# less /proc/lock_stat
-01 lock_stat version 0.2
+01 lock_stat version 0.3
02 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
03 class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total
04 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
05
-06 &inode->i_data.tree_lock-W: 15 21657 0.18 1093295.30 11547131054.85 58 10415 0.16 87.51 6387.60
-07 &inode->i_data.tree_lock-R: 0 0 0.00 0.00 0.00 23302 231198 0.25 8.45 98023.38
-08 --------------------------
-09 &inode->i_data.tree_lock 0 [<ffffffff8027c08f>] add_to_page_cache+0x5f/0x190
-10
-11 ...............................................................................................................................................................................................
-12
-13 dcache_lock: 1037 1161 0.38 45.32 774.51 6611 243371 0.15 306.48 77387.24
-14 -----------
-15 dcache_lock 180 [<ffffffff802c0d7e>] sys_getcwd+0x11e/0x230
-16 dcache_lock 165 [<ffffffff802c002a>] d_alloc+0x15a/0x210
-17 dcache_lock 33 [<ffffffff8035818d>] _atomic_dec_and_lock+0x4d/0x70
-18 dcache_lock 1 [<ffffffff802beef8>] shrink_dcache_parent+0x18/0x130
+06 &mm->mmap_sem-W: 233 538 18446744073708 22924.27 607243.51 1342 45806 1.71 8595.89 1180582.34
+07 &mm->mmap_sem-R: 205 587 18446744073708 28403.36 731975.00 1940 412426 0.58 187825.45 6307502.88
+08 ---------------
+09 &mm->mmap_sem 487 [<ffffffff8053491f>] do_page_fault+0x466/0x928
+10 &mm->mmap_sem 179 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
+11 &mm->mmap_sem 279 [<ffffffff80210a57>] sys_mmap+0x75/0xce
+12 &mm->mmap_sem 76 [<ffffffff802a490b>] sys_munmap+0x32/0x59
+13 ---------------
+14 &mm->mmap_sem 270 [<ffffffff80210a57>] sys_mmap+0x75/0xce
+15 &mm->mmap_sem 431 [<ffffffff8053491f>] do_page_fault+0x466/0x928
+16 &mm->mmap_sem 138 [<ffffffff802a490b>] sys_munmap+0x32/0x59
+17 &mm->mmap_sem 145 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
+18
+19 ...............................................................................................................................................................................................
+20
+21 dcache_lock: 621 623 0.52 118.26 1053.02 6745 91930 0.29 316.29 118423.41
+22 -----------
+23 dcache_lock 179 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
+24 dcache_lock 113 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
+25 dcache_lock 99 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
+26 dcache_lock 104 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a
+27 -----------
+28 dcache_lock 192 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
+29 dcache_lock 98 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
+30 dcache_lock 72 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
+31 dcache_lock 112 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a
This excerpt shows the first two lock class statistics. Line 01 shows the
output version - each time the format changes this will be updated. Line 02-04
-show the header with column descriptions. Lines 05-10 and 13-18 show the actual
+show the header with column descriptions. Lines 05-18 and 20-31 show the actual
statistics. These statistics come in two parts; the actual stats separated by a
-short separator (line 08, 14) from the contention points.
+short separator (line 08, 13) from the contention points.
-The first lock (05-10) is a read/write lock, and shows two lines above the
+The first lock (05-18) is a read/write lock, and shows two lines above the
short separator. The contention points don't match the column descriptors,
-they have two: contentions and [<IP>] symbol.
+they have two: contentions and [<IP>] symbol. The second set of contention
+points are the points we're contending with.
+The integer part of the time values is in us.
View the top contending locks:
extern void block_signals(void);
extern void unblock_signals(void);
-#define local_save_flags(flags) do { typecheck(unsigned long, flags); \
+#define raw_local_save_flags(flags) do { typecheck(unsigned long, flags); \
(flags) = get_signals(); } while(0)
-#define local_irq_restore(flags) do { typecheck(unsigned long, flags); \
+#define raw_local_irq_restore(flags) do { typecheck(unsigned long, flags); \
set_signals(flags); } while(0)
-#define local_irq_save(flags) do { local_save_flags(flags); \
- local_irq_disable(); } while(0)
+#define raw_local_irq_save(flags) do { raw_local_save_flags(flags); \
+ raw_local_irq_disable(); } while(0)
-#define local_irq_enable() unblock_signals()
-#define local_irq_disable() block_signals()
+#define raw_local_irq_enable() unblock_signals()
+#define raw_local_irq_disable() block_signals()
#define irqs_disabled() \
({ \
unsigned long flags; \
- local_save_flags(flags); \
+ raw_local_save_flags(flags); \
(flags == 0); \
})
int __ret_gu; \
unsigned long __val_gu; \
__chk_user_ptr(ptr); \
+ might_fault(); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_x(1, __ret_gu, __val_gu, ptr); \
int __ret_pu; \
__typeof__(*(ptr)) __pu_val; \
__chk_user_ptr(ptr); \
+ might_fault(); \
__pu_val = x; \
switch (sizeof(*(ptr))) { \
case 1: \
static __always_inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
- might_sleep();
- return __copy_to_user_inatomic(to, from, n);
+ might_fault();
+ return __copy_to_user_inatomic(to, from, n);
}
static __always_inline unsigned long
static __always_inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
- might_sleep();
+ might_fault();
if (__builtin_constant_p(n)) {
unsigned long ret;
static __always_inline unsigned long __copy_from_user_nocache(void *to,
const void __user *from, unsigned long n)
{
- might_sleep();
+ might_fault();
if (__builtin_constant_p(n)) {
unsigned long ret;
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
int ret = 0;
+
+ might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic(dst, (__force void *)src, size);
switch (size) {
int __copy_to_user(void __user *dst, const void *src, unsigned size)
{
int ret = 0;
+
+ might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst, src, size);
switch (size) {
int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
{
int ret = 0;
+
+ might_fault();
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst,
(__force void *)src, size);
#define __do_strncpy_from_user(dst, src, count, res) \
do { \
int __d0, __d1, __d2; \
- might_sleep(); \
+ might_fault(); \
__asm__ __volatile__( \
" testl %1,%1\n" \
" jz 2f\n" \
#define __do_clear_user(addr,size) \
do { \
int __d0; \
- might_sleep(); \
+ might_fault(); \
__asm__ __volatile__( \
"0: rep; stosl\n" \
" movl %2,%0\n" \
unsigned long
clear_user(void __user *to, unsigned long n)
{
- might_sleep();
+ might_fault();
if (access_ok(VERIFY_WRITE, to, n))
__do_clear_user(to, n);
return n;
unsigned long mask = -__addr_ok(s);
unsigned long res, tmp;
- might_sleep();
+ might_fault();
__asm__ __volatile__(
" testl %0, %0\n"
#define __do_strncpy_from_user(dst,src,count,res) \
do { \
long __d0, __d1, __d2; \
- might_sleep(); \
+ might_fault(); \
__asm__ __volatile__( \
" testq %1,%1\n" \
" jz 2f\n" \
unsigned long __clear_user(void __user *addr, unsigned long size)
{
long __d0;
- might_sleep();
+ might_fault();
/* no memory constraint because it doesn't change any memory gcc knows
about */
asm volatile(
({ \
int __ret = 0; \
\
- if (unlikely(c)) { \
+ if (!oops_in_progress && unlikely(c)) { \
if (debug_locks_off() && !debug_locks_silent) \
WARN_ON(1); \
__ret = 1; \
} both;
};
+#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } }
+
#ifdef CONFIG_FUTEX
extern void exit_robust_list(struct task_struct *curr);
extern void exit_pi_state_list(struct task_struct *curr);
(__x < 0) ? -__x : __x; \
})
+#ifdef CONFIG_PROVE_LOCKING
+void might_fault(void);
+#else
+static inline void might_fault(void)
+{
+ might_sleep();
+}
+#endif
+
extern struct atomic_notifier_head panic_notifier_list;
extern long (*panic_blink)(long time);
NORET_TYPE void panic(const char * fmt, ...)
extern int core_kernel_text(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
+extern int func_ptr_is_kernel_text(void *ptr);
+
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);
struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
};
+#define LOCKSTAT_POINTS 4
+
/*
* The lock-class itself:
*/
int name_version;
#ifdef CONFIG_LOCK_STAT
- unsigned long contention_point[4];
+ unsigned long contention_point[LOCKSTAT_POINTS];
+ unsigned long contending_point[LOCKSTAT_POINTS];
#endif
};
struct lock_class_stats {
unsigned long contention_point[4];
+ unsigned long contending_point[4];
struct lock_time read_waittime;
struct lock_time write_waittime;
struct lock_time read_holdtime;
const char *name;
#ifdef CONFIG_LOCK_STAT
int cpu;
+ unsigned long ip;
#endif
};
#ifdef CONFIG_LOCK_STAT
extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
-extern void lock_acquired(struct lockdep_map *lock);
+extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);
#define LOCK_CONTENDED(_lock, try, lock) \
do { \
lock_contended(&(_lock)->dep_map, _RET_IP_); \
lock(_lock); \
} \
- lock_acquired(&(_lock)->dep_map); \
+ lock_acquired(&(_lock)->dep_map, _RET_IP_); \
} while (0)
#else /* CONFIG_LOCK_STAT */
#define lock_contended(lockdep_map, ip) do {} while (0)
-#define lock_acquired(lockdep_map) do {} while (0)
+#define lock_acquired(lockdep_map, ip) do {} while (0)
#define LOCK_CONTENDED(_lock, try, lock) \
lock(_lock)
# define lock_map_release(l) do { } while (0)
#endif
+#ifdef CONFIG_PROVE_LOCKING
+# define might_lock(lock) \
+do { \
+ typecheck(struct lockdep_map *, &(lock)->dep_map); \
+ lock_acquire(&(lock)->dep_map, 0, 0, 0, 2, NULL, _THIS_IP_); \
+ lock_release(&(lock)->dep_map, 0, _THIS_IP_); \
+} while (0)
+# define might_lock_read(lock) \
+do { \
+ typecheck(struct lockdep_map *, &(lock)->dep_map); \
+ lock_acquire(&(lock)->dep_map, 0, 0, 1, 2, NULL, _THIS_IP_); \
+ lock_release(&(lock)->dep_map, 0, _THIS_IP_); \
+} while (0)
+#else
+# define might_lock(lock) do { } while (0)
+# define might_lock_read(lock) do { } while (0)
+#endif
+
#endif /* __LINUX_LOCKDEP_H */
/*
* NOTE: mutex_trylock() follows the spin_trylock() convention,
* not the down_trylock() convention!
+ *
+ * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
*/
extern int mutex_trylock(struct mutex *lock);
extern void mutex_unlock(struct mutex *lock);
#include <linux/seqlock.h>
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
-#define RCU_SECONDS_TILL_STALL_CHECK ( 3 * HZ) /* for rcp->jiffies_stall */
+#define RCU_SECONDS_TILL_STALL_CHECK (10 * HZ) /* for rcp->jiffies_stall */
#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ) /* for rcp->jiffies_stall */
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
\
set_fs(KERNEL_DS); \
pagefault_disable(); \
- ret = __get_user(retval, (__force typeof(retval) __user *)(addr)); \
+ ret = __copy_from_user_inatomic(&(retval), (__force typeof(retval) __user *)(addr), sizeof(retval)); \
pagefault_enable(); \
set_fs(old_fs); \
ret; \
* group, which consolidates times for all threads in the
* group including the group leader.
*/
+ thread_group_cputime(p, &cputime);
spin_lock_irq(&p->parent->sighand->siglock);
psig = p->parent->signal;
sig = p->signal;
- thread_group_cputime(p, &cputime);
psig->cutime =
cputime_add(psig->cutime,
cputime_add(cputime.utime,
return 1;
return module_text_address(addr) != NULL;
}
+
+/*
+ * On some architectures (PPC64, IA64) function pointers
+ * are actually only tokens to some data that then holds the
+ * real function address. As a result, to find if a function
+ * pointer is part of the kernel text, we need to do some
+ * special dereferencing first.
+ */
+int func_ptr_is_kernel_text(void *ptr)
+{
+ unsigned long addr;
+ addr = (unsigned long) dereference_function_descriptor(ptr);
+ if (core_kernel_text(addr))
+ return 1;
+ return module_text_address(addr) != NULL;
+}
static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS];
-/*
- * Take mm->mmap_sem, when futex is shared
- */
-static inline void futex_lock_mm(struct rw_semaphore *fshared)
-{
- if (fshared)
- down_read(fshared);
-}
-
-/*
- * Release mm->mmap_sem, when the futex is shared
- */
-static inline void futex_unlock_mm(struct rw_semaphore *fshared)
-{
- if (fshared)
- up_read(fshared);
-}
-
/*
* We hash on the keys returned from get_futex_key (see below).
*/
&& key1->both.offset == key2->both.offset);
}
+/*
+ * Take a reference to the resource addressed by a key.
+ * Can be called while holding spinlocks.
+ *
+ */
+static void get_futex_key_refs(union futex_key *key)
+{
+ if (!key->both.ptr)
+ return;
+
+ switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
+ case FUT_OFF_INODE:
+ atomic_inc(&key->shared.inode->i_count);
+ break;
+ case FUT_OFF_MMSHARED:
+ atomic_inc(&key->private.mm->mm_count);
+ break;
+ }
+}
+
+/*
+ * Drop a reference to the resource addressed by a key.
+ * The hash bucket spinlock must not be held.
+ */
+static void drop_futex_key_refs(union futex_key *key)
+{
+ if (!key->both.ptr)
+ return;
+
+ switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
+ case FUT_OFF_INODE:
+ iput(key->shared.inode);
+ break;
+ case FUT_OFF_MMSHARED:
+ mmdrop(key->private.mm);
+ break;
+ }
+}
+
/**
* get_futex_key - Get parameters which are the keys for a futex.
* @uaddr: virtual address of the futex
* For other futexes, it points to ¤t->mm->mmap_sem and
* caller must have taken the reader lock. but NOT any spinlocks.
*/
-static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
- union futex_key *key)
+static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
struct page *page;
int err;
return -EFAULT;
key->private.mm = mm;
key->private.address = address;
+ get_futex_key_refs(key);
return 0;
}
- /*
- * The futex is hashed differently depending on whether
- * it's in a shared or private mapping. So check vma first.
- */
- vma = find_extend_vma(mm, address);
- if (unlikely(!vma))
- return -EFAULT;
- /*
- * Permissions.
- */
- if (unlikely((vma->vm_flags & (VM_IO|VM_READ)) != VM_READ))
- return (vma->vm_flags & VM_IO) ? -EPERM : -EACCES;
+again:
+ err = get_user_pages_fast(address, 1, 0, &page);
+ if (err < 0)
+ return err;
+
+ lock_page(page);
+ if (!page->mapping) {
+ unlock_page(page);
+ put_page(page);
+ goto again;
+ }
/*
* Private mappings are handled in a simple way.
*
* NOTE: When userspace waits on a MAP_SHARED mapping, even if
* it's a read-only handle, it's expected that futexes attach to
- * the object not the particular process. Therefore we use
- * VM_MAYSHARE here, not VM_SHARED which is restricted to shared
- * mappings of _writable_ handles.
+ * the object not the particular process.
*/
- if (likely(!(vma->vm_flags & VM_MAYSHARE))) {
- key->both.offset |= FUT_OFF_MMSHARED; /* reference taken on mm */
+ if (PageAnon(page)) {
+ key->both.offset |= FUT_OFF_MMSHARED; /* ref taken on mm */
key->private.mm = mm;
key->private.address = address;
- return 0;
+ } else {
+ key->both.offset |= FUT_OFF_INODE; /* inode-based key */
+ key->shared.inode = page->mapping->host;
+ key->shared.pgoff = page->index;
}
- /*
- * Linear file mappings are also simple.
- */
- key->shared.inode = vma->vm_file->f_path.dentry->d_inode;
- key->both.offset |= FUT_OFF_INODE; /* inode-based key. */
- if (likely(!(vma->vm_flags & VM_NONLINEAR))) {
- key->shared.pgoff = (((address - vma->vm_start) >> PAGE_SHIFT)
- + vma->vm_pgoff);
- return 0;
- }
+ get_futex_key_refs(key);
- /*
- * We could walk the page table to read the non-linear
- * pte, and get the page index without fetching the page
- * from swap. But that's a lot of code to duplicate here
- * for a rare case, so we simply fetch the page.
- */
- err = get_user_pages(current, mm, address, 1, 0, 0, &page, NULL);
- if (err >= 0) {
- key->shared.pgoff =
- page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
- put_page(page);
- return 0;
- }
- return err;
-}
-
-/*
- * Take a reference to the resource addressed by a key.
- * Can be called while holding spinlocks.
- *
- */
-static void get_futex_key_refs(union futex_key *key)
-{
- if (key->both.ptr == NULL)
- return;
- switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
- case FUT_OFF_INODE:
- atomic_inc(&key->shared.inode->i_count);
- break;
- case FUT_OFF_MMSHARED:
- atomic_inc(&key->private.mm->mm_count);
- break;
- }
+ unlock_page(page);
+ put_page(page);
+ return 0;
}
-/*
- * Drop a reference to the resource addressed by a key.
- * The hash bucket spinlock must not be held.
- */
-static void drop_futex_key_refs(union futex_key *key)
+static inline
+void put_futex_key(int fshared, union futex_key *key)
{
- if (!key->both.ptr)
- return;
- switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
- case FUT_OFF_INODE:
- iput(key->shared.inode);
- break;
- case FUT_OFF_MMSHARED:
- mmdrop(key->private.mm);
- break;
- }
+ drop_futex_key_refs(key);
}
static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
/*
* Fault handling.
- * if fshared is non NULL, current->mm->mmap_sem is already held
*/
-static int futex_handle_fault(unsigned long address,
- struct rw_semaphore *fshared, int attempt)
+static int futex_handle_fault(unsigned long address, int attempt)
{
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
if (attempt > 2)
return ret;
- if (!fshared)
- down_read(&mm->mmap_sem);
+ down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (vma && address >= vma->vm_start &&
(vma->vm_flags & VM_WRITE)) {
current->min_flt++;
}
}
- if (!fshared)
- up_read(&mm->mmap_sem);
+ up_read(&mm->mmap_sem);
return ret;
}
/* pi_mutex gets initialized later */
pi_state->owner = NULL;
atomic_set(&pi_state->refcount, 1);
+ pi_state->key = FUTEX_KEY_INIT;
current->pi_state_cache = pi_state;
struct list_head *next, *head = &curr->pi_state_list;
struct futex_pi_state *pi_state;
struct futex_hash_bucket *hb;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
if (!futex_cmpxchg_enabled)
return;
* Wake up all waiters hashed on the physical page that is mapped
* to this virtual address:
*/
-static int futex_wake(u32 __user *uaddr, struct rw_semaphore *fshared,
- int nr_wake, u32 bitset)
+static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
struct plist_head *head;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
int ret;
if (!bitset)
return -EINVAL;
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr, fshared, &key);
if (unlikely(ret != 0))
goto out;
spin_unlock(&hb->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key);
return ret;
}
* to this virtual address:
*/
static int
-futex_wake_op(u32 __user *uaddr1, struct rw_semaphore *fshared,
- u32 __user *uaddr2,
+futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
int nr_wake, int nr_wake2, int op)
{
- union futex_key key1, key2;
+ union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb1, *hb2;
struct plist_head *head;
struct futex_q *this, *next;
int ret, op_ret, attempt = 0;
retryfull:
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr1, fshared, &key1);
if (unlikely(ret != 0))
goto out;
*/
if (attempt++) {
ret = futex_handle_fault((unsigned long)uaddr2,
- fshared, attempt);
+ attempt);
if (ret)
goto out;
goto retry;
}
- /*
- * If we would have faulted, release mmap_sem,
- * fault it in and start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(dummy, uaddr2);
if (ret)
return ret;
if (hb1 != hb2)
spin_unlock(&hb2->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
return ret;
}
* Requeue all waiters hashed on one physical page to another
* physical page.
*/
-static int futex_requeue(u32 __user *uaddr1, struct rw_semaphore *fshared,
- u32 __user *uaddr2,
+static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
int nr_wake, int nr_requeue, u32 *cmpval)
{
- union futex_key key1, key2;
+ union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb1, *hb2;
struct plist_head *head1;
struct futex_q *this, *next;
int ret, drop_count = 0;
retry:
- futex_lock_mm(fshared);
-
ret = get_futex_key(uaddr1, fshared, &key1);
if (unlikely(ret != 0))
goto out;
if (hb1 != hb2)
spin_unlock(&hb2->lock);
- /*
- * If we would have faulted, release mmap_sem, fault
- * it in and start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(curval, uaddr1);
if (!ret)
drop_futex_key_refs(&key1);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
return ret;
}
* private futexes.
*/
static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *newowner,
- struct rw_semaphore *fshared)
+ struct task_struct *newowner, int fshared)
{
u32 newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
struct futex_pi_state *pi_state = q->pi_state;
handle_fault:
spin_unlock(q->lock_ptr);
- ret = futex_handle_fault((unsigned long)uaddr, fshared, attempt++);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt++);
spin_lock(q->lock_ptr);
static long futex_wait_restart(struct restart_block *restart);
-static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
+static int futex_wait(u32 __user *uaddr, int fshared,
u32 val, ktime_t *abs_time, u32 bitset)
{
struct task_struct *curr = current;
q.pi_state = NULL;
q.bitset = bitset;
retry:
- futex_lock_mm(fshared);
-
+ q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, fshared, &q.key);
if (unlikely(ret != 0))
goto out_release_sem;
if (unlikely(ret)) {
queue_unlock(&q, hb);
- /*
- * If we would have faulted, release mmap_sem, fault it in and
- * start all over again.
- */
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
if (!ret)
/* Only actually queue if *uaddr contained val. */
queue_me(&q, hb);
- /*
- * Now the futex is queued and we have checked the data, we
- * don't want to hold mmap_sem while we sleep.
- */
- futex_unlock_mm(fshared);
-
/*
* There might have been scheduling since the queue_me(), as we
* cannot hold a spinlock across the get_user() in case it
queue_unlock(&q, hb);
out_release_sem:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &q.key);
return ret;
}
static long futex_wait_restart(struct restart_block *restart)
{
u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
- struct rw_semaphore *fshared = NULL;
+ int fshared = 0;
ktime_t t;
t.tv64 = restart->futex.time;
restart->fn = do_no_restart_syscall;
if (restart->futex.flags & FLAGS_SHARED)
- fshared = ¤t->mm->mmap_sem;
+ fshared = 1;
return (long)futex_wait(uaddr, fshared, restart->futex.val, &t,
restart->futex.bitset);
}
* if there are waiters then it will block, it does PI, etc. (Due to
* races the kernel might see a 0 value of the futex too.)
*/
-static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
+static int futex_lock_pi(u32 __user *uaddr, int fshared,
int detect, ktime_t *time, int trylock)
{
struct hrtimer_sleeper timeout, *to = NULL;
q.pi_state = NULL;
retry:
- futex_lock_mm(fshared);
-
+ q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, fshared, &q.key);
if (unlikely(ret != 0))
goto out_release_sem;
* exit to complete.
*/
queue_unlock(&q, hb);
- futex_unlock_mm(fshared);
cond_resched();
goto retry;
*/
queue_me(&q, hb);
- /*
- * Now the futex is queued and we have checked the data, we
- * don't want to hold mmap_sem while we sleep.
- */
- futex_unlock_mm(fshared);
-
WARN_ON(!q.pi_state);
/*
* Block on the PI mutex:
ret = ret ? 0 : -EWOULDBLOCK;
}
- futex_lock_mm(fshared);
spin_lock(q.lock_ptr);
if (!ret) {
/* Unqueue and drop the lock */
unqueue_me_pi(&q);
- futex_unlock_mm(fshared);
if (to)
destroy_hrtimer_on_stack(&to->timer);
queue_unlock(&q, hb);
out_release_sem:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &q.key);
if (to)
destroy_hrtimer_on_stack(&to->timer);
return ret;
queue_unlock(&q, hb);
if (attempt++) {
- ret = futex_handle_fault((unsigned long)uaddr, fshared,
- attempt);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt);
if (ret)
goto out_release_sem;
goto retry_unlocked;
}
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
if (!ret && (uval != -EFAULT))
goto retry;
* This is the in-kernel slowpath: we look up the PI state (if any),
* and do the rt-mutex unlock.
*/
-static int futex_unlock_pi(u32 __user *uaddr, struct rw_semaphore *fshared)
+static int futex_unlock_pi(u32 __user *uaddr, int fshared)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
u32 uval;
struct plist_head *head;
- union futex_key key;
+ union futex_key key = FUTEX_KEY_INIT;
int ret, attempt = 0;
retry:
*/
if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
return -EPERM;
- /*
- * First take all the futex related locks:
- */
- futex_lock_mm(fshared);
ret = get_futex_key(uaddr, fshared, &key);
if (unlikely(ret != 0))
out_unlock:
spin_unlock(&hb->lock);
out:
- futex_unlock_mm(fshared);
+ put_futex_key(fshared, &key);
return ret;
spin_unlock(&hb->lock);
if (attempt++) {
- ret = futex_handle_fault((unsigned long)uaddr, fshared,
- attempt);
+ ret = futex_handle_fault((unsigned long)uaddr, attempt);
if (ret)
goto out;
uval = 0;
goto retry_unlocked;
}
- futex_unlock_mm(fshared);
-
ret = get_user(uval, uaddr);
if (!ret && (uval != -EFAULT))
goto retry;
* PI futexes happens in exit_pi_state():
*/
if (!pi && (uval & FUTEX_WAITERS))
- futex_wake(uaddr, &curr->mm->mmap_sem, 1,
- FUTEX_BITSET_MATCH_ANY);
+ futex_wake(uaddr, 1, 1, FUTEX_BITSET_MATCH_ANY);
}
return 0;
}
{
int ret = -ENOSYS;
int cmd = op & FUTEX_CMD_MASK;
- struct rw_semaphore *fshared = NULL;
+ int fshared = 0;
if (!(op & FUTEX_PRIVATE_FLAG))
- fshared = ¤t->mm->mmap_sem;
+ fshared = 1;
switch (cmd) {
case FUTEX_WAIT:
#ifdef CONFIG_LOCK_STAT
static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
-static int lock_contention_point(struct lock_class *class, unsigned long ip)
+static int lock_point(unsigned long points[], unsigned long ip)
{
int i;
- for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
- if (class->contention_point[i] == 0) {
- class->contention_point[i] = ip;
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
+ if (points[i] == 0) {
+ points[i] = ip;
break;
}
- if (class->contention_point[i] == ip)
+ if (points[i] == ip)
break;
}
for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
stats.contention_point[i] += pcs->contention_point[i];
+ for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++)
+ stats.contending_point[i] += pcs->contending_point[i];
+
lock_time_add(&pcs->read_waittime, &stats.read_waittime);
lock_time_add(&pcs->write_waittime, &stats.write_waittime);
memset(cpu_stats, 0, sizeof(struct lock_class_stats));
}
memset(class->contention_point, 0, sizeof(class->contention_point));
+ memset(class->contending_point, 0, sizeof(class->contending_point));
}
static struct lock_class_stats *get_lock_stats(struct lock_class *class)
struct held_lock *hlock, *prev_hlock;
struct lock_class_stats *stats;
unsigned int depth;
- int i, point;
+ int i, contention_point, contending_point;
depth = curr->lockdep_depth;
if (DEBUG_LOCKS_WARN_ON(!depth))
found_it:
hlock->waittime_stamp = sched_clock();
- point = lock_contention_point(hlock_class(hlock), ip);
+ contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
+ contending_point = lock_point(hlock_class(hlock)->contending_point,
+ lock->ip);
stats = get_lock_stats(hlock_class(hlock));
- if (point < ARRAY_SIZE(stats->contention_point))
- stats->contention_point[point]++;
+ if (contention_point < LOCKSTAT_POINTS)
+ stats->contention_point[contention_point]++;
+ if (contending_point < LOCKSTAT_POINTS)
+ stats->contending_point[contending_point]++;
if (lock->cpu != smp_processor_id())
stats->bounces[bounce_contended + !!hlock->read]++;
put_lock_stats(stats);
}
static void
-__lock_acquired(struct lockdep_map *lock)
+__lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
struct task_struct *curr = current;
struct held_lock *hlock, *prev_hlock;
put_lock_stats(stats);
lock->cpu = cpu;
+ lock->ip = ip;
}
void lock_contended(struct lockdep_map *lock, unsigned long ip)
}
EXPORT_SYMBOL_GPL(lock_contended);
-void lock_acquired(struct lockdep_map *lock)
+void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
- __lock_acquired(lock);
+ __lock_acquired(lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
{
printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
- printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
+ printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
printk("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
printk("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
- printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
+ printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
printk("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
static void snprint_time(char *buf, size_t bufsiz, s64 nr)
{
- unsigned long rem;
+ s64 div;
+ s32 rem;
nr += 5; /* for display rounding */
- rem = do_div(nr, 1000); /* XXX: do_div_signed */
- snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, (int)rem/10);
+ div = div_s64_rem(nr, 1000, &rem);
+ snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
}
static void seq_time(struct seq_file *m, s64 time)
if (stats->read_holdtime.nr)
namelen += 2;
- for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
char sym[KSYM_SYMBOL_LEN];
char ip[32];
stats->contention_point[i],
ip, sym);
}
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
+ char sym[KSYM_SYMBOL_LEN];
+ char ip[32];
+
+ if (class->contending_point[i] == 0)
+ break;
+
+ if (!i)
+ seq_line(m, '-', 40-namelen, namelen);
+
+ sprint_symbol(sym, class->contending_point[i]);
+ snprintf(ip, sizeof(ip), "[<%p>]",
+ (void *)class->contending_point[i]);
+ seq_printf(m, "%40s %14lu %29s %s\n", name,
+ stats->contending_point[i],
+ ip, sym);
+ }
if (i) {
seq_puts(m, "\n");
seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
static void seq_header(struct seq_file *m)
{
- seq_printf(m, "lock_stat version 0.2\n");
+ seq_printf(m, "lock_stat version 0.3\n");
seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
"%14s %14s\n",
* We also put the fastpath first in the kernel image, to make sure the
* branch is predicted by the CPU as default-untaken.
*/
-static void noinline __sched
+static __used noinline void __sched
__mutex_lock_slowpath(atomic_t *lock_count);
/***
EXPORT_SYMBOL(mutex_lock);
#endif
-static noinline void __sched __mutex_unlock_slowpath(atomic_t *lock_count);
+static __used noinline void __sched __mutex_unlock_slowpath(atomic_t *lock_count);
/***
* mutex_unlock - release the mutex
}
done:
- lock_acquired(&lock->dep_map);
+ lock_acquired(&lock->dep_map, ip);
/* got the lock - rejoice! */
mutex_remove_waiter(lock, &waiter, task_thread_info(task));
debug_mutex_set_owner(lock, task_thread_info(task));
/*
* Release the lock, slowpath:
*/
-static noinline void
+static __used noinline void
__mutex_unlock_slowpath(atomic_t *lock_count)
{
__mutex_unlock_common_slowpath(lock_count, 1);
}
EXPORT_SYMBOL(mutex_lock_killable);
-static noinline void __sched
+static __used noinline void __sched
__mutex_lock_slowpath(atomic_t *lock_count)
{
struct mutex *lock = container_of(lock_count, struct mutex, count);
while (nb && nr_to_call) {
next_nb = rcu_dereference(nb->next);
+
+#ifdef CONFIG_DEBUG_NOTIFIERS
+ if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {
+ WARN(1, "Invalid notifier called!");
+ nb = next_nb;
+ continue;
+ }
+#endif
ret = nb->notifier_call(nb, val, v);
if (nr_calls)
struct task_struct *tsk,
struct task_cputime *times)
{
- struct signal_struct *sig;
+ struct task_cputime *totals, *tot;
int i;
- struct task_cputime *tot;
- sig = tsk->signal;
- if (unlikely(!sig) || !sig->cputime.totals) {
+ totals = tsk->signal->cputime.totals;
+ if (!totals) {
times->utime = tsk->utime;
times->stime = tsk->stime;
times->sum_exec_runtime = tsk->se.sum_exec_runtime;
return;
}
+
times->stime = times->utime = cputime_zero;
times->sum_exec_runtime = 0;
for_each_possible_cpu(i) {
- tot = per_cpu_ptr(tsk->signal->cputime.totals, i);
+ tot = per_cpu_ptr(totals, i);
times->utime = cputime_add(times->utime, tot->utime);
times->stime = cputime_add(times->stime, tot->stime);
times->sum_exec_runtime += tot->sum_exec_runtime;
/* OK, time to rat on our buddy... */
- printk(KERN_ERR "RCU detected CPU stalls:");
+ printk(KERN_ERR "INFO: RCU detected CPU stalls:");
for_each_possible_cpu(cpu) {
if (cpu_isset(cpu, rcp->cpumask))
printk(" %d", cpu);
{
unsigned long flags;
- printk(KERN_ERR "RCU detected CPU %d stall (t=%lu/%lu jiffies)\n",
+ printk(KERN_ERR "INFO: RCU detected CPU %d stall (t=%lu/%lu jiffies)\n",
smp_processor_id(), jiffies,
jiffies - rcp->gp_start);
dump_stack();
if (p == rq->idle) {
p->stime = cputime_add(p->stime, steal);
- account_group_system_time(p, steal);
if (atomic_read(&rq->nr_iowait) > 0)
cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
else
/*
* Underflow?
*/
- if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
+ if (DEBUG_LOCKS_WARN_ON(val > preempt_count() - (!!kernel_locked())))
return;
/*
* Is the spinlock portion underflowing?
/*
* Zero means infinite timeout - no checking done:
*/
-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
+unsigned long __read_mostly sysctl_hung_task_timeout_secs = 480;
unsigned long __read_mostly sysctl_hung_task_warnings = 10;
struct task_cputime cputime;
cputime_t cutime, cstime;
- spin_lock_irq(¤t->sighand->siglock);
thread_group_cputime(current, &cputime);
+ spin_lock_irq(¤t->sighand->siglock);
cutime = current->signal->cutime;
cstime = current->signal->cstime;
spin_unlock_irq(¤t->sighand->siglock);
If unsure, say N.
+config DEBUG_NOTIFIERS
+ bool "Debug notifier call chains"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on sanity checking for notifier call chains.
+ This is most useful for kernel developers to make sure that
+ modules properly unregister themselves from notifier chains.
+ This is a relatively cheap check but if you care about maximum
+ performance, say N.
+
config FRAME_POINTER
bool "Compile the kernel with frame pointers"
depends on DEBUG_KERNEL && \
}
up_read(¤t->mm->mmap_sem);
}
+
+#ifdef CONFIG_PROVE_LOCKING
+void might_fault(void)
+{
+ might_sleep();
+ /*
+ * it would be nicer only to annotate paths which are not under
+ * pagefault_disable, however that requires a larger audit and
+ * providing helpers like get_user_atomic.
+ */
+ if (!in_atomic() && current->mm)
+ might_lock_read(¤t->mm->mmap_sem);
+}
+EXPORT_SYMBOL(might_fault);
+#endif
projects / linux-2.6-omap-h63xx.git / commitdiff