6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adrián Larumbe [ Upstream commit 985f5e12f3cdf43030e13c2bbd154913133b5c3f ] When a VM is created, caller has to specify the range of the address space carve-out set aside for mapping kernel BO's. That means vm_bind mappings of UM-exposed BO's should not intersect with that region, but at the moment we're not checking this. At first, I thought of giving these values to drm_gpuvm_init() through its reserve_{offset, range} arguments, but it turns out that is meant for VM address spans that are not managed through the usual drm_gpuvm split/merge circuit, so storing the end of the user VA range at VM creation time and doing a quick check in the vm_bind ioctl path was the simplest workaround. The new check also makes sure vm_bind range doesn't overflow the size of a 64-bit unsigned integer. That was already being done further down the call stack inside drm_gpuvm_sm_map -> drm_gpuvm_range_valid, but it's best to fail early in the driver before GPUVM functions are invoked so that we won't waste time allocating vm_bind context resources. Fixes: 12cf826bf1dd ("drm/panthor: Support sparse mappings") Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") Reviewed-by: Boris Brezillon Signed-off-by: Adrián Larumbe Reviewed-by: Steven Price Link: https://patch.msgid.link/20260720-vm_bind_checks-v6-1-c2c7dbe93a73@collabora.com Signed-off-by: Steven Price Signed-off-by: Sasha Levin --- drivers/gpu/drm/panthor/panthor_mmu.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 5647a24741095..d985f324772ae 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -313,6 +313,9 @@ struct panthor_vm { u64 end; } kernel_auto_va; + /** @user_va_range: Upper boundary of VAs VM users can map objects against. */ + u64 user_va_range; + /** @as: Address space related fields. */ struct { /** @@ -2385,6 +2388,8 @@ panthor_vm_create(struct panthor_device *ptdev, bool for_mcu, va_range = full_va_range; } + vm->user_va_range = kernel_va_start; + mutex_init(&vm->mm_lock); drm_mm_init(&vm->mm, kernel_va_start, kernel_va_size); vm->kernel_auto_va.start = auto_kernel_va_start; @@ -2471,6 +2476,10 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file, if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz)) return -EINVAL; + /* We don't allow mappings that overlap with kbo's reserved range */ + if (range_overflows(op->va, op->size, vm->user_va_range)) + return -EINVAL; + switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) { case DRM_PANTHOR_VM_BIND_OP_TYPE_MAP: gem = drm_gem_object_lookup(file, op->bo_handle); -- 2.53.0