From e6a1a89d572c31b62d6dcf11a371c7323852d9b2 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 15 Apr 2009 18:22:41 +0900 Subject: dma-debug: add dma_debug_resize_entries() to adjust the number of dma_debug_entries We use a static value for the number of dma_debug_entries. It can be overwritten by a kernel command line option. Some IOMMUs (e.g. GART) can't set an appropriate value by a kernel command line option because they can't know such value until they finish initializing up their hardware. This patch adds dma_debug_resize_entries() enables IOMMUs to adjust the number of dma_debug_entries anytime. Signed-off-by: FUJITA Tomonori Acked-by: Joerg Roedel Cc: fujita.tomonori@lab.ntt.co.jp Cc: akpm@linux-foundation.org LKML-Reference: <20090415182234R.fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 66 insertions(+), 6 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index d3da7edc034f..5d61019330cd 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -85,6 +85,7 @@ static u32 show_num_errors = 1; static u32 num_free_entries; static u32 min_free_entries; +static u32 nr_total_entries; /* number of preallocated entries requested by kernel cmdline */ static u32 req_entries; @@ -257,6 +258,21 @@ static void add_dma_entry(struct dma_debug_entry *entry) put_hash_bucket(bucket, &flags); } +static struct dma_debug_entry *__dma_entry_alloc(void) +{ + struct dma_debug_entry *entry; + + entry = list_entry(free_entries.next, struct dma_debug_entry, list); + list_del(&entry->list); + memset(entry, 0, sizeof(*entry)); + + num_free_entries -= 1; + if (num_free_entries < min_free_entries) + min_free_entries = num_free_entries; + + return entry; +} + /* struct dma_entry allocator * * The next two functions implement the allocator for @@ -276,9 +292,7 @@ static struct dma_debug_entry *dma_entry_alloc(void) goto out; } - entry = list_entry(free_entries.next, struct dma_debug_entry, list); - list_del(&entry->list); - memset(entry, 0, sizeof(*entry)); + entry = __dma_entry_alloc(); #ifdef CONFIG_STACKTRACE entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES; @@ -286,9 +300,6 @@ static struct dma_debug_entry *dma_entry_alloc(void) entry->stacktrace.skip = 2; save_stack_trace(&entry->stacktrace); #endif - num_free_entries -= 1; - if (num_free_entries < min_free_entries) - min_free_entries = num_free_entries; out: spin_unlock_irqrestore(&free_entries_lock, flags); @@ -310,6 +321,53 @@ static void dma_entry_free(struct dma_debug_entry *entry) spin_unlock_irqrestore(&free_entries_lock, flags); } +int dma_debug_resize_entries(u32 num_entries) +{ + int i, delta, ret = 0; + unsigned long flags; + struct dma_debug_entry *entry; + LIST_HEAD(tmp); + + spin_lock_irqsave(&free_entries_lock, flags); + + if (nr_total_entries < num_entries) { + delta = num_entries - nr_total_entries; + + spin_unlock_irqrestore(&free_entries_lock, flags); + + for (i = 0; i < delta; i++) { + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + break; + + list_add_tail(&entry->list, &tmp); + } + + spin_lock_irqsave(&free_entries_lock, flags); + + list_splice(&tmp, &free_entries); + nr_total_entries += i; + num_free_entries += i; + } else { + delta = nr_total_entries - num_entries; + + for (i = 0; i < delta && !list_empty(&free_entries); i++) { + entry = __dma_entry_alloc(); + kfree(entry); + } + + nr_total_entries -= i; + } + + if (nr_total_entries != num_entries) + ret = 1; + + spin_unlock_irqrestore(&free_entries_lock, flags); + + return ret; +} +EXPORT_SYMBOL(dma_debug_resize_entries); + /* * DMA-API debugging init code * @@ -490,6 +548,8 @@ void dma_debug_init(u32 num_entries) return; } + nr_total_entries = num_free_entries; + printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n"); } -- cgit v1.2.2 From ed888aef427365d19f887c271a3a906d16422d24 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 22 May 2009 17:16:04 +0200 Subject: dma-debug: re-add dma memory leak detection This is basically a revert of commit 314eeac9 but now in a fixed version. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index cdd205d6bf7c..e47e1a08c337 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -105,6 +105,11 @@ static const char *type2name[4] = { "single", "page", static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE", "DMA_FROM_DEVICE", "DMA_NONE" }; +/* little merge helper - remove it after the merge window */ +#ifndef BUS_NOTIFY_UNBOUND_DRIVER +#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005 +#endif + /* * The access to some variables in this macro is racy. We can't use atomic_t * here because all these variables are exported to debugfs. Some of them even @@ -458,9 +463,60 @@ out_err: return -ENOMEM; } +static int device_dma_allocations(struct device *dev) +{ + struct dma_debug_entry *entry; + unsigned long flags; + int count = 0, i; + + for (i = 0; i < HASH_SIZE; ++i) { + spin_lock_irqsave(&dma_entry_hash[i].lock, flags); + list_for_each_entry(entry, &dma_entry_hash[i].list, list) { + if (entry->dev == dev) + count += 1; + } + spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags); + } + + return count; +} + +static int dma_debug_device_change(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + int count; + + + switch (action) { + case BUS_NOTIFY_UNBOUND_DRIVER: + count = device_dma_allocations(dev); + if (count == 0) + break; + err_printk(dev, NULL, "DMA-API: device driver has pending " + "DMA allocations while released from device " + "[count=%d]\n", count); + break; + default: + break; + } + + return 0; +} + void dma_debug_add_bus(struct bus_type *bus) { - /* FIXME: register notifier */ + struct notifier_block *nb; + + nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); + if (nb == NULL) { + printk(KERN_ERR "dma_debug_add_bus: out of memory\n"); + return; + } + + nb->notifier_call = dma_debug_device_change; + + bus_register_notifier(bus, nb); } /* -- cgit v1.2.2 From 15aedea439c4d7dbec17c99b5e1594c01b979833 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 27 May 2009 09:43:01 +0900 Subject: dma-debug: use sg_dma_address accessor instead of using dma_address directly Architectures might not have dma_address in struct scatterlist (PARISC doesn't). Directly accessing to dma_address in struct scatterlist is wrong; we need to use sg_dma_address() accesssor instead. Signed-off-by: FUJITA Tomonori Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index e47e1a08c337..1b5bb82f106a 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -840,7 +840,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, entry->dev = dev; entry->paddr = sg_phys(s); entry->size = s->length; - entry->dev_addr = s->dma_address; + entry->dev_addr = sg_dma_address(s); entry->direction = direction; entry->sg_call_ents = nents; entry->sg_mapped_ents = mapped_ents; @@ -872,7 +872,7 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, .type = dma_debug_sg, .dev = dev, .paddr = sg_phys(s), - .dev_addr = s->dma_address, + .dev_addr = sg_dma_address(s), .size = s->length, .direction = dir, .sg_call_ents = 0, @@ -996,8 +996,8 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, s->dma_address, s->dma_length, 0, - direction, true); + check_sync(dev, sg_dma_address(s), s->dma_length, 0, + direction, true); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu); @@ -1012,8 +1012,8 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, s->dma_address, s->dma_length, 0, - direction, false); + check_sync(dev, sg_dma_address(s), s->dma_length, 0, + direction, false); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_device); -- cgit v1.2.2 From 884d05970bfbc3db368f23460dc4ce63257f240d Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 27 May 2009 09:43:02 +0900 Subject: dma-debug: use sg_dma_len accessor debug_dma_map_sg() and debug_dma_unmap_sg() use length in struct scatterlist while debug_dma_sync_sg_for_cpu() and debug_dma_sync_sg_for_device() use dma_length. This causes bugs warnings on some IOMMU implementations since these values are not same; the length doesn't represent the dma length. We always need to use sg_dma_len() accessor to get the dma length of a scatterlist entry. Signed-off-by: FUJITA Tomonori Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 1b5bb82f106a..51f95e5b6265 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -839,7 +839,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, entry->type = dma_debug_sg; entry->dev = dev; entry->paddr = sg_phys(s); - entry->size = s->length; + entry->size = sg_dma_len(s); entry->dev_addr = sg_dma_address(s); entry->direction = direction; entry->sg_call_ents = nents; @@ -847,7 +847,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, if (!PageHighMem(sg_page(s))) { check_for_stack(dev, sg_virt(s)); - check_for_illegal_area(dev, sg_virt(s), s->length); + check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); } add_dma_entry(entry); @@ -873,7 +873,7 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, .dev = dev, .paddr = sg_phys(s), .dev_addr = sg_dma_address(s), - .size = s->length, + .size = sg_dma_len(s), .direction = dir, .sg_call_ents = 0, }; @@ -996,7 +996,7 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, sg_dma_address(s), s->dma_length, 0, + check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, direction, true); } } @@ -1012,7 +1012,7 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, sg_dma_address(s), s->dma_length, 0, + check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, direction, false); } } -- cgit v1.2.2 From 88f3907f6f447899544beadf491dccb32015dacb Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Wed, 27 May 2009 09:43:03 +0900 Subject: dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device DMA-mapping.txt says that debug_dma_sync_sg family must be called with the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the dma_map_sg call. debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device can't handle this properly; they need to use the sg_mapped_ents in struct dma_debug_entry as debug_dma_unmap_sg() does. Signed-off-by: FUJITA Tomonori Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 48 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 11 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 51f95e5b6265..1abed176d35a 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -855,13 +855,32 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(debug_dma_map_sg); +static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s) +{ + struct dma_debug_entry *entry; + struct hash_bucket *bucket; + unsigned long flags; + int mapped_ents = 0; + struct dma_debug_entry ref; + + ref.dev = dev; + ref.dev_addr = sg_dma_address(s); + ref.size = sg_dma_len(s), + + bucket = get_hash_bucket(&ref, &flags); + entry = hash_bucket_find(bucket, &ref); + if (entry) + mapped_ents = entry->sg_mapped_ents; + put_hash_bucket(bucket, &flags); + + return mapped_ents; +} + void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, int dir) { - struct dma_debug_entry *entry; struct scatterlist *s; int mapped_ents = 0, i; - unsigned long flags; if (unlikely(global_disable)) return; @@ -881,14 +900,9 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, if (mapped_ents && i >= mapped_ents) break; - if (mapped_ents == 0) { - struct hash_bucket *bucket; + if (!i) { ref.sg_call_ents = nelems; - bucket = get_hash_bucket(&ref, &flags); - entry = hash_bucket_find(bucket, &ref); - if (entry) - mapped_ents = entry->sg_mapped_ents; - put_hash_bucket(bucket, &flags); + mapped_ents = get_nr_mapped_entries(dev, s); } check_unmap(&ref); @@ -990,12 +1004,18 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, int direction) { struct scatterlist *s; - int i; + int mapped_ents = 0, i; if (unlikely(global_disable)) return; for_each_sg(sg, s, nelems, i) { + if (!i) + mapped_ents = get_nr_mapped_entries(dev, s); + + if (i >= mapped_ents) + break; + check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, direction, true); } @@ -1006,12 +1026,18 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, int direction) { struct scatterlist *s; - int i; + int mapped_ents = 0, i; if (unlikely(global_disable)) return; for_each_sg(sg, s, nelems, i) { + if (!i) + mapped_ents = get_nr_mapped_entries(dev, s); + + if (i >= mapped_ents) + break; + check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, direction, false); } -- cgit v1.2.2 From 2e507d849f1834d3fe9aae71b7aabf4c2a3827b8 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 22 May 2009 18:24:20 +0200 Subject: dma-debug: add variables and checks for driver filter This patch adds the state variables for the driver filter and a function to check if the filter is enabled and matches to the current device. The check is built into the err_printk function. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index cdd205d6bf7c..c01f64780caf 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -99,6 +99,15 @@ static struct dentry *show_num_errors_dent __read_mostly; static struct dentry *num_free_entries_dent __read_mostly; static struct dentry *min_free_entries_dent __read_mostly; +/* per-driver filter related state */ + +#define NAME_MAX_LEN 64 + +static char current_driver_name[NAME_MAX_LEN] __read_mostly; +static struct device_driver *current_driver __read_mostly; + +static DEFINE_RWLOCK(driver_name_lock); + static const char *type2name[4] = { "single", "page", "scather-gather", "coherent" }; @@ -128,9 +137,47 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) #endif } +static bool driver_filter(struct device *dev) +{ + /* driver filter off */ + if (likely(!current_driver_name[0])) + return true; + + /* driver filter on and initialized */ + if (current_driver && dev->driver == current_driver) + return true; + + /* driver filter on but not yet initialized */ + if (!current_driver && current_driver_name[0]) { + struct device_driver *drv = get_driver(dev->driver); + unsigned long flags; + bool ret = false; + + if (!drv) + return false; + + /* lock to protect against change of current_driver_name */ + read_lock_irqsave(&driver_name_lock, flags); + + if (drv->name && + strncmp(current_driver_name, drv->name, 63) == 0) { + current_driver = drv; + ret = true; + } + + read_unlock_irqrestore(&driver_name_lock, flags); + put_driver(drv); + + return ret; + } + + return false; +} + #define err_printk(dev, entry, format, arg...) do { \ error_count += 1; \ - if (show_all_errors || show_num_errors > 0) { \ + if (driver_filter(dev) && \ + (show_all_errors || show_num_errors > 0)) { \ WARN(1, "%s %s: " format, \ dev_driver_string(dev), \ dev_name(dev) , ## arg); \ -- cgit v1.2.2 From 8a6fc708b9bb48a79a385bdc2be0959ee2ab788d Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 22 May 2009 21:23:13 +0200 Subject: dma-debug: add debugfs file for driver filter This patch adds the dma-api/driver_filter file to debugfs. The root user can write a driver name into this file to see only dma-api errors for that particular driver in the kernel log. Writing an empty string to that file disables the driver filter. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 101 insertions(+), 1 deletion(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index c01f64780caf..c6330b1a7be7 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -23,9 +23,11 @@ #include #include #include +#include #include #include #include +#include #include #include @@ -98,6 +100,7 @@ static struct dentry *show_all_errors_dent __read_mostly; static struct dentry *show_num_errors_dent __read_mostly; static struct dentry *num_free_entries_dent __read_mostly; static struct dentry *min_free_entries_dent __read_mostly; +static struct dentry *filter_dent __read_mostly; /* per-driver filter related state */ @@ -160,7 +163,8 @@ static bool driver_filter(struct device *dev) read_lock_irqsave(&driver_name_lock, flags); if (drv->name && - strncmp(current_driver_name, drv->name, 63) == 0) { + strncmp(current_driver_name, drv->name, + NAME_MAX_LEN-1) == 0) { current_driver = drv; ret = true; } @@ -454,6 +458,97 @@ out_err: return -ENOMEM; } +static ssize_t filter_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + unsigned long flags; + char buf[NAME_MAX_LEN + 1]; + int len; + + if (!current_driver_name[0]) + return 0; + + /* + * We can't copy to userspace directly because current_driver_name can + * only be read under the driver_name_lock with irqs disabled. So + * create a temporary copy first. + */ + read_lock_irqsave(&driver_name_lock, flags); + len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name); + read_unlock_irqrestore(&driver_name_lock, flags); + + return simple_read_from_buffer(user_buf, count, ppos, buf, len); +} + +static ssize_t filter_write(struct file *file, const char __user *userbuf, + size_t count, loff_t *ppos) +{ + unsigned long flags; + char buf[NAME_MAX_LEN]; + size_t len = NAME_MAX_LEN - 1; + int i; + + /* + * We can't copy from userspace directly. Access to + * current_driver_name is protected with a write_lock with irqs + * disabled. Since copy_from_user can fault and may sleep we + * need to copy to temporary buffer first + */ + len = min(count, len); + if (copy_from_user(buf, userbuf, len)) + return -EFAULT; + + buf[len] = 0; + + write_lock_irqsave(&driver_name_lock, flags); + + /* Now handle the string we got from userspace very carefully. + * The rules are: + * - only use the first token we got + * - token delimiter is everything looking like a space + * character (' ', '\n', '\t' ...) + * + */ + if (!isalnum(buf[0])) { + /* + If the first character userspace gave us is not + * alphanumerical then assume the filter should be + * switched off. + */ + if (current_driver_name[0]) + printk(KERN_INFO "DMA-API: switching off dma-debug " + "driver filter\n"); + current_driver_name[0] = 0; + current_driver = NULL; + goto out_unlock; + } + + /* + * Now parse out the first token and use it as the name for the + * driver to filter for. + */ + for (i = 0; i < NAME_MAX_LEN; ++i) { + current_driver_name[i] = buf[i]; + if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0) + break; + } + current_driver_name[i] = 0; + current_driver = NULL; + + printk(KERN_INFO "DMA-API: enable driver filter for driver [%s]\n", + current_driver_name); + +out_unlock: + write_unlock_irqrestore(&driver_name_lock, flags); + + return count; +} + +const struct file_operations filter_fops = { + .read = filter_read, + .write = filter_write, +}; + static int dma_debug_fs_init(void) { dma_debug_dent = debugfs_create_dir("dma-api", NULL); @@ -497,6 +592,11 @@ static int dma_debug_fs_init(void) if (!min_free_entries_dent) goto out_err; + filter_dent = debugfs_create_file("driver_filter", 0644, + dma_debug_dent, NULL, &filter_fops); + if (!filter_dent) + goto out_err; + return 0; out_err: -- cgit v1.2.2 From 1745de5e5639457513fe43440f2800e23c3cbc7d Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 22 May 2009 21:49:51 +0200 Subject: dma-debug: add dma_debug_driver kernel command line This patch add the dma_debug_driver= boot parameter to enable the driver filter for early boot. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index c6330b1a7be7..d0618aa13b49 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1109,3 +1109,21 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(debug_dma_sync_sg_for_device); +static int __init dma_debug_driver_setup(char *str) +{ + int i; + + for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) { + current_driver_name[i] = *str; + if (*str == 0) + break; + } + + if (current_driver_name[0]) + printk(KERN_INFO "DMA-API: enable driver filter for " + "driver [%s]\n", current_driver_name); + + + return 1; +} +__setup("dma_debug_driver=", dma_debug_driver_setup); -- cgit v1.2.2 From 7caf6a49bb17d0377210693af5737563b31aa5ee Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 5 Jun 2009 12:01:35 +0200 Subject: dma-debug: change hash_bucket_find from first-fit to best-fit Some device drivers map the same physical address multiple times to a dma address. Without an IOMMU this results in the same dma address being put into the dma-debug hash multiple times. With a first-fit match in hash_bucket_find() this function may return the wrong dma_debug_entry. This can result in false positive warnings. This patch fixes it by changing the first-fit behavior of hash_bucket_find() into a best-fit algorithm. Reported-by: Torsten Kaiser Reported-by: FUJITA Tomonori Signed-off-by: Joerg Roedel Cc: lethal@linux-sh.org Cc: just.for.lkml@googlemail.com Cc: hancockrwd@gmail.com Cc: jens.axboe@oracle.com Cc: bharrosh@panasas.com Cc: FUJITA Tomonori Cc: Linus Torvalds Cc: LKML-Reference: <20090605104132.GE24836@amd.com> Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index cdd205d6bf7c..8fcc09c91e1b 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -186,15 +186,50 @@ static void put_hash_bucket(struct hash_bucket *bucket, static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket, struct dma_debug_entry *ref) { - struct dma_debug_entry *entry; + struct dma_debug_entry *entry, *ret = NULL; + int matches = 0, match_lvl, last_lvl = 0; list_for_each_entry(entry, &bucket->list, list) { - if ((entry->dev_addr == ref->dev_addr) && - (entry->dev == ref->dev)) + if ((entry->dev_addr != ref->dev_addr) || + (entry->dev != ref->dev)) + continue; + + /* + * Some drivers map the same physical address multiple + * times. Without a hardware IOMMU this results in the + * same device addresses being put into the dma-debug + * hash multiple times too. This can result in false + * positives being reported. Therfore we implement a + * best-fit algorithm here which returns the entry from + * the hash which fits best to the reference value + * instead of the first-fit. + */ + matches += 1; + match_lvl = 0; + entry->size == ref->size ? ++match_lvl : match_lvl; + entry->type == ref->type ? ++match_lvl : match_lvl; + entry->direction == ref->direction ? ++match_lvl : match_lvl; + + if (match_lvl == 3) { + /* perfect-fit - return the result */ return entry; + } else if (match_lvl > last_lvl) { + /* + * We found an entry that fits better then the + * previous one + */ + last_lvl = match_lvl; + ret = entry; + } } - return NULL; + /* + * If we have multiple matches but no perfect-fit, just return + * NULL. + */ + ret = (matches == 1) ? ret : NULL; + + return ret; } /* -- cgit v1.2.2 From 312325094785566a0e42a88c1bf6e7eb54c5d70e Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Jun 2009 15:07:08 +0200 Subject: dma-debug: comment style fixes Last patch series introduced some new comment which does not fit the Kernel comment style guidelines. Fix it with this patch. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 77053d9ef513..b8a61ff08544 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -542,7 +542,8 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, write_lock_irqsave(&driver_name_lock, flags); - /* Now handle the string we got from userspace very carefully. + /* + * Now handle the string we got from userspace very carefully. * The rules are: * - only use the first token we got * - token delimiter is everything looking like a space @@ -551,7 +552,7 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, */ if (!isalnum(buf[0])) { /* - If the first character userspace gave us is not + * If the first character userspace gave us is not * alphanumerical then assume the filter should be * switched off. */ -- cgit v1.2.2 From c17e2cf7376a2010b8b114fdeebd4e340a5e9cb2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Jun 2009 15:19:29 +0200 Subject: dma-debug: code style fixes This patch changes the recent updates to dma-debug to conform with coding style guidelines of Linux and the -tip tree. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index b8a61ff08544..9561825c14a4 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -501,8 +501,8 @@ out_err: static ssize_t filter_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { - unsigned long flags; char buf[NAME_MAX_LEN + 1]; + unsigned long flags; int len; if (!current_driver_name[0]) @@ -523,9 +523,9 @@ static ssize_t filter_read(struct file *file, char __user *user_buf, static ssize_t filter_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { - unsigned long flags; char buf[NAME_MAX_LEN]; - size_t len = NAME_MAX_LEN - 1; + unsigned long flags; + size_t len; int i; /* @@ -534,7 +534,7 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, * disabled. Since copy_from_user can fault and may sleep we * need to copy to temporary buffer first */ - len = min(count, len); + len = min(count, NAME_MAX_LEN - 1); if (copy_from_user(buf, userbuf, len)) return -EFAULT; @@ -1040,18 +1040,19 @@ EXPORT_SYMBOL(debug_dma_map_sg); static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s) { - struct dma_debug_entry *entry; + struct dma_debug_entry *entry, ref; struct hash_bucket *bucket; unsigned long flags; - int mapped_ents = 0; - struct dma_debug_entry ref; + int mapped_ents; - ref.dev = dev; + ref.dev = dev; ref.dev_addr = sg_dma_address(s); - ref.size = sg_dma_len(s), + ref.size = sg_dma_len(s), + + bucket = get_hash_bucket(&ref, &flags); + entry = hash_bucket_find(bucket, &ref); + mapped_ents = 0; - bucket = get_hash_bucket(&ref, &flags); - entry = hash_bucket_find(bucket, &ref); if (entry) mapped_ents = entry->sg_mapped_ents; put_hash_bucket(bucket, &flags); -- cgit v1.2.2 From e7ed70eedccc78e79ce6da2155e9caf90aff4003 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Jun 2009 15:39:24 +0200 Subject: dma-debug: use pr_* instead of printk(KERN_* ...) The pr_* macros are shorter than the old printk(KERN_ ...) variant. Change the dma-debug code to use the new macros and save a few unnecessary line breaks. If lines don't break the source code can also be grepped more easily. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 36 +++++++++++++++--------------------- 1 file changed, 15 insertions(+), 21 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 9561825c14a4..24c4a2c5d61c 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -139,7 +139,7 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) { #ifdef CONFIG_STACKTRACE if (entry) { - printk(KERN_WARNING "Mapped at:\n"); + pr_warning("Mapped at:\n"); print_stack_trace(&entry->stacktrace, 0); } #endif @@ -377,8 +377,7 @@ static struct dma_debug_entry *dma_entry_alloc(void) spin_lock_irqsave(&free_entries_lock, flags); if (list_empty(&free_entries)) { - printk(KERN_ERR "DMA-API: debugging out of memory " - "- disabling\n"); + pr_err("DMA-API: debugging out of memory - disabling\n"); global_disable = true; goto out; } @@ -483,8 +482,7 @@ static int prealloc_memory(u32 num_entries) num_free_entries = num_entries; min_free_entries = num_entries; - printk(KERN_INFO "DMA-API: preallocated %d debug entries\n", - num_entries); + pr_info("DMA-API: preallocated %d debug entries\n", num_entries); return 0; @@ -534,7 +532,7 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, * disabled. Since copy_from_user can fault and may sleep we * need to copy to temporary buffer first */ - len = min(count, NAME_MAX_LEN - 1); + len = min(count, (size_t)(NAME_MAX_LEN - 1)); if (copy_from_user(buf, userbuf, len)) return -EFAULT; @@ -557,8 +555,7 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, * switched off. */ if (current_driver_name[0]) - printk(KERN_INFO "DMA-API: switching off dma-debug " - "driver filter\n"); + pr_info("DMA-API: switching off dma-debug driver filter\n"); current_driver_name[0] = 0; current_driver = NULL; goto out_unlock; @@ -576,8 +573,8 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf, current_driver_name[i] = 0; current_driver = NULL; - printk(KERN_INFO "DMA-API: enable driver filter for driver [%s]\n", - current_driver_name); + pr_info("DMA-API: enable driver filter for driver [%s]\n", + current_driver_name); out_unlock: write_unlock_irqrestore(&driver_name_lock, flags); @@ -594,7 +591,7 @@ static int dma_debug_fs_init(void) { dma_debug_dent = debugfs_create_dir("dma-api", NULL); if (!dma_debug_dent) { - printk(KERN_ERR "DMA-API: can not create debugfs directory\n"); + pr_err("DMA-API: can not create debugfs directory\n"); return -ENOMEM; } @@ -693,7 +690,7 @@ void dma_debug_add_bus(struct bus_type *bus) nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); if (nb == NULL) { - printk(KERN_ERR "dma_debug_add_bus: out of memory\n"); + pr_err("dma_debug_add_bus: out of memory\n"); return; } @@ -718,8 +715,7 @@ void dma_debug_init(u32 num_entries) } if (dma_debug_fs_init() != 0) { - printk(KERN_ERR "DMA-API: error creating debugfs entries " - "- disabling\n"); + pr_err("DMA-API: error creating debugfs entries - disabling\n"); global_disable = true; return; @@ -729,8 +725,7 @@ void dma_debug_init(u32 num_entries) num_entries = req_entries; if (prealloc_memory(num_entries) != 0) { - printk(KERN_ERR "DMA-API: debugging out of memory error " - "- disabled\n"); + pr_err("DMA-API: debugging out of memory error - disabled\n"); global_disable = true; return; @@ -738,7 +733,7 @@ void dma_debug_init(u32 num_entries) nr_total_entries = num_free_entries; - printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n"); + pr_info("DMA-API: debugging enabled by kernel config\n"); } static __init int dma_debug_cmdline(char *str) @@ -747,8 +742,7 @@ static __init int dma_debug_cmdline(char *str) return -EINVAL; if (strncmp(str, "off", 3) == 0) { - printk(KERN_INFO "DMA-API: debugging disabled on kernel " - "command line\n"); + pr_info("DMA-API: debugging disabled on kernel command line\n"); global_disable = true; } @@ -1239,8 +1233,8 @@ static int __init dma_debug_driver_setup(char *str) } if (current_driver_name[0]) - printk(KERN_INFO "DMA-API: enable driver filter for " - "driver [%s]\n", current_driver_name); + pr_info("DMA-API: enable driver filter for driver [%s]\n", + current_driver_name); return 1; -- cgit v1.2.2 From be81c6ea23b8b471141734ef4bc005f5127aaf43 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Jun 2009 15:46:19 +0200 Subject: dma-debug: disable/enable irqs only once in device_dma_allocations There is no need to disable/enable irqs on each loop iteration. Just disable irqs for the whole time the loop runs. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 24c4a2c5d61c..27b369da52c0 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -649,15 +649,19 @@ static int device_dma_allocations(struct device *dev) unsigned long flags; int count = 0, i; + local_irq_save(flags); + for (i = 0; i < HASH_SIZE; ++i) { - spin_lock_irqsave(&dma_entry_hash[i].lock, flags); + spin_lock(&dma_entry_hash[i].lock); list_for_each_entry(entry, &dma_entry_hash[i].list, list) { if (entry->dev == dev) count += 1; } - spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags); + spin_unlock(&dma_entry_hash[i].lock); } + local_irq_restore(flags); + return count; } -- cgit v1.2.2 From 0bf841281e58d0b3cc9fe9dc4383df7694bde6bd Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 8 Jun 2009 15:53:46 +0200 Subject: dma-debug: simplify logic in driver_filter() This patch makes the driver_filter function more readable by reorganizing the code. The removal of a code code block to an upper indentation level makes hard-to-read line-wraps unnecessary. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 27b369da52c0..ad65fc0317d9 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -147,6 +147,10 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) static bool driver_filter(struct device *dev) { + struct device_driver *drv; + unsigned long flags; + bool ret; + /* driver filter off */ if (likely(!current_driver_name[0])) return true; @@ -155,32 +159,28 @@ static bool driver_filter(struct device *dev) if (current_driver && dev->driver == current_driver) return true; - /* driver filter on but not yet initialized */ - if (!current_driver && current_driver_name[0]) { - struct device_driver *drv = get_driver(dev->driver); - unsigned long flags; - bool ret = false; - - if (!drv) - return false; - - /* lock to protect against change of current_driver_name */ - read_lock_irqsave(&driver_name_lock, flags); + if (current_driver || !current_driver_name[0]) + return false; - if (drv->name && - strncmp(current_driver_name, drv->name, - NAME_MAX_LEN-1) == 0) { - current_driver = drv; - ret = true; - } + /* driver filter on but not yet initialized */ + drv = get_driver(dev->driver); + if (!drv) + return false; - read_unlock_irqrestore(&driver_name_lock, flags); - put_driver(drv); + /* lock to protect against change of current_driver_name */ + read_lock_irqsave(&driver_name_lock, flags); - return ret; + ret = false; + if (drv->name && + strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) { + current_driver = drv; + ret = true; } - return false; + read_unlock_irqrestore(&driver_name_lock, flags); + put_driver(drv); + + return ret; } #define err_printk(dev, entry, format, arg...) do { \ -- cgit v1.2.2 From e5e8c5b90a1ae249930fcf7403f3757686cf1a7b Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 11 Jun 2009 10:03:42 +0200 Subject: dma-debug: check for sg_call_ents in best-fit algorithm too If we don't check for sg_call_ents the hash_bucket_find function might still return the wrong dma_debug_entry for sg mappings. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index ad65fc0317d9..c71e2dd2750f 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -262,11 +262,12 @@ static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket, */ matches += 1; match_lvl = 0; - entry->size == ref->size ? ++match_lvl : match_lvl; - entry->type == ref->type ? ++match_lvl : match_lvl; - entry->direction == ref->direction ? ++match_lvl : match_lvl; + entry->size == ref->size ? ++match_lvl : 0; + entry->type == ref->type ? ++match_lvl : 0; + entry->direction == ref->direction ? ++match_lvl : 0; + entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0; - if (match_lvl == 3) { + if (match_lvl == 4) { /* perfect-fit - return the result */ return entry; } else if (match_lvl > last_lvl) { @@ -1076,16 +1077,14 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, .dev_addr = sg_dma_address(s), .size = sg_dma_len(s), .direction = dir, - .sg_call_ents = 0, + .sg_call_ents = nelems, }; if (mapped_ents && i >= mapped_ents) break; - if (!i) { - ref.sg_call_ents = nelems; + if (!i) mapped_ents = get_nr_mapped_entries(dev, s); - } check_unmap(&ref); } -- cgit v1.2.2 From aa010efb7b6cd0dfbea8ecf37a6ab587dc2a8560 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 12 Jun 2009 15:25:06 +0200 Subject: dma-debug: be more careful when building reference entries The current code is not very careful when it builds reference dma_debug_entries which get passed to hash_bucket_find(). But since this function changed to a best-fit algorithm these entries have to be more acurate. This patch adds this higher level of accuracy. Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 134 ++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 91 insertions(+), 43 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index c71e2dd2750f..3b93129a968c 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -874,72 +874,68 @@ static void check_for_illegal_area(struct device *dev, void *addr, u64 size) "[addr=%p] [size=%llu]\n", addr, size); } -static void check_sync(struct device *dev, dma_addr_t addr, - u64 size, u64 offset, int direction, bool to_cpu) +static void check_sync(struct device *dev, + struct dma_debug_entry *ref, + bool to_cpu) { - struct dma_debug_entry ref = { - .dev = dev, - .dev_addr = addr, - .size = size, - .direction = direction, - }; struct dma_debug_entry *entry; struct hash_bucket *bucket; unsigned long flags; - bucket = get_hash_bucket(&ref, &flags); + bucket = get_hash_bucket(ref, &flags); - entry = hash_bucket_find(bucket, &ref); + entry = hash_bucket_find(bucket, ref); if (!entry) { err_printk(dev, NULL, "DMA-API: device driver tries " "to sync DMA memory it has not allocated " "[device address=0x%016llx] [size=%llu bytes]\n", - (unsigned long long)addr, size); + (unsigned long long)ref->dev_addr, ref->size); goto out; } - if ((offset + size) > entry->size) { + if (ref->size > entry->size) { err_printk(dev, entry, "DMA-API: device driver syncs" " DMA memory outside allocated range " "[device address=0x%016llx] " - "[allocation size=%llu bytes] [sync offset=%llu] " - "[sync size=%llu]\n", entry->dev_addr, entry->size, - offset, size); + "[allocation size=%llu bytes] " + "[sync offset+size=%llu]\n", + entry->dev_addr, entry->size, + ref->size); } - if (direction != entry->direction) { + if (ref->direction != entry->direction) { err_printk(dev, entry, "DMA-API: device driver syncs " "DMA memory with different direction " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); } if (entry->direction == DMA_BIDIRECTIONAL) goto out; if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) && - !(direction == DMA_TO_DEVICE)) + !(ref->direction == DMA_TO_DEVICE)) err_printk(dev, entry, "DMA-API: device driver syncs " "device read-only DMA memory for cpu " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) && - !(direction == DMA_FROM_DEVICE)) + !(ref->direction == DMA_FROM_DEVICE)) err_printk(dev, entry, "DMA-API: device driver syncs " "device write-only DMA memory to device " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); out: put_hash_bucket(bucket, &flags); @@ -1037,19 +1033,16 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(debug_dma_map_sg); -static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s) +static int get_nr_mapped_entries(struct device *dev, + struct dma_debug_entry *ref) { - struct dma_debug_entry *entry, ref; + struct dma_debug_entry *entry; struct hash_bucket *bucket; unsigned long flags; int mapped_ents; - ref.dev = dev; - ref.dev_addr = sg_dma_address(s); - ref.size = sg_dma_len(s), - - bucket = get_hash_bucket(&ref, &flags); - entry = hash_bucket_find(bucket, &ref); + bucket = get_hash_bucket(ref, &flags); + entry = hash_bucket_find(bucket, ref); mapped_ents = 0; if (entry) @@ -1084,7 +1077,7 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, break; if (!i) - mapped_ents = get_nr_mapped_entries(dev, s); + mapped_ents = get_nr_mapped_entries(dev, &ref); check_unmap(&ref); } @@ -1139,10 +1132,19 @@ EXPORT_SYMBOL(debug_dma_free_coherent); void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, 0, direction, true); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, true); } EXPORT_SYMBOL(debug_dma_sync_single_for_cpu); @@ -1150,10 +1152,19 @@ void debug_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, 0, direction, false); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, false); } EXPORT_SYMBOL(debug_dma_sync_single_for_device); @@ -1162,10 +1173,19 @@ void debug_dma_sync_single_range_for_cpu(struct device *dev, unsigned long offset, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, offset, direction, true); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = offset + size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, true); } EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu); @@ -1174,10 +1194,19 @@ void debug_dma_sync_single_range_for_device(struct device *dev, unsigned long offset, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, offset, direction, false); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = offset + size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, false); } EXPORT_SYMBOL(debug_dma_sync_single_range_for_device); @@ -1191,14 +1220,24 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { + + struct dma_debug_entry ref = { + .type = dma_debug_sg, + .dev = dev, + .paddr = sg_phys(s), + .dev_addr = sg_dma_address(s), + .size = sg_dma_len(s), + .direction = direction, + .sg_call_ents = nelems, + }; + if (!i) - mapped_ents = get_nr_mapped_entries(dev, s); + mapped_ents = get_nr_mapped_entries(dev, &ref); if (i >= mapped_ents) break; - check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, - direction, true); + check_sync(dev, &ref, true); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu); @@ -1213,14 +1252,23 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nelems, i) { + + struct dma_debug_entry ref = { + .type = dma_debug_sg, + .dev = dev, + .paddr = sg_phys(s), + .dev_addr = sg_dma_address(s), + .size = sg_dma_len(s), + .direction = direction, + .sg_call_ents = nelems, + }; if (!i) - mapped_ents = get_nr_mapped_entries(dev, s); + mapped_ents = get_nr_mapped_entries(dev, &ref); if (i >= mapped_ents) break; - check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, - direction, false); + check_sync(dev, &ref, false); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_device); -- cgit v1.2.2 From c79ee4e466dd12347f112e2af306dca35198458f Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 16 Jun 2009 12:23:58 +0200 Subject: dma-debug: fix off-by-one error in overlap function This patch fixes a bug in the overlap function which returned true if one region ends exactly before the second region begins. This is no overlap but the function returned true in that case. Cc: stable@kernel.org Reported-by: Andrew Randrianasulu Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 3b93129a968c..a9b6b5c9e091 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -862,7 +862,7 @@ static inline bool overlap(void *addr, u64 size, void *start, void *end) return ((addr >= start && addr < end) || (addr2 >= start && addr2 < end) || - ((addr < start) && (addr2 >= end))); + ((addr < start) && (addr2 > end))); } static void check_for_illegal_area(struct device *dev, void *addr, u64 size) -- cgit v1.2.2 From b0a5b83ee0fce9dbf8ff5fe1f8c9ae7dfafe458c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 16 Jun 2009 16:11:14 +0200 Subject: dma-debug: Put all hash-chain locks into the same lock class Alan Cox reported that lockdep runs out of its stack-trace entries with certain configs: BUG: MAX_STACK_TRACE_ENTRIES too low This happens because there are 1024 hash buckets, each with a separate lock. Lockdep puts each lock into a separate lock class and tracks them independently. But in reality we never take more than one of the buckets, so they really belong into a single lock-class. Annotate the has bucket lock init accordingly. [ Impact: reduce the lockdep footprint of dma-debug ] Reported-by: Alan Cox Signed-off-by: Ingo Molnar Signed-off-by: Joerg Roedel --- lib/dma-debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index a9b6b5c9e091..c9187fed0b93 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -716,7 +716,7 @@ void dma_debug_init(u32 num_entries) for (i = 0; i < HASH_SIZE; ++i) { INIT_LIST_HEAD(&dma_entry_hash[i].list); - dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED; + spin_lock_init(&dma_entry_hash[i].lock); } if (dma_debug_fs_init() != 0) { -- cgit v1.2.2 From f39d1b9792881ce4eb982ec8cc65258bf95674b5 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 10 Jul 2009 21:38:02 +0200 Subject: dma-debug: Fix the overlap() function to be correct and readable Linus noticed how unclean and buggy the overlap() function is: - It uses convoluted (and bug-causing) positive checks for range overlap - instead of using a more natural negative check. - Even the positive checks are buggy: a positive intersection check has four natural cases while we checked only for three, missing the (addr < start && addr2 == end) case for example. - The variables are mis-named, making it non-obvious how the check was done. - It needlessly uses u64 instead of unsigned long. Since these are kernel memory pointers and we explicitly exclude highmem ranges anyway we cannot ever overflow 32 bits, even if we could. (and on 64-bit it doesnt matter anyway) All in one, this function needs a total revamp. I used Linus's suggestions minus the paranoid checks (we cannot overflow really because if we get totally bad DMA ranges passed far more things break in the systems than just DMA debugging). I also fixed a few other small details i noticed. Reported-by: Linus Torvalds Cc: Joerg Roedel Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index c9187fed0b93..65b0d99b6d0a 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -856,22 +856,21 @@ static void check_for_stack(struct device *dev, void *addr) "stack [addr=%p]\n", addr); } -static inline bool overlap(void *addr, u64 size, void *start, void *end) +static inline bool overlap(void *addr, unsigned long len, void *start, void *end) { - void *addr2 = (char *)addr + size; + unsigned long a1 = (unsigned long)addr; + unsigned long b1 = a1 + len; + unsigned long a2 = (unsigned long)start; + unsigned long b2 = (unsigned long)end; - return ((addr >= start && addr < end) || - (addr2 >= start && addr2 < end) || - ((addr < start) && (addr2 > end))); + return !(b1 <= a2 || a1 >= b2); } -static void check_for_illegal_area(struct device *dev, void *addr, u64 size) +static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len) { - if (overlap(addr, size, _text, _etext) || - overlap(addr, size, __start_rodata, __end_rodata)) - err_printk(dev, NULL, "DMA-API: device driver maps " - "memory from kernel text or rodata " - "[addr=%p] [size=%llu]\n", addr, size); + if (overlap(addr, len, _text, _etext) || + overlap(addr, len, __start_rodata, __end_rodata)) + err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len); } static void check_sync(struct device *dev, @@ -969,7 +968,8 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, entry->type = dma_debug_single; if (!PageHighMem(page)) { - void *addr = ((char *)page_address(page)) + offset; + void *addr = page_address(page) + offset; + check_for_stack(dev, addr); check_for_illegal_area(dev, addr, size); } -- cgit v1.2.2 From ec9c96ef3cc0124cb94375b17faaa8cff5dfdf97 Mon Sep 17 00:00:00 2001 From: Kyle McMartin Date: Wed, 19 Aug 2009 21:17:08 -0400 Subject: dma-debug: Fix check_unmap null pointer dereference While it's debatable whether or not a NULL device argument to the DMA API functions is valid... since it certainly isn't valid on devices with an IOMMU... dma-debug really shouldn't be dereferencing null pointers either. Guard against that in err_printk and the driver_filter functions. A Fedora rawhide user was seeing this in one of the dvb drivers resulting in an oops on boot. [ A patch has been sent for testing to the driver, but I feel the dma debugging support should be fixed as well. (There's still a pile of legacy garbage in the kernel passing null pointers to dma_{alloc,free}_*. :( ] Signed-off-by: Kyle McMartin Cc: mchehab@infradead.org Cc: Joerg Roedel LKML-Reference: <20090820011708.GP25206@bombadil.infradead.org> Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'lib/dma-debug.c') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 65b0d99b6d0a..58a9f9fc609a 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -156,9 +156,13 @@ static bool driver_filter(struct device *dev) return true; /* driver filter on and initialized */ - if (current_driver && dev->driver == current_driver) + if (current_driver && dev && dev->driver == current_driver) return true; + /* driver filter on, but we can't filter on a NULL device... */ + if (!dev) + return false; + if (current_driver || !current_driver_name[0]) return false; @@ -183,17 +187,17 @@ static bool driver_filter(struct device *dev) return ret; } -#define err_printk(dev, entry, format, arg...) do { \ - error_count += 1; \ - if (driver_filter(dev) && \ - (show_all_errors || show_num_errors > 0)) { \ - WARN(1, "%s %s: " format, \ - dev_driver_string(dev), \ - dev_name(dev) , ## arg); \ - dump_entry_trace(entry); \ - } \ - if (!show_all_errors && show_num_errors > 0) \ - show_num_errors -= 1; \ +#define err_printk(dev, entry, format, arg...) do { \ + error_count += 1; \ + if (driver_filter(dev) && \ + (show_all_errors || show_num_errors > 0)) { \ + WARN(1, "%s %s: " format, \ + dev ? dev_driver_string(dev) : "NULL", \ + dev ? dev_name(dev) : "NULL", ## arg); \ + dump_entry_trace(entry); \ + } \ + if (!show_all_errors && show_num_errors > 0) \ + show_num_errors -= 1; \ } while (0); /* -- cgit v1.2.2