patch "VMCI: Use threaded irqs instead of tasklets" added to char-misc-linus
Subsystems (3)
This is a note to let you know that I've just added the patch titled
VMCI: Use threaded irqs instead of tasklets
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 3daed6345d5880464f46adab871d208e1baa2f3a Mon Sep 17 00:00:00 2001
From: Vishnu Dasa <[email protected]>
Date: Tue, 29 Nov 2022 23:05:11 -0800
Subject: VMCI: Use threaded irqs instead of tasklets
The vmci_dispatch_dgs() tasklet function calls vmci_read_data() which uses wait_event() resulting in invalid sleep in an atomic context (and therefore potentially in a deadlock).
Use threaded irqs to fix this issue and completely remove usage of tasklets.
[ 20.264639] BUG: sleeping function called from invalid context at drivers/misc/vmw_vmci/vmci_guest.c:145
[ 20.264643] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 762, name: vmtoolsd
[ 20.264645] preempt_count: 101, expected: 0
[ 20.264646] RCU nest depth: 0, expected: 0
[ 20.264647] 1 lock held by vmtoolsd/762:
[ 20.264648] #0: ffff0000874ae440 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: vsock_connect+0x60/0x330 [vsock]
[ 20.264658] Preemption disabled at:
[ 20.264659] [<ffff80000151d7d8>] vmci_send_datagram+0x44/0xa0 [vmw_vmci]
[ 20.264665] CPU: 0 PID: 762 Comm: vmtoolsd Not tainted 5.19.0-0.rc8.20220727git39c3c396f813.60.fc37.aarch64 #1
[ 20.264667] Hardware name: VMware, Inc. VBSA/VBSA, BIOS VEFI 12/31/2020
[ 20.264668] Call trace:
[ 20.264669] dump_backtrace+0xc4/0x130
[ 20.264672] show_stack+0x24/0x80
[ 20.264673] dump_stack_lvl+0x88/0xb4
[ 20.264676] dump_stack+0x18/0x34
[ 20.264677] __might_resched+0x1a0/0x280
[ 20.264679] __might_sleep+0x58/0x90
[ 20.264681] vmci_read_data+0x74/0x120 [vmw_vmci]
[ 20.264683] vmci_dispatch_dgs+0x64/0x204 [vmw_vmci]
[ 20.264686] tasklet_action_common.constprop.0+0x13c/0x150
[ 20.264688] tasklet_action+0x40/0x50
[ 20.264689] __do_softirq+0x23c/0x6b4
[ 20.264690] __irq_exit_rcu+0x104/0x214
[ 20.264691] irq_exit_rcu+0x1c/0x50
[ 20.264693] el1_interrupt+0x38/0x6c
[ 20.264695] el1h_64_irq_handler+0x18/0x24
[ 20.264696] el1h_64_irq+0x68/0x6c
[ 20.264697] preempt_count_sub+0xa4/0xe0
[ 20.264698] _raw_spin_unlock_irqrestore+0x64/0xb0
[ 20.264701] vmci_send_datagram+0x7c/0xa0 [vmw_vmci]
[ 20.264703] vmci_datagram_dispatch+0x84/0x100 [vmw_vmci]
[ 20.264706] vmci_datagram_send+0x2c/0x40 [vmw_vmci]
[ 20.264709] vmci_transport_send_control_pkt+0xb8/0x120 [vmw_vsock_vmci_transport]
[ 20.264711] vmci_transport_connect+0x40/0x7c [vmw_vsock_vmci_transport]
[ 20.264713] vsock_connect+0x278/0x330 [vsock]
[ 20.264715] __sys_connect_file+0x8c/0xc0
[ 20.264718] __sys_connect+0x84/0xb4
[ 20.264720] __arm64_sys_connect+0x2c/0x3c
[ 20.264721] invoke_syscall+0x78/0x100
[ 20.264723] el0_svc_common.constprop.0+0x68/0x124
[ 20.264724] do_el0_svc+0x38/0x4c
[ 20.264725] el0_svc+0x60/0x180
[ 20.264726] el0t_64_sync_handler+0x11c/0x150
[ 20.264728] el0t_64_sync+0x190/0x194--- drivers/misc/vmw_vmci/vmci_guest.c | 49 ++++++++++++------------------ 1 file changed, 19 insertions(+), 30 deletions(-)
drivers/misc/vmw_vmci/vmci_guest.c +19 -30
@@ -56,8 +56,6 @@ struct vmci_guest_device {bool exclusive_vectors; -struct tasklet_struct datagram_tasklet; -struct tasklet_struct bm_tasklet;struct wait_queue_head inout_wq;void *data_buffer;
@@ -304,9 +302,8 @@ static int vmci_check_host_caps(struct pci_dev *pdev)* This function assumes that it has exclusive access to the data * in register(s) for the duration of the call. */ -static void vmci_dispatch_dgs (unsigned long data) +static void vmci_dispatch_dgs (struct vmci_guest_device *vmci_dev) { -struct vmci_guest_device *vmci_dev = (struct vmci_guest_device *)data;u8 *dg_in_buffer = vmci_dev->data_buffer;struct vmci_datagram *dg;size_t dg_in_buffer_size =VMCI_MAX_DG_SIZE ;
@@ -465,10 +462,8 @@ static void vmci_dispatch_dgs(unsigned long data)* Scans the notification bitmap for raised flags, clears them * and handles the notifications. */ -static void vmci_process_bitmap (unsigned long data) +static void vmci_process_bitmap (struct vmci_guest_device *dev) { -struct vmci_guest_device *dev = (struct vmci_guest_device *)data; -if (!dev->notification_bitmap) {dev_dbg (dev->dev,"No bitmap present in %s\n" , __func__);return ;
@@ -486,13 +481,13 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev)struct vmci_guest_device *dev = _dev;/* -* If we are using MSI-X with exclusive vectors then we simply schedule -* the datagram tasklet, since we know the interrupt was meant for us. +* If we are using MSI-X with exclusive vectors then we simply call +* vmci_dispatch_dgs(), since we know the interrupt was meant for us. * Otherwise we must read the ICR to determine what to do. */ if (dev->exclusive_vectors) { -tasklet_schedule (&dev->datagram_tasklet); +vmci_dispatch_dgs (dev); }else {unsigned int icr;
@@ -502,12 +497,12 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev)return IRQ_NONE ;if (icr &VMCI_ICR_DATAGRAM ) { -tasklet_schedule (&dev->datagram_tasklet); +vmci_dispatch_dgs (dev); icr &= ~VMCI_ICR_DATAGRAM ; }if (icr &VMCI_ICR_NOTIFICATION ) { -tasklet_schedule (&dev->bm_tasklet); +vmci_process_bitmap (dev); icr &= ~VMCI_ICR_NOTIFICATION ; }
@@ -536,7 +531,7 @@ static irqreturn_t vmci_interrupt_bm(int irq, void *_dev)struct vmci_guest_device *dev = _dev;/* For MSI-X we can just assume it was meant for us. */ -tasklet_schedule (&dev->bm_tasklet); +vmci_process_bitmap (dev);return IRQ_HANDLED ; }
@@ -638,10 +633,6 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, vmci_dev->iobase = iobase; vmci_dev->mmio_base = mmio_base; -tasklet_init (&vmci_dev->datagram_tasklet, - vmci_dispatch_dgs, (unsigned long )vmci_dev); -tasklet_init (&vmci_dev->bm_tasklet, - vmci_process_bitmap, (unsigned long )vmci_dev);init_waitqueue_head (&vmci_dev->inout_wq);if (mmio_base !=NULL ) {
@@ -808,8 +799,9 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,* Request IRQ for legacy or MSI interrupts, or for first * MSI-X vector. */ - error =request_irq (pci_irq_vector (pdev,0 ), vmci_interrupt, -IRQF_SHARED ,KBUILD_MODNAME , vmci_dev); + error =request_threaded_irq (pci_irq_vector (pdev,0 ),NULL , + vmci_interrupt,IRQF_SHARED , +KBUILD_MODNAME , vmci_dev);if (error) {dev_err (&pdev->dev,"Irq %u in use: %d\n" ,pci_irq_vector (pdev,0 ), error);
@@ -823,9 +815,9 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,* between the vectors. */ if (vmci_dev->exclusive_vectors) { - error =request_irq (pci_irq_vector (pdev,1 ), - vmci_interrupt_bm,0 ,KBUILD_MODNAME , - vmci_dev); + error =request_threaded_irq (pci_irq_vector (pdev,1 ),NULL , + vmci_interrupt_bm,0 , +KBUILD_MODNAME , vmci_dev);if (error) { dev_err(&pdev->dev, "Failed to allocate irq %u: %d\n",
@@ -833,9 +825,11 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, goto err_free_irq; }if (caps_in_use &VMCI_CAPS_DMA_DATAGRAM ) { - error =request_irq (pci_irq_vector (pdev,2 ), - vmci_interrupt_dma_datagram, -0 ,KBUILD_MODNAME , vmci_dev); + error =request_threaded_irq (pci_irq_vector (pdev,2 ), +NULL , + vmci_interrupt_dma_datagram, +0 ,KBUILD_MODNAME , + vmci_dev);if (error) { dev_err(&pdev->dev, "Failed to allocate irq %u: %d\n",
@@ -871,8 +865,6 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, err_free_irq:free_irq (pci_irq_vector (pdev,0 ), vmci_dev); -tasklet_kill (&vmci_dev->datagram_tasklet); -tasklet_kill (&vmci_dev->bm_tasklet); err_disable_msi:pci_free_irq_vectors (pdev);
@@ -943,9 +935,6 @@ static void vmci_guest_remove_device(struct pci_dev *pdev)free_irq (pci_irq_vector (pdev,0 ), vmci_dev);pci_free_irq_vectors (pdev); -tasklet_kill (&vmci_dev->datagram_tasklet); -tasklet_kill (&vmci_dev->bm_tasklet); -if (vmci_dev->notification_bitmap) {/* * The device reset above cleared the bitmap state of the
Signature · 1 line
2.39.1