diff options
Diffstat (limited to 'kernel/locking/lockdep.c')
-rw-r--r-- | kernel/locking/lockdep.c | 74 |
1 files changed, 41 insertions, 33 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 44c8d0d..9776da8 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -47,7 +47,6 @@ #include <linux/stringify.h> #include <linux/bitops.h> #include <linux/gfp.h> -#include <linux/kmemcheck.h> #include <linux/random.h> #include <linux/jhash.h> @@ -76,6 +75,19 @@ module_param(lock_stat, int, 0644); #define lock_stat 0 #endif +#ifdef CONFIG_BOOTPARAM_LOCKDEP_CROSSRELEASE_FULLSTACK +static int crossrelease_fullstack = 1; +#else +static int crossrelease_fullstack; +#endif +static int __init allow_crossrelease_fullstack(char *str) +{ + crossrelease_fullstack = 1; + return 0; +} + +early_param("crossrelease_fullstack", allow_crossrelease_fullstack); + /* * lockdep_lock: protects the lockdep graph, the hashes and the * class/list/hash allocators. @@ -1873,10 +1885,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, struct held_lock *next, int distance, struct stack_trace *trace, int (*save)(struct stack_trace *trace)) { + struct lock_list *uninitialized_var(target_entry); struct lock_list *entry; - int ret; struct lock_list this; - struct lock_list *uninitialized_var(target_entry); + int ret; /* * Prove that the new <prev> -> <next> dependency would not @@ -1890,8 +1902,17 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, this.class = hlock_class(next); this.parent = NULL; ret = check_noncircular(&this, hlock_class(prev), &target_entry); - if (unlikely(!ret)) + if (unlikely(!ret)) { + if (!trace->entries) { + /* + * If @save fails here, the printing might trigger + * a WARN but because of the !nr_entries it should + * not do bad things. + */ + save(trace); + } return print_circular_bug(&this, target_entry, next, prev, trace); + } else if (unlikely(ret < 0)) return print_bfs_bug(ret); @@ -1938,7 +1959,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, return print_bfs_bug(ret); - if (save && !save(trace)) + if (!trace->entries && !save(trace)) return 0; /* @@ -1958,20 +1979,6 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, if (!ret) return 0; - /* - * Debugging printouts: - */ - if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) { - graph_unlock(); - printk("\n new dependency: "); - print_lock_name(hlock_class(prev)); - printk(KERN_CONT " => "); - print_lock_name(hlock_class(next)); - printk(KERN_CONT "\n"); - dump_stack(); - if (!graph_lock()) - return 0; - } return 2; } @@ -1986,8 +1993,12 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) { int depth = curr->lockdep_depth; struct held_lock *hlock; - struct stack_trace trace; - int (*save)(struct stack_trace *trace) = save_trace; + struct stack_trace trace = { + .nr_entries = 0, + .max_entries = 0, + .entries = NULL, + .skip = 0, + }; /* * Debugging checks. @@ -2018,18 +2029,11 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) */ if (hlock->read != 2 && hlock->check) { int ret = check_prev_add(curr, hlock, next, - distance, &trace, save); + distance, &trace, save_trace); if (!ret) return 0; /* - * Stop saving stack_trace if save_trace() was - * called at least once: - */ - if (save && ret == 2) - save = NULL; - - /* * Stop after the first non-trylock entry, * as non-trylock entries have added their * own direct dependencies already, so this @@ -3233,8 +3237,6 @@ static void __lockdep_init_map(struct lockdep_map *lock, const char *name, { int i; - kmemcheck_mark_initialized(lock, sizeof(*lock)); - for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++) lock->class_cache[i] = NULL; @@ -4871,8 +4873,14 @@ static void add_xhlock(struct held_lock *hlock) xhlock->trace.nr_entries = 0; xhlock->trace.max_entries = MAX_XHLOCK_TRACE_ENTRIES; xhlock->trace.entries = xhlock->trace_entries; - xhlock->trace.skip = 3; - save_stack_trace(&xhlock->trace); + + if (crossrelease_fullstack) { + xhlock->trace.skip = 3; + save_stack_trace(&xhlock->trace); + } else { + xhlock->trace.nr_entries = 1; + xhlock->trace.entries[0] = hlock->acquire_ip; + } } static inline int same_context_xhlock(struct hist_lock *xhlock) |