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2020-11-05uio: free uio id after uio file node is freedLang Dai1-2/+2
[ Upstream commit 8fd0e2a6df262539eaa28b0a2364cca10d1dc662 ] uio_register_device() do two things. 1) get an uio id from a global pool, e.g. the id is <A> 2) create file nodes like /sys/class/uio/uio<A> uio_unregister_device() do two things. 1) free the uio id <A> and return it to the global pool 2) free the file node /sys/class/uio/uio<A> There is a situation is that one worker is calling uio_unregister_device(), and another worker is calling uio_register_device(). If the two workers are X and Y, they go as below sequence, 1) X free the uio id <AAA> 2) Y get an uio id <AAA> 3) Y create file node /sys/class/uio/uio<AAA> 4) X free the file note /sys/class/uio/uio<AAA> Then it will failed at the 3rd step and cause the phenomenon we saw as it is creating a duplicated file node. Failure reports as follows: sysfs: cannot create duplicate filename '/class/uio/uio10' Call Trace: sysfs_do_create_link_sd.isra.2+0x9e/0xb0 sysfs_create_link+0x25/0x40 device_add+0x2c4/0x640 __uio_register_device+0x1c5/0x576 [uio] adf_uio_init_bundle_dev+0x231/0x280 [intel_qat] adf_uio_register+0x1c0/0x340 [intel_qat] adf_dev_start+0x202/0x370 [intel_qat] adf_dev_start_async+0x40/0xa0 [intel_qat] process_one_work+0x14d/0x410 worker_thread+0x4b/0x460 kthread+0x105/0x140 ? process_one_work+0x410/0x410 ? kthread_bind+0x40/0x40 ret_from_fork+0x1f/0x40 Code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 ec c4 ff ff 4c 89 e2 48 89 de 48 c7 c7 e8 b4 ee b4 e8 6a d4 d7 ff <0f> 0b 48 89 df e8 20 fa f3 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84 ---[ end trace a7531c1ed5269e84 ]--- c6xxvf b002:00:00.0: Failed to register UIO devices c6xxvf b002:00:00.0: Failed to register UIO devices Signed-off-by: Lang Dai <lang.dai@intel.com> Link: https://lore.kernel.org/r/1600054002-17722-1-git-send-email-lang.dai@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27driver: uio: fix possible use-after-free in __uio_register_deviceLiu Jian1-2/+4
[ Upstream commit 221a1f4ac12d2ab46246c160b2e00d1b1160d5d9 ] In uio_dev_add_attributes() error handing case, idev is used after device_unregister(), in which 'idev' has been released, touch idev cause use-after-free. Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are open") Signed-off-by: Liu Jian <liujian56@huawei.com> Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27driver: uio: fix possible memory leak in __uio_register_deviceLiu Jian1-1/+3
[ Upstream commit 1a392b3de7c5747506b38fc14b2e79977d3c7770 ] 'idev' is malloced in __uio_register_device() and leak free it before leaving from the uio_get_minor() error handing case, it will cause memory leak. Fixes: a93e7b331568 ("uio: Prevent device destruction while fds are open") Signed-off-by: Liu Jian <liujian56@huawei.com> Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-15Revert "uio: use request_threaded_irq instead"Xiubo Li1-6/+2
commit 3d27c4de8d4fb2d4099ff324671792aa2578c6f9 upstream. Since mutex lock in irq hanler is useless currently, here will remove it together with it. This reverts commit 9421e45f5ff3d558cf8b75a8cc0824530caf3453. Reported-by: james.r.harris@intel.com CC: Ahsan Atta <ahsan.atta@intel.com> Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: fix possible circular locking dependencyXiubo Li1-10/+6
commit b34e9a15b37b8ddbf06a4da142b0c39c74211eb4 upstream. The call trace: XXX/1910 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<ffffffff97008c87>] might_fault+0x57/0xb0 but task is already holding lock: (&idev->info_lock){+.+...}, at: [<ffffffffc0638a06>] uio_write+0x46/0x130 [uio] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&idev->info_lock){+.+...}: [<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0 [<ffffffff975edad3>] mutex_lock_nested+0x93/0x410 [<ffffffffc063873d>] uio_mmap+0x2d/0x170 [uio] [<ffffffff97016b58>] mmap_region+0x428/0x650 [<ffffffff97017138>] do_mmap+0x3b8/0x4e0 [<ffffffff96ffaba3>] vm_mmap_pgoff+0xd3/0x120 [<ffffffff97015261>] SyS_mmap_pgoff+0x1f1/0x270 [<ffffffff96e387c2>] SyS_mmap+0x22/0x30 [<ffffffff975ff315>] system_call_fastpath+0x1c/0x21 -> #0 (&mm->mmap_sem){++++++}: [<ffffffff96f30e9c>] __lock_acquire+0xdac/0x15f0 [<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0 [<ffffffff97008cb4>] might_fault+0x84/0xb0 [<ffffffffc0638a74>] uio_write+0xb4/0x130 [uio] [<ffffffff9706ffa3>] vfs_write+0xc3/0x1f0 [<ffffffff97070e2a>] SyS_write+0x8a/0x100 [<ffffffff975ff315>] system_call_fastpath+0x1c/0x21 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&idev->info_lock); lock(&mm->mmap_sem); lock(&idev->info_lock); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by XXX/1910: #0: (&idev->info_lock){+.+...}, at: [<ffffffffc0638a06>] uio_write+0x46/0x130 [uio] stack backtrace: CPU: 0 PID: 1910 Comm: XXX Kdump: loaded Not tainted #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 Call Trace: [<ffffffff975e9211>] dump_stack+0x19/0x1b [<ffffffff975e260a>] print_circular_bug+0x1f9/0x207 [<ffffffff96f2f6a7>] check_prevs_add+0x957/0x960 [<ffffffff96f30e9c>] __lock_acquire+0xdac/0x15f0 [<ffffffff96f2fb19>] ? mark_held_locks+0xb9/0x140 [<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0 [<ffffffff97008c87>] ? might_fault+0x57/0xb0 [<ffffffff97008cb4>] might_fault+0x84/0xb0 [<ffffffff97008c87>] ? might_fault+0x57/0xb0 [<ffffffffc0638a74>] uio_write+0xb4/0x130 [uio] [<ffffffff9706ffa3>] vfs_write+0xc3/0x1f0 [<ffffffff9709349c>] ? fget_light+0xfc/0x510 [<ffffffff97070e2a>] SyS_write+0x8a/0x100 [<ffffffff975ff315>] system_call_fastpath+0x1c/0x21 Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: fix wrong return value from uio_mmap()Hailong Liu1-1/+1
commit e7de2590f18a272e63732b9d519250d1b522b2c4 upstream. uio_mmap has multiple fail paths to set return value to nonzero then goto out. However, it always returns *0* from the *out* at end, and this will mislead callers who check the return value of this function. Fixes: 57c5f4df0a5a0ee ("uio: fix crash after the device is unregistered") CC: Xiubo Li <xiubli@redhat.com> Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn> Cc: stable <stable@vger.kernel.org> Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: fix crash after the device is unregisteredXiubo Li1-16/+88
commit 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9 upstream. For the target_core_user use case, after the device is unregistered it maybe still opened in user space, then the kernel will crash, like: [ 251.163692] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 251.163820] IP: [<ffffffffc0736213>] show_name+0x23/0x40 [uio] [ 251.163965] PGD 8000000062694067 PUD 62696067 PMD 0 [ 251.164097] Oops: 0000 [#1] SMP ... [ 251.165605] e1000 mptscsih mptbase drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod [ 251.166014] CPU: 0 PID: 13380 Comm: tcmu-runner Kdump: loaded Not tainted 3.10.0-916.el7.test.x86_64 #1 [ 251.166381] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 251.166747] task: ffff971eb91db0c0 ti: ffff971e9e384000 task.ti: ffff971e9e384000 [ 251.167137] RIP: 0010:[<ffffffffc0736213>] [<ffffffffc0736213>] show_name+0x23/0x40 [uio] [ 251.167563] RSP: 0018:ffff971e9e387dc8 EFLAGS: 00010282 [ 251.167978] RAX: 0000000000000000 RBX: ffff971e9e3f8000 RCX: ffff971eb8368d98 [ 251.168408] RDX: ffff971e9e3f8000 RSI: ffffffffc0738084 RDI: ffff971e9e3f8000 [ 251.168856] RBP: ffff971e9e387dd0 R08: ffff971eb8bc0018 R09: 0000000000000000 [ 251.169296] R10: 0000000000001000 R11: ffffffffa09d444d R12: ffffffffa1076e80 [ 251.169750] R13: ffff971e9e387f18 R14: 0000000000000001 R15: ffff971e9cfb1c80 [ 251.170213] FS: 00007ff37d175880(0000) GS:ffff971ebb600000(0000) knlGS:0000000000000000 [ 251.170693] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 251.171248] CR2: 0000000000000008 CR3: 00000000001f6000 CR4: 00000000003607f0 [ 251.172071] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 251.172640] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 251.173236] Call Trace: [ 251.173789] [<ffffffffa0c9b2d3>] dev_attr_show+0x23/0x60 [ 251.174356] [<ffffffffa0f561b2>] ? mutex_lock+0x12/0x2f [ 251.174892] [<ffffffffa0ac6d9f>] sysfs_kf_seq_show+0xcf/0x1f0 [ 251.175433] [<ffffffffa0ac54e6>] kernfs_seq_show+0x26/0x30 [ 251.175981] [<ffffffffa0a63be0>] seq_read+0x110/0x3f0 [ 251.176609] [<ffffffffa0ac5d45>] kernfs_fop_read+0xf5/0x160 [ 251.177158] [<ffffffffa0a3d3af>] vfs_read+0x9f/0x170 [ 251.177707] [<ffffffffa0a3e27f>] SyS_read+0x7f/0xf0 [ 251.178268] [<ffffffffa0f648af>] system_call_fastpath+0x1c/0x21 [ 251.178823] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 d3 e8 7e 96 56 e0 48 8b 80 d8 02 00 00 48 89 df 48 c7 c6 84 80 73 c0 <48> 8b 50 08 31 c0 e8 e2 67 44 e0 5b 48 98 5d c3 0f 1f 00 66 2e [ 251.180115] RIP [<ffffffffc0736213>] show_name+0x23/0x40 [uio] [ 251.180820] RSP <ffff971e9e387dc8> [ 251.181473] CR2: 0000000000000008 CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz> CC: Mike Christie <mchristi@redhat.com> Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: change to use the mutex lock instead of the spin lockXiubo Li1-19/+13
commit 543af5861f41af0a5d2432f6fb5976af50f9cee5 upstream. We are hitting a regression with the following commit: commit a93e7b331568227500186a465fee3c2cb5dffd1f Author: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Date: Mon May 14 13:32:23 2018 +1200 uio: Prevent device destruction while fds are open The problem is the addition of spin_lock_irqsave in uio_write. This leads to hitting uio_write -> copy_from_user -> _copy_from_user -> might_fault and the logs filling up with sleeping warnings. I also noticed some uio drivers allocate memory, sleep, grab mutexes from callouts like open() and release and uio is now doing spin_lock_irqsave while calling them. Reported-by: Mike Christie <mchristi@redhat.com> CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: use request_threaded_irq insteadXiubo Li1-2/+3
commit 9421e45f5ff3d558cf8b75a8cc0824530caf3453 upstream. Prepraing for changing to use mutex lock. Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: Prevent device destruction while fds are openHamish Martin1-26/+72
commit a93e7b331568227500186a465fee3c2cb5dffd1f upstream. Prevent destruction of a uio_device while user space apps hold open file descriptors to that device. Further, access to the 'info' member of the struct uio_device is protected by spinlock. This is to ensure stale pointers to data not under control of the UIO subsystem are not dereferenced. Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [4.14 change __poll_t to unsigned int] Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15uio: Reduce return paths from uio_write()Hamish Martin1-8/+17
commit 81daa406c2cc97d85eef9409400404efc2a3f756 upstream. Drive all return paths for uio_write() through a single block at the end of the function. Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27uio: Fix an Oops on loadDan Carpenter1-2/+5
commit 432798195bbce1f8cd33d1c0284d0538835e25fb upstream. I was trying to solve a double free but I introduced a more serious NULL dereference bug. The problem is that if there is an IRQ which triggers immediately, then we need "info->uio_dev" but it's not set yet. This patch puts the original initialization back to how it was and just sets info->uio_dev to NULL on the error path so it should solve both the Oops and the double free. Fixes: f019f07ecf6a ("uio: potential double frees if __uio_register_device() fails") Reported-by: Mathias Thore <Mathias.Thore@infinera.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable <stable@vger.kernel.org> Tested-by: Mathias Thore <Mathias.Thore@infinera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13uio: ensure class is registered before devicesAlexandre Belloni1-0/+9
[ Upstream commit ae61cf5b9913027c6953a79ed3894da4f47061bd ] When both uio and the uio drivers are built in the kernel, it is possible for a driver to register devices before the uio class is registered. This may result in a NULL pointer dereference later on in get_device_parent() when accessing the class glue_dirs spinlock. The trace looks like that: Unable to handle kernel NULL pointer dereference at virtual address 00000140 [...] [<ffff0000089cc234>] _raw_spin_lock+0x14/0x48 [<ffff0000084f56bc>] device_add+0x154/0x6a0 [<ffff0000084f5e48>] device_create_groups_vargs+0x120/0x128 [<ffff0000084f5edc>] device_create+0x54/0x60 [<ffff0000086e72c0>] __uio_register_device+0x120/0x4a8 [<ffff000008528b7c>] jaguar2_pci_probe+0x2d4/0x558 [<ffff0000083fc18c>] local_pci_probe+0x3c/0xb8 [<ffff0000083fd81c>] pci_device_probe+0x11c/0x180 [<ffff0000084f88bc>] driver_probe_device+0x22c/0x2d8 [<ffff0000084f8a24>] __driver_attach+0xbc/0xc0 [<ffff0000084f69fc>] bus_for_each_dev+0x4c/0x98 [<ffff0000084f81b8>] driver_attach+0x20/0x28 [<ffff0000084f7d08>] bus_add_driver+0x1b8/0x228 [<ffff0000084f93c0>] driver_register+0x60/0xf8 [<ffff0000083fb918>] __pci_register_driver+0x40/0x48 Return EPROBE_DEFER in that case so the driver can register the device later. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-19uio: potential double frees if __uio_register_device() failsDan Carpenter1-2/+1
[ Upstream commit f019f07ecf6a6b8bd6d7853bce70925d90af02d1 ] The uio_unregister_device() function assumes that if "info->uio_dev" is non-NULL that means "info" is fully allocated. Setting info->uio_de has to be the last thing in the function. In the current code, if request_threaded_irq() fails then we return with info->uio_dev set to non-NULL but info is not fully allocated and it can lead to double frees. Fixes: beafc54c4e2f ("UIO: Add the User IO core code") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-17uio: fix incorrect memory leak cleanupSuman Anna1-4/+4
Commit 75f0aef6220d ("uio: fix memory leak") has fixed up some memory leaks during the failure paths of the addition of uio attributes, but still is not correct entirely. A kobject_uevent() failure still needs a kobject_put() and the kobject container structure allocation failure before the kobject_init() doesn't need a kobject_put(). Fix this properly. Fixes: 75f0aef6220d ("uio: fix memory leak") Signed-off-by: Suman Anna <s-anna@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08uio: Allow handling of non page-aligned memory regionsMichal Sojka1-1/+1
Since commit b65502879556 ("uio: we cannot mmap unaligned page contents") addresses and sizes of UIO memory regions must be page-aligned. If the address in the BAR register is not page-aligned (which is the case of the mf264 card), the mentioned commit forces the UIO driver to round the address down to the page size. Then, there is no easy way for user-space to learn the offset of the actual memory region within the page, because the offset seen in /sys/class/uio/uio?/maps/map?/offset is calculated from the rounded address and thus it is always zero. Fix that problem by including the offset in struct uio_mem. UIO drivers can set this field and userspace can read its value from /sys/class/uio/uio?/maps/map?/offset. The following commits update the uio_mf264 driver to set this new offs field. Drivers for hardware with page-aligned BARs need not to be modified provided that they initialize struct uio_info (which contains uio_mem) with zeros. Signed-off-by: Michal Sojka <sojkam1@fel.cvut.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar1-1/+1
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-25mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang1-3/+3
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-02uio: add missing error codesDan Carpenter1-4/+12
My static checker complains that "ret" could be uninitialized at the end, which is true but it's more likely that it would be set to zero. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04uio: fix false positive __might_sleep warning splatMichal Hocko1-0/+1
Andy has reported a __might_sleep warning [ 5174.883617] WARNING: CPU: 0 PID: 1532 at /home/agrover/git/kernel/kernel/sched/core.c:7389 __might_sleep+0x7d/0x90() [ 5174.884407] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa02a5821>] uio_read+0x91/0x170 [uio] [ 5174.885198] Modules linked in: tcm_loop target_core_user uio target_core_pscsi target_core_file target_core_iblock iscsi_target_mod target_core_mod uinput fuse nfsv3 nfs_acl nfs lockd grace fscache sunrpc microcode i2c_piix4 virtio_balloon i2c_core xfs libcrc32c crc32c_intel virtio_net virtio_blk [ 5174.887351] CPU: 0 PID: 1532 Comm: tcmu-runner Not tainted 4.2.0-rc7+ [ 5174.887853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 [ 5174.888633] ffffffff81a3b870 ffff880045393ca8 ffffffff817afaae 0000000000000000 [ 5174.889224] ffff880045393cf8 ffff880045393ce8 ffffffff8109a846 ffff880045393cd8 [ 5174.889793] ffffffffa02a7150 00000000000002dc 0000000000000000 ffff880045008000 [ 5174.890375] Call Trace: [ 5174.890562] [<ffffffff817afaae>] dump_stack+0x4c/0x65 [ 5174.890938] [<ffffffff8109a846>] warn_slowpath_common+0x86/0xc0 [ 5174.891388] [<ffffffff8109a8c6>] warn_slowpath_fmt+0x46/0x50 [ 5174.891808] [<ffffffffa02a5821>] ? uio_read+0x91/0x170 [uio] [ 5174.892237] [<ffffffffa02a5821>] ? uio_read+0x91/0x170 [uio] [ 5174.892653] [<ffffffff810c584d>] __might_sleep+0x7d/0x90 [ 5174.893055] [<ffffffff811ea023>] __might_fault+0x43/0xa0 [ 5174.893448] [<ffffffff817b31ce>] ? schedule+0x3e/0x90 [ 5174.893820] [<ffffffffa02a58c2>] uio_read+0x132/0x170 [uio] [ 5174.894240] [<ffffffff810cbb80>] ? wake_up_q+0x70/0x70 [ 5174.894620] [<ffffffff81236168>] __vfs_read+0x28/0xe0 [ 5174.894993] [<ffffffff81353233>] ? security_file_permission+0xa3/0xc0 [ 5174.895541] [<ffffffff8123678f>] ? rw_verify_area+0x4f/0xf0 [ 5174.896006] [<ffffffff812368ba>] vfs_read+0x8a/0x140 [ 5174.896391] [<ffffffff817b28f5>] ? __schedule+0x425/0xcc0 [ 5174.896788] [<ffffffff812375d9>] SyS_read+0x49/0xb0 The warning is a false positive because uio_read doesn't depent on TASK_INTERRUPTIBLE after copy_to_user so it is safe to silence the warning by an explicit setting the state to TASK_RUNNING in the path which might call into TASK_RUNNING. Reported-by: Andy Grover <agrover@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05uio: Destroy uio_idr on module exitJohannes Thumshirn1-0/+1
Destroy uio_idr on module exit, reclaiming the allocated memory. This was detected by the following semantic patch (written by Luis Rodriguez <mcgrof@suse.com>) <SmPL> @ defines_module_init @ declarer name module_init, module_exit; declarer name DEFINE_IDR; identifier init; @@ module_init(init); @ defines_module_exit @ identifier exit; @@ module_exit(exit); @ declares_idr depends on defines_module_init && defines_module_exit @ identifier idr; @@ DEFINE_IDR(idr); @ on_exit_calls_destroy depends on declares_idr && defines_module_exit @ identifier declares_idr.idr, defines_module_exit.exit; @@ exit(void) { ... idr_destroy(&idr); ... } @ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @ identifier declares_idr.idr, defines_module_exit.exit; @@ exit(void) { ... +idr_destroy(&idr); } </SmPL> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24uio: don't free irq that was not requestedStephen Hemminger1-1/+2
UIO base driver should only free_irq that it has requested. UIO supports drivers without interrupts (irq == 0) or custom handlers. This fixes warnings like: WARNING: CPU: 1 PID: 5478 at kernel/irq/manage.c:1244 __free_irq+0xa9/0x1e0() Trying to free already-free IRQ 0 Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-20uio: Request/free irq separate from dev lifecycleBrian Russell1-1/+11
Separate irq request/free from the device lifecycle. After device unregister the parent module can call pci_disable_msi. >From the PCI MSI how to: "Before calling this function, a device driver must always call free_irq() on any interrupt for which it previously called request_irq(). Failure to do so results in a BUG_ON(), leaving the device with MSI enabled and thus leaking its vector." So we need to separately free the irq at unregister to allow the device to be kept around in the case of it still having open FDs. Signed-off-by: Brian Russell <brussell@brocade.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07uio: support memory sizes larger than 32 bitsCristian Stoica1-2/+2
This is a completion to 27a90700a4275c5178b883b65927affdafa5185c The size field is also increased to allow values larger than 32 bits on platforms that have more than 32 bit physical addresses. Signed-off-by: Cristian Stoica <cristian.stoica@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-03uio: Export definition of struct uio_deviceAndy Grover1-12/+0
In order to prevent a O(n) search of the filesystem to link up its uio node with its target configuration, TCMU needs to know the minor number that UIO assigned. Expose the definition of this struct so TCMU can access this field. Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-06-18Revert "uio: fix vma io range check in mmap"Greg Kroah-Hartman1-1/+1
This reverts commit ddb09754e6c7239e302c7b675df9bbd415f8de5d. Linus objected to this originally, I can see why it might be needed, but given that no one spoke up defending this patch, I'm going to revert it. If you have hardware that requires this change, please speak up in the future and defend the patch. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Bin Wang <binw@marvell.com> Cc: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Cc: Norbert Ciosek <norbertciosek@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28uio: fix vma io range check in mmapBin Wang1-1/+1
the vma range size is always page size aligned in mmap, while the real io space range may not be page aligned, thus leading to range check failure in the uio_mmap_physical(). for example, in a case of io range size "mem->size == 1KB", and we have (vma->vm_end - vma->vm_start) == 4KB, due to "len" is aligned to page size in do_mmap_pgoff(). now fix this issue by align mem->size to page size in the check. Signed-off-by: Bin Wang <binw@marvell.com> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-20uio: fix devm_request_irq usageAaro Koskinen1-1/+1
Commit e6789cd3dfb553077606ccafeb05e0043f072481 (uio: Simplify uio error path by using devres functions) converted uio to use devm_request_irq(). This introduced a change in behaviour since the IRQ is associated with the parent device instead of the created UIO device. The IRQ will remain active after uio_unregister_device() is called, and some drivers will crash because of this. The patch fixes this. Signed-off-by: Aaro Koskinen <aaro.koskinen@nsn.com> Cc: stable <stable@vger.kernel.org> # 3.13 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-02uio: we cannot mmap unaligned page contentsLinus Torvalds1-0/+2
In commit 7314e613d5ff ("Fix a few incorrectly checked [io_]remap_pfn_range() calls") the uio driver started more properly checking the passed-in user mapping arguments against the size of the actual uio driver data. That in turn exposed that some driver authors apparently didn't realize that mmap can only work on a page granularity, and had tried to use it with smaller mappings, with the new size check catching that out. So since it's not just the user mmap() arguments that can be confused, make the uio mmap code also verify that the uio driver has the memory allocated at page boundaries in order for mmap to work. If the device memory isn't properly aligned, we return [ENODEV] The fildes argument refers to a file whose type is not supported by mmap(). as per the open group documentation on mmap. Reported-by: Holger Brunck <holger.brunck@keymile.com> Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-07Merge tag 'char-misc-3.13-rc1' of ↵Linus Torvalds1-20/+18
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc patches from Greg KH: "Here's the big char/misc driver patchset for 3.13-rc1. Lots of stuff in here, including some new drivers for Intel's "MIC" co-processor devices, and a new eeprom driver. Other things include the driver attribute cleanups, extcon driver updates, hyperv updates, and a raft of other miscellaneous driver fixes. All of these have been in linux-next for a while" * tag 'char-misc-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (121 commits) misc: mic: Fixes for randconfig build errors and warnings. tifm: fix error return code in tifm_7xx1_probe() w1-gpio: Use devm_* functions w1-gpio: Detect of_gpio_error for first gpio uio: Pass pointers to virt_to_page(), not integers uio: fix memory leak misc/at24: avoid infinite loop on write() misc/93xx46: avoid infinite loop on write() misc: atmel_pwm: add deferred-probing support mei: wd: host_init propagate error codes from called functions mei: replace stray pr_debug with dev_dbg mei: bus: propagate error code returned by mei_me_cl_by_id mei: mei_cl_link remove duplicated check for open_handle_count mei: print correct device state during unexpected reset mei: nfc: fix memory leak in error path lkdtm: add tests for additional page permissions lkdtm: adjust recursion size to avoid warnings lkdtm: isolate stack corruption test mei: move host_clients_map cleanup to device init mei: me: downgrade two errors to debug level ...
2013-10-30uio: Pass pointers to virt_to_page(), not integersBen Hutchings1-2/+4
Most architectures define virt_to_page() as a macro that casts its argument such that an argument of type unsigned long will be accepted without complaint. However, the proper type is void *, and passing unsigned long results in a warning on MIPS. Compile-tested only. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-30uio: fix memory leakCong Ding1-6/+10
we have to call kobject_put() to clean up the kobject after function kobject_init(), kobject_add(), or kobject_uevent() is called. Signed-off-by: Cong Ding <dinggnu@gmail.com> Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29Fix a few incorrectly checked [io_]remap_pfn_range() callsLinus Torvalds1-2/+15
Nico Golde reports a few straggling uses of [io_]remap_pfn_range() that really should use the vm_iomap_memory() helper. This trivially converts two of them to the helper, and comments about why the third one really needs to continue to use remap_pfn_range(), and adds the missing size check. Reported-by: Nico Golde <nico@ngolde.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org.
2013-09-26uio: Simplify uio error path by using devres functionsMichal Simek1-12/+4
Using devres functions simplify driver error path. - Use devm_kzalloc - Use devm_request_irq Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-03Merge tag 'driver-core-3.12-rc1' of ↵Linus Torvalds1-9/+13
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core patches from Greg KH: "Here's the big driver core pull request for 3.12-rc1. Lots of tiny changes here fixing up the way sysfs attributes are created, to try to make drivers simpler, and fix a whole class race conditions with creations of device attributes after the device was announced to userspace. All the various pieces are acked by the different subsystem maintainers" * tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (119 commits) firmware loader: fix pending_fw_head list corruption drivers/base/memory.c: introduce help macro to_memory_block dynamic debug: line queries failing due to uninitialized local variable sysfs: sysfs_create_groups returns a value. debugfs: provide debugfs_create_x64() when disabled rbd: convert bus code to use bus_groups firmware: dcdbas: use binary attribute groups sysfs: add sysfs_create/remove_groups for when SYSFS is not enabled driver core: add #include <linux/sysfs.h> to core files. HID: convert bus code to use dev_groups Input: serio: convert bus code to use drv_groups Input: gameport: convert bus code to use drv_groups driver core: firmware: use __ATTR_RW() driver core: core: use DEVICE_ATTR_RO driver core: bus: use DRIVER_ATTR_WO() driver core: create write-only attribute macros for devices and drivers sysfs: create __ATTR_WO() driver-core: platform: convert bus code to use dev_groups workqueue: convert bus code to use dev_groups MEI: convert bus code to use dev_groups ...
2013-08-13uio: drop unused vma_count member in uio_device structUwe Kleine-König1-16/+0
vma_count is used write-only and so fails to be useful. So remove it. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-13uio: provide vm access to UIO_MEM_PHYS mapsUwe Kleine-König1-9/+17
This makes it possible to let gdb access mappings of the process that is being debugged. uio_mmap_logical was moved and uio_vm_ops renamed to group related code and differentiate to new stuff. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25UIO: convert class code to use dev_groupsGreg Kroah-Hartman1-9/+13
The dev_attrs field of struct class is going away soon, dev_groups should be used instead. This converts the uio class code to use the correct field. Cc: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-04uio: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFTLibin1-1/+1
(*->vm_end - *->vm_start) >> PAGE_SHIFT operation is implemented as a inline funcion vma_pages() in linux/mm.h, so using it. Signed-off-by: Libin <huawei.libin@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-29drivers: uio: Fix UIO device registration failureDamian Hobson-Garcia1-0/+1
Until recently uio_get_minor() returned 0 for success and a negative value on failure. This became non-negative for suceess and negative for failure. Restore the original return value spec so that we can successfully initialize UIO devices with a non-zero minor device number. Cc: "Hans J. Koch" <hjk@hansjkoch.de> Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28uio: convert to idr_alloc()Tejun Heo1-15/+4
Convert to the much saner new idr interface. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Hans J. Koch" <hjk@hansjkoch.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: kill vma flag VM_RESERVED and mm->reserved_vm counterKonstantin Khlebnikov1-3/+1
A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA, currently it lost original meaning but still has some effects: | effect | alternative flags -+------------------------+--------------------------------------------- 1| account as reserved_vm | VM_IO 2| skip in core dump | VM_IO, VM_DONTDUMP 3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP 4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP This patch removes reserved_vm counter from mm_struct. Seems like nobody cares about it, it does not exported into userspace directly, it only reduces total_vm showed in proc. Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP. remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP. remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP. [akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-18uio: Support physical addresses >32 bits on 32-bit systemsKai Jiang1-4/+3
To support >32-bit physical addresses for UIO_MEM_PHYS type we need to extend the width of 'addr' in struct uio_mem. Numerous platforms like embedded PPC, ARM, and X86 have support for systems with larger physical address than logical. Since 'addr' may contain a physical, logical, or virtual address the easiest solution is to just change the type to 'phys_addr_t' which should always be greater than or equal to the sizeof(void *) such that it can properly hold any of the address types. For physical address we can support up to a 44-bit physical address on a typical 32-bit system as we utilize remap_pfn_range() for the mapping of the memory region and pfn's are represnted by shifting the address by the page size (typically 4k). Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23drivers:uio:change the goto label to consistent with othersWanlong Gao1-4/+3
Remove one *goto* label in uio.c. Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-20uio: fix allocating minor id for uio deviceHillf Danton1-1/+7
The number of uio devices that could be used should be less than UIO_MAX_DEVICES by design, and this work guards any cases in which id more than UIO_MAX_DEVICES is utilized. Signed-off-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-20uio: fix finding mm index for vmaHillf Danton1-5/+3
When finding mm index for vma it looks more flexible that the mm could be sparse, and both the size of mm and the pgoff of vma could give correct selection. Signed-off-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11uio: Change mail address of Hans J. KochHans J. Koch1-1/+1
My old mail address doesn't exist anymore. This changes all occurrences to my new address. Signed-off-by: Hans J. Koch <hjk@hansjkoch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds1-94/+69
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (31 commits) driver core: Display error codes when class suspend fails Driver core: Add section count to memory_block struct Driver core: Add mutex for adding/removing memory blocks Driver core: Move find_memory_block routine hpilo: Despecificate driver from iLO generation driver core: Convert link_mem_sections to use find_memory_block_hinted. driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted. kobject: Introduce kset_find_obj_hinted. driver core: fix build for CONFIG_BLOCK not enabled driver-core: base: change to new flag variable sysfs: only access bin file vm_ops with the active lock sysfs: Fail bin file mmap if vma close is implemented. FW_LOADER: fix kconfig dependency warning on HOTPLUG uio: Statically allocate uio_class and use class .dev_attrs. uio: Support 2^MINOR_BITS minors uio: Cleanup irq handling. uio: Don't clear driver data uio: Fix lack of locking in init_uio_class SYSFS: Allow boot time switching between deprecated and modern sysfs layout driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices ...
2010-10-22uio: Statically allocate uio_class and use class .dev_attrs.Eric W. Biederman1-35/+18
Instead of adding uio class attributes manually after the uio device has been created and we have sent a uevent to userspace, use the class attribute mechanism. This removes races and makes the code simpler. At the same time don't bother to dynamically allocate a struct class for uio, just declare one statically. Less code is needed and it is easier to set the class parameters.tune the class Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22uio: Support 2^MINOR_BITS minorsEric W. Biederman1-6/+37
register_chrdev limits uio devices to 256 minor numbers which causes problems on one system I have with 384+ uio devices. So instead set UIO_MAX_DEVICES to the maximum number of minors and use alloc_chrdev_region to reserve the uio minors. The final result is that the code works the same but the uio driver now supports any minor the idr allocator comes up with. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-18 01:52:59 +0300