diff options
Diffstat (limited to 'kernel/dma/debug.c')
-rw-r--r-- | kernel/dma/debug.c | 320 |
1 files changed, 161 insertions, 159 deletions
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 14de1271463f..e43c6de2bce4 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -53,15 +53,16 @@ enum map_err_types { * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping * @list: node on pre-allocated free_entries list * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent + * @dev_addr: dma address * @size: length of the mapping * @type: single, page, sg, coherent * @direction: enum dma_data_direction * @sg_call_ents: 'nents' from dma_map_sg * @sg_mapped_ents: 'mapped_ents' from dma_map_sg - * @pfn: page frame of the start address - * @offset: offset of mapping relative to pfn + * @paddr: physical start address of the mapping * @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; @@ -72,8 +73,7 @@ struct dma_debug_entry { int direction; int sg_call_ents; int sg_mapped_ents; - unsigned long pfn; - size_t offset; + phys_addr_t paddr; enum map_err_types map_err_type; #ifdef CONFIG_STACKTRACE unsigned int stack_len; @@ -138,7 +138,7 @@ 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", }; @@ -350,11 +350,10 @@ static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, unsigned long *flags) { - unsigned int max_range = dma_get_max_seg_size(ref->dev); struct dma_debug_entry *entry, index = *ref; - unsigned int range = 0; + int limit = min(HASH_SIZE, (index.dev_addr >> HASH_FN_SHIFT) + 1); - while (range <= max_range) { + for (int i = 0; i < limit; i++) { entry = __hash_bucket_find(*bucket, ref, containing_match); if (entry) @@ -364,7 +363,6 @@ static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, * Nothing found, go back a hash bucket */ put_hash_bucket(*bucket, *flags); - range += (1 << HASH_FN_SHIFT); index.dev_addr -= (1 << HASH_FN_SHIFT); *bucket = get_hash_bucket(&index, flags); } @@ -389,45 +387,6 @@ static void hash_bucket_del(struct dma_debug_entry *entry) list_del(&entry->list); } -static unsigned long long phys_addr(struct dma_debug_entry *entry) -{ - if (entry->type == dma_debug_resource) - return __pfn_to_phys(entry->pfn) + entry->offset; - - return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset; -} - -/* - * Dump mapping entries for debugging purposes - */ -void debug_dma_dump_mappings(struct device *dev) -{ - int idx; - - for (idx = 0; idx < HASH_SIZE; idx++) { - struct hash_bucket *bucket = &dma_entry_hash[idx]; - struct dma_debug_entry *entry; - unsigned long flags; - - spin_lock_irqsave(&bucket->lock, flags); - - list_for_each_entry(entry, &bucket->list, list) { - if (!dev || dev == entry->dev) { - dev_info(entry->dev, - "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n", - type2name[entry->type], idx, - phys_addr(entry), entry->pfn, - entry->dev_addr, entry->size, - dir2name[entry->direction], - maperr2str[entry->map_err_type]); - } - } - - spin_unlock_irqrestore(&bucket->lock, flags); - cond_resched(); - } -} - /* * For each mapping (initial cacheline in the case of * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a @@ -447,8 +406,11 @@ void debug_dma_dump_mappings(struct device *dev) * dma_active_cacheline entry to track per event. dma_map_sg(), on the * other hand, consumes a single dma_debug_entry, but inserts 'nents' * entries into the tree. + * + * Use __GFP_NOWARN because the printk from an OOM, to netconsole, could end + * up right back in the DMA debugging code, leading to a deadlock. */ -static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT); +static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC | __GFP_NOWARN); static DEFINE_SPINLOCK(radix_lock); #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1) #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT) @@ -456,8 +418,8 @@ static DEFINE_SPINLOCK(radix_lock); static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry) { - return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) + - (entry->offset >> L1_CACHE_SHIFT); + return ((entry->paddr >> PAGE_SHIFT) << CACHELINE_PER_PAGE_SHIFT) + + (offset_in_page(entry->paddr) >> L1_CACHE_SHIFT); } static int active_cacheline_read_overlap(phys_addr_t cln) @@ -549,10 +511,74 @@ static void active_cacheline_remove(struct dma_debug_entry *entry) } /* + * Dump mappings entries on kernel space for debugging purposes + */ +void debug_dma_dump_mappings(struct device *dev) +{ + int idx; + phys_addr_t cln; + + for (idx = 0; idx < HASH_SIZE; idx++) { + struct hash_bucket *bucket = &dma_entry_hash[idx]; + struct dma_debug_entry *entry; + unsigned long flags; + + spin_lock_irqsave(&bucket->lock, flags); + list_for_each_entry(entry, &bucket->list, list) { + if (!dev || dev == entry->dev) { + cln = to_cacheline_number(entry); + dev_info(entry->dev, + "%s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s\n", + type2name[entry->type], idx, + &entry->paddr, entry->dev_addr, + entry->size, &cln, + dir2name[entry->direction], + maperr2str[entry->map_err_type]); + } + } + spin_unlock_irqrestore(&bucket->lock, flags); + + cond_resched(); + } +} + +/* + * Dump mappings entries on user space via debugfs + */ +static int dump_show(struct seq_file *seq, void *v) +{ + int idx; + phys_addr_t cln; + + for (idx = 0; idx < HASH_SIZE; idx++) { + struct hash_bucket *bucket = &dma_entry_hash[idx]; + struct dma_debug_entry *entry; + unsigned long flags; + + spin_lock_irqsave(&bucket->lock, flags); + list_for_each_entry(entry, &bucket->list, list) { + cln = to_cacheline_number(entry); + seq_printf(seq, + "%s %s %s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s\n", + dev_driver_string(entry->dev), + dev_name(entry->dev), + type2name[entry->type], idx, + &entry->paddr, entry->dev_addr, + entry->size, &cln, + dir2name[entry->direction], + maperr2str[entry->map_err_type]); + } + spin_unlock_irqrestore(&bucket->lock, flags); + } + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dump); + +/* * Wrapper function for adding an entry to the hash. * This function takes care of locking itself. */ -static void add_dma_entry(struct dma_debug_entry *entry) +static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) { struct hash_bucket *bucket; unsigned long flags; @@ -564,13 +590,12 @@ static void add_dma_entry(struct dma_debug_entry *entry) rc = active_cacheline_insert(entry); if (rc == -ENOMEM) { - pr_err("cacheline tracking ENOMEM, dma-debug disabled\n"); + pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n"); global_disable = true; + } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { + err_printk(entry->dev, entry, + "cacheline tracking EEXIST, overlapping mappings aren't supported\n"); } - - /* TODO: report -EEXIST errors here as overlapping mappings are - * not supported by the DMA API - */ } static int dma_debug_create_entries(gfp_t gfp) @@ -606,15 +631,19 @@ 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)); } } @@ -625,8 +654,10 @@ 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) { @@ -636,13 +667,17 @@ 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), @@ -767,34 +802,7 @@ static const struct file_operations filter_fops = { .llseek = default_llseek, }; -static int dump_show(struct seq_file *seq, void *v) -{ - int idx; - - for (idx = 0; idx < HASH_SIZE; idx++) { - struct hash_bucket *bucket = &dma_entry_hash[idx]; - struct dma_debug_entry *entry; - unsigned long flags; - - spin_lock_irqsave(&bucket->lock, flags); - list_for_each_entry(entry, &bucket->list, list) { - seq_printf(seq, - "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n", - dev_name(entry->dev), - dev_driver_string(entry->dev), - type2name[entry->type], idx, - phys_addr(entry), entry->pfn, - entry->dev_addr, entry->size, - dir2name[entry->direction], - maperr2str[entry->map_err_type]); - } - spin_unlock_irqrestore(&bucket->lock, flags); - } - return 0; -} -DEFINE_SHOW_ATTRIBUTE(dump); - -static void dma_debug_fs_init(void) +static int __init dma_debug_fs_init(void) { struct dentry *dentry = debugfs_create_dir("dma-api", NULL); @@ -807,7 +815,10 @@ static void dma_debug_fs_init(void) debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries); debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops); debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops); + + return 0; } +core_initcall_sync(dma_debug_fs_init); static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) { @@ -859,7 +870,7 @@ 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; @@ -892,8 +903,6 @@ static int dma_debug_init(void) spin_lock_init(&dma_entry_hash[i].lock); } - dma_debug_fs_init(); - nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES); for (i = 0; i < nr_pages; ++i) dma_debug_create_entries(GFP_KERNEL); @@ -927,7 +936,7 @@ static __init int dma_debug_cmdline(char *str) global_disable = true; } - return 0; + return 1; } static __init int dma_debug_entries_cmdline(char *str) @@ -936,7 +945,7 @@ static __init int dma_debug_entries_cmdline(char *str) return -EINVAL; if (!get_option(&str, &nr_prealloc_entries)) nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; - return 0; + return 1; } __setup("dma_debug=", dma_debug_cmdline); @@ -984,16 +993,16 @@ static void check_unmap(struct dma_debug_entry *ref) "[mapped as %s] [unmapped as %s]\n", ref->dev_addr, ref->size, type2name[entry->type], type2name[ref->type]); - } else if ((entry->type == dma_debug_coherent) && - (phys_addr(ref) != phys_addr(entry))) { + } else if (entry->type == dma_debug_coherent && + ref->paddr != entry->paddr) { err_printk(ref->dev, entry, "device driver frees " "DMA memory with different CPU address " "[device address=0x%016llx] [size=%llu bytes] " - "[cpu alloc address=0x%016llx] " - "[cpu free address=0x%016llx]", + "[cpu alloc address=0x%pa] " + "[cpu free address=0x%pa]", ref->dev_addr, ref->size, - phys_addr(entry), - phys_addr(ref)); + &entry->paddr, + &ref->paddr); } if (ref->sg_call_ents && ref->type == dma_debug_sg && @@ -1033,9 +1042,13 @@ static void check_unmap(struct dma_debug_entry *ref) } hash_bucket_del(entry); - dma_entry_free(entry); - put_hash_bucket(bucket, flags); + + /* + * Free the entry outside of bucket_lock to avoid ABBA deadlocks + * between that and radix_lock. + */ + dma_entry_free(entry); } static void check_for_stack(struct device *dev, @@ -1066,20 +1079,10 @@ static void check_for_stack(struct device *dev, } } -static inline bool overlap(void *addr, unsigned long len, void *start, void *end) -{ - unsigned long a1 = (unsigned long)addr; - unsigned long b1 = a1 + len; - unsigned long a2 = (unsigned long)start; - unsigned long b2 = (unsigned long)end; - - return !(b1 <= a2 || a1 >= b2); -} - static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len) { - if (overlap(addr, len, _stext, _etext) || - overlap(addr, len, __start_rodata, __end_rodata)) + if (memory_intersects(_stext, _etext, addr, len) || + memory_intersects(__start_rodata, __end_rodata, addr, len)) err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len); } @@ -1160,7 +1163,6 @@ out: static void check_sg_segment(struct device *dev, struct scatterlist *sg) { -#ifdef CONFIG_DMA_API_DEBUG_SG unsigned int max_seg = dma_get_max_seg_size(dev); u64 start, end, boundary = dma_get_seg_boundary(dev); @@ -1181,7 +1183,6 @@ static void check_sg_segment(struct device *dev, struct scatterlist *sg) if ((start ^ end) & ~boundary) err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n", start, end, boundary); -#endif } void debug_dma_map_single(struct device *dev, const void *addr, @@ -1201,7 +1202,8 @@ void debug_dma_map_single(struct device *dev, const void *addr, EXPORT_SYMBOL(debug_dma_map_single); void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, - size_t size, int direction, dma_addr_t dma_addr) + size_t size, int direction, dma_addr_t dma_addr, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1217,8 +1219,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, entry->dev = dev; entry->type = dma_debug_single; - entry->pfn = page_to_pfn(page); - entry->offset = offset; + entry->paddr = page_to_phys(page) + offset; entry->dev_addr = dma_addr; entry->size = size; entry->direction = direction; @@ -1232,7 +1233,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, check_for_illegal_area(dev, addr, size); } - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) @@ -1273,13 +1274,13 @@ void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) } EXPORT_SYMBOL(debug_dma_mapping_error); -void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, +void debug_dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, int direction) { struct dma_debug_entry ref = { .type = dma_debug_single, .dev = dev, - .dev_addr = addr, + .dev_addr = dma_addr, .size = size, .direction = direction, }; @@ -1290,7 +1291,8 @@ void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, } void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, - int nents, int mapped_ents, int direction) + int nents, int mapped_ents, int direction, + unsigned long attrs) { struct dma_debug_entry *entry; struct scatterlist *s; @@ -1299,6 +1301,12 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, if (unlikely(dma_debug_disabled())) return; + for_each_sg(sg, s, nents, i) { + check_for_stack(dev, sg_page(s), s->offset); + if (!PageHighMem(sg_page(s))) + check_for_illegal_area(dev, sg_virt(s), s->length); + } + for_each_sg(sg, s, mapped_ents, i) { entry = dma_entry_alloc(); if (!entry) @@ -1306,23 +1314,16 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, entry->type = dma_debug_sg; entry->dev = dev; - entry->pfn = page_to_pfn(sg_page(s)); - entry->offset = s->offset; + entry->paddr = sg_phys(s); entry->size = sg_dma_len(s); entry->dev_addr = sg_dma_address(s); entry->direction = direction; entry->sg_call_ents = nents; entry->sg_mapped_ents = mapped_ents; - check_for_stack(dev, sg_page(s), s->offset); - - if (!PageHighMem(sg_page(s))) { - check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); - } - check_sg_segment(dev, s); - add_dma_entry(entry); + add_dma_entry(entry, attrs); } } @@ -1359,8 +1360,7 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, struct dma_debug_entry ref = { .type = dma_debug_sg, .dev = dev, - .pfn = page_to_pfn(sg_page(s)), - .offset = s->offset, + .paddr = sg_phys(s), .dev_addr = sg_dma_address(s), .size = sg_dma_len(s), .direction = dir, @@ -1377,8 +1377,21 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, } } +static phys_addr_t virt_to_paddr(void *virt) +{ + struct page *page; + + if (is_vmalloc_addr(virt)) + page = vmalloc_to_page(virt); + else + page = virt_to_page(virt); + + return page_to_phys(page) + offset_in_page(virt); +} + void debug_dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t dma_addr, void *virt) + dma_addr_t dma_addr, void *virt, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1398,27 +1411,21 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size, entry->type = dma_debug_coherent; entry->dev = dev; - entry->offset = offset_in_page(virt); + entry->paddr = virt_to_paddr(virt); entry->size = size; entry->dev_addr = dma_addr; entry->direction = DMA_BIDIRECTIONAL; - if (is_vmalloc_addr(virt)) - entry->pfn = vmalloc_to_pfn(virt); - else - entry->pfn = page_to_pfn(virt_to_page(virt)); - - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_free_coherent(struct device *dev, size_t size, - void *virt, dma_addr_t addr) + void *virt, dma_addr_t dma_addr) { struct dma_debug_entry ref = { .type = dma_debug_coherent, .dev = dev, - .offset = offset_in_page(virt), - .dev_addr = addr, + .dev_addr = dma_addr, .size = size, .direction = DMA_BIDIRECTIONAL, }; @@ -1427,10 +1434,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size, if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt)) return; - if (is_vmalloc_addr(virt)) - ref.pfn = vmalloc_to_pfn(virt); - else - ref.pfn = page_to_pfn(virt_to_page(virt)); + ref.paddr = virt_to_paddr(virt); if (unlikely(dma_debug_disabled())) return; @@ -1439,7 +1443,8 @@ void debug_dma_free_coherent(struct device *dev, size_t size, } void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, - int direction, dma_addr_t dma_addr) + int direction, dma_addr_t dma_addr, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1452,14 +1457,13 @@ void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, entry->type = dma_debug_resource; entry->dev = dev; - entry->pfn = PHYS_PFN(addr); - entry->offset = offset_in_page(addr); + entry->paddr = addr; entry->size = size; entry->dev_addr = dma_addr; entry->direction = direction; entry->map_err_type = MAP_ERR_NOT_CHECKED; - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr, @@ -1530,8 +1534,7 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, struct dma_debug_entry ref = { .type = dma_debug_sg, .dev = dev, - .pfn = page_to_pfn(sg_page(s)), - .offset = s->offset, + .paddr = sg_phys(s), .dev_addr = sg_dma_address(s), .size = sg_dma_len(s), .direction = direction, @@ -1562,8 +1565,7 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, struct dma_debug_entry ref = { .type = dma_debug_sg, .dev = dev, - .pfn = page_to_pfn(sg_page(s)), - .offset = s->offset, + .paddr = sg_phys(sg), .dev_addr = sg_dma_address(s), .size = sg_dma_len(s), .direction = direction, |