6 files changed, 284 insertions, 3 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 9960be04cbbe..bb1326d3839c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -194,4 +194,10 @@ config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 config NLATTR
         bool
 
+#
+# Generic 64-bit atomic support is selected if needed
+#
+config GENERIC_ATOMIC64
+       bool
+
 endmenu
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 116a35051be6..6b0c2d8a2129 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -300,7 +300,7 @@ config DEBUG_OBJECTS_ENABLE_DEFAULT
 
 config DEBUG_SLAB
         bool "Debug slab memory allocations"
-        depends on DEBUG_KERNEL && SLAB
+        depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
         help
           Say Y here to have the kernel do limited verification on memory
           allocation as well as poisoning memory on free to catch use of freed
@@ -312,7 +312,7 @@ config DEBUG_SLAB_LEAK
 
 config SLUB_DEBUG_ON
         bool "SLUB debugging on by default"
-        depends on SLUB && SLUB_DEBUG
+        depends on SLUB && SLUB_DEBUG && !KMEMCHECK
         default n
         help
           Boot with debugging on by default. SLUB boots by default with
@@ -996,3 +996,5 @@ config DMA_API_DEBUG
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"
+
+source "lib/Kconfig.kmemcheck"
diff --git a/lib/Kconfig.kmemcheck b/lib/Kconfig.kmemcheck
new file mode 100644
index 000000000000..603c81b66549
--- /dev/null
+++ b/lib/Kconfig.kmemcheck
@@ -0,0 +1,91 @@
+config HAVE_ARCH_KMEMCHECK
+        bool
+
+menuconfig KMEMCHECK
+        bool "kmemcheck: trap use of uninitialized memory"
+        depends on DEBUG_KERNEL
+        depends on !X86_USE_3DNOW
+        depends on SLUB || SLAB
+        depends on !CC_OPTIMIZE_FOR_SIZE
+        depends on !FUNCTION_TRACER
+        select FRAME_POINTER
+        select STACKTRACE
+        default n
+        help
+          This option enables tracing of dynamically allocated kernel memory
+          to see if memory is used before it has been given an initial value.
+          Be aware that this requires half of your memory for bookkeeping and
+          will insert extra code at *every* read and write to tracked memory
+          thus slow down the kernel code (but user code is unaffected).
+
+          The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable
+          or enable kmemcheck at boot-time. If the kernel is started with
+          kmemcheck=0, the large memory and CPU overhead is not incurred.
+
+choice
+        prompt "kmemcheck: default mode at boot"
+        depends on KMEMCHECK
+        default KMEMCHECK_ONESHOT_BY_DEFAULT
+        help
+          This option controls the default behaviour of kmemcheck when the
+          kernel boots and no kmemcheck= parameter is given.
+
+config KMEMCHECK_DISABLED_BY_DEFAULT
+        bool "disabled"
+        depends on KMEMCHECK
+
+config KMEMCHECK_ENABLED_BY_DEFAULT
+        bool "enabled"
+        depends on KMEMCHECK
+
+config KMEMCHECK_ONESHOT_BY_DEFAULT
+        bool "one-shot"
+        depends on KMEMCHECK
+        help
+          In one-shot mode, only the first error detected is reported before
+          kmemcheck is disabled.
+
+endchoice
+
+config KMEMCHECK_QUEUE_SIZE
+        int "kmemcheck: error queue size"
+        depends on KMEMCHECK
+        default 64
+        help
+          Select the maximum number of errors to store in the queue. Since
+          errors can occur virtually anywhere and in any context, we need a
+          temporary storage area which is guarantueed not to generate any
+          other faults. The queue will be emptied as soon as a tasklet may
+          be scheduled. If the queue is full, new error reports will be
+          lost.
+
+config KMEMCHECK_SHADOW_COPY_SHIFT
+        int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)"
+        depends on KMEMCHECK
+        range 2 8
+        default 5
+        help
+          Select the number of shadow bytes to save along with each entry of
+          the queue. These bytes indicate what parts of an allocation are
+          initialized, uninitialized, etc. and will be displayed when an
+          error is detected to help the debugging of a particular problem.
+
+config KMEMCHECK_PARTIAL_OK
+        bool "kmemcheck: allow partially uninitialized memory"
+        depends on KMEMCHECK
+        default y
+        help
+          This option works around certain GCC optimizations that produce
+          32-bit reads from 16-bit variables where the upper 16 bits are
+          thrown away afterwards. This may of course also hide some real
+          bugs.
+
+config KMEMCHECK_BITOPS_OK
+        bool "kmemcheck: allow bit-field manipulation"
+        depends on KMEMCHECK
+        default n
+        help
+          This option silences warnings that would be generated for bit-field
+          accesses where not all the bits are initialized at the same time.
+          This may also hide some real bugs.
+
diff --git a/lib/Makefile b/lib/Makefile
index 34c5c0e6222e..8e9bcf9d3261 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -95,6 +95,8 @@ obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o
 
 obj-$(CONFIG_GENERIC_CSUM) += checksum.o
 
+obj-$(CONFIG_GENERIC_ATOMIC64) += atomic64.o
+
 hostprogs-y     := gen_crc32table
 clean-files     := crc32table.h
 
diff --git a/lib/atomic64.c b/lib/atomic64.c
new file mode 100644
index 000000000000..c5e725562416
--- /dev/null
+++ b/lib/atomic64.c
@@ -0,0 +1,175 @@
+/*
+ * Generic implementation of 64-bit atomics using spinlocks,
+ * useful on processors that don't have 64-bit atomic instructions.
+ *
+ * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+
+/*
+ * We use a hashed array of spinlocks to provide exclusive access
+ * to each atomic64_t variable.  Since this is expected to used on
+ * systems with small numbers of CPUs (<= 4 or so), we use a
+ * relatively small array of 16 spinlocks to avoid wasting too much
+ * memory on the spinlock array.
+ */
+#define NR_LOCKS        16
+
+/*
+ * Ensure each lock is in a separate cacheline.
+ */
+static union {
+        spinlock_t lock;
+        char pad[L1_CACHE_BYTES];
+} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp;
+
+static inline spinlock_t *lock_addr(const atomic64_t *v)
+{
+        unsigned long addr = (unsigned long) v;
+
+        addr >>= L1_CACHE_SHIFT;
+        addr ^= (addr >> 8) ^ (addr >> 16);
+        return &atomic64_lock[addr & (NR_LOCKS - 1)].lock;
+}
+
+long long atomic64_read(const atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+void atomic64_set(atomic64_t *v, long long i)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+
+        spin_lock_irqsave(lock, flags);
+        v->counter = i;
+        spin_unlock_irqrestore(lock, flags);
+}
+
+void atomic64_add(long long a, atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+
+        spin_lock_irqsave(lock, flags);
+        v->counter += a;
+        spin_unlock_irqrestore(lock, flags);
+}
+
+long long atomic64_add_return(long long a, atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter += a;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+void atomic64_sub(long long a, atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+
+        spin_lock_irqsave(lock, flags);
+        v->counter -= a;
+        spin_unlock_irqrestore(lock, flags);
+}
+
+long long atomic64_sub_return(long long a, atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter -= a;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+long long atomic64_dec_if_positive(atomic64_t *v)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter - 1;
+        if (val >= 0)
+                v->counter = val;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter;
+        if (val == o)
+                v->counter = n;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+long long atomic64_xchg(atomic64_t *v, long long new)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        long long val;
+
+        spin_lock_irqsave(lock, flags);
+        val = v->counter;
+        v->counter = new;
+        spin_unlock_irqrestore(lock, flags);
+        return val;
+}
+
+int atomic64_add_unless(atomic64_t *v, long long a, long long u)
+{
+        unsigned long flags;
+        spinlock_t *lock = lock_addr(v);
+        int ret = 1;
+
+        spin_lock_irqsave(lock, flags);
+        if (v->counter != u) {
+                v->counter += a;
+                ret = 0;
+        }
+        spin_unlock_irqrestore(lock, flags);
+        return ret;
+}
+
+static int init_atomic64_lock(void)
+{
+        int i;
+
+        for (i = 0; i < NR_LOCKS; ++i)
+                spin_lock_init(&atomic64_lock[i].lock);
+        return 0;
+}
+
+pure_initcall(init_atomic64_lock);
diff --git a/lib/kobject.c b/lib/kobject.c
index bacf6fe4f7a0..b512b746d2af 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -793,11 +793,16 @@ static struct kset *kset_create(const char *name,
                                 struct kobject *parent_kobj)
 {
         struct kset *kset;
+        int retval;
 
         kset = kzalloc(sizeof(*kset), GFP_KERNEL);
         if (!kset)
                 return NULL;
-        kobject_set_name(&kset->kobj, name);
+        retval = kobject_set_name(&kset->kobj, name);
+        if (retval) {
+                kfree(kset);
+                return NULL;
+        }
         kset->uevent_ops = uevent_ops;
         kset->kobj.parent = parent_kobj;