summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2012-08-29drm/radeon: fix reading CB_COLORn_MASK from the CSMarek Olšák
Signed-off-by: Marek Olšák <maraeo@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2012-08-29watchdog: da9052: Remove duplicate inclusion of delay.hSachin Kamat
delay.h header file was included twice. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-08-29watchdog: fix watchdog-test.c build warningRandy Dunlap
Fix compiler warning by making the function static: Documentation/watchdog/src/watchdog-test.c:34:6: warning: no previous prototype for 'term' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-08-29Merge branch 'drm-intel-fixes' of ↵Dave Airlie
git://people.freedesktop.org/~danvet/drm-intel into drm-fixes Daniel writes: "Just a few smaller things: - Fix up a pipe vs. plane confusion from a refactoring, fixes a regression from 3.1 (Anhua Xu). - Fix ivb sprite pixel formats (Vijay). - Fixup ppgtt pde placement for machines where the Bios artifically limits the availbale gtt space in the name of ... product differentiation (Chris). This fixes an oops. - Yet another no_lvds quirk entry." * 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel: i915: Quirk no_lvds on Gigabyte GA-D525TUD ITX motherboard drm/i915: Use the correct size of the GTT for placing the per-process entries drm/i915: fix color order for BGR formats on IVB drm/i915: fix wrong order of parameters in port checking functions
2012-08-29Merge branch 'drm-nouveau-fixes' of ↵Dave Airlie
git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes Ben says its just a single fix to avoid the wrong pcopy units being used. * 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6: drm/nvc0/copy: check PUNITS to determine which copy engines are disabled
2012-08-29drm/nvc0/copy: check PUNITS to determine which copy engines are disabledBen Skeggs
On some Fermi chipsets (NVCE particularly) PCOPY1 doesn't exist. And if what I've seen on Kepler is true of Fermi too, chipsets of the same type can have different PCOPY units available. This should fix a v3.5 regression reported by a number of people effecting suspend/resume on NVC8/NVCE chipsets. Cc: stable@vger.kernel.org [3.5] Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2012-08-28Btrfs: fix that repair code is spuriously executed for transid failuresStefan Behrens
If verify_parent_transid() fails for all mirrors, the current code calls repair_io_failure() anyway which means: - that the disk block is rewritten without repairing anything and - that a kernel log message is printed which misleadingly claims that a read error was corrected. This is an example: parent transid verify failed on 615015833600 wanted 110423 found 110424 parent transid verify failed on 615015833600 wanted 110423 found 110424 btrfs read error corrected: ino 1 off 615015833600 (dev /dev/...) It is wrong to ignore the results from verify_parent_transid() and to call repair_eb_io_failure() when the verification of the transids failed. This commit fixes the issue. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28Btrfs: fix ordered extent leak when failing to start a transactionLiu Bo
We cannot just return error before freeing ordered extent and releasing reserved space when we fail to start a transacion. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28Btrfs: fix a dio write regressionLiu Bo
This bug is introduced by commit 3b8bde746f6f9bd36a9f05f5f3b6e334318176a9 (Btrfs: lock extents as we map them in DIO). In dio write, we should unlock the section which we didn't do IO on in case that we fall back to buffered write. But we need to not only unlock the section but also cleanup reserved space for the section. This bug was found while running xfstests 133, with this 133 no longer complains. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28Btrfs: fix deadlock with freeze and sync V2Josef Bacik
We can deadlock with freeze right now because we unconditionally start a transaction in our ->sync_fs() call. To fix this just check and see if we have a running transaction to commit. This saves us from the deadlock because at this point we'll have the umount sem for the sb so we're safe from freezes coming in after we've done our check. With this patch the freeze xfstests no longer deadlocks. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28Btrfs: revert checksum error statistic which can cause a BUG()Stefan Behrens
Commit 442a4f6308e694e0fa6025708bd5e4e424bbf51c added btrfs device statistic counters for detected IO and checksum errors to Linux 3.5. The statistic part that counts checksum errors in end_bio_extent_readpage() can cause a BUG() in a subfunction: "kernel BUG at fs/btrfs/volumes.c:3762!" That part is reverted with the current patch. However, the counting of checksum errors in the scrub context remains active, and the counting of detected IO errors (read, write or flush errors) in all contexts remains active. Cc: stable <stable@vger.kernel.org> # 3.5 Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28Btrfs: remove superblock writing after fatal errorStefan Behrens
With commit acce952b0, btrfs was changed to flag the filesystem with BTRFS_SUPER_FLAG_ERROR and switch to read-only mode after a fatal error happened like a write I/O errors of all mirrors. In such situations, on unmount, the superblock is written in btrfs_error_commit_super(). This is done with the intention to be able to evaluate the error flag on the next mount. A warning is printed in this case during the next mount and the log tree is ignored. The issue is that it is possible that the superblock points to a root that was not written (due to write I/O errors). The result is that the filesystem cannot be mounted. btrfsck also does not start and all the other btrfs-progs tools fail to start as well. However, mount -o recovery is working well and does the right things to recover the filesystem (i.e., don't use the log root, clear the free space cache and use the next mountable root that is stored in the root backup array). This patch removes the writing of the superblock when BTRFS_SUPER_FLAG_ERROR is set, and removes the handling of the error flag in the mount function. These lines can be used to reproduce the issue (using /dev/sdm): SCRATCH_DEV=/dev/sdm SCRATCH_MNT=/mnt echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup create foo ls -alLF /dev/mapper/foo mkfs.btrfs /dev/mapper/foo mount /dev/mapper/foo $SCRATCH_MNT echo bar > $SCRATCH_MNT/foo sync echo 0 25165824 error | dmsetup reload foo dmsetup resume foo ls -alF $SCRATCH_MNT touch $SCRATCH_MNT/1 ls -alF $SCRATCH_MNT sleep 35 echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup reload foo dmsetup resume foo sleep 1 umount $SCRATCH_MNT btrfsck /dev/mapper/foo dmsetup remove foo Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-08-28Btrfs: allow delayed refs to be mergedJosef Bacik
Daniel Blueman reported a bug with fio+balance on a ramdisk setup. Basically what happens is the balance relocates a tree block which will drop the implicit refs for all of its children and adds a full backref. Once the block is relocated we have to add the implicit refs back, so when we cow the block again we add the implicit refs for its children back. The problem comes when the original drop ref doesn't get run before we add the implicit refs back. The delayed ref stuff will specifically prefer ADD operations over DROP to keep us from freeing up an extent that will have references to it, so we try to add the implicit ref before it is actually removed and we panic. This worked fine before because the add would have just canceled the drop out and we would have been fine. But the backref walking work needs to be able to freeze the delayed ref stuff in time so we have this ever increasing sequence number that gets attached to all new delayed ref updates which makes us not merge refs and we run into this issue. So to fix this we need to merge delayed refs. So everytime we run a clustered ref we need to try and merge all of its delayed refs. The backref walking stuff locks the delayed ref head before processing, so if we have it locked we are safe to merge any refs inside of the sequence number. If there is no sequence number we can merge all refs. Doing this not only fixes our bug but keeps the delayed ref code from adding and removing useless refs and batching together multiple refs into one search instead of one search per delayed ref, which will really help our commit times. I ran this with Daniels test and 276 and I haven't seen any problems. Thanks, Reported-by: Daniel J Blueman <daniel@quora.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: fix enospc problems when deleting a subvolJosef Bacik
Subvol delete is a special kind of awful where we use the global reserve to cover the ENOSPC requirements. The problem is once we're done removing everything we do a btrfs_update_inode(), which by default will try to do the delayed update stuff which will use it's own reserve. There will be no space in this reserve and we'll return ENOSPC. So instead use btrfs_update_inode_fallback() which will just fallback to updating the inode item in the case of enospc. This is fine because the global reserve covers the space requirements for this. With this patch I can now delete a subvol on a problem image Dave Sterba sent me. Thanks, Reported-by: David Sterba <dave@jikos.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28Btrfs: fix wrong mtime and ctime when creating snapshotsMiao Xie
When we created a new snapshot, the mtime and ctime of its parent directory were not updated. Fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28Btrfs: fix race in run_clustered_refsArne Jansen
With commit commit d1270cd91f308c9d22b2804720c36ccd32dbc35e Author: Arne Jansen <sensille@gmx.net> Date: Tue Sep 13 15:16:43 2011 +0200 Btrfs: put back delayed refs that are too new I added a window where the delayed_ref's head->ref_mod code can diverge from the sum of the remaining refs, because we release the head->mutex in the middle. This leads to btrfs_lookup_extent_info returning wrong numbers. This patch fixes this by adjusting the head's ref_mod with each delayed ref we run. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28Btrfs: don't run __tree_mod_log_free_eb on leavesChris Mason
When we split a leaf, we may end up inserting a new root on top of that leaf. The reflog code was incorrectly assuming the old root was always a node. This makes sure we skip over leaves. Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28Btrfs: increase the size of the free space cacheJosef Bacik
Arne was complaining about the space cache having mismatching generation numbers when debugging a deadlock. This is because we can run out of space in our preallocated range for our space cache if you have a pretty fragmented amount of space in your pinned space. So just increase the amount of space we preallocate for space cache so we can be sure to have enough space. This will only really affect data ranges since their the only chunks that end up larger than 256MB. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28Btrfs: barrier before waitqueue_activeJosef Bacik
We need a barrir before calling waitqueue_active otherwise we will miss wakeups. So in places that do atomic_dec(); then atomic_read() use atomic_dec_return() which imply a memory barrier (see memory-barriers.txt) and then add an explicit memory barrier everywhere else that need them. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: fix deadlock in wait_for_more_refsArne Jansen
Commit a168650c introduced a waiting mechanism to prevent busy waiting in btrfs_run_delayed_refs. This can deadlock with btrfs_run_ordered_operations, where a tree_mod_seq is held while waiting for the io to complete, while the end_io calls btrfs_run_delayed_refs. This whole mechanism is unnecessary. If not enough runnable refs are available to satisfy count, just return as count is more like a guideline than a strict requirement. In case we have to run all refs, commit transaction makes sure that no other threads are working in the transaction anymore, so we just assert here that no refs are blocked. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28btrfs: fix second lock in btrfs_delete_delayed_items()Fengguang Wu
Fix a real bug caught by coccinelle. fs/btrfs/delayed-inode.c:1013:1-11: second lock on line 1013 Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-08-28Btrfs: don't allocate a seperate csums array for direct readsJosef Bacik
We've been allocating a big array for csums instead of storing them in the io_tree like we do for buffered reads because previously we were locking the entire range, so we didn't have an extent state for each sector of the range. But now that we do the range locking as we map the buffers we can limit the mapping lenght to sectorsize and use the private part of the io_tree for our csums. This allows us to avoid an extra memory allocation for direct reads which could incur latency. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: do not strdup non existent stringsJosef Bacik
When we close devices we add back empty devices for some reason that escapes me. In the case of a missing dev we don't allocate an rcu_string for it's name, so check to see if the device has a name and if it doesn't don't bother strdup()'ing it. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: do not use missing devices when showing devnameJosef Bacik
If you do the following mkfs.btrfs /dev/sdb /dev/sdc rmmod btrfs dd if=/dev/zero of=/dev/sdb bs=1M count=1 mount -o degraded /dev/sdc /mnt/btrfs-test the box will panic trying to deref the name for the missing dev since it is the lower numbered devid. So fix show_devname to not use missing devices. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: fix that error value is changed by mistakeStefan Behrens
In iterate_inodes_from_logical() the error result from extent_from_logical() is patched by mistake. Typically ENOENT is patched to EINVAL because (-ENOENT & BTRFS_EXTENT_FLAG_TREE_BLOCK) evaluates to true. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
2012-08-28Btrfs: lock extents as we map them in DIOJosef Bacik
A deadlock in xfstests 113 was uncovered by commit d187663ef24cd3d033f0cbf2867e70b36a3a90b8 This is because we would not return EIOCBQUEUED for short AIO reads, instead we'd wait for the DIO to complete and then return the amount of data we transferred, which would allow our stuff to unlock the remaning amount. But with this change this no longer happens, so if we have a short AIO read (for example if we try to read past EOF), we could leave the section from EOF to the end of where we tried to read locked. Fixing this is tricky since there is no clear way to know exactly how much data DIO truly submitted for IO, so to make this less hard on ourselves and less combersome we need to lock the extents as we try to map them, and then we unlock any areas we didn't actually map. This makes us completely safe from deadlocks and reliance on a particular behavior of the DIO code. This also lays the groundwork for allowing us to use the normal csum storage method for reads which means we can remove an allocation. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28Btrfs: fix some endian bugs handling the root timesDan Carpenter
"trans->transid" is cpu endian but we want to store the data as little endian. "item->ctime.nsec" is only 32 bits, not 64. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-08-28Btrfs: unlock on error in btrfs_delalloc_reserve_metadata()Dan Carpenter
We should release this mutex before returning the error code. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-08-28Btrfs: checking for NULL instead of IS_ERRDan Carpenter
add_qgroup_rb() never returns NULL, only error pointers. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-08-28Btrfs: fix some error codes in btrfs_qgroup_inherit()Dan Carpenter
These are returning zero when it should be returning a negative error code. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-08-28Btrfs: fix a misplaced address operator in a conditionStefan Behrens
This should obviously not be "if (&flag)" but "if (flag)". Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
2012-08-28ARM: dma-mapping: IOMMU allocates pages from atomic_pool with GFP_ATOMICHiroshi Doyu
Make use of the same atomic pool as DMA does, and skip a kernel page mapping which can involve sleep'able operations at allocating a kernel page table. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: dma-mapping: Introduce __atomic_get_pages() for __iommu_get_pages()Hiroshi Doyu
Support atomic allocation in __iommu_get_pages(). Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> [moved __atomic_get_pages() under #ifdef CONFIG_ARM_DMA_USE_IOMMU to avoid unused fuction warning for no-IOMMU case] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: dma-mapping: Refactor out to introduce __in_atomic_poolHiroshi Doyu
Check the given range("start", "size") is included in "atomic_pool" or not. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: dma-mapping: atomic_pool with struct page **pagesHiroshi Doyu
struct page **pages is necessary to align with non atomic path in __iommu_get_pages(). atomic_pool() has the intialized **pages instead of just *page. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: Kirkwood: increase atomic coherent pool sizeMarek Szyprowski
The default 256 KiB coherent pool may be too small for some of the Kirkwood devices, so increase it to make sure that devices will be able to allocate their buffers with GFP_ATOMIC flag. Suggested-by: Josh Coombs <josh.coombs@gmail.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Jason Cooper <jason@lakedaemon.net>
2012-08-28ARM: DMA-Mapping: print warning when atomic coherent allocation failsMarek Szyprowski
Print a loud warning when system runs out of memory from atomic DMA coherent pool to let users notice the potential problem. Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: DMA-Mapping: add function for setting coherent pool size from platform codeMarek Szyprowski
Some platforms might require to increase atomic coherent pool to make sure that their device will be able to allocate all their buffers from atomic context. This function can be also used to decrease atomic coherent pool size if coherent allocations are not used for the given sub-platform. Suggested-by: Josh Coombs <josh.coombs@gmail.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2012-08-28ARM: relax conditions required for enabling Contiguous Memory AllocatorMarek Szyprowski
Contiguous Memory Allocator requires only paging and MMU enabled not particular CPU architectures, so there is no need for strict dependency on CPU type. This enables to use CMA on some older ARM v5 systems which also might need large contiguous blocks for the multimedia processing hw modules. Reported-by: Prabhakar Lad <prabhakar.lad@ti.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Prabhakar Lad <prabhakar.lad@ti.com>
2012-08-28mm: cma: fix alignment requirements for contiguous regionsMarek Szyprowski
Contiguous Memory Allocator requires each of its regions to be aligned in such a way that it is possible to change migration type for all pageblocks holding it and then isolate page of largest possible order from the buddy allocator (which is MAX_ORDER-1). This patch relaxes alignment requirements by one order, because MAX_ORDER alignment is not really needed. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> CC: Michal Nazarewicz <mina86@mina86.com> Acked-by: Michal Nazarewicz <mina86@mina86.com>
2012-08-28ALSA: hda - Don't trust codec EPSS bit for IDT 92HD83xx & coTakashi Iwai
These codecs seem reporting EPSS but require longer delay for the proper D3 transition. For example, D3_STOP_CLOCK_OK bit won't be set correctly even after D3. In this patch, codec->epss flag is overridden for avoid the misbehavior. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-08-28ALSA: hda - Avoid unnecessary parameter read for EPSSTakashi Iwai
EPSS parameter should be static, so we can read it once and remember. This also allows more easily to override the wrong EPSS capability reported from a codec by changing the flag in the codec initialization step. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-08-28uprobes: Remove "verify" argument from set_orig_insn()Oleg Nesterov
Nobody does set_orig_insn(verify => false), and I think nobody will. Remove this argument. IIUC set_orig_insn(verify => false) was needed to single-step without xol area. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Fold uprobe_reset_state() into uprobe_dup_mmap()Oleg Nesterov
Now that we have uprobe_dup_mmap() we can fold uprobe_reset_state() into the new hook and remove it. mmput()->uprobe_clear_state() can't be called before dup_mmap(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Introduce MMF_HAS_UPROBESOleg Nesterov
Add the new MMF_HAS_UPROBES flag. It is set by install_breakpoint() and it is copied by dup_mmap(), uprobe_pre_sstep_notifier() checks it to avoid the slow path if the task was never probed. Perhaps it makes sense to check it in valid_vma(is_register => false) as well. This needs the new dup_mmap()->uprobe_dup_mmap() hook. We can't use uprobe_reset_state() or put MMF_HAS_UPROBES into MMF_INIT_MASK, we need oldmm->mmap_sem to avoid the race with uprobe_register() or mmap() from another thread. Currently we never clear this bit, it can be false-positive after uprobe_unregister() or uprobe_munmap() or if dup_mmap() hits the probed VM_DONTCOPY vma. But this is fine correctness-wise and has no effect unless the task hits the non-uprobe breakpoint. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Do not use -EEXIST in install_breakpoint() pathsOleg Nesterov
-EEXIST from install_breakpoint() no longer makes sense, all callers should simply treat it as "success". Change the code to return zero and simplify register_for_each_vma(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Change uprobe_mmap() to ignore the errors but check ↵Oleg Nesterov
fatal_signal_pending() Once install_breakpoint() fails uprobe_mmap() "ignores" all other uprobes and returns the error. It was never really needed to to stop after the first error, and in fact it was always wrong at least in -ENOTSUPP case. Change uprobe_mmap() to ignore the errors and always return 0. This is not what we want in the long term, but until we teach the callers to handle the failure it would be better to remove the pointless complications. And this doesn't look too bad, the only "reasonable" error is ENOMEM but in this case the caller should be oom-killed in the likely case or the system has more serious problems. However it makes sense to stop if fatal_signal_pending() == T. In particular this helps if the task was oom-killed. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Kill dup_mmap()->uprobe_mmap(), simplify uprobe_mmap/munmapOleg Nesterov
1. Kill dup_mmap()->uprobe_mmap(), it was only needed to calculate new_mm->uprobes_state.count removed by the previous patch. If the forking process has a pending uprobe (int3) in vma, it will be copied by copy_page_range(), note that it checks vma->anon_vma so "Don't copy ptes" is not possible after install_breakpoint() which does anon_vma_prepare(). 2. Remove is_swbp_at_addr() and "int count" in uprobe_mmap(). Again, this was needed for uprobes_state.count. As a side effect this fixes the bug pointed out by Srikar, this code lacked the necessary put_uprobe(). 3. uprobe_munmap() becomes a nop after the previous patch. Remove the meaningless code but do not remove the helper, we will need it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Kill uprobes_state->countOleg Nesterov
uprobes_state->count is only needed to avoid the slow path in uprobe_pre_sstep_notifier(). It is also checked in uprobe_munmap() but ironically its only goal to decrement this counter. However, it is very broken. Just some examples: - uprobe_mmap() can race with uprobe_unregister() and wrongly increment the counter if it hits the non-uprobe "int3". Note that install_breakpoint() checks ->consumers first and returns -EEXIST if it is NULL. "atomic_sub() if error" in uprobe_mmap() looks obviously wrong too. - uprobe_munmap() can race with uprobe_register() and wrongly decrement the counter by the same reason. - Suppose an appication tries to increase the mmapped area via sys_mremap(). vma_adjust() does uprobe_munmap(whole_vma) first, this can nullify the counter temporarily and race with another thread which can hit the bp, the application will be killed by SIGTRAP. - Suppose an application mmaps 2 consecutive areas in the same file and one (or both) of these areas has uprobes. In the likely case mmap_region()->vma_merge() suceeds. Like above, this leads to uprobe_munmap/uprobe_mmap from vma_merge()->vma_adjust() but then mmap_region() does another uprobe_mmap(resulting_vma) and doubles the counter. This patch only removes this counter and fixes the compile errors, then we will try to cleanup the changed code and add something else instead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28uprobes: Remove check for uprobe variable in handle_swbp()Sebastian Andrzej Siewior
by the time we get here (after we pass cleanup_ret) uprobe is always is set. If it is NULL we leave very early in the code. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Oleg Nesterov <oleg@redhat.com>