From 5acd67ceb38debe2fbf70ea35e2dec9f7ab01bbd Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Tue, 14 Jul 2026 13:55:01 -0700 Subject: iommu/tegra241-cmdqv: Don't run the error ISR before probe sets up vintfs __tegra241_cmdqv_probe() requests the error IRQ before it has allocated the cmdqv->vintfs array and set cmdqv->num_vintfs. A CMDQV left enabled with a latched error across a kexec fires the IRQ as soon as it is requested, and tegra241_cmdqv_isr() then walks the uninitialized cmdqv->vintfs array. Request the IRQ only after cmdqv->vintfs is allocated and zeroed, so that a latched interrupt firing early runs the ISR against a valid array of NULL slots that it safely skips. Fixes: 918eb5c856f6 ("iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Nicolin Chen Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 34 ++++++++++++++------------ 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c index cc80426558d5..8d6da7b0f6ba 100644 --- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c +++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c @@ -983,17 +983,6 @@ __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res, cmdqv->dev = smmu->impl_dev; cmdqv->base_phys = res->start; - if (cmdqv->irq > 0) { - ret = request_threaded_irq(irq, NULL, tegra241_cmdqv_isr, - IRQF_ONESHOT, "tegra241-cmdqv", - cmdqv); - if (ret) { - dev_err(cmdqv->dev, "failed to request irq (%d): %d\n", - cmdqv->irq, ret); - goto iounmap; - } - } - regval = readl_relaxed(REG_CMDQV(cmdqv, PARAM)); cmdqv->num_vintfs = 1 << FIELD_GET(CMDQV_NUM_VINTF_LOG2, regval); cmdqv->num_vcmdqs = 1 << FIELD_GET(CMDQV_NUM_VCMDQ_LOG2, regval); @@ -1004,10 +993,25 @@ __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res, cmdqv->vintfs = kzalloc_objs(*cmdqv->vintfs, cmdqv->num_vintfs); if (!cmdqv->vintfs) - goto free_irq; + goto iounmap; ida_init(&cmdqv->vintf_ids); + /* + * Request the IRQ only after cmdqv->vintfs is allocated and zeroed, so + * the ISR would not walk an uninitialized array. + */ + if (cmdqv->irq > 0) { + ret = request_threaded_irq(irq, NULL, tegra241_cmdqv_isr, + IRQF_ONESHOT, "tegra241-cmdqv", + cmdqv); + if (ret) { + dev_err(cmdqv->dev, "failed to request irq (%d): %d\n", + cmdqv->irq, ret); + goto free_vintfs; + } + } + #ifdef CONFIG_IOMMU_DEBUGFS if (!cmdqv_debugfs_dir) { cmdqv_debugfs_dir = @@ -1022,9 +1026,9 @@ __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res, return new_smmu; -free_irq: - if (cmdqv->irq > 0) - free_irq(cmdqv->irq, cmdqv); +free_vintfs: + ida_destroy(&cmdqv->vintf_ids); + kfree(cmdqv->vintfs); iounmap: iounmap(base); return NULL; -- cgit v1.2.3