_ptr();
+        struct_resource();
+        addr();
+        escaped_str();
+        hex_string();
+        mac();
+        ip();
+        uuid();
+        dentry();
+        struct_va_format();
+        struct_clk();
+        bitmap();
+        netdev_features();
+}
+
+static int __init
+test_printf_init(void)
+{
+        test_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
+        if (!test_buffer)
+                return -ENOMEM;
+
+        test_basic();
+        test_number();
+        test_string();
+        test_pointer();
+
+        kfree(test_buffer);
+
+        if (failed_tests == 0)
+                pr_info("all %u tests passed\n", total_tests);
+        else
+                pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
+
+        return failed_tests ? -EINVAL : 0;
+}
+
+module_init(test_printf_init);
+
+MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
+MODULE_LICENSE("GPL");
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 95cd63b43b99..f9cee8e1233c 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1449,6 +1449,8 @@ int kptr_restrict __read_mostly;
  *        (legacy clock framework) of the clock
  * - 'Cr' For a clock, it prints the current rate of the clock
  *
+ * ** Please update also Documentation/printk-formats.txt when making changes **
+ *
  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  * function pointers are really function descriptors, which contain a
  * pointer to the real address.
@@ -1457,7 +1459,7 @@ static noinline_for_stack
 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
               struct printf_spec spec)
 {
-        int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
+        const int default_width = 2 * sizeof(void *);
 
         if (!ptr && *fmt != 'K') {
                 /*
@@ -1769,14 +1771,14 @@ qualifier:
 
         case 'n':
                 /*
-                 * Since %n poses a greater security risk than utility, treat
-                 * it as an invalid format specifier. Warn about its use so
-                 * that new instances don't get added.
+                 * Since %n poses a greater security risk than
+                 * utility, treat it as any other invalid or
+                 * unsupported format specifier.
                  */
-                WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
                 /* Fall-through */
 
         default:
+                WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
                 spec->type = FORMAT_TYPE_INVALID;
                 return fmt - start;
         }
@@ -1811,41 +1813,16 @@ qualifier:
  * @fmt: The format string to use
  * @args: Arguments for the format string
  *
- * This function follows C99 vsnprintf, but has some extensions:
- * %pS output the name of a text symbol with offset
- * %ps output the name of a text symbol without offset
- * %pF output the name of a function pointer with its offset
- * %pf output the name of a function pointer without its offset
- * %pB output the name of a backtrace symbol with its offset
- * %pR output the address range in a struct resource with decoded flags
- * %pr output the address range in a struct resource with raw flags
- * %pb output the bitmap with field width as the number of bits
- * %pbl output the bitmap as range list with field width as the number of bits
- * %pM output a 6-byte MAC address with colons
- * %pMR output a 6-byte MAC address with colons in reversed order
- * %pMF output a 6-byte MAC address with dashes
- * %pm output a 6-byte MAC address without colons
- * %pmR output a 6-byte MAC address without colons in reversed order
- * %pI4 print an IPv4 address without leading zeros
- * %pi4 print an IPv4 address with leading zeros
- * %pI6 print an IPv6 address with colons
- * %pi6 print an IPv6 address without colons
- * %pI6c print an IPv6 address as specified by RFC 5952
- * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
- * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
- * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
- *   case.
- * %*pE[achnops] print an escaped buffer
- * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
- *           bytes of the input)
- * %pC output the name (Common Clock Framework) or address (legacy clock
- *     framework) of a clock
- * %pCn output the name (Common Clock Framework) or address (legacy clock
- *      framework) of a clock
- * %pCr output the current rate of a clock
- * %n is ignored
+ * This function generally follows C99 vsnprintf, but has some
+ * extensions and a few limitations:
+ *
+ * %n is unsupported
+ * %p* is handled by pointer()
  *
- * ** Please update Documentation/printk-formats.txt when making changes **
+ * See pointer() or Documentation/printk-formats.txt for more
+ * extensive description.
+ *
+ * ** Please update the documentation in both places when making changes **
  *
  * The return value is the number of characters which would
  * be generated for the given input, excluding the trailing
@@ -1944,10 +1921,15 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
                         break;
 
                 case FORMAT_TYPE_INVALID:
-                        if (str < end)
-                                *str = '%';
-                        ++str;
-                        break;
+                        /*
+                         * Presumably the arguments passed gcc's type
+                         * checking, but there is no safe or sane way
+                         * for us to continue parsing the format and
+                         * fetching from the va_list; the remaining
+                         * specifiers and arguments would be out of
+                         * sync.
+                         */
+                        goto out;
 
                 default:
                         switch (spec.type) {
@@ -1992,6 +1974,7 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
                 }
         }
 
+out:
         if (size > 0) {
                 if (str < end)
                         *str = '\0';
@@ -2189,9 +2172,10 @@ do {									\
 
                 switch (spec.type) {
                 case FORMAT_TYPE_NONE:
-                case FORMAT_TYPE_INVALID:
                 case FORMAT_TYPE_PERCENT_CHAR:
                         break;
+                case FORMAT_TYPE_INVALID:
+                        goto out;
 
                 case FORMAT_TYPE_WIDTH:
                 case FORMAT_TYPE_PRECISION:
@@ -2253,6 +2237,7 @@ do {									\
                 }
         }
 
+out:
         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
 #undef save_arg
 }
@@ -2286,7 +2271,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
         char *str, *end;
         const char *args = (const char *)bin_buf;
 
-        if (WARN_ON_ONCE((int) size < 0))
+        if (WARN_ON_ONCE(size > INT_MAX))
                 return 0;
 
         str = buf;
@@ -2375,12 +2360,14 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
                         break;
 
                 case FORMAT_TYPE_PERCENT_CHAR:
-                case FORMAT_TYPE_INVALID:
                         if (str < end)
                                 *str = '%';
                         ++str;
                         break;
 
+                case FORMAT_TYPE_INVALID:
+                        goto out;
+
                 default: {
                         unsigned long long num;
 
@@ -2423,6 +2410,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
                 } /* switch(spec.type) */
         } /* while(*fmt) */
 
+out:
         if (size > 0) {
                 if (str < end)
                         *str = '\0';