Commit graph

44 commits

Author SHA1 Message Date
Kyle McMartin
ec9c96ef3c 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 <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>
2009-08-21 10:04:24 +02:00
Ingo Molnar
f39d1b9792 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 <torvalds@linux-foundation.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10 22:18:45 +02:00
Ingo Molnar
b0a5b83ee0 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 <alan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-17 16:26:04 +02:00
Joerg Roedel
c79ee4e466 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 <randrik@mail.ru>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-16 12:29:40 +02:00
Joerg Roedel
aa010efb7b 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 <joerg.roedel@amd.com>
2009-06-15 11:10:14 +02:00
Joerg Roedel
e5e8c5b90a 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 <joerg.roedel@amd.com>
2009-06-15 11:08:54 +02:00
Joerg Roedel
0bf841281e 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 <joerg.roedel@amd.com>
2009-06-08 15:53:46 +02:00
Joerg Roedel
be81c6ea23 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 <joerg.roedel@amd.com>
2009-06-08 15:46:19 +02:00
Joerg Roedel
e7ed70eedc 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 <joerg.roedel@amd.com>
2009-06-08 15:39:24 +02:00
Joerg Roedel
c17e2cf737 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 <joerg.roedel@amd.com>
2009-06-08 15:19:29 +02:00
Joerg Roedel
3123250947 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 <joerg.roedel@amd.com>
2009-06-08 15:07:08 +02:00
Ingo Molnar
62a6f465f6 Merge branch 'dma-debug/2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu 2009-06-07 11:36:02 +02:00
Joerg Roedel
7caf6a49bb 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 <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>
2009-06-07 10:04:53 +02:00
Joerg Roedel
bdc2911cde Merge branches 'dma-debug/fixes' and 'dma-debug/driver-filter' into dma-debug/2.6.31 2009-06-02 16:45:02 +02:00
Joerg Roedel
1745de5e56 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 <joerg.roedel@amd.com>
2009-06-02 16:21:41 +02:00
Joerg Roedel
8a6fc708b9 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 <joerg.roedel@amd.com>
2009-06-02 16:21:18 +02:00
Joerg Roedel
2e507d849f 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 <joerg.roedel@amd.com>
2009-06-02 14:54:55 +02:00
FUJITA Tomonori
88f3907f6f 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 <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-29 14:27:05 +02:00
FUJITA Tomonori
884d05970b 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 <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-29 14:26:55 +02:00
FUJITA Tomonori
15aedea439 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 <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-05-29 14:26:42 +02:00
Joerg Roedel
ed888aef42 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 <joerg.roedel@amd.com>
2009-05-28 17:09:07 +02:00
Ingo Molnar
41fb454ebe Merge commit 'v2.6.30-rc5' into core/iommu
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>
2009-05-11 14:44:31 +02:00
Joerg Roedel
314eeac9e3 dma-debug: remove broken dma memory leak detection for 2.6.30
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>
2009-04-26 18:23:56 +02:00
FUJITA Tomonori
e6a1a89d57 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 <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>
2009-04-15 12:22:37 +02:00
Randy Dunlap
93c36ed834 dma-debug: fix printk formats (i386)
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>
2009-03-30 14:28:59 -07:00
Joerg Roedel
9537a48ed4 dma-debug: make memory range checks more consistent
Impact: extend on-kernel-stack DMA debug checks to all !highmem pages

We only checked dma_map_single() - extend it to dma_map_page()
and dma_map_sg() as well.

Also, fix dma_map_single() corner case bug: make sure we dont
stack-check highmem (not mapped) pages.

Reported-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
LKML-Reference: <1237818908-26516-1-git-send-email-joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-24 08:39:32 +01:00
FUJITA Tomonori
35d40952db dma-debug: warn of unmapping an invalid dma address
Impact: extend DMA-debug checks

Calling dma_unmap families against an invalid dma address should be a
bug.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20090319103743N.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-19 08:39:48 +01:00
Joerg Roedel
41531c8f5f dma-debug: add a check dma memory leaks
Impact: allow architectures to monitor busses for dma mem leakage

This patch adds checking code to detect if a device has pending DMA
operations when it is about to be unbound from its device driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-17 12:56:49 +01:00
Joerg Roedel
2e34bde185 dma-debug: add checks for kernel text and rodata
Impact: get notified if a device dma maps illegal areas

This patch adds a check to print a warning message when a device driver
tries to map a memory area from the kernel text segment or rodata.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-17 12:56:48 +01:00
David Woodhouse
6c132d1bcd dma-debug: print stacktrace of mapping path on unmap error
Impact: saves stacktrace of a dma mapping and prints it if there is an  error

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-17 12:56:48 +01:00
David Woodhouse
ac26c18bd3 dma-debug: add function to dump dma mappings
This adds a function to dump the DMA mappings that the debugging code is
aware of -- either for a single device, or for _all_ devices.

This can be useful for debugging -- sticking a call to it in the DMA
page fault handler, for example, to see if the faulting address _should_
be mapped or not, and hence work out whether it's IOMMU bugs we're
seeing, or driver bugs.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-03-17 12:56:39 +01:00
Joerg Roedel
a31fba5d68 dma-debug: add checks for sync_single_sg_*
Impact: add debug callbacks for dma_sync_sg_* functions

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:21 +01:00
Joerg Roedel
948408ba3e dma-debug: add checks for sync_single_range_*
Impact: add debug callbacks for dma_sync_single_range_for_* functions

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:21 +01:00
Joerg Roedel
b9d2317e0c dma-debug: add checks for sync_single_*
Impact: add debug callbacks for dma_sync_single_for_* functions

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:20 +01:00
Joerg Roedel
6bfd449876 dma-debug: add checking for [alloc|free]_coherent
Impact: add debug callbacks for dma_[alloc|free]_coherent

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:19 +01:00
Joerg Roedel
972aa45cea dma-debug: add add checking for map/unmap_sg
Impact: add debug callbacks for dma_{un}map_sg

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:18 +01:00
Joerg Roedel
f62bc980e6 dma-debug: add checking for map/unmap_page/single
Impact: add debug callbacks for dma_{un}map_[page|single]

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:18 +01:00
Joerg Roedel
2d62ece14f dma-debug: add core checking functions
Impact: add functions to check on dma unmap and sync

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:17 +01:00
Joerg Roedel
788dcfa6f1 dma-debug: add debugfs interface
Impact: add debugfs interface for configuring DMA-API debugging

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:16 +01:00
Joerg Roedel
59d3daafa1 dma-debug: add kernel command line parameters
Impact: add dma_debug= and dma_debug_entries= kernel parameters

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:16 +01:00
Joerg Roedel
6bf078715c dma-debug: add initialization code
Impact: add code to initialize dma-debug core data structures

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:15 +01:00
Joerg Roedel
3b1e79ed73 dma-debug: add allocator code
Impact: add allocator code for struct dma_debug_entry

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:15 +01:00
Joerg Roedel
30dfa90cc8 dma-debug: add hash functions for dma_debug_entries
Impact: implement necessary functions for the core hash

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 20:35:04 +01:00
Joerg Roedel
f2f45e5f3c dma-debug: add header file and core data structures
Impact: add groundwork for DMA-API debugging

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 15:11:12 +01:00