vdasa at vmware.com
2022-Nov-30 07:05 UTC
[PATCH] VMCI: Use threaded irqs instead of tasklets
From: Vishnu Dasa <vdasa at vmware.com>
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
Signed-off-by: Vishnu Dasa <vdasa at vmware.com>
Suggested-by: Zack Rusin <zackr at vmware.com>
Reported-by: Nadav Amit <namit at vmware.com>
Reported-by: Nathan Chancellor <nathan at kernel.org>
Tested-by: Nathan Chancellor <nathan at kernel.org>
Fixes: 463713eb6164 ("VMCI: dma dg: add support for DMA datagrams
receive")
Cc: <stable at vger.kernel.org> # v5.18+
Cc: VMware PV-Drivers Reviewers <pv-drivers at vmware.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Bryan Tan <bryantan at vmware.com>
---
drivers/misc/vmw_vmci/vmci_guest.c | 49 ++++++++++++------------------
1 file changed, 19 insertions(+), 30 deletions(-)
diff --git a/drivers/misc/vmw_vmci/vmci_guest.c
b/drivers/misc/vmw_vmci/vmci_guest.c
index aa7b05de97dd..6ab717b4a5db 100644
--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -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
--
2.34.1