#include #include #include "usb.h" static int uas_is_interface(struct usb_host_interface *intf) { return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE && intf->desc.bInterfaceSubClass == USB_SC_SCSI && intf->desc.bInterfaceProtocol == USB_PR_UAS); } static int uas_find_uas_alt_setting(struct usb_interface *intf) { int i; for (i = 0; i < intf->num_altsetting; i++) { struct usb_host_interface *alt = &intf->altsetting[i]; if (uas_is_interface(alt)) return alt->desc.bAlternateSetting; } return -ENODEV; } static int uas_find_endpoints(struct usb_host_interface *alt, struct usb_host_endpoint *eps[]) { struct usb_host_endpoint *endpoint = alt->endpoint; unsigned i, n_endpoints = alt->desc.bNumEndpoints; for (i = 0; i < n_endpoints; i++) { unsigned char *extra = endpoint[i].extra; int len = endpoint[i].extralen; while (len >= 3) { if (extra[1] == USB_DT_PIPE_USAGE) { unsigned pipe_id = extra[2]; if (pipe_id > 0 && pipe_id < 5) eps[pipe_id - 1] = &endpoint[i]; break; } len -= extra[0]; extra += extra[0]; } } if (!eps[0] || !eps[1] || !eps[2] || !eps[3]) return -ENODEV; return 0; } static int uas_use_uas_driver(struct usb_interface *intf, const struct usb_device_id *id, unsigned long *flags_ret) { struct usb_host_endpoint *eps[4] = { }; struct usb_device *udev = interface_to_usbdev(intf); struct usb_hcd *hcd = bus_to_hcd(udev->bus); unsigned long flags = id->driver_info; int r, alt; alt = uas_find_uas_alt_setting(intf); if (alt < 0) return 0; r = uas_find_endpoints(&intf->altsetting[alt], eps); if (r < 0) return 0; /* * ASMedia has a number of usb3 to sata bridge chips, at the time of * this writing the following versions exist: * ASM1051 - no uas support version * ASM1051 - with broken (*) uas support * ASM1053 - with working uas support, but problems with large xfers * ASM1153 - with working uas support * * Devices with these chips re-use a number of device-ids over the * entire line, so the device-id is useless to determine if we're * dealing with an ASM1051 (which we want to avoid). * * The ASM1153 can be identified by config.MaxPower == 0, * where as the ASM105x models have config.MaxPower == 36. * * Differentiating between the ASM1053 and ASM1051 is trickier, when * connected over USB-3 we can look at the number of streams supported, * ASM1051 supports 32 streams, where as early ASM1053 versions support * 16 streams, newer ASM1053-s also support 32 streams, but have a * different prod-id. * * (*) ASM1051 chips do work with UAS with some disks (with the * US_FL_NO_REPORT_OPCODES quirk), but are broken with other disks */ if (le16_to_cpu(udev->descriptor.idVendor) == 0x174c && (le16_to_cpu(udev->descriptor.idProduct) == 0x5106 || le16_to_cpu(udev->descriptor.idProduct) == 0x55aa)) { if (udev->actconfig->desc.bMaxPower == 0) { /* ASM1153, do nothing */ } else if (udev->speed < USB_SPEED_SUPER) { /* No streams info, assume ASM1051 */ flags |= US_FL_IGNORE_UAS; } else if (usb_ss_max_streams(&eps[1]->ss_ep_comp) == 32) { /* Possibly an ASM1051, disable uas */ flags |= US_FL_IGNORE_UAS; } else { /* ASM1053, these have issues with large transfers */ flags |= US_FL_MAX_SECTORS_240; } } usb_stor_adjust_quirks(udev, &flags); if (flags & US_FL_IGNORE_UAS) { dev_warn(&udev->dev, "UAS is blacklisted for this device, using usb-storage instead\n"); return 0; } if (udev->bus->sg_tablesize == 0) { dev_warn(&udev->dev, "The driver for the USB controller %s does not support scatter-gather which is\n", hcd->driver->description); dev_warn(&udev->dev, "required by the UAS driver. Please try an other USB controller if you wish to use UAS.\n"); return 0; } if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) { dev_warn(&udev->dev, "USB controller %s does not support streams, which are required by the UAS driver.\n", hcd_to_bus(hcd)->bus_name); dev_warn(&udev->dev, "Please try an other USB controller if you wish to use UAS.\n"); return 0; } if (flags_ret) *flags_ret = flags; return 1; } tion value='0' selected='selected'>includemode:
authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /drivers/usb/mtu3/mtu3_gadget.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'drivers/usb/mtu3/mtu3_gadget.c')