From ec185dd3ab257dc2a60953fdf1b6622f524cc5b7 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 14 Jun 2021 17:33:10 -0500 Subject: [PATCH 1/8] optee: Fix memory leak when failing to register shm pages Free the previously allocated pages when we encounter an error condition while attempting to register the pages with the secure world. Fixes: a249dd200d03 ("tee: optee: Fix dynamic shm pool allocations") Fixes: 5a769f6ff439 ("optee: Fix multi page dynamic shm pool alloc") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/optee/shm_pool.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/tee/optee/shm_pool.c b/drivers/tee/optee/shm_pool.c index d767eebf30bd..da06ce9b9313 100644 --- a/drivers/tee/optee/shm_pool.c +++ b/drivers/tee/optee/shm_pool.c @@ -32,8 +32,10 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm, struct page **pages; pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL); - if (!pages) - return -ENOMEM; + if (!pages) { + rc = -ENOMEM; + goto err; + } for (i = 0; i < nr_pages; i++) { pages[i] = page; @@ -44,8 +46,14 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm, rc = optee_shm_register(shm->ctx, shm, pages, nr_pages, (unsigned long)shm->kaddr); kfree(pages); + if (rc) + goto err; } + return 0; + +err: + __free_pages(page, order); return rc; } From adf752af454e91e123e85e3784972d166837af73 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 14 Jun 2021 17:33:11 -0500 Subject: [PATCH 2/8] optee: Refuse to load the driver under the kdump kernel Fix a hung task issue, seen when booting the kdump kernel, that is caused by all of the secure world threads being in a permanent suspended state: INFO: task swapper/0:1 blocked for more than 120 seconds. Not tainted 5.4.83 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. swapper/0 D 0 1 0 0x00000028 Call trace: __switch_to+0xc8/0x118 __schedule+0x2e0/0x700 schedule+0x38/0xb8 schedule_timeout+0x258/0x388 wait_for_completion+0x16c/0x4b8 optee_cq_wait_for_completion+0x28/0xa8 optee_disable_shm_cache+0xb8/0xf8 optee_probe+0x560/0x61c platform_drv_probe+0x58/0xa8 really_probe+0xe0/0x338 driver_probe_device+0x5c/0xf0 device_driver_attach+0x74/0x80 __driver_attach+0x64/0xe0 bus_for_each_dev+0x84/0xd8 driver_attach+0x30/0x40 bus_add_driver+0x188/0x1e8 driver_register+0x64/0x110 __platform_driver_register+0x54/0x60 optee_driver_init+0x20/0x28 do_one_initcall+0x54/0x24c kernel_init_freeable+0x1e8/0x2c0 kernel_init+0x18/0x118 ret_from_fork+0x10/0x18 The invoke_fn hook returned OPTEE_SMC_RETURN_ETHREAD_LIMIT, indicating that the secure world threads were all in a suspended state at the time of the kernel crash. This intermittently prevented the kdump kernel from booting, resulting in a failure to collect the kernel dump. Make kernel dump collection more reliable on systems utilizing OP-TEE by refusing to load the driver under the kdump kernel. Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/optee/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index ddb8f9ecf307..5288cd767d82 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -612,6 +613,16 @@ static int optee_probe(struct platform_device *pdev) u32 sec_caps; int rc; + /* + * The kernel may have crashed at the same time that all available + * secure world threads were suspended and we cannot reschedule the + * suspended threads without access to the crashed kernel's wait_queue. + * Therefore, we cannot reliably initialize the OP-TEE driver in the + * kdump kernel. + */ + if (is_kdump_kernel()) + return -ENODEV; + invoke_fn = get_invoke_func(&pdev->dev); if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn); From f25889f93184db8b07a543cc2bbbb9a8fcaf4333 Mon Sep 17 00:00:00 2001 From: Allen Pais Date: Mon, 14 Jun 2021 17:33:12 -0500 Subject: [PATCH 3/8] optee: fix tee out of memory failure seen during kexec reboot The following out of memory errors are seen on kexec reboot from the optee core. [ 0.368428] tee_bnxt_fw optee-clnt0: tee_shm_alloc failed [ 0.368461] tee_bnxt_fw: probe of optee-clnt0 failed with error -22 tee_shm_release() is not invoked on dma shm buffer. Implement .shutdown() method to handle the release of the buffers correctly. More info: https://github.com/OP-TEE/optee_os/issues/3637 Cc: stable@vger.kernel.org Signed-off-by: Allen Pais Reviewed-by: Tyler Hicks Reviewed-by: Jens Wiklander Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/optee/core.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 5288cd767d82..0987074d7ed0 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -573,6 +573,13 @@ static optee_invoke_fn *get_invoke_func(struct device *dev) return ERR_PTR(-EINVAL); } +/* optee_remove - Device Removal Routine + * @pdev: platform device information struct + * + * optee_remove is called by platform subsystem to alert the driver + * that it should release the device + */ + static int optee_remove(struct platform_device *pdev) { struct optee *optee = platform_get_drvdata(pdev); @@ -603,6 +610,18 @@ static int optee_remove(struct platform_device *pdev) return 0; } +/* optee_shutdown - Device Removal Routine + * @pdev: platform device information struct + * + * platform_shutdown is called by the platform subsystem to alert + * the driver that a shutdown, reboot, or kexec is happening and + * device must be disabled. + */ +static void optee_shutdown(struct platform_device *pdev) +{ + optee_disable_shm_cache(platform_get_drvdata(pdev)); +} + static int optee_probe(struct platform_device *pdev) { optee_invoke_fn *invoke_fn; @@ -739,6 +758,7 @@ MODULE_DEVICE_TABLE(of, optee_dt_match); static struct platform_driver optee_driver = { .probe = optee_probe, .remove = optee_remove, + .shutdown = optee_shutdown, .driver = { .name = "optee", .of_match_table = optee_dt_match, From b5c10dd04b7418793517e3286cde5c04759a86de Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 14 Jun 2021 17:33:13 -0500 Subject: [PATCH 4/8] optee: Clear stale cache entries during initialization The shm cache could contain invalid addresses if optee_disable_shm_cache() was not called from the .shutdown hook of the previous kernel before a kexec. These addresses could be unmapped or they could point to mapped but unintended locations in memory. Clear the shared memory cache, while being careful to not translate the addresses returned from OPTEE_SMC_DISABLE_SHM_CACHE, during driver initialization. Once all pre-cache shm objects are removed, proceed with enabling the cache so that we know that we can handle cached shm objects with confidence later in the .shutdown hook. Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/optee/call.c | 36 ++++++++++++++++++++++++++++--- drivers/tee/optee/core.c | 9 ++++++++ drivers/tee/optee/optee_private.h | 1 + 3 files changed, 43 insertions(+), 3 deletions(-) diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index 6e6eb836e9b6..387e94768182 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -416,11 +416,13 @@ void optee_enable_shm_cache(struct optee *optee) } /** - * optee_disable_shm_cache() - Disables caching of some shared memory allocation - * in OP-TEE + * __optee_disable_shm_cache() - Disables caching of some shared memory + * allocation in OP-TEE * @optee: main service struct + * @is_mapped: true if the cached shared memory addresses were mapped by this + * kernel, are safe to dereference, and should be freed */ -void optee_disable_shm_cache(struct optee *optee) +static void __optee_disable_shm_cache(struct optee *optee, bool is_mapped) { struct optee_call_waiter w; @@ -439,6 +441,13 @@ void optee_disable_shm_cache(struct optee *optee) if (res.result.status == OPTEE_SMC_RETURN_OK) { struct tee_shm *shm; + /* + * Shared memory references that were not mapped by + * this kernel must be ignored to prevent a crash. + */ + if (!is_mapped) + continue; + shm = reg_pair_to_ptr(res.result.shm_upper32, res.result.shm_lower32); tee_shm_free(shm); @@ -449,6 +458,27 @@ void optee_disable_shm_cache(struct optee *optee) optee_cq_wait_final(&optee->call_queue, &w); } +/** + * optee_disable_shm_cache() - Disables caching of mapped shared memory + * allocations in OP-TEE + * @optee: main service struct + */ +void optee_disable_shm_cache(struct optee *optee) +{ + return __optee_disable_shm_cache(optee, true); +} + +/** + * optee_disable_unmapped_shm_cache() - Disables caching of shared memory + * allocations in OP-TEE which are not + * currently mapped + * @optee: main service struct + */ +void optee_disable_unmapped_shm_cache(struct optee *optee) +{ + return __optee_disable_shm_cache(optee, false); +} + #define PAGELIST_ENTRIES_PER_PAGE \ ((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 0987074d7ed0..651d49b53d3b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -716,6 +716,15 @@ static int optee_probe(struct platform_device *pdev) optee->memremaped_shm = memremaped_shm; optee->pool = pool; + /* + * Ensure that there are no pre-existing shm objects before enabling + * the shm cache so that there's no chance of receiving an invalid + * address during shutdown. This could occur, for example, if we're + * kexec booting from an older kernel that did not properly cleanup the + * shm cache. + */ + optee_disable_unmapped_shm_cache(optee); + optee_enable_shm_cache(optee); if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index e25b216a14ef..dbdd367be156 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -159,6 +159,7 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session); void optee_enable_shm_cache(struct optee *optee); void optee_disable_shm_cache(struct optee *optee); +void optee_disable_unmapped_shm_cache(struct optee *optee); int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm, struct page **pages, size_t num_pages, From dc7019b7d0e188d4093b34bd0747ed0d668c63bf Mon Sep 17 00:00:00 2001 From: Jens Wiklander Date: Mon, 14 Jun 2021 17:33:14 -0500 Subject: [PATCH 5/8] tee: add tee_shm_alloc_kernel_buf() Adds a new function tee_shm_alloc_kernel_buf() to allocate shared memory from a kernel driver. This function can later be made more lightweight by unnecessary dma-buf export. Cc: stable@vger.kernel.org Reviewed-by: Tyler Hicks Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/tee_shm.c | 18 ++++++++++++++++++ include/linux/tee_drv.h | 1 + 2 files changed, 19 insertions(+) diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 00472f5ce22e..c65e44707cd6 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -193,6 +193,24 @@ err_dev_put: } EXPORT_SYMBOL_GPL(tee_shm_alloc); +/** + * 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) +{ + return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf); + struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, size_t length, u32 flags) { diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 54269e47ac9a..8990f7628387 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -332,6 +332,7 @@ void *tee_get_drvdata(struct tee_device *teedev); * @returns a pointer to 'struct tee_shm' */ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags); +struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size); /** * tee_shm_register() - Register shared memory buffer From 376e4199e327a5cf29b8ec8fb0f64f3d8b429819 Mon Sep 17 00:00:00 2001 From: Sumit Garg Date: Mon, 14 Jun 2021 17:33:15 -0500 Subject: [PATCH 6/8] tee: Correct inappropriate usage of TEE_SHM_DMA_BUF flag Currently TEE_SHM_DMA_BUF flag has been inappropriately used to not register shared memory allocated for private usage by underlying TEE driver: OP-TEE in this case. So rather add a new flag as TEE_SHM_PRIV that can be utilized by underlying TEE drivers for private allocation and usage of shared memory. With this corrected, allow tee_shm_alloc_kernel_buf() to allocate a shared memory region without the backing of dma-buf. Cc: stable@vger.kernel.org Signed-off-by: Sumit Garg Co-developed-by: Tyler Hicks Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander --- drivers/tee/optee/call.c | 2 +- drivers/tee/optee/core.c | 3 ++- drivers/tee/optee/rpc.c | 5 +++-- drivers/tee/optee/shm_pool.c | 8 ++++++-- drivers/tee/tee_shm.c | 4 ++-- include/linux/tee_drv.h | 1 + 6 files changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index 387e94768182..945f03da0223 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -184,7 +184,7 @@ static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params, struct optee_msg_arg *ma; shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params), - TEE_SHM_MAPPED); + TEE_SHM_MAPPED | TEE_SHM_PRIV); if (IS_ERR(shm)) return shm; diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 651d49b53d3b..5ce13b099d7d 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -278,7 +278,8 @@ static void optee_release(struct tee_context *ctx) if (!ctxdata) return; - shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED); + shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), + TEE_SHM_MAPPED | TEE_SHM_PRIV); if (!IS_ERR(shm)) { arg = tee_shm_get_va(shm, 0); /* diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c index 1849180b0278..efbaff7ad7e5 100644 --- a/drivers/tee/optee/rpc.c +++ b/drivers/tee/optee/rpc.c @@ -314,7 +314,7 @@ static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx, shm = cmd_alloc_suppl(ctx, sz); break; case OPTEE_RPC_SHM_TYPE_KERNEL: - shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED); + shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED | TEE_SHM_PRIV); break; default: arg->ret = TEEC_ERROR_BAD_PARAMETERS; @@ -502,7 +502,8 @@ void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param, switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) { case OPTEE_SMC_RPC_FUNC_ALLOC: - shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED); + shm = tee_shm_alloc(ctx, param->a1, + TEE_SHM_MAPPED | TEE_SHM_PRIV); if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) { reg_pair_from_64(¶m->a1, ¶m->a2, pa); reg_pair_from_64(¶m->a4, ¶m->a5, diff --git a/drivers/tee/optee/shm_pool.c b/drivers/tee/optee/shm_pool.c index da06ce9b9313..c41a9a501a6e 100644 --- a/drivers/tee/optee/shm_pool.c +++ b/drivers/tee/optee/shm_pool.c @@ -27,7 +27,11 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm, shm->paddr = page_to_phys(page); shm->size = PAGE_SIZE << order; - if (shm->flags & TEE_SHM_DMA_BUF) { + /* + * Shared memory private to the OP-TEE driver doesn't need + * to be registered with OP-TEE. + */ + if (!(shm->flags & TEE_SHM_PRIV)) { unsigned int nr_pages = 1 << order, i; struct page **pages; @@ -60,7 +64,7 @@ err: static void pool_op_free(struct tee_shm_pool_mgr *poolm, struct tee_shm *shm) { - if (shm->flags & TEE_SHM_DMA_BUF) + if (!(shm->flags & TEE_SHM_PRIV)) optee_shm_unregister(shm->ctx, shm); free_pages((unsigned long)shm->kaddr, get_order(shm->size)); diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index c65e44707cd6..8a9384a64f3e 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -117,7 +117,7 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags) return ERR_PTR(-EINVAL); } - if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) { + if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF | TEE_SHM_PRIV))) { dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags); return ERR_PTR(-EINVAL); } @@ -207,7 +207,7 @@ EXPORT_SYMBOL_GPL(tee_shm_alloc); */ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) { - return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED); } EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf); diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 8990f7628387..3ebfea0781f1 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -27,6 +27,7 @@ #define TEE_SHM_USER_MAPPED BIT(4) /* Memory mapped in user space */ #define TEE_SHM_POOL BIT(5) /* Memory allocated from pool */ #define TEE_SHM_KERNEL_MAPPED BIT(6) /* Memory mapped in kernel space */ +#define TEE_SHM_PRIV BIT(7) /* Memory private to TEE driver */ struct device; struct tee_device; From dfb703ad2a8d366b829818a558337be779746575 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 14 Jun 2021 17:33:16 -0500 Subject: [PATCH 7/8] tpm_ftpm_tee: Free and unregister TEE shared memory during kexec dma-buf backed shared memory cannot be reliably freed and unregistered during a kexec operation even when tee_shm_free() is called on the shm from a .shutdown hook. The problem occurs because dma_buf_put() calls fput() which then uses task_work_add(), with the TWA_RESUME parameter, to queue tee_shm_release() to be called before the current task returns to user mode. However, the current task never returns to user mode before the kexec completes so the memory is never freed nor unregistered. Use tee_shm_alloc_kernel_buf() to avoid dma-buf backed shared memory allocation so that tee_shm_free() can directly call tee_shm_release(). This will ensure that the shm can be freed and unregistered during a kexec operation. Fixes: 09e574831b27 ("tpm/tpm_ftpm_tee: A driver for firmware TPM running inside TEE") Fixes: 1760eb689ed6 ("tpm/tpm_ftpm_tee: add shutdown call back") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Sumit Garg Acked-by: Jarkko Sakkinen Signed-off-by: Jens Wiklander --- drivers/char/tpm/tpm_ftpm_tee.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c index 2ccdf8ac6994..6e3235565a4d 100644 --- a/drivers/char/tpm/tpm_ftpm_tee.c +++ b/drivers/char/tpm/tpm_ftpm_tee.c @@ -254,11 +254,11 @@ static int ftpm_tee_probe(struct device *dev) pvt_data->session = sess_arg.session; /* Allocate dynamic shared memory with fTPM TA */ - pvt_data->shm = tee_shm_alloc(pvt_data->ctx, - MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE, - TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + pvt_data->shm = tee_shm_alloc_kernel_buf(pvt_data->ctx, + MAX_COMMAND_SIZE + + MAX_RESPONSE_SIZE); if (IS_ERR(pvt_data->shm)) { - dev_err(dev, "%s: tee_shm_alloc failed\n", __func__); + dev_err(dev, "%s: tee_shm_alloc_kernel_buf failed\n", __func__); rc = -ENOMEM; goto out_shm_alloc; } From 914ab19e471d8fb535ed50dff108b0a615f3c2d8 Mon Sep 17 00:00:00 2001 From: Allen Pais Date: Mon, 14 Jun 2021 17:33:17 -0500 Subject: [PATCH 8/8] firmware: tee_bnxt: Release TEE shm, session, and context during kexec Implement a .shutdown hook that will be called during a kexec operation so that the TEE shared memory, session, and context that were set up during .probe can be properly freed/closed. Additionally, don't use dma-buf backed shared memory for the fw_shm_pool. dma-buf backed shared memory cannot be reliably freed and unregistered during a kexec operation even when tee_shm_free() is called on the shm from a .shutdown hook. The problem occurs because dma_buf_put() calls fput() which then uses task_work_add(), with the TWA_RESUME parameter, to queue tee_shm_release() to be called before the current task returns to user mode. However, the current task never returns to user mode before the kexec completes so the memory is never freed nor unregistered. Use tee_shm_alloc_kernel_buf() to avoid dma-buf backed shared memory allocation so that tee_shm_free() can directly call tee_shm_release(). This will ensure that the shm can be freed and unregistered during a kexec operation. Fixes: 246880958ac9 ("firmware: broadcom: add OP-TEE based BNXT f/w manager") Cc: stable@vger.kernel.org Signed-off-by: Allen Pais Co-developed-by: Tyler Hicks Signed-off-by: Tyler Hicks Reviewed-by: Sumit Garg Acked-by: Florian Fainelli Signed-off-by: Jens Wiklander --- drivers/firmware/broadcom/tee_bnxt_fw.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/broadcom/tee_bnxt_fw.c b/drivers/firmware/broadcom/tee_bnxt_fw.c index ed10da5313e8..a5bf4c3f6dc7 100644 --- a/drivers/firmware/broadcom/tee_bnxt_fw.c +++ b/drivers/firmware/broadcom/tee_bnxt_fw.c @@ -212,10 +212,9 @@ static int tee_bnxt_fw_probe(struct device *dev) pvt_data.dev = dev; - fw_shm_pool = tee_shm_alloc(pvt_data.ctx, MAX_SHM_MEM_SZ, - TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + fw_shm_pool = tee_shm_alloc_kernel_buf(pvt_data.ctx, MAX_SHM_MEM_SZ); if (IS_ERR(fw_shm_pool)) { - dev_err(pvt_data.dev, "tee_shm_alloc failed\n"); + dev_err(pvt_data.dev, "tee_shm_alloc_kernel_buf failed\n"); err = PTR_ERR(fw_shm_pool); goto out_sess; } @@ -242,6 +241,14 @@ static int tee_bnxt_fw_remove(struct device *dev) return 0; } +static void tee_bnxt_fw_shutdown(struct device *dev) +{ + tee_shm_free(pvt_data.fw_shm_pool); + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); + tee_client_close_context(pvt_data.ctx); + pvt_data.ctx = NULL; +} + static const struct tee_client_device_id tee_bnxt_fw_id_table[] = { {UUID_INIT(0x6272636D, 0x2019, 0x0716, 0x42, 0x43, 0x4D, 0x5F, 0x53, 0x43, 0x48, 0x49)}, @@ -257,6 +264,7 @@ static struct tee_client_driver tee_bnxt_fw_driver = { .bus = &tee_bus_type, .probe = tee_bnxt_fw_probe, .remove = tee_bnxt_fw_remove, + .shutdown = tee_bnxt_fw_shutdown, }, };