diff options
Diffstat (limited to 'kernel/dma/debug.c')
| -rw-r--r-- | kernel/dma/debug.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index f190651bcadd..a6e3792b15f8 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -62,7 +62,8 @@ enum map_err_types { * @pfn: page frame of the start address * @offset: offset of mapping relative to pfn * @map_err_type: track whether dma_mapping_error() was checked - * @stacktrace: support backtraces when a violation is detected + * @stack_len: number of backtrace entries in @stack_entries + * @stack_entries: stack of backtrace history */ struct dma_debug_entry { struct list_head list; @@ -139,7 +140,7 @@ static const char *const maperr2str[] = { static const char *type2name[] = { [dma_debug_single] = "single", - [dma_debug_sg] = "scather-gather", + [dma_debug_sg] = "scatter-gather", [dma_debug_coherent] = "coherent", [dma_debug_resource] = "resource", }; @@ -637,15 +638,19 @@ static struct dma_debug_entry *__dma_entry_alloc(void) return entry; } -static void __dma_entry_alloc_check_leak(void) +/* + * This should be called outside of free_entries_lock scope to avoid potential + * deadlocks with serial consoles that use DMA. + */ +static void __dma_entry_alloc_check_leak(u32 nr_entries) { - u32 tmp = nr_total_entries % nr_prealloc_entries; + u32 tmp = nr_entries % nr_prealloc_entries; /* Shout each time we tick over some multiple of the initial pool */ if (tmp < DMA_DEBUG_DYNAMIC_ENTRIES) { pr_info("dma_debug_entry pool grown to %u (%u00%%)\n", - nr_total_entries, - (nr_total_entries / nr_prealloc_entries)); + nr_entries, + (nr_entries / nr_prealloc_entries)); } } @@ -656,8 +661,10 @@ static void __dma_entry_alloc_check_leak(void) */ static struct dma_debug_entry *dma_entry_alloc(void) { + bool alloc_check_leak = false; struct dma_debug_entry *entry; unsigned long flags; + u32 nr_entries; spin_lock_irqsave(&free_entries_lock, flags); if (num_free_entries == 0) { @@ -667,13 +674,17 @@ static struct dma_debug_entry *dma_entry_alloc(void) pr_err("debugging out of memory - disabling\n"); return NULL; } - __dma_entry_alloc_check_leak(); + alloc_check_leak = true; + nr_entries = nr_total_entries; } entry = __dma_entry_alloc(); spin_unlock_irqrestore(&free_entries_lock, flags); + if (alloc_check_leak) + __dma_entry_alloc_check_leak(nr_entries); + #ifdef CONFIG_STACKTRACE entry->stack_len = stack_trace_save(entry->stack_entries, ARRAY_SIZE(entry->stack_entries), @@ -866,7 +877,7 @@ static int dma_debug_device_change(struct notifier_block *nb, unsigned long acti return 0; } -void dma_debug_add_bus(struct bus_type *bus) +void dma_debug_add_bus(const struct bus_type *bus) { struct notifier_block *nb; |