Merge branches 'core/debug', 'core/futexes', 'core/locking', 'core/rc…

…u', 'core/signal', 'core/urgent' and 'core/xen' into core/core
torvalds · Nov 24, 2008 · b19b3c7 · b19b3c7
8 parents ed31348 + 6003ab0 + 42569c3 + 7918baa + 29cbda7 + 2b5fe6d + b0788ca + 8dd2337
commit b19b3c7
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Showing 28 changed files with 315 additions and 267 deletions.
diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt
@@ -71,35 +71,50 @@ Look at the current lock statistics:
 
 # 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:
 

diff --git a/arch/um/include/asm/system.h b/arch/um/include/asm/system.h
@@ -11,21 +11,21 @@ extern int get_signals(void);
 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); \
 })
 

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
@@ -157,6 +157,7 @@ extern int __get_user_bad(void);
  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); \
@@ -241,6 +242,7 @@ extern void __put_user_8(void);
  int __ret_pu; \
  __typeof__(*(ptr)) __pu_val; \
  __chk_user_ptr(ptr); \
+ might_fault(); \
  __pu_val = x; \
  switch (sizeof(*(ptr))) { \
  case 1: \

diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
@@ -82,8 +82,8 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
 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
@@ -137,7 +137,7 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
 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;
 
@@ -159,7 +159,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n)
 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;
 

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
@@ -29,6 +29,8 @@ static __always_inline __must_check
 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) {
@@ -71,6 +73,8 @@ static __always_inline __must_check
 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) {
@@ -113,6 +117,8 @@ static __always_inline __must_check
 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);

diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
@@ -39,7 +39,7 @@ static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned lon
 #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" \
@@ -126,7 +126,7 @@ EXPORT_SYMBOL(strncpy_from_user);
 #define __do_clear_user(addr,size) \
 do { \
  int __d0; \
- might_sleep(); \
+ might_fault(); \
  __asm__ __volatile__( \
  "0: rep; stosl\n" \
  " movl %2,%0\n" \
@@ -155,7 +155,7 @@ do { \
 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;
@@ -197,7 +197,7 @@ long strnlen_user(const char __user *s, long n)
  unsigned long mask = -__addr_ok(s);
  unsigned long res, tmp;
 
- might_sleep();
+ might_fault();
 
  __asm__ __volatile__(
  " testl %0, %0\n"

diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
@@ -15,7 +15,7 @@
 #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" \
@@ -64,7 +64,7 @@ EXPORT_SYMBOL(strncpy_from_user);
 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(

diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
@@ -17,7 +17,7 @@ extern int debug_locks_off(void);
 ({ \
  int __ret = 0; \
  \
- if (unlikely(c)) {  \
+ if (!oops_in_progress && unlikely(c)) { \
  if (debug_locks_off() && !debug_locks_silent) \
  WARN_ON(1); \
  __ret = 1; \

diff --git a/include/linux/futex.h b/include/linux/futex.h
@@ -164,6 +164,8 @@ union futex_key {
  } 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);

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
@@ -141,6 +141,15 @@ extern int _cond_resched(void);
  (__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, ...)
@@ -188,6 +197,8 @@ extern unsigned long long memparse(const char *ptr, char **retptr);
 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);
 

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
@@ -73,6 +73,8 @@ struct lock_class_key {
  struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
 };
 
+#define LOCKSTAT_POINTS 4
+
 /*
  * The lock-class itself:
  */
@@ -119,7 +121,8 @@ struct lock_class {
  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
 };
 
@@ -144,6 +147,7 @@ enum bounce_type {
 
 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;
@@ -165,6 +169,7 @@ struct lockdep_map {
  const char *name;
 #ifdef CONFIG_LOCK_STAT
  int cpu;
+ unsigned long ip;
 #endif
 };
 
@@ -356,21 +361,21 @@ struct lock_class_key { };
 #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 { \
  if (!try(_lock)) { \
  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)
@@ -481,4 +486,22 @@ static inline void print_irqtrace_events(struct task_struct *curr)
 # 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 */
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
@@ -144,6 +144,8 @@ extern int __must_check mutex_lock_killable(struct mutex *lock);
 /*
  * 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);

diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
@@ -41,7 +41,7 @@
 #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 */
 

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
@@ -78,7 +78,7 @@ static inline unsigned long __copy_from_user_nocache(void *to,
  \
  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; \

diff --git a/kernel/exit.c b/kernel/exit.c
@@ -1321,10 +1321,10 @@ static int wait_task_zombie(struct task_struct *p, int options,
  * 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,