diff options
Diffstat (limited to 'lib/ref_tracker.c')
| -rw-r--r-- | lib/ref_tracker.c | 179 |
1 files changed, 149 insertions, 30 deletions
diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c index dc7b14aa3431..cf5609b1ca79 100644 --- a/lib/ref_tracker.c +++ b/lib/ref_tracker.c @@ -1,11 +1,16 @@ // SPDX-License-Identifier: GPL-2.0-or-later + +#define pr_fmt(fmt) "ref_tracker: " fmt + #include <linux/export.h> +#include <linux/list_sort.h> #include <linux/ref_tracker.h> #include <linux/slab.h> #include <linux/stacktrace.h> #include <linux/stackdepot.h> #define REF_TRACKER_STACK_ENTRIES 16 +#define STACK_BUF_SIZE 1024 struct ref_tracker { struct list_head head; /* anchor into dir->list or dir->quarantine */ @@ -14,6 +19,141 @@ struct ref_tracker { depot_stack_handle_t free_stack_handle; }; +struct ref_tracker_dir_stats { + int total; + int count; + struct { + depot_stack_handle_t stack_handle; + unsigned int count; + } stacks[]; +}; + +static struct ref_tracker_dir_stats * +ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit) +{ + struct ref_tracker_dir_stats *stats; + struct ref_tracker *tracker; + + stats = kmalloc(struct_size(stats, stacks, limit), + GFP_NOWAIT | __GFP_NOWARN); + if (!stats) + return ERR_PTR(-ENOMEM); + stats->total = 0; + stats->count = 0; + + list_for_each_entry(tracker, &dir->list, head) { + depot_stack_handle_t stack = tracker->alloc_stack_handle; + int i; + + ++stats->total; + for (i = 0; i < stats->count; ++i) + if (stats->stacks[i].stack_handle == stack) + break; + if (i >= limit) + continue; + if (i >= stats->count) { + stats->stacks[i].stack_handle = stack; + stats->stacks[i].count = 0; + ++stats->count; + } + ++stats->stacks[i].count; + } + + return stats; +} + +struct ostream { + char *buf; + int size, used; +}; + +#define pr_ostream(stream, fmt, args...) \ +({ \ + struct ostream *_s = (stream); \ +\ + if (!_s->buf) { \ + pr_err(fmt, ##args); \ + } else { \ + int ret, len = _s->size - _s->used; \ + ret = snprintf(_s->buf + _s->used, len, pr_fmt(fmt), ##args); \ + _s->used += min(ret, len); \ + } \ +}) + +static void +__ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir, + unsigned int display_limit, struct ostream *s) +{ + struct ref_tracker_dir_stats *stats; + unsigned int i = 0, skipped; + depot_stack_handle_t stack; + char *sbuf; + + lockdep_assert_held(&dir->lock); + + if (list_empty(&dir->list)) + return; + + stats = ref_tracker_get_stats(dir, display_limit); + if (IS_ERR(stats)) { + pr_ostream(s, "%s@%pK: couldn't get stats, error %pe\n", + dir->name, dir, stats); + return; + } + + sbuf = kmalloc(STACK_BUF_SIZE, GFP_NOWAIT | __GFP_NOWARN); + + for (i = 0, skipped = stats->total; i < stats->count; ++i) { + stack = stats->stacks[i].stack_handle; + if (sbuf && !stack_depot_snprint(stack, sbuf, STACK_BUF_SIZE, 4)) + sbuf[0] = 0; + pr_ostream(s, "%s@%pK has %d/%d users at\n%s\n", dir->name, dir, + stats->stacks[i].count, stats->total, sbuf); + skipped -= stats->stacks[i].count; + } + + if (skipped) + pr_ostream(s, "%s@%pK skipped reports about %d/%d users.\n", + dir->name, dir, skipped, stats->total); + + kfree(sbuf); + + kfree(stats); +} + +void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + struct ostream os = {}; + + __ref_tracker_dir_pr_ostream(dir, display_limit, &os); +} +EXPORT_SYMBOL(ref_tracker_dir_print_locked); + +void ref_tracker_dir_print(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + unsigned long flags; + + spin_lock_irqsave(&dir->lock, flags); + ref_tracker_dir_print_locked(dir, display_limit); + spin_unlock_irqrestore(&dir->lock, flags); +} +EXPORT_SYMBOL(ref_tracker_dir_print); + +int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size) +{ + struct ostream os = { .buf = buf, .size = size }; + unsigned long flags; + + spin_lock_irqsave(&dir->lock, flags); + __ref_tracker_dir_pr_ostream(dir, 16, &os); + spin_unlock_irqrestore(&dir->lock, flags); + + return os.used; +} +EXPORT_SYMBOL(ref_tracker_dir_snprint); + void ref_tracker_dir_exit(struct ref_tracker_dir *dir) { struct ref_tracker *tracker, *n; @@ -27,13 +167,13 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) kfree(tracker); dir->quarantine_avail++; } - list_for_each_entry_safe(tracker, n, &dir->list, head) { - pr_err("leaked reference.\n"); - if (tracker->alloc_stack_handle) - stack_depot_print(tracker->alloc_stack_handle); + if (!list_empty(&dir->list)) { + ref_tracker_dir_print_locked(dir, 16); leak = true; - list_del(&tracker->head); - kfree(tracker); + list_for_each_entry_safe(tracker, n, &dir->list, head) { + list_del(&tracker->head); + kfree(tracker); + } } spin_unlock_irqrestore(&dir->lock, flags); WARN_ON_ONCE(leak); @@ -42,28 +182,6 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) } EXPORT_SYMBOL(ref_tracker_dir_exit); -void ref_tracker_dir_print(struct ref_tracker_dir *dir, - unsigned int display_limit) -{ - struct ref_tracker *tracker; - unsigned long flags; - unsigned int i = 0; - - spin_lock_irqsave(&dir->lock, flags); - list_for_each_entry(tracker, &dir->list, head) { - if (i < display_limit) { - pr_err("leaked reference.\n"); - if (tracker->alloc_stack_handle) - stack_depot_print(tracker->alloc_stack_handle); - i++; - } else { - break; - } - } - spin_unlock_irqrestore(&dir->lock, flags); -} -EXPORT_SYMBOL(ref_tracker_dir_print); - int ref_tracker_alloc(struct ref_tracker_dir *dir, struct ref_tracker **trackerp, gfp_t gfp) @@ -71,7 +189,7 @@ int ref_tracker_alloc(struct ref_tracker_dir *dir, unsigned long entries[REF_TRACKER_STACK_ENTRIES]; struct ref_tracker *tracker; unsigned int nr_entries; - gfp_t gfp_mask = gfp; + gfp_t gfp_mask = gfp | __GFP_NOWARN; unsigned long flags; WARN_ON_ONCE(dir->dead); @@ -119,7 +237,8 @@ int ref_tracker_free(struct ref_tracker_dir *dir, return -EEXIST; } nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 1); - stack_handle = stack_depot_save(entries, nr_entries, GFP_ATOMIC); + stack_handle = stack_depot_save(entries, nr_entries, + GFP_NOWAIT | __GFP_NOWARN); spin_lock_irqsave(&dir->lock, flags); if (tracker->dead) { |