From aa63a74d4535a1d97b60e46655a1361c42565b89 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 6 Apr 2022 15:01:50 -0700 Subject: topology/sysfs: Hide PPIN on systems that do not support it. Systems that do not support a Protected Processor Identification Number currently report: # cat /sys/devices/system/cpu/cpu0/topology/ppin 0x0 which is confusing/wrong. Add a ".is_visible" function to suppress inclusion of the ppin file. Fixes: ab28e944197f ("topology/sysfs: Add PPIN in sysfs under cpu topology") Signed-off-by: Tony Luck Link: https://lore.kernel.org/r/20220406220150.63855-1-tony.luck@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/topology.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/topology.c b/drivers/base/topology.c index e9d1efcda89b..706dbf8bf249 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -152,9 +152,21 @@ static struct attribute *default_attrs[] = { NULL }; +static umode_t topology_is_visible(struct kobject *kobj, + struct attribute *attr, int unused) +{ + struct device *dev = kobj_to_dev(kobj); + + if (attr == &dev_attr_ppin.attr && !topology_ppin(dev->id)) + return 0; + + return attr->mode; +} + static const struct attribute_group topology_attr_group = { .attrs = default_attrs, .bin_attrs = bin_attrs, + .is_visible = topology_is_visible, .name = "topology" }; -- cgit v1.2.3 From db1e59483dfd8d4e956575302520bb8f7e20c79b Mon Sep 17 00:00:00 2001 From: Darren Hart Date: Mon, 11 Apr 2022 13:53:34 -0700 Subject: topology: make core_mask include at least cluster_siblings Ampere Altra defines CPU clusters in the ACPI PPTT. They share a Snoop Control Unit, but have no shared CPU-side last level cache. cpu_coregroup_mask() will return a cpumask with weight 1, while cpu_clustergroup_mask() will return a cpumask with weight 2. As a result, build_sched_domain() will BUG() once per CPU with: BUG: arch topology borken the CLS domain not a subset of the MC domain The MC level cpumask is then extended to that of the CLS child, and is later removed entirely as redundant. This sched domain topology is an improvement over previous topologies, or those built without SCHED_CLUSTER, particularly for certain latency sensitive workloads. With the current scheduler model and heuristics, this is a desirable default topology for Ampere Altra and Altra Max system. Rather than create a custom sched domains topology structure and introduce new logic in arch/arm64 to detect these systems, update the core_mask so coregroup is never a subset of clustergroup, extending it to cluster_siblings if necessary. Only do this if CONFIG_SCHED_CLUSTER is enabled to avoid also changing the topology (MC) when CONFIG_SCHED_CLUSTER is disabled. This has the added benefit over a custom topology of working for both symmetric and asymmetric topologies. It does not address systems where the CLUSTER topology is above a populated MC topology, but these are not considered today and can be addressed separately if and when they appear. The final sched domain topology for a 2 socket Ampere Altra system is unchanged with or without CONFIG_SCHED_CLUSTER, and the BUG is avoided: For CPU0: CONFIG_SCHED_CLUSTER=y CLS [0-1] DIE [0-79] NUMA [0-159] CONFIG_SCHED_CLUSTER is not set DIE [0-79] NUMA [0-159] Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Catalin Marinas Cc: Will Deacon Cc: Peter Zijlstra Cc: Vincent Guittot Cc: D. Scott Phillips Cc: Ilkka Koskinen Cc: # 5.16.x Suggested-by: Barry Song Reviewed-by: Barry Song Reviewed-by: Dietmar Eggemann Acked-by: Sudeep Holla Signed-off-by: Darren Hart Link: https://lore.kernel.org/r/c8fe9fce7c86ed56b4c455b8c902982dc2303868.1649696956.git.darren@os.amperecomputing.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/arch_topology.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 1d6636ebaac5..5497c5ab7318 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -667,6 +667,15 @@ const struct cpumask *cpu_coregroup_mask(int cpu) core_mask = &cpu_topology[cpu].llc_sibling; } + /* + * For systems with no shared cpu-side LLC but with clusters defined, + * extend core_mask to cluster_siblings. The sched domain builder will + * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled. + */ + if (IS_ENABLED(CONFIG_SCHED_CLUSTER) && + cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling)) + core_mask = &cpu_topology[cpu].cluster_sibling; + return core_mask; } -- cgit v1.2.3 From 1dc9f1a66e1718479e1c4f95514e1750602a3cb9 Mon Sep 17 00:00:00 2001 From: Wang Qing Date: Sun, 10 Apr 2022 19:36:19 -0700 Subject: arch_topology: Do not set llc_sibling if llc_id is invalid When ACPI is not enabled, cpuid_topo->llc_id = cpu_topo->llc_id = -1, which will set llc_sibling 0xff(...), this is misleading. Don't set llc_sibling(default 0) if we don't know the cache topology. Reviewed-by: Sudeep Holla Signed-off-by: Wang Qing Fixes: 37c3ec2d810f ("arm64: topology: divorce MC scheduling domain from core_siblings") Cc: stable Link: https://lore.kernel.org/r/1649644580-54626-1-git-send-email-wangqing@vivo.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/arch_topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 5497c5ab7318..f73b836047cf 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -693,7 +693,7 @@ void update_siblings_masks(unsigned int cpuid) for_each_online_cpu(cpu) { cpu_topo = &cpu_topology[cpu]; - if (cpuid_topo->llc_id == cpu_topo->llc_id) { + if (cpu_topo->llc_id != -1 && cpuid_topo->llc_id == cpu_topo->llc_id) { cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling); cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling); } -- cgit v1.2.3 From c95ce3a23dcda678f6f7811dd39b6d14eeb6f192 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 22 Apr 2022 08:26:53 +0200 Subject: topology: Fix up build warning in topology_is_visible() Commit aa63a74d4535 ("topology/sysfs: Hide PPIN on systems that do not support it.") caused a build warning on some configurations: drivers/base/topology.c: In function 'topology_is_visible': drivers/base/topology.c:158:24: warning: unused variable 'dev' [-Wunused-variable] 158 | struct device *dev = kobj_to_dev(kobj); Fix this up by getting rid of the variable entirely. Fixes: aa63a74d4535 ("topology/sysfs: Hide PPIN on systems that do not support it.") Cc: Tony Luck Reported-by: Stephen Rothwell Link: https://lore.kernel.org/r/20220422062653.3899972-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/topology.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/topology.c b/drivers/base/topology.c index 706dbf8bf249..ac6ad9ab67f9 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -155,9 +155,7 @@ static struct attribute *default_attrs[] = { static umode_t topology_is_visible(struct kobject *kobj, struct attribute *attr, int unused) { - struct device *dev = kobj_to_dev(kobj); - - if (attr == &dev_attr_ppin.attr && !topology_ppin(dev->id)) + if (attr == &dev_attr_ppin.attr && !topology_ppin(kobj_to_dev(kobj)->id)) return 0; return attr->mode; -- cgit v1.2.3 From 25f3bcfc54bcf7b0e45d140ec8bfbbf10ba11869 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 18 Apr 2022 08:49:51 +0800 Subject: driver core: Add dma_cleanup callback in bus_type The bus_type structure defines dma_configure() callback for bus drivers to configure DMA on the devices. This adds the paired dma_cleanup() callback and calls it during driver unbinding so that bus drivers can do some cleanup work. One use case for this paired DMA callbacks is for the bus driver to check for DMA ownership conflicts during driver binding, where multiple devices belonging to a same IOMMU group (the minimum granularity of isolation and protection) may be assigned to kernel drivers or user space respectively. Without this change, for example, the vfio driver has to listen to a bus BOUND_DRIVER event and then BUG_ON() in case of dma ownership conflict. This leads to bad user experience since careless driver binding operation may crash the system if the admin overlooks the group restriction. Aside from bad design, this leads to a security problem as a root user, even with lockdown=integrity, can force the kernel to BUG. With this change, the bus driver could check and set the DMA ownership in driver binding process and fail on ownership conflicts. The DMA ownership should be released during driver unbinding. Signed-off-by: Lu Baolu Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20220418005000.897664-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/base/dd.c | 5 +++++ include/linux/device/bus.h | 3 +++ 2 files changed, 8 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 3fc3b5940bb3..94b7ac9bf459 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -671,6 +671,8 @@ sysfs_failed: if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev); + if (dev->bus && dev->bus->dma_cleanup) + dev->bus->dma_cleanup(dev); pinctrl_bind_failed: device_links_no_driver(dev); device_unbind_cleanup(dev); @@ -1199,6 +1201,9 @@ static void __device_release_driver(struct device *dev, struct device *parent) device_remove(dev); + if (dev->bus && dev->bus->dma_cleanup) + dev->bus->dma_cleanup(dev); + device_links_driver_cleanup(dev); device_unbind_cleanup(dev); diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index a039ab809753..d8b29ccd07e5 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -59,6 +59,8 @@ struct fwnode_handle; * bus supports. * @dma_configure: Called to setup DMA configuration on a device on * this bus. + * @dma_cleanup: Called to cleanup DMA configuration on a device on + * this bus. * @pm: Power management operations of this bus, callback the specific * device driver's pm-ops. * @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU @@ -103,6 +105,7 @@ struct bus_type { int (*num_vf)(struct device *dev); int (*dma_configure)(struct device *dev); + void (*dma_cleanup)(struct device *dev); const struct dev_pm_ops *pm; -- cgit v1.2.3 From 4a6d9dd564d0e7339fc15ecc5ce66db4ad842be2 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 18 Apr 2022 08:49:52 +0800 Subject: amba: Stop sharing platform_dma_configure() Stop sharing platform_dma_configure() helper as they are about to have their own bus dma_configure callbacks. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20220418005000.897664-4-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/amba/bus.c | 19 ++++++++++++++++++- drivers/base/platform.c | 3 +-- include/linux/platform_device.h | 2 -- 3 files changed, 19 insertions(+), 5 deletions(-) (limited to 'drivers/base') diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index d3bd14aaabf6..76b52bd2c2a4 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -20,6 +20,8 @@ #include #include #include +#include +#include #define to_amba_driver(d) container_of(d, struct amba_driver, drv) @@ -273,6 +275,21 @@ static void amba_shutdown(struct device *dev) drv->shutdown(to_amba_device(dev)); } +static int amba_dma_configure(struct device *dev) +{ + enum dev_dma_attr attr; + int ret = 0; + + if (dev->of_node) { + ret = of_dma_configure(dev, dev->of_node, true); + } else if (has_acpi_companion(dev)) { + attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode)); + ret = acpi_dma_configure(dev, attr); + } + + return ret; +} + #ifdef CONFIG_PM /* * Hooks to provide runtime PM of the pclk (bus clock). It is safe to @@ -341,7 +358,7 @@ struct bus_type amba_bustype = { .probe = amba_probe, .remove = amba_remove, .shutdown = amba_shutdown, - .dma_configure = platform_dma_configure, + .dma_configure = amba_dma_configure, .pm = &amba_pm, }; EXPORT_SYMBOL_GPL(amba_bustype); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 8cc272fd5c99..d7915734d931 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1454,8 +1454,7 @@ static void platform_shutdown(struct device *_dev) drv->shutdown(dev); } - -int platform_dma_configure(struct device *dev) +static int platform_dma_configure(struct device *dev) { enum dev_dma_attr attr; int ret = 0; diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 7c96f169d274..17fde717df68 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -328,8 +328,6 @@ extern int platform_pm_restore(struct device *dev); #define platform_pm_restore NULL #endif -extern int platform_dma_configure(struct device *dev); - #ifdef CONFIG_PM_SLEEP #define USE_PLATFORM_PM_SLEEP_OPS \ .suspend = platform_pm_suspend, \ -- cgit v1.2.3 From 512881eacfa72c2136b27b9934b7b27504a9efc2 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 18 Apr 2022 08:49:53 +0800 Subject: bus: platform,amba,fsl-mc,PCI: Add device DMA ownership management The devices on platform/amba/fsl-mc/PCI buses could be bound to drivers with the device DMA managed by kernel drivers or user-space applications. Unfortunately, multiple devices may be placed in the same IOMMU group because they cannot be isolated from each other. The DMA on these devices must either be entirely under kernel control or userspace control, never a mixture. Otherwise the driver integrity is not guaranteed because they could access each other through the peer-to-peer accesses which by-pass the IOMMU protection. This checks and sets the default DMA mode during driver binding, and cleanups during driver unbinding. In the default mode, the device DMA is managed by the device driver which handles DMA operations through the kernel DMA APIs (see Documentation/core-api/dma-api.rst). For cases where the devices are assigned for userspace control through the userspace driver framework(i.e. VFIO), the drivers(for example, vfio_pci/ vfio_platfrom etc.) may set a new flag (driver_managed_dma) to skip this default setting in the assumption that the drivers know what they are doing with the device DMA. Calling iommu_device_use_default_domain() before {of,acpi}_dma_configure is currently a problem. As things stand, the IOMMU driver ignored the initial iommu_probe_device() call when the device was added, since at that point it had no fwspec yet. In this situation, {of,acpi}_iommu_configure() are retriggering iommu_probe_device() after the IOMMU driver has seen the firmware data via .of_xlate to learn that it actually responsible for the given device. As the result, before that gets fixed, iommu_use_default_domain() goes at the end, and calls arch_teardown_dma_ops() if it fails. Cc: Greg Kroah-Hartman Cc: Bjorn Helgaas Cc: Stuart Yoder Cc: Laurentiu Tudor Signed-off-by: Lu Baolu Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jason Gunthorpe Reviewed-by: Robin Murphy Tested-by: Eric Auger Link: https://lore.kernel.org/r/20220418005000.897664-5-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/amba/bus.c | 18 ++++++++++++++++++ drivers/base/platform.c | 18 ++++++++++++++++++ drivers/bus/fsl-mc/fsl-mc-bus.c | 24 ++++++++++++++++++++++-- drivers/pci/pci-driver.c | 18 ++++++++++++++++++ include/linux/amba/bus.h | 8 ++++++++ include/linux/fsl/mc.h | 8 ++++++++ include/linux/pci.h | 8 ++++++++ include/linux/platform_device.h | 8 ++++++++ 8 files changed, 108 insertions(+), 2 deletions(-) (limited to 'drivers/base') diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 76b52bd2c2a4..a0ec61232b6c 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #define to_amba_driver(d) container_of(d, struct amba_driver, drv) @@ -277,6 +279,7 @@ static void amba_shutdown(struct device *dev) static int amba_dma_configure(struct device *dev) { + struct amba_driver *drv = to_amba_driver(dev->driver); enum dev_dma_attr attr; int ret = 0; @@ -287,9 +290,23 @@ static int amba_dma_configure(struct device *dev) ret = acpi_dma_configure(dev, attr); } + if (!ret && !drv->driver_managed_dma) { + ret = iommu_device_use_default_domain(dev); + if (ret) + arch_teardown_dma_ops(dev); + } + return ret; } +static void amba_dma_cleanup(struct device *dev) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + + if (!drv->driver_managed_dma) + iommu_device_unuse_default_domain(dev); +} + #ifdef CONFIG_PM /* * Hooks to provide runtime PM of the pclk (bus clock). It is safe to @@ -359,6 +376,7 @@ struct bus_type amba_bustype = { .remove = amba_remove, .shutdown = amba_shutdown, .dma_configure = amba_dma_configure, + .dma_cleanup = amba_dma_cleanup, .pm = &amba_pm, }; EXPORT_SYMBOL_GPL(amba_bustype); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d7915734d931..70bc30cf575c 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -30,6 +30,8 @@ #include #include #include +#include +#include #include "base.h" #include "power/power.h" @@ -1456,6 +1458,7 @@ static void platform_shutdown(struct device *_dev) static int platform_dma_configure(struct device *dev) { + struct platform_driver *drv = to_platform_driver(dev->driver); enum dev_dma_attr attr; int ret = 0; @@ -1466,9 +1469,23 @@ static int platform_dma_configure(struct device *dev) ret = acpi_dma_configure(dev, attr); } + if (!ret && !drv->driver_managed_dma) { + ret = iommu_device_use_default_domain(dev); + if (ret) + arch_teardown_dma_ops(dev); + } + return ret; } +static void platform_dma_cleanup(struct device *dev) +{ + struct platform_driver *drv = to_platform_driver(dev->driver); + + if (!drv->driver_managed_dma) + iommu_device_unuse_default_domain(dev); +} + static const struct dev_pm_ops platform_dev_pm_ops = { SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL) USE_PLATFORM_PM_SLEEP_OPS @@ -1483,6 +1500,7 @@ struct bus_type platform_bus_type = { .remove = platform_remove, .shutdown = platform_shutdown, .dma_configure = platform_dma_configure, + .dma_cleanup = platform_dma_cleanup, .pm = &platform_dev_pm_ops, }; EXPORT_SYMBOL_GPL(platform_bus_type); diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 8fd4a356a86e..76648c4fdaf4 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "fsl-mc-private.h" @@ -140,15 +141,33 @@ static int fsl_mc_dma_configure(struct device *dev) { struct device *dma_dev = dev; struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver); u32 input_id = mc_dev->icid; + int ret; while (dev_is_fsl_mc(dma_dev)) dma_dev = dma_dev->parent; if (dev_of_node(dma_dev)) - return of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id); + ret = of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id); + else + ret = acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id); + + if (!ret && !mc_drv->driver_managed_dma) { + ret = iommu_device_use_default_domain(dev); + if (ret) + arch_teardown_dma_ops(dev); + } + + return ret; +} + +static void fsl_mc_dma_cleanup(struct device *dev) +{ + struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver); - return acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id); + if (!mc_drv->driver_managed_dma) + iommu_device_unuse_default_domain(dev); } static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, @@ -312,6 +331,7 @@ struct bus_type fsl_mc_bus_type = { .match = fsl_mc_bus_match, .uevent = fsl_mc_bus_uevent, .dma_configure = fsl_mc_dma_configure, + .dma_cleanup = fsl_mc_dma_cleanup, .dev_groups = fsl_mc_dev_groups, .bus_groups = fsl_mc_bus_groups, }; diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 4ceeb75fc899..f83f7fbac68f 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "pci.h" #include "pcie/portdrv.h" @@ -1601,6 +1602,7 @@ static int pci_bus_num_vf(struct device *dev) */ static int pci_dma_configure(struct device *dev) { + struct pci_driver *driver = to_pci_driver(dev->driver); struct device *bridge; int ret = 0; @@ -1616,9 +1618,24 @@ static int pci_dma_configure(struct device *dev) } pci_put_host_bridge_device(bridge); + + if (!ret && !driver->driver_managed_dma) { + ret = iommu_device_use_default_domain(dev); + if (ret) + arch_teardown_dma_ops(dev); + } + return ret; } +static void pci_dma_cleanup(struct device *dev) +{ + struct pci_driver *driver = to_pci_driver(dev->driver); + + if (!driver->driver_managed_dma) + iommu_device_unuse_default_domain(dev); +} + struct bus_type pci_bus_type = { .name = "pci", .match = pci_bus_match, @@ -1632,6 +1649,7 @@ struct bus_type pci_bus_type = { .pm = PCI_PM_OPS_PTR, .num_vf = pci_bus_num_vf, .dma_configure = pci_dma_configure, + .dma_cleanup = pci_dma_cleanup, }; EXPORT_SYMBOL(pci_bus_type); diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h index 6562f543c3e0..2ddce9bcd00e 100644 --- a/include/linux/amba/bus.h +++ b/include/linux/amba/bus.h @@ -79,6 +79,14 @@ struct amba_driver { void (*remove)(struct amba_device *); void (*shutdown)(struct amba_device *); const struct amba_id *id_table; + /* + * For most device drivers, no need to care about this flag as long as + * all DMAs are handled through the kernel DMA API. For some special + * ones, for example VFIO drivers, they know how to manage the DMA + * themselves and set this flag so that the IOMMU layer will allow them + * to setup and manage their own I/O address space. + */ + bool driver_managed_dma; }; /* diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h index 7b6c42bfb660..27efef8affb1 100644 --- a/include/linux/fsl/mc.h +++ b/include/linux/fsl/mc.h @@ -32,6 +32,13 @@ struct fsl_mc_io; * @shutdown: Function called at shutdown time to quiesce the device * @suspend: Function called when a device is stopped * @resume: Function called when a device is resumed + * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA. + * For most device drivers, no need to care about this flag + * as long as all DMAs are handled through the kernel DMA API. + * For some special ones, for example VFIO drivers, they know + * how to manage the DMA themselves and set this flag so that + * the IOMMU layer will allow them to setup and manage their + * own I/O address space. * * Generic DPAA device driver object for device drivers that are registered * with a DPRC bus. This structure is to be embedded in each device-specific @@ -45,6 +52,7 @@ struct fsl_mc_driver { void (*shutdown)(struct fsl_mc_device *dev); int (*suspend)(struct fsl_mc_device *dev, pm_message_t state); int (*resume)(struct fsl_mc_device *dev); + bool driver_managed_dma; }; #define to_fsl_mc_driver(_drv) \ diff --git a/include/linux/pci.h b/include/linux/pci.h index 60adf42460ab..b933d2b08d4d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -895,6 +895,13 @@ struct module; * created once it is bound to the driver. * @driver: Driver model structure. * @dynids: List of dynamically added device IDs. + * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA. + * For most device drivers, no need to care about this flag + * as long as all DMAs are handled through the kernel DMA API. + * For some special ones, for example VFIO drivers, they know + * how to manage the DMA themselves and set this flag so that + * the IOMMU layer will allow them to setup and manage their + * own I/O address space. */ struct pci_driver { struct list_head node; @@ -913,6 +920,7 @@ struct pci_driver { const struct attribute_group **dev_groups; struct device_driver driver; struct pci_dynids dynids; + bool driver_managed_dma; }; static inline struct pci_driver *to_pci_driver(struct device_driver *drv) diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 17fde717df68..b3d9c744f1e5 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -210,6 +210,14 @@ struct platform_driver { struct device_driver driver; const struct platform_device_id *id_table; bool prevent_deferred_probe; + /* + * For most device drivers, no need to care about this flag as long as + * all DMAs are handled through the kernel DMA API. For some special + * ones, for example VFIO drivers, they know how to manage the DMA + * themselves and set this flag so that the IOMMU layer will allow them + * to setup and manage their own I/O address space. + */ + bool driver_managed_dma; }; #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \ -- cgit v1.2.3 From 581dd69830341d299b0c097fc366097ab497d679 Mon Sep 17 00:00:00 2001 From: Thiébaud Weksteen Date: Mon, 2 May 2022 10:49:52 +1000 Subject: firmware_loader: use kernel credentials when reading firmware MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Device drivers may decide to not load firmware when probed to avoid slowing down the boot process should the firmware filesystem not be available yet. In this case, the firmware loading request may be done when a device file associated with the driver is first accessed. The credentials of the userspace process accessing the device file may be used to validate access to the firmware files requested by the driver. Ensure that the kernel assumes the responsibility of reading the firmware. This was observed on Android for a graphic driver loading their firmware when the device file (e.g. /dev/mali0) was first opened by userspace (i.e. surfaceflinger). The security context of surfaceflinger was used to validate the access to the firmware file (e.g. /vendor/firmware/mali.bin). Previously, Android configurations were not setting up the firmware_class.path command line argument and were relying on the userspace fallback mechanism. In this case, the security context of the userspace daemon (i.e. ueventd) was consistently used to read firmware files. More Android devices are now found to set firmware_class.path which gives the kernel the opportunity to read the firmware directly (via kernel_read_file_from_path_initns). In this scenario, the current process credentials were used, even if unrelated to the loading of the firmware file. Signed-off-by: Thiébaud Weksteen Cc: # 5.10 Reviewed-by: Paul Moore Acked-by: Luis Chamberlain Link: https://lore.kernel.org/r/20220502004952.3970800-1-tweek@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_loader/main.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index 94d1789a233e..406a907a4cae 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -735,6 +735,8 @@ _request_firmware(const struct firmware **firmware_p, const char *name, size_t offset, u32 opt_flags) { struct firmware *fw = NULL; + struct cred *kern_cred = NULL; + const struct cred *old_cred; bool nondirect = false; int ret; @@ -751,6 +753,18 @@ _request_firmware(const struct firmware **firmware_p, const char *name, if (ret <= 0) /* error or already assigned */ goto out; + /* + * We are about to try to access the firmware file. Because we may have been + * called by a driver when serving an unrelated request from userland, we use + * the kernel credentials to read the file. + */ + kern_cred = prepare_kernel_cred(NULL); + if (!kern_cred) { + ret = -ENOMEM; + goto out; + } + old_cred = override_creds(kern_cred); + ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL); /* Only full reads can support decompression, platform, and sysfs. */ @@ -776,6 +790,9 @@ _request_firmware(const struct firmware **firmware_p, const char *name, } else ret = assign_fw(fw, device); + revert_creds(old_cred); + put_cred(kern_cred); + out: if (ret < 0) { fw_abort_batch_reqs(fw); -- cgit v1.2.3