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2014-03-04dma debug: account for cachelines and read-only mappings in overlap trackingDan Williams1-46/+85
While debug_dma_assert_idle() checks if a given *page* is actively undergoing dma the valid granularity of a dma mapping is a *cacheline*. Sander's testing shows that the warning message "DMA-API: exceeded 7 overlapping mappings of pfn..." is falsely triggering. The test is simply mapping multiple cachelines in a given page. Ultimately we want overlap tracking to be valid as it is a real api violation, so we need to track active mappings by cachelines. Update the active dma tracking to use the page-frame-relative cacheline of the mapping as the key, and update debug_dma_assert_idle() to check for all possible mapped cachelines for a given page. However, the need to track active mappings is only relevant when the dma-mapping is writable by the device. In fact it is fairly standard for read-only mappings to have hundreds or thousands of overlapping mappings at once. Limiting the overlap tracking to writable (!DMA_TO_DEVICE) eliminates this class of false-positive overlap reports. Note, the radix gang lookup is sub-optimal. It would be best if it stopped fetching entries once the search passed a page boundary. Nevertheless, this implementation does not perturb the original net_dma failing case. That is to say the extra overhead does not show up in terms of making the failing case pass due to a timing change. References: http://marc.info/?l=linux-netdev&m=139232263419315&w=2 http://marc.info/?l=linux-netdev&m=139217088107122&w=2 Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Reported-by: Dave Jones <davej@redhat.com> Tested-by: Dave Jones <davej@redhat.com> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Francois Romieu <romieu@fr.zoreil.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29dma-debug: fix overlap detectionDan Williams1-3/+7
Commit 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()") was reworked to expand the overlap counter to the full range expressable by 3 tag bits, but it has a thinko in treating the overlap counter as a pure reference count for the entry. Instead of deleting when the reference-count drops to zero, we need to delete when the overlap-count drops below zero. Also, when detecting overflow we can just test the overlap-count > MAX rather than applying special meaning to 0. Regression report available here: http://marc.info/?l=linux-netdev&m=139073373932386&w=2 This patch, now tested on the original net_dma case, sees the expected handful of reports before the eventual data corruption occurs. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Cc: Francois Romieu <romieu@fr.zoreil.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21dma-debug: introduce debug_dma_assert_idle()Dan Williams1-13/+180
Record actively mapped pages and provide an api for asserting a given page is dma inactive before execution proceeds. Placing debug_dma_assert_idle() in cow_user_page() flagged the violation of the dma-api in the NET_DMA implementation (see commit 77873803363c "net_dma: mark broken"). The implementation includes the capability to count, in a limited way, repeat mappings of the same page that occur without an intervening unmap. This 'overlap' counter is limited to the few bits of tag space in a radix tree. This mechanism is added to mitigate false negative cases where, for example, a page is dma mapped twice and debug_dma_assert_idle() is called after the page is un-mapped once. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-22dma-debug: update DMA debug API to better handle multiple mappings of a bufferAlexander Duyck1-5/+19
There were reports of the igb driver unmapping buffers without calling dma_mapping_error. On closer inspection issues were found in the DMA debug API and how it handled multiple mappings of the same buffer. The issue I found is the fact that the debug_dma_mapping_error would only set the map_err_type to MAP_ERR_CHECKED in the case that the was only one match for device and device address. However in the case of non-IOMMU, multiple addresses existed and as a result it was not setting this field once a second mapping was instantiated. I have resolved this by changing the search so that it instead will now set MAP_ERR_CHECKED on the first buffer that matches the device and DMA address that is currently in the state MAP_ERR_NOT_CHECKED. A secondary side effect of this patch is that in the case of multiple buffers using the same address only the last mapping will have a valid map_err_type. The previous mappings will all end up with map_err_type set to MAP_ERR_CHECKED because of the dma_mapping_error call in debug_dma_map_page. However this behavior may be preferable as it means you will likely only see one real error per multi-mapped buffer, versus the current behavior of multiple false errors mer multi-mapped buffer. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Reviewed-by: Shuah Khan <shuah.khan@hp.com> Tested-by: Shuah Khan <shuah.khan@hp.com> Cc: Jakub Kicinski <kubakici@wp.pl> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-22dma-debug: fix locking bug in check_unmap()Alexander Duyck1-9/+12
In check_unmap() it is possible to get into a dead-locked state if dma_mapping_error is called. The problem is that the bucket is locked in check_unmap, and locked again by debug_dma_mapping_error which is called by dma_mapping_error. To resolve that we must release the lock on the bucket before making the call to dma_mapping_error. [akpm@linux-foundation.org: restore 80-col trickery to be consistent with the rest of the file] Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Reviewed-by: Shuah Khan <shuah.khan@hp.com> Tested-by: Shuah Khan <shuah.khan@hp.com> Cc: Jakub Kicinski <kubakici@wp.pl> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-17dma-debug: fix to not have dependency on get_dma_ops() interfaceShuah Khan1-22/+7
dma-debug depends on get_dma_ops() interface. Several architectures do not define dma_ops and get_dma_ops(). When dma debug interfaces are used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(), compilation fails. Changing dma-debug to call dma_mapping_error() instead of defining its own that calls get_dma_ops(), such that the internal use of dma_mapping_error() doesn't interfere with the debug_dma_mapping_error() interface's mapping error checks. Moving dma_mapping_error() checks in check_unmap() under the dma debug entry not found is sufficient to fix the problem. Reference: https://lkml.org/lkml/2012/10/26/367 Signed-off-by: Shuah Khan <shuah.khan@hp.com> Reported-by: Mark Salter <msalter@redhat.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2012-10-24dma-debug: New interfaces to debug dma mapping errorsShuah Khan1-4/+67
Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail to check dma mapping errors on addresses returned by dma_map_single() and dma_map_page() interfaces. This interface clears a flag set by debug_dma_map_page() to indicate that dma_mapping_error() has been called by the driver. When driver does unmap, debug_dma_unmap() checks the flag and if this flag is still set, prints warning message that includes call trace that leads up to the unmap. This interface can be called from dma_mapping_error() routines to enable dma mapping error check debugging. Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with CONFIG_DMA_API_DEBUG enabled and disabled. Signed-off-by: Shuah Khan <shuah.khan@hp.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-10-19lib/dma-debug.c: fix __hash_bucket_find()Ming Lei1-2/+2
If there is only one match, the unique matched entry should be returned. Without the fix, the upcoming dma debug interfaces ("dma-debug: new interfaces to debug dma mapping errors") can't work reliably because only device and dma_addr are passed to dma_mapping_error(). Signed-off-by: Ming Lei <ming.lei@canonical.com> Reported-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Tested-by: Shuah Khan <shuah.khan@hp.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-02dma-debug: Remove local BUS_NOTIFY_UNBOUND_DRIVER defineShuah Khan1-5/+0
Remove local BUS_NOTIFY_UNBOUND_DRIVER define. This is not used since BUS_NOTIFY_UNBOUND_DRIVER is defined in include/linux/device.h Signed-off-by: Shuah Khan <shuah.khan@hp.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-07-02dma-debug: debugfs_create_bool() takes a u32 pointerDan Carpenter1-2/+2
Even though it has "bool" in the name, you have pass a u32 pointer to debugfs_create_bool(). Otherwise you get memory corruption in write_file_bool(). Fortunately in this case the corruption happens in an alignment hole between variables so it doesn't cause any problems. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-04-12dma-debug: release free_entries_lock before saving stack traceJakub Kicinski1-5/+5
Saving stack trace can take a while and once the entry is allocated free_entries_lock is no longer needed. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-01-24Remove useless get_driver()/put_driver() callsAlan Stern1-2/+1
As part of the removal of get_driver()/put_driver(), this patch (as1512) gets rid of various useless and unnecessary calls in several drivers. In some cases it may be desirable to pin the driver by calling try_module_get(), but that can be done later. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: "David S. Miller" <davem@davemloft.net> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: Michael Buesch <m@bues.ch> CC: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-21Fix comparison using wrong pointer variable in dma debug codeThomas Jarosch1-1/+1
cppcheck reported: [lib/dma-debug.c:248] -> [lib/dma-debug.c:248]: (style) Same expression on both sides of '=='. Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-10-31lib: dma-debug needs export.h for EXPORT_SYMBOLPaul Gortmaker1-0/+1
There are no modular calls here, so just the minimal header for the EXPORT_SYMBOL macro will suffice. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-08-23dma-debug: hash_bucket_find needs to allow for offsets within an entryNeil Horman1-7/+61
Summary: Users of the pci_dma_sync_single_* api allow users to sync address ranges within the range of a mapped entry (i.e. you can dma map address X to dma_addr_t A and then pci_dma_sync_single on dma_addr_t A+1. The dma-debug library however assume dma syncs will always occur using the base address of a mapped region, and uses that assumption to find entries in its hash table. Since thats often (but not always the case), the dma debug library can give us false errors about missing entries, which are reported as syncing of memory not allocated by the driver. This was noted in the cxgb3 driver as this error: WARNING: at lib/dma-debug.c:902 check_sync+0xdd/0x48c() Hardware name: To be filled by O.E.M. cxgb3 0000:01:00.0: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x00000000fff97800] [size=1984 bytes] Modules linked in: autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 ip6table_filter ip6_tables ipv6 uinput snd_hda_codec_intelhdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer e1000e snd soundcore r8169 cxgb3 iTCO_wdt snd_page_alloc mii shpchp i2c_i801 iTCO_vendor_support mdio microcode firewire_ohci firewire_core crc_itu_t ata_generic pata_acpi i915 drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded: scsi_wait_scan] Pid: 1818, comm: ifconfig Not tainted 2.6.35-0.23.rc3.git6.fc14.x86_64 #1 Call Trace: [<ffffffff81050f71>] warn_slowpath_common+0x85/0x9d [<ffffffff8105102c>] warn_slowpath_fmt+0x46/0x48 [<ffffffff8124658e>] ? check_sync+0x39/0x48c [<ffffffff8107c470>] ? trace_hardirqs_on+0xd/0xf [<ffffffff81246632>] check_sync+0xdd/0x48c [<ffffffff81246ca6>] debug_dma_sync_single_for_device+0x3f/0x41 [<ffffffffa011615c>] ? pci_map_page+0x84/0x97 [cxgb3] [<ffffffffa0117bc3>] pci_dma_sync_single_for_device.clone.0+0x65/0x6e [cxgb3] [<ffffffffa0117ed1>] refill_fl+0x305/0x30a [cxgb3] [<ffffffffa011857d>] t3_sge_alloc_qset+0x6a7/0x821 [cxgb3] [<ffffffffa010a07b>] cxgb_up+0x4d0/0xe62 [cxgb3] [<ffffffff81086037>] ? __module_text_address+0x12/0x58 [<ffffffffa010aa4c>] cxgb_open+0x3f/0x309 [cxgb3] [<ffffffff813e9f6c>] __dev_open+0x8e/0xbc [<ffffffff813e7ca5>] __dev_change_flags+0xbe/0x142 [<ffffffff813e9ea8>] dev_change_flags+0x21/0x57 [<ffffffff81445937>] devinet_ioctl+0x29a/0x54b [<ffffffff811f9a87>] ? inode_has_perm+0xaa/0xce [<ffffffff81446ed2>] inet_ioctl+0x8f/0xa7 [<ffffffff813d683a>] sock_do_ioctl+0x29/0x48 [<ffffffff813d6c83>] sock_ioctl+0x213/0x222 [<ffffffff81137f78>] vfs_ioctl+0x32/0xa6 [<ffffffff811384e2>] do_vfs_ioctl+0x47a/0x4b3 [<ffffffff81138571>] sys_ioctl+0x56/0x79 [<ffffffff81009c32>] system_call_fastpath+0x16/0x1b ---[ end trace 69a4d4cc77b58004 ]--- (some edits by Joerg Roedel) Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Jay Fenalson <fenlason@redhat.com> CC: Divy LeRay <divy@chelsio.com> CC: Stanislaw Gruszka <sgruszka@redhat.com> CC: Joerg Roedel <joerg.roedel@amd.com> CC: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-04-07dma-debug: print information about leaked entryStanislaw Gruszka1-5/+13
When driver leak dma mapping, print additional information about one of leaked entries, to to help investigate problem. Patch should be useful for debugging drivers, which maps many different class of buffers. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann1-0/+1
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-04-07dma-debug: Cleanup for copy-loop in filter_write()Dan Carpenter1-1/+1
Earlier in this function we set the last byte of "buf" to NULL so we always hit the break statement and "i" is never equal to NAME_MAX_LEN. This patch doesn't change how the driver works but it silences a Smatch warning and it makes it clearer that we don't write past the end of the array. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-01-22Merge branches 'amd-iommu/fixes' and 'dma-debug/fixes' into iommu/fixesJoerg Roedel1-1/+1
2010-01-22lib/dma-debug.c: mark file-local struct symbol static.Thiago Farina1-1/+1
warning: symbol 'filter_fops' was not declared. Should it be static? Signed-off-by: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-01-11dma-debug: allow DMA_BIDIRECTIONAL mappings to be synced with ↵Krzysztof Halasa1-4/+3
DMA_FROM_DEVICE and There is no need to perform full BIDIR sync (copying the buffers in case of swiotlb and similar schemes) if we know that the owner (CPU or device) hasn't altered the data. Addresses the false-positive reported at http://bugzilla.kernel.org/show_bug.cgi?id=14169 Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl> Cc: David Miller <davem@davemloft.net> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-31dma-debug: Fix bug causing build warningIngo Molnar1-3/+2
Stephen Rothwell reported the following build warning: lib/dma-debug.c: In function 'dma_debug_device_change': lib/dma-debug.c:680: warning: 'return' with no value, in function returning non-void Introduced by commit f797d9881b62c2ddb1d2e7bd80d87141949c84aa ("dma-debug: Do not add notifier when dma debugging is disabled"). Return 0 [notify-done] when disabled. (this is standard bus notifier behavior.) Signed-off-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> LKML-Reference: <20091231125624.GA14666@liondog.tnic> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-21dma-debug: Do not add notifier when dma debugging is disabled.Shaun Ruffell1-0/+5
If CONFIG_HAVE_DMA_API_DEBUG is defined and "dma_debug=off" is specified on the kernel command line, when you detach a driver from a device you can cause the following NULL pointer dereference: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c0580d35>] dma_debug_device_change+0x5d/0x117 The problem is that the dma_debug_device_change notifier function is added to the bus notifier chain even though the dma_entry_hash array was never initialized. If dma debugging is disabled, this patch both prevents dma_debug_device_change notifiers from being added to the chain, and additionally ensures that the dma_debug_device_change notifier function is a no-op. Cc: stable@kernel.org Signed-off-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa1-1/+1
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-10-29dma-debug: Fix compile warning with PAE enabledJoerg Roedel1-2/+4
When PAE is enabled in the kernel configuration the size of phys_addr_t differs from the size of a void pointer. The gcc prints a warning about that in dma-debug code. This patch fixes the warning by converting the output to unsigned long long instead of a pointer. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-08-21dma-debug: Fix check_unmap null pointer dereferenceKyle McMartin1-12/+16
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 <kyle@redhat.com> Cc: mchehab@infradead.org Cc: Joerg Roedel <joerg.roedel@amd.com> LKML-Reference: <20090820011708.GP25206@bombadil.infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10dma-debug: Fix the overlap() function to be correct and readableIngo Molnar1-12/+12
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 <torvalds@linux-foundation.org> Cc: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17dma-debug: Put all hash-chain locks into the same lock classIngo Molnar1-1/+1
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 <alan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-16dma-debug: fix off-by-one error in overlap functionJoerg Roedel1-1/+1
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 <randrik@mail.ru> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-15dma-debug: be more careful when building reference entriesJoerg Roedel1-43/+91
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 <joerg.roedel@amd.com>
2009-06-15dma-debug: check for sg_call_ents in best-fit algorithm tooJoerg Roedel1-8/+7
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 <joerg.roedel@amd.com>
2009-06-08dma-debug: simplify logic in driver_filter()Joerg Roedel1-21/+21
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 <joerg.roedel@amd.com>
2009-06-08dma-debug: disable/enable irqs only once in device_dma_allocationsJoerg Roedel1-2/+6
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 <joerg.roedel@amd.com>
2009-06-08dma-debug: use pr_* instead of printk(KERN_* ...)Joerg Roedel1-21/+15
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 <joerg.roedel@amd.com>
2009-06-08dma-debug: code style fixesJoerg Roedel1-11/+12
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 <joerg.roedel@amd.com>
2009-06-08dma-debug: comment style fixesJoerg Roedel1-2/+3
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 <joerg.roedel@amd.com>
2009-06-07Merge branch 'dma-debug/2.6.31' of ↵Ingo Molnar1-22/+269
git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu
2009-06-07dma-debug: change hash_bucket_find from first-fit to best-fitJoerg Roedel1-4/+39
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 <just.for.lkml@googlemail.com> Reported-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> 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 <fujita.tomonori@lab.ntt.co.jp> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> LKML-Reference: <20090605104132.GE24836@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-02Merge branches 'dma-debug/fixes' and 'dma-debug/driver-filter' into ↵Joerg Roedel1-1/+166
dma-debug/2.6.31
2009-06-02dma-debug: add dma_debug_driver kernel command lineJoerg Roedel1-0/+18
This patch add the dma_debug_driver= boot parameter to enable the driver filter for early boot. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-02dma-debug: add debugfs file for driver filterJoerg Roedel1-1/+101
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 <joerg.roedel@amd.com>
2009-06-02dma-debug: add variables and checks for driver filterJoerg Roedel1-1/+48
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 <joerg.roedel@amd.com>
2009-05-29dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_deviceFUJITA Tomonori1-11/+37
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 <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-29dma-debug: use sg_dma_len accessorFUJITA Tomonori1-5/+5
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 <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-29dma-debug: use sg_dma_address accessor instead of using dma_address directlyFUJITA Tomonori1-6/+6
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 <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-28dma-debug: re-add dma memory leak detectionJoerg Roedel1-1/+57
This is basically a revert of commit 314eeac9 but now in a fixed version. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-11Merge commit 'v2.6.30-rc5' into core/iommuIngo Molnar1-52/+1
Merge reason: core/iommu was on an .30-rc1 base, update it to .30-rc5 to refresh. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-26dma-debug: remove broken dma memory leak detection for 2.6.30Joerg Roedel1-52/+1
The feature needs some more work because the notfier which is used to check for pending allocations is called before the device drivers ->remove() function. Therefore this feature reports false positives. A real fix for this issue is to introduce a new notifier event which sent _after_ the driver has deinitialized itself. That will done for the next kernel version. [ Impact: reduce the scope of CONFIG_DMA_API_DEBUG=y checks ] Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Cc: iommu@lists.linux-foundation.org LKML-Reference: <1240576557-22442-1-git-send-email-joerg.roedel@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-15dma-debug: add dma_debug_resize_entries() to adjust the number of ↵FUJITA Tomonori1-6/+66
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 <fujita.tomonori@lab.ntt.co.jp> Acked-by: Joerg Roedel <joerg.roedel@amd.com> 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 <mingo@elte.hu>
2009-03-30dma-debug: fix printk formats (i386)Randy Dunlap1-4/+4
Fix printk format warnings in dma-debug: lib/dma-debug.c:645: warning: format '%016llx' expects type 'long long unsigned int', but argument 6 has type 'dma_addr_t' lib/dma-debug.c:662: warning: format '%016llx' expects type 'long long unsigned int', but argument 6 has type 'dma_addr_t' lib/dma-debug.c:676: warning: format '%016llx' expects type 'long long unsigned int', but argument 6 has type 'dma_addr_t' lib/dma-debug.c:686: warning: format '%016llx' expects type 'long long unsigned int', but argument 6 has type 'dma_addr_t' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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