From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- drivers/tee/tee_shm.c | 512 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 512 insertions(+) create mode 100644 drivers/tee/tee_shm.c (limited to 'drivers/tee/tee_shm.c') diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c new file mode 100644 index 000000000..b1c6231de --- /dev/null +++ b/drivers/tee/tee_shm.c @@ -0,0 +1,512 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015-2017, 2019-2021 Linaro Limited + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "tee_private.h" + +static void shm_put_kernel_pages(struct page **pages, size_t page_count) +{ + size_t n; + + for (n = 0; n < page_count; n++) + put_page(pages[n]); +} + +static int shm_get_kernel_pages(unsigned long start, size_t page_count, + struct page **pages) +{ + struct page *page; + size_t n; + + if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) || + is_kmap_addr((void *)start))) + return -EINVAL; + + page = virt_to_page(start); + for (n = 0; n < page_count; n++) { + pages[n] = page + n; + get_page(pages[n]); + } + + return page_count; +} + +static void release_registered_pages(struct tee_shm *shm) +{ + if (shm->pages) { + if (shm->flags & TEE_SHM_USER_MAPPED) + unpin_user_pages(shm->pages, shm->num_pages); + else + shm_put_kernel_pages(shm->pages, shm->num_pages); + + kfree(shm->pages); + } +} + +static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) +{ + if (shm->flags & TEE_SHM_POOL) { + teedev->pool->ops->free(teedev->pool, shm); + } else if (shm->flags & TEE_SHM_DYNAMIC) { + int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm); + + if (rc) + dev_err(teedev->dev.parent, + "unregister shm %p failed: %d", shm, rc); + + release_registered_pages(shm); + } + + teedev_ctx_put(shm->ctx); + + kfree(shm); + + tee_device_put(teedev); +} + +static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size, + size_t align, u32 flags, int id) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + void *ret; + int rc; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + if (!teedev->pool) { + /* teedev has been detached from driver */ + ret = ERR_PTR(-EINVAL); + goto err_dev_put; + } + + shm = kzalloc(sizeof(*shm), GFP_KERNEL); + if (!shm) { + ret = ERR_PTR(-ENOMEM); + goto err_dev_put; + } + + refcount_set(&shm->refcount, 1); + shm->flags = flags; + shm->id = id; + + /* + * We're assigning this as it is needed if the shm is to be + * registered. If this function returns OK then the caller expected + * to call teedev_ctx_get() or clear shm->ctx in case it's not + * needed any longer. + */ + shm->ctx = ctx; + + rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align); + if (rc) { + ret = ERR_PTR(rc); + goto err_kfree; + } + + teedev_ctx_get(ctx); + return shm; +err_kfree: + kfree(shm); +err_dev_put: + tee_device_put(teedev); + return ret; +} + +/** + * tee_shm_alloc_user_buf() - Allocate shared memory for user space + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * Memory allocated as user space shared memory is automatically freed when + * the TEE file pointer is closed. The primary usage of this function is + * when the TEE driver doesn't support registering ordinary user space + * memory. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size) +{ + u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + void *ret; + int id; + + mutex_lock(&teedev->mutex); + id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); + mutex_unlock(&teedev->mutex); + if (id < 0) + return ERR_PTR(id); + + shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id); + if (IS_ERR(shm)) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, id); + mutex_unlock(&teedev->mutex); + return shm; + } + + mutex_lock(&teedev->mutex); + ret = idr_replace(&teedev->idr, shm, id); + mutex_unlock(&teedev->mutex); + if (IS_ERR(ret)) { + tee_shm_free(shm); + return ret; + } + + return shm; +} + +/** + * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * The returned memory registered in secure world and is suitable to be + * passed as a memory buffer in parameter argument to + * tee_client_invoke_func(). The memory allocated is later freed with a + * call to tee_shm_free(). + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) +{ + u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; + + return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf); + +/** + * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared + * kernel buffer + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * This function returns similar shared memory as + * tee_shm_alloc_kernel_buf(), but with the difference that the memory + * might not be registered in secure world in case the driver supports + * passing memory not registered in advance. + * + * This function should normally only be used internally in the TEE + * drivers. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) +{ + u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL; + + return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); + +static struct tee_shm * +register_shm_helper(struct tee_context *ctx, unsigned long addr, + size_t length, u32 flags, int id) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + unsigned long start; + size_t num_pages; + void *ret; + int rc; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + if (!teedev->desc->ops->shm_register || + !teedev->desc->ops->shm_unregister) { + ret = ERR_PTR(-ENOTSUPP); + goto err_dev_put; + } + + teedev_ctx_get(ctx); + + shm = kzalloc(sizeof(*shm), GFP_KERNEL); + if (!shm) { + ret = ERR_PTR(-ENOMEM); + goto err_ctx_put; + } + + refcount_set(&shm->refcount, 1); + shm->flags = flags; + shm->ctx = ctx; + shm->id = id; + addr = untagged_addr(addr); + start = rounddown(addr, PAGE_SIZE); + shm->offset = addr - start; + shm->size = length; + num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE; + shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL); + if (!shm->pages) { + ret = ERR_PTR(-ENOMEM); + goto err_free_shm; + } + + if (flags & TEE_SHM_USER_MAPPED) + rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, + shm->pages); + else + rc = shm_get_kernel_pages(start, num_pages, shm->pages); + if (rc > 0) + shm->num_pages = rc; + if (rc != num_pages) { + if (rc >= 0) + rc = -ENOMEM; + ret = ERR_PTR(rc); + goto err_put_shm_pages; + } + + rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages, + shm->num_pages, start); + if (rc) { + ret = ERR_PTR(rc); + goto err_put_shm_pages; + } + + return shm; +err_put_shm_pages: + if (flags & TEE_SHM_USER_MAPPED) + unpin_user_pages(shm->pages, shm->num_pages); + else + shm_put_kernel_pages(shm->pages, shm->num_pages); + kfree(shm->pages); +err_free_shm: + kfree(shm); +err_ctx_put: + teedev_ctx_put(ctx); +err_dev_put: + tee_device_put(teedev); + return ret; +} + +/** + * tee_shm_register_user_buf() - Register a userspace shared memory buffer + * @ctx: Context that registers the shared memory + * @addr: The userspace address of the shared buffer + * @length: Length of the shared buffer + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, + unsigned long addr, size_t length) +{ + u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC; + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + void *ret; + int id; + + if (!access_ok((void __user *)addr, length)) + return ERR_PTR(-EFAULT); + + mutex_lock(&teedev->mutex); + id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); + mutex_unlock(&teedev->mutex); + if (id < 0) + return ERR_PTR(id); + + shm = register_shm_helper(ctx, addr, length, flags, id); + if (IS_ERR(shm)) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, id); + mutex_unlock(&teedev->mutex); + return shm; + } + + mutex_lock(&teedev->mutex); + ret = idr_replace(&teedev->idr, shm, id); + mutex_unlock(&teedev->mutex); + if (IS_ERR(ret)) { + tee_shm_free(shm); + return ret; + } + + return shm; +} + +/** + * tee_shm_register_kernel_buf() - Register kernel memory to be shared with + * secure world + * @ctx: Context that registers the shared memory + * @addr: The buffer + * @length: Length of the buffer + * + * @returns a pointer to 'struct tee_shm' + */ + +struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx, + void *addr, size_t length) +{ + u32 flags = TEE_SHM_DYNAMIC; + + return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1); +} +EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf); + +static int tee_shm_fop_release(struct inode *inode, struct file *filp) +{ + tee_shm_put(filp->private_data); + return 0; +} + +static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct tee_shm *shm = filp->private_data; + size_t size = vma->vm_end - vma->vm_start; + + /* Refuse sharing shared memory provided by application */ + if (shm->flags & TEE_SHM_USER_MAPPED) + return -EINVAL; + + /* check for overflowing the buffer's size */ + if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT) + return -EINVAL; + + return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT, + size, vma->vm_page_prot); +} + +static const struct file_operations tee_shm_fops = { + .owner = THIS_MODULE, + .release = tee_shm_fop_release, + .mmap = tee_shm_fop_mmap, +}; + +/** + * tee_shm_get_fd() - Increase reference count and return file descriptor + * @shm: Shared memory handle + * @returns user space file descriptor to shared memory + */ +int tee_shm_get_fd(struct tee_shm *shm) +{ + int fd; + + if (shm->id < 0) + return -EINVAL; + + /* matched by tee_shm_put() in tee_shm_op_release() */ + refcount_inc(&shm->refcount); + fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR); + if (fd < 0) + tee_shm_put(shm); + return fd; +} + +/** + * tee_shm_free() - Free shared memory + * @shm: Handle to shared memory to free + */ +void tee_shm_free(struct tee_shm *shm) +{ + tee_shm_put(shm); +} +EXPORT_SYMBOL_GPL(tee_shm_free); + +/** + * tee_shm_get_va() - Get virtual address of a shared memory plus an offset + * @shm: Shared memory handle + * @offs: Offset from start of this shared memory + * @returns virtual address of the shared memory + offs if offs is within + * the bounds of this shared memory, else an ERR_PTR + */ +void *tee_shm_get_va(struct tee_shm *shm, size_t offs) +{ + if (!shm->kaddr) + return ERR_PTR(-EINVAL); + if (offs >= shm->size) + return ERR_PTR(-EINVAL); + return (char *)shm->kaddr + offs; +} +EXPORT_SYMBOL_GPL(tee_shm_get_va); + +/** + * tee_shm_get_pa() - Get physical address of a shared memory plus an offset + * @shm: Shared memory handle + * @offs: Offset from start of this shared memory + * @pa: Physical address to return + * @returns 0 if offs is within the bounds of this shared memory, else an + * error code. + */ +int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa) +{ + if (offs >= shm->size) + return -EINVAL; + if (pa) + *pa = shm->paddr + offs; + return 0; +} +EXPORT_SYMBOL_GPL(tee_shm_get_pa); + +/** + * tee_shm_get_from_id() - Find shared memory object and increase reference + * count + * @ctx: Context owning the shared memory + * @id: Id of shared memory object + * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure + */ +struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id) +{ + struct tee_device *teedev; + struct tee_shm *shm; + + if (!ctx) + return ERR_PTR(-EINVAL); + + teedev = ctx->teedev; + mutex_lock(&teedev->mutex); + shm = idr_find(&teedev->idr, id); + /* + * If the tee_shm was found in the IDR it must have a refcount + * larger than 0 due to the guarantee in tee_shm_put() below. So + * it's safe to use refcount_inc(). + */ + if (!shm || shm->ctx != ctx) + shm = ERR_PTR(-EINVAL); + else + refcount_inc(&shm->refcount); + mutex_unlock(&teedev->mutex); + return shm; +} +EXPORT_SYMBOL_GPL(tee_shm_get_from_id); + +/** + * tee_shm_put() - Decrease reference count on a shared memory handle + * @shm: Shared memory handle + */ +void tee_shm_put(struct tee_shm *shm) +{ + struct tee_device *teedev = shm->ctx->teedev; + bool do_release = false; + + mutex_lock(&teedev->mutex); + if (refcount_dec_and_test(&shm->refcount)) { + /* + * refcount has reached 0, we must now remove it from the + * IDR before releasing the mutex. This will guarantee that + * the refcount_inc() in tee_shm_get_from_id() never starts + * from 0. + */ + if (shm->id >= 0) + idr_remove(&teedev->idr, shm->id); + do_release = true; + } + mutex_unlock(&teedev->mutex); + + if (do_release) + tee_shm_release(teedev, shm); +} +EXPORT_SYMBOL_GPL(tee_shm_put); -- cgit v1.2.3