Messages in this thread | | | From | John Garry <> | Subject | Re: [PATCH/RFC] driver core: Postpone DMA tear-down until after devres release | Date | Tue, 26 Mar 2019 11:41:38 +0000 |
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> > Memory is incorrectly freed using the direct ops, as dma_map_ops = NULL. > Oops... > > After reversing the order of the calls to arch_teardown_dma_ops() and > devres_release_all(), dma_map_ops is still valid, and the DMA memory is > now released using __iommu_free_attrs(): > > +sata_rcar ee300000.sata: dmam_release:32: size 2048 vaddr ffffff8012145000 dma_handle 0x0x00000000fffff000 attrs 0x0 > +sata_rcar ee300000.sata: dma_free_attrs:289: size 2048, ops = iommu_dma_ops > +sata_rcar ee300000.sata: dma_free_attrs:311: calling __iommu_free_attrs() > --- > drivers/base/dd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 8ac10af17c0043a3..d62487d024559620 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -968,9 +968,9 @@ static void __device_release_driver(struct device *dev, struct device *parent) > drv->remove(dev); > > device_links_driver_cleanup(dev); > - arch_teardown_dma_ops(dev); > > devres_release_all(dev); > + arch_teardown_dma_ops(dev); > dev->driver = NULL;
Hi guys,
Could there still be the same problem in the error path of really_probe():
static int really_probe(struct device *dev, struct device_driver *drv) {
[...]
goto done;
probe_failed: arch_teardown_dma_ops(dev); dma_failed: if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev); pinctrl_bind_failed: device_links_no_driver(dev); devres_release_all(dev); driver_sysfs_remove(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL);
We seem to be able to call arch_teardown_dma_ops() prior to devres_release_all() if we reach probe_failed label.
We have seen this crash when our driver probe fails on a dev branch based on v5.1-rc1:
[ 87.896707] hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2 [ 87.909765] scsi host1: hisi_sas_v3_hw [ 89.127958] hisi_sas_v3_hw 0000:74:02.0: evaluate _DSM failed [ 89.134043] BUG: Bad page state in process swapper/0 pfn:313f5 [ 89.139965] page:ffff7e0000c4fd40 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 89.147960] flags: 0xfffe00000001000(reserved) [ 89.152398] raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48 0000000000000000 [ 89.160130] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 89.167861] page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set [ 89.174290] bad because of flags: 0x1000(reserved) [ 89.179070] Modules linked in: [ 89.182117] CPU: 49 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-43081-g22d97fd-dirty #1433 [ 89.190453] Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI RC0 - V1.12.01 01/29/2019 [ 89.198876] Call trace: [ 89.201316] dump_backtrace+0x0/0x118 [ 89.204965] show_stack+0x14/0x1c [ 89.208272] dump_stack+0xa4/0xc8 [ 89.211576] bad_page+0xe4/0x13c [ 89.214791] free_pages_check_bad+0x4c/0xc0 [ 89.218961] __free_pages_ok+0x30c/0x340 [ 89.222871] __free_pages+0x30/0x44 [ 89.226347] __dma_direct_free_pages+0x30/0x38 [ 89.230777] dma_direct_free+0x24/0x38 [ 89.234513] dma_free_attrs+0x9c/0xd8 [ 89.238161] dmam_release+0x20/0x28 [ 89.241640] release_nodes+0x17c/0x220 [ 89.245375] devres_release_all+0x34/0x54 [ 89.249371] really_probe+0xc4/0x2c8 [ 89.252933] driver_probe_device+0x58/0xfc [ 89.257016] device_driver_attach+0x68/0x70 [ 89.261185] __driver_attach+0x94/0xdc [ 89.264921] bus_for_each_dev+0x5c/0xb4 [ 89.268744] driver_attach+0x20/0x28 [ 89.272306] bus_add_driver+0x14c/0x200 [ 89.276128] driver_register+0x6c/0x124 [ 89.279953] __pci_register_driver+0x48/0x50 [ 89.284213] sas_v3_pci_driver_init+0x20/0x28 [ 89.288557] do_one_initcall+0x40/0x25c [ 89.292381] kernel_init_freeable+0x2b8/0x3c0 [ 89.296727] kernel_init+0x10/0x100 [ 89.300202] ret_from_fork+0x10/0x18 [ 89.303773] Disabling lock debugging due to kernel taint [ 89.309076] BUG: Bad page state in process swapper/0 pfn:313f6 [ 89.314988] page:ffff7e0000c4fd80 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 89.322983] flags: 0xfffe00000001000(reserved) [ 89.327417] raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88 0000000000000000 [ 89.335149] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
Thanks, John
> dev_set_drvdata(dev, NULL); > if (dev->pm_domain && dev->pm_domain->dismiss) >
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