diff options
| -rw-r--r-- | MAINTAINERS | 2 | ||||
| -rw-r--r-- | include/linux/atomic.h | 34 | ||||
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | include/uapi/linux/stddef.h | 4 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 79 | ||||
| -rw-r--r-- | kernel/sched/core.c | 18 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 61 | ||||
| -rw-r--r-- | kernel/time/tick-sched.h | 2 | ||||
| -rwxr-xr-x | tools/lib/lockdep/run_tests.sh | 12 |
9 files changed, 158 insertions, 58 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index fbd6f5288116..1c32f8a3d6c4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6403,7 +6403,7 @@ KPROBES M: Ananth N Mavinakayanahalli <ananth@in.ibm.com> M: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> M: "David S. Miller" <davem@davemloft.net> -M: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> +M: Masami Hiramatsu <mhiramat@kernel.org> S: Maintained F: Documentation/kprobes.txt F: include/linux/kprobes.h diff --git a/include/linux/atomic.h b/include/linux/atomic.h index df4f369254c0..506c3531832e 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -559,25 +559,25 @@ static inline int atomic_dec_if_positive(atomic_t *v) #endif /** - * fetch_or - perform *ptr |= mask and return old value of *ptr - * @ptr: pointer to value - * @mask: mask to OR on the value - * - * cmpxchg based fetch_or, macro so it works for different integer types + * atomic_fetch_or - perform *p |= mask and return old value of *p + * @p: pointer to atomic_t + * @mask: mask to OR on the atomic_t */ -#ifndef fetch_or -#define fetch_or(ptr, mask) \ -({ typeof(*(ptr)) __old, __val = *(ptr); \ - for (;;) { \ - __old = cmpxchg((ptr), __val, __val | (mask)); \ - if (__old == __val) \ - break; \ - __val = __old; \ - } \ - __old; \ -}) -#endif +#ifndef atomic_fetch_or +static inline int atomic_fetch_or(atomic_t *p, int mask) +{ + int old, val = atomic_read(p); + + for (;;) { + old = atomic_cmpxchg(p, val, val | mask); + if (old == val) + break; + val = old; + } + return old; +} +#endif #ifdef CONFIG_GENERIC_ATOMIC64 #include <asm-generic/atomic64.h> diff --git a/include/linux/sched.h b/include/linux/sched.h index 60bba7e032dc..52c4847b05e2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -720,7 +720,7 @@ struct signal_struct { struct task_cputime cputime_expires; #ifdef CONFIG_NO_HZ_FULL - unsigned long tick_dep_mask; + atomic_t tick_dep_mask; #endif struct list_head cpu_timers[3]; @@ -1549,7 +1549,7 @@ struct task_struct { #endif #ifdef CONFIG_NO_HZ_FULL - unsigned long tick_dep_mask; + atomic_t tick_dep_mask; #endif unsigned long nvcsw, nivcsw; /* context switch counts */ u64 start_time; /* monotonic time in nsec */ diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h index aa9f10428743..621fa8ac4425 100644 --- a/include/uapi/linux/stddef.h +++ b/include/uapi/linux/stddef.h @@ -1 +1,5 @@ #include <linux/compiler.h> + +#ifndef __always_inline +#define __always_inline inline +#endif diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 53ab2f85d77e..2324ba5310db 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2000,6 +2000,77 @@ static inline int get_first_held_lock(struct task_struct *curr, } /* + * Returns the next chain_key iteration + */ +static u64 print_chain_key_iteration(int class_idx, u64 chain_key) +{ + u64 new_chain_key = iterate_chain_key(chain_key, class_idx); + + printk(" class_idx:%d -> chain_key:%016Lx", + class_idx, + (unsigned long long)new_chain_key); + return new_chain_key; +} + +static void +print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next) +{ + struct held_lock *hlock; + u64 chain_key = 0; + int depth = curr->lockdep_depth; + int i; + + printk("depth: %u\n", depth + 1); + for (i = get_first_held_lock(curr, hlock_next); i < depth; i++) { + hlock = curr->held_locks + i; + chain_key = print_chain_key_iteration(hlock->class_idx, chain_key); + + print_lock(hlock); + } + + print_chain_key_iteration(hlock_next->class_idx, chain_key); + print_lock(hlock_next); +} + +static void print_chain_keys_chain(struct lock_chain *chain) +{ + int i; + u64 chain_key = 0; + int class_id; + + printk("depth: %u\n", chain->depth); + for (i = 0; i < chain->depth; i++) { + class_id = chain_hlocks[chain->base + i]; + chain_key = print_chain_key_iteration(class_id + 1, chain_key); + + print_lock_name(lock_classes + class_id); + printk("\n"); + } +} + +static void print_collision(struct task_struct *curr, + struct held_lock *hlock_next, + struct lock_chain *chain) +{ + printk("\n"); + printk("======================\n"); + printk("[chain_key collision ]\n"); + print_kernel_ident(); + printk("----------------------\n"); + printk("%s/%d: ", current->comm, task_pid_nr(current)); + printk("Hash chain already cached but the contents don't match!\n"); + + printk("Held locks:"); + print_chain_keys_held_locks(curr, hlock_next); + + printk("Locks in cached chain:"); + print_chain_keys_chain(chain); + + printk("\nstack backtrace:\n"); + dump_stack(); +} + +/* * Checks whether the chain and the current held locks are consistent * in depth and also in content. If they are not it most likely means * that there was a collision during the calculation of the chain_key. @@ -2014,14 +2085,18 @@ static int check_no_collision(struct task_struct *curr, i = get_first_held_lock(curr, hlock); - if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) + if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) { + print_collision(curr, hlock, chain); return 0; + } for (j = 0; j < chain->depth - 1; j++, i++) { id = curr->held_locks[i].class_idx - 1; - if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) + if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) { + print_collision(curr, hlock, chain); return 0; + } } #endif return 1; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d8465eeab8b3..8b489fcac37b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -321,6 +321,24 @@ static inline void init_hrtick(void) } #endif /* CONFIG_SCHED_HRTICK */ +/* + * cmpxchg based fetch_or, macro so it works for different integer types + */ +#define fetch_or(ptr, mask) \ + ({ \ + typeof(ptr) _ptr = (ptr); \ + typeof(mask) _mask = (mask); \ + typeof(*_ptr) _old, _val = *_ptr; \ + \ + for (;;) { \ + _old = cmpxchg(_ptr, _val, _val | _mask); \ + if (_old == _val) \ + break; \ + _val = _old; \ + } \ + _old; \ +}) + #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) /* * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 084b79f5917e..58e3310c9b21 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -157,52 +157,50 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) cpumask_var_t tick_nohz_full_mask; cpumask_var_t housekeeping_mask; bool tick_nohz_full_running; -static unsigned long tick_dep_mask; +static atomic_t tick_dep_mask; -static void trace_tick_dependency(unsigned long dep) +static bool check_tick_dependency(atomic_t *dep) { - if (dep & TICK_DEP_MASK_POSIX_TIMER) { + int val = atomic_read(dep); + + if (val & TICK_DEP_MASK_POSIX_TIMER) { trace_tick_stop(0, TICK_DEP_MASK_POSIX_TIMER); - return; + return true; } - if (dep & TICK_DEP_MASK_PERF_EVENTS) { + if (val & TICK_DEP_MASK_PERF_EVENTS) { trace_tick_stop(0, TICK_DEP_MASK_PERF_EVENTS); - return; + return true; } - if (dep & TICK_DEP_MASK_SCHED) { + if (val & TICK_DEP_MASK_SCHED) { trace_tick_stop(0, TICK_DEP_MASK_SCHED); - return; + return true; } - if (dep & TICK_DEP_MASK_CLOCK_UNSTABLE) + if (val & TICK_DEP_MASK_CLOCK_UNSTABLE) { trace_tick_stop(0, TICK_DEP_MASK_CLOCK_UNSTABLE); + return true; + } + + return false; } static bool can_stop_full_tick(struct tick_sched *ts) { WARN_ON_ONCE(!irqs_disabled()); - if (tick_dep_mask) { - trace_tick_dependency(tick_dep_mask); + if (check_tick_dependency(&tick_dep_mask)) return false; - } - if (ts->tick_dep_mask) { - trace_tick_dependency(ts->tick_dep_mask); + if (check_tick_dependency(&ts->tick_dep_mask)) return false; - } - if (current->tick_dep_mask) { - trace_tick_dependency(current->tick_dep_mask); + if (check_tick_dependency(¤t->tick_dep_mask)) return false; - } - if (current->signal->tick_dep_mask) { - trace_tick_dependency(current->signal->tick_dep_mask); + if (check_tick_dependency(¤t->signal->tick_dep_mask)) return false; - } return true; } @@ -259,12 +257,12 @@ static void tick_nohz_full_kick_all(void) preempt_enable(); } -static void tick_nohz_dep_set_all(unsigned long *dep, +static void tick_nohz_dep_set_all(atomic_t *dep, enum tick_dep_bits bit) { - unsigned long prev; + int prev; - prev = fetch_or(dep, BIT_MASK(bit)); + prev = atomic_fetch_or(dep, BIT(bit)); if (!prev) tick_nohz_full_kick_all(); } @@ -280,7 +278,7 @@ void tick_nohz_dep_set(enum tick_dep_bits bit) void tick_nohz_dep_clear(enum tick_dep_bits bit) { - clear_bit(bit, &tick_dep_mask); + atomic_andnot(BIT(bit), &tick_dep_mask); } /* @@ -289,12 +287,12 @@ void tick_nohz_dep_clear(enum tick_dep_bits bit) */ void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { - unsigned long prev; + int prev; struct tick_sched *ts; ts = per_cpu_ptr(&tick_cpu_sched, cpu); - prev = fetch_or(&ts->tick_dep_mask, BIT_MASK(bit)); + prev = atomic_fetch_or(&ts->tick_dep_mask, BIT(bit)); if (!prev) { preempt_disable(); /* Perf needs local kick that is NMI safe */ @@ -313,7 +311,7 @@ void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { struct tick_sched *ts = per_cpu_ptr(&tick_cpu_sched, cpu); - clear_bit(bit, &ts->tick_dep_mask); + atomic_andnot(BIT(bit), &ts->tick_dep_mask); } /* @@ -331,7 +329,7 @@ void tick_nohz_dep_set_task(struct task_struct *tsk, enum tick_dep_bits bit) void tick_nohz_dep_clear_task(struct task_struct *tsk, enum tick_dep_bits bit) { - clear_bit(bit, &tsk->tick_dep_mask); + atomic_andnot(BIT(bit), &tsk->tick_dep_mask); } /* @@ -345,7 +343,7 @@ void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits bit) void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bit) { - clear_bit(bit, &sig->tick_dep_mask); + atomic_andnot(BIT(bit), &sig->tick_dep_mask); } /* @@ -366,7 +364,8 @@ void __tick_nohz_task_switch(void) ts = this_cpu_ptr(&tick_cpu_sched); if (ts->tick_stopped) { - if (current->tick_dep_mask || current->signal->tick_dep_mask) + if (atomic_read(¤t->tick_dep_mask) || + atomic_read(¤t->signal->tick_dep_mask)) tick_nohz_full_kick(); } out: diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index eb4e32566a83..bf38226e5c17 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -60,7 +60,7 @@ struct tick_sched { u64 next_timer; ktime_t idle_expires; int do_timer_last; - unsigned long tick_dep_mask; + atomic_t tick_dep_mask; }; extern struct tick_sched *tick_get_tick_sched(int cpu); diff --git a/tools/lib/lockdep/run_tests.sh b/tools/lib/lockdep/run_tests.sh index 5334ad9d39b7..1069d96248c1 100755 --- a/tools/lib/lockdep/run_tests.sh +++ b/tools/lib/lockdep/run_tests.sh @@ -3,7 +3,7 @@ make &> /dev/null for i in `ls tests/*.c`; do - testname=$(basename -s .c "$i") + testname=$(basename "$i" .c) gcc -o tests/$testname -pthread -lpthread $i liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &> /dev/null echo -ne "$testname... " if [ $(timeout 1 ./tests/$testname | wc -l) -gt 0 ]; then @@ -11,11 +11,13 @@ for i in `ls tests/*.c`; do else echo "FAILED!" fi - rm tests/$testname + if [ -f "tests/$testname" ]; then + rm tests/$testname + fi done for i in `ls tests/*.c`; do - testname=$(basename -s .c "$i") + testname=$(basename "$i" .c) gcc -o tests/$testname -pthread -lpthread -Iinclude $i &> /dev/null echo -ne "(PRELOAD) $testname... " if [ $(timeout 1 ./lockdep ./tests/$testname | wc -l) -gt 0 ]; then @@ -23,5 +25,7 @@ for i in `ls tests/*.c`; do else echo "FAILED!" fi - rm tests/$testname + if [ -f "tests/$testname" ]; then + rm tests/$testname + fi done |