kernel.git/drivers/usb/core/hcd.c, branch linux-5.4.y

USB: HCD: Fix URB giveback issue in tasklet function

2022-08-25T09:17:26Z

commit 26c6c2f8a907c9e3a2f24990552a4d77235791e6 upstream. Usb core introduce the mechanism of giveback of URB in tasklet context to reduce hardware interrupt handling time. On some test situation(such as FIO with 4KB block size), when tasklet callback function called to giveback URB, interrupt handler add URB node to the bh->head list also. If check bh->head list again after finish all URB giveback of local_list, then it may introduce a "dynamic balance" between giveback URB and add URB to bh->head list. This tasklet callback function may not exit for a long time, which will cause other tasklet function calls to be delayed. Some real-time applications(such as KB and Mouse) will see noticeable lag. In order to prevent the tasklet function from occupying the cpu for a long time at a time, new URBS will not be added to the local_list even though the bh->head list is not empty. But also need to ensure the left URB giveback to be processed in time, so add a member high_prio for structure giveback_urb_bh to prioritize tasklet and schelule this tasklet again if bh->head list is not empty. At the same time, we are able to prioritize tasklet through structure member high_prio. So, replace the local high_prio_bh variable with this structure member in usb_hcd_giveback_urb. Fixes: 94dfd7edfd5c ("USB: HCD: support giveback of URB in tasklet context") Cc: stable Reviewed-by: Alan Stern Signed-off-by: Weitao Wang Link: https://lore.kernel.org/r/20220726074918.5114-1-WeitaoWang-oc@zhaoxin.com Signed-off-by: Greg Kroah-Hartman

usb: core: hcd: Add support for deferring roothub registration

2022-06-14T16:11:24Z

commit a44623d9279086c89f631201d993aa332f7c9e66 upstream. It has been observed with certain PCIe USB cards (like Inateck connected to AM64 EVM or J7200 EVM) that as soon as the primary roothub is registered, port status change is handled even before xHC is running leading to cold plug USB devices not detected. For such cases, registering both the root hubs along with the second HCD is required. Add support for deferring roothub registration in usb_add_hcd(), so that both primary and secondary roothubs are registered along with the second HCD. This patch has been added and reverted earier as it triggered a race in usb device enumeration. That race is now fixed in 5.16-rc3, and in stable back to 5.4 commit 6cca13de26ee ("usb: hub: Fix locking issues with address0_mutex") commit 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") CC: stable@vger.kernel.org # 5.4+ Suggested-by: Mathias Nyman Tested-by: Chris Chiu Acked-by: Alan Stern Signed-off-by: Kishon Vijay Abraham I Link: https://lore.kernel.org/r/20220510091630.16564-2-kishon@ti.com Signed-off-by: Greg Kroah-Hartman

USB: core: Fix hang in usb_kill_urb by adding memory barriers

2022-02-01T16:24:35Z

commit 26fbe9772b8c459687930511444ce443011f86bf upstream. The syzbot fuzzer has identified a bug in which processes hang waiting for usb_kill_urb() to return. It turns out the issue is not unlinking the URB; that works just fine. Rather, the problem arises when the wakeup notification that the URB has completed is not received. The reason is memory-access ordering on SMP systems. In outline form, usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on different CPUs perform the following actions: CPU 0 CPU 1 ---------------------------- --------------------------------- usb_kill_urb(): __usb_hcd_giveback_urb(): ... ... atomic_inc(&urb->reject); atomic_dec(&urb->use_count); ... ... wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); if (atomic_read(&urb->reject)) wake_up(&usb_kill_urb_queue); Confining your attention to urb->reject and urb->use_count, you can see that the overall pattern of accesses on CPU 0 is: write urb->reject, then read urb->use_count; whereas the overall pattern of accesses on CPU 1 is: write urb->use_count, then read urb->reject. This pattern is referred to in memory-model circles as SB (for "Store Buffering"), and it is well known that without suitable enforcement of the desired order of accesses -- in the form of memory barriers -- it is entirely possible for one or both CPUs to execute their reads ahead of their writes. The end result will be that sometimes CPU 0 sees the old un-decremented value of urb->use_count while CPU 1 sees the old un-incremented value of urb->reject. Consequently CPU 0 ends up on the wait queue and never gets woken up, leading to the observed hang in usb_kill_urb(). The same pattern of accesses occurs in usb_poison_urb() and the failure pathway of usb_hcd_submit_urb(). The problem is fixed by adding suitable memory barriers. To provide proper memory-access ordering in the SB pattern, a full barrier is required on both CPUs. The atomic_inc() and atomic_dec() accesses themselves don't provide any memory ordering, but since they are present, we can use the optimized smp_mb__after_atomic() memory barrier in the various routines to obtain the desired effect. This patch adds the necessary memory barriers. CC: Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: Fix "slab-out-of-bounds Write" bug in usb_hcd_poll_rh_status

2022-01-16T08:15:38Z

commit 1d7d4c07932e04355d6e6528d44a2f2c9e354346 upstream. When the USB core code for getting root-hub status reports was originally written, it was assumed that the hub driver would be its only caller. But this isn't true now; user programs can use usbfs to communicate with root hubs and get status reports. When they do this, they may use a transfer_buffer that is smaller than the data returned by the HCD, which will lead to a buffer overflow error when usb_hcd_poll_rh_status() tries to store the status data. This was discovered by syzbot: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline] BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776 Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062 This patch fixes the bug by reducing the amount of status data if it won't fit in the transfer_buffer. If some data gets discarded then the URB's completion status is set to -EOVERFLOW rather than 0, to let the user know what happened. Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com Signed-off-by: Alan Stern Cc: Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

Revert "usb: core: hcd: Add support for deferring roothub registration"

2021-11-06T12:59:45Z

This reverts commit 20c9fdde30fbe797aec0e0a04fb77013fe473886 which is commit 58877b0824da15698bd85a0a9dbfa8c354e6ecb7 upstream. It has been reported to be causing problems in Arch and Fedora bug reports. Reported-by: Hans de Goede Link: https://bbs.archlinux.org/viewtopic.php?pid=2000956#p2000956 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2019542 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2019576 Link: https://lore.kernel.org/r/42bcbea6-5eb8-16c7-336a-2cb72e71bc36@redhat.com Cc: Mathias Nyman Cc: Chris Chiu Cc: Alan Stern Cc: Kishon Vijay Abraham I Signed-off-by: Greg Kroah-Hartman

usb: core: hcd: Add support for deferring roothub registration

2021-09-30T08:09:21Z

commit 58877b0824da15698bd85a0a9dbfa8c354e6ecb7 upstream. It has been observed with certain PCIe USB cards (like Inateck connected to AM64 EVM or J7200 EVM) that as soon as the primary roothub is registered, port status change is handled even before xHC is running leading to cold plug USB devices not detected. For such cases, registering both the root hubs along with the second HCD is required. Add support for deferring roothub registration in usb_add_hcd(), so that both primary and secondary roothubs are registered along with the second HCD. CC: stable@vger.kernel.org # 5.4+ Suggested-by: Mathias Nyman Tested-by: Chris Chiu Acked-by: Alan Stern Signed-off-by: Kishon Vijay Abraham I Link: https://lore.kernel.org/r/20210909064200.16216-2-kishon@ti.com Signed-off-by: Greg Kroah-Hartman

USB: Fix incorrect DMA allocations for local memory pool drivers

2019-12-21T10:04:21Z

commit f8c63edfd78905320e86b6b2be2b7a5ac768fa4e upstream. Fix commit 7b81cb6bddd2 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities") where local memory USB drivers erroneously allocate DMA memory instead of pool memory, causing OHCI Unrecoverable Error, disabled HC died; cleaning up The order between hcd_uses_dma() and hcd->localmem_pool is now arranged as in hcd_buffer_alloc() and hcd_buffer_free(), with the test for hcd->localmem_pool placed first. As an alternative, one might consider adjusting hcd_uses_dma() with static inline bool hcd_uses_dma(struct usb_hcd *hcd) { - return IS_ENABLED(CONFIG_HAS_DMA) && (hcd->driver->flags & HCD_DMA); + return IS_ENABLED(CONFIG_HAS_DMA) && + (hcd->driver->flags & HCD_DMA) && + (hcd->localmem_pool == NULL); } One can also consider unsetting HCD_DMA for local memory pool drivers. Fixes: 7b81cb6bddd2 ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities") Cc: stable Signed-off-by: Fredrik Noring Link: https://lore.kernel.org/r/20191210172905.GA52526@sx9 Signed-off-by: Greg Kroah-Hartman

usb: core: phy: add support for PHY calibration

2019-09-03T13:54:55Z

Some PHYs (for example Exynos5 USB3.0 DRD PHY) require calibration to be done after every USB HCD reset. Generic PHY framework has been already extended with phy_calibrate() function in commit 36914111e682 ("drivers: phy: add calibrate method"). This patch adds support for it to generic PHY handling code in USB HCD core. Signed-off-by: Marek Szyprowski Tested-by: Anand Moon Tested-by: Jochen Sprickerhof Link: https://lore.kernel.org/r/20190829053028.32438-2-m.szyprowski@samsung.com Signed-off-by: Greg Kroah-Hartman

usb: remove a stale comment in hcd_alloc_coherent

2019-09-03T13:26:11Z

Now that we have the local memory pool implemented there is no need to use dma_declare_coherent_memory. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20190903084615.19161-5-hch@lst.de Signed-off-by: Greg Kroah-Hartman

usb: add a HCD_DMA flag instead of guestimating DMA capabilities

2019-08-21T17:03:35Z

The usb core is the only major place in the kernel that checks for a non-NULL device dma_mask to see if a device is DMA capable. This is generally a bad idea, as all major busses always set up a DMA mask, even if the device is not DMA capable - in fact bus layers like PCI can't even know if a device is DMA capable at enumeration time. This leads to lots of workaround in HCD drivers, and also prevented us from setting up a DMA mask for platform devices by default last time we tried. Replace this guess with an explicit HCD_DMA that is set by drivers that appear to have DMA support. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20190816062435.881-4-hch@lst.de Signed-off-by: Greg Kroah-Hartman