diff options
| author | Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> | 2024-12-09 15:27:57 +0100 |
|---|---|---|
| committer | Bjorn Andersson <andersson@kernel.org> | 2025-01-06 18:36:59 -0600 |
| commit | 1e76b546e6fca7eb568161f408133904ca6bcf4f (patch) | |
| tree | 6aeb48975bca0fc260e12642f114d2191f18dbaf | |
| parent | b628510397b5cafa1f5d3e848a28affd1c635302 (diff) | |
firmware: qcom: scm: Cleanup global '__scm' on probe failures
If SCM driver fails the probe, it should not leave global '__scm'
variable assigned, because external users of this driver will assume the
probe finished successfully. For example TZMEM parts ('__scm->mempool')
are initialized later in the probe, but users of it (__scm_smc_call())
rely on the '__scm' variable.
This fixes theoretical NULL pointer exception, triggered via introducing
probe deferral in SCM driver with call trace:
qcom_tzmem_alloc+0x70/0x1ac (P)
qcom_tzmem_alloc+0x64/0x1ac (L)
qcom_scm_assign_mem+0x78/0x194
qcom_rmtfs_mem_probe+0x2d4/0x38c
platform_probe+0x68/0xc8
Fixes: 40289e35ca52 ("firmware: qcom: scm: enable the TZ mem allocator")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20241209-qcom-scm-missing-barriers-and-all-sort-of-srap-v2-4-9061013c8d92@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
| -rw-r--r-- | drivers/firmware/qcom/qcom_scm.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c index 4a1c05a7bf20..2380775508ac 100644 --- a/drivers/firmware/qcom/qcom_scm.c +++ b/drivers/firmware/qcom/qcom_scm.c @@ -2038,13 +2038,17 @@ static int qcom_scm_probe(struct platform_device *pdev) irq = platform_get_irq_optional(pdev, 0); if (irq < 0) { - if (irq != -ENXIO) - return irq; + if (irq != -ENXIO) { + ret = irq; + goto err; + } } else { ret = devm_request_threaded_irq(__scm->dev, irq, NULL, qcom_scm_irq_handler, IRQF_ONESHOT, "qcom-scm", __scm); - if (ret < 0) - return dev_err_probe(scm->dev, ret, "Failed to request qcom-scm irq\n"); + if (ret < 0) { + dev_err_probe(scm->dev, ret, "Failed to request qcom-scm irq\n"); + goto err; + } } __get_convention(); @@ -2063,14 +2067,18 @@ static int qcom_scm_probe(struct platform_device *pdev) qcom_scm_disable_sdi(); ret = of_reserved_mem_device_init(__scm->dev); - if (ret && ret != -ENODEV) - return dev_err_probe(__scm->dev, ret, - "Failed to setup the reserved memory region for TZ mem\n"); + if (ret && ret != -ENODEV) { + dev_err_probe(__scm->dev, ret, + "Failed to setup the reserved memory region for TZ mem\n"); + goto err; + } ret = qcom_tzmem_enable(__scm->dev); - if (ret) - return dev_err_probe(__scm->dev, ret, - "Failed to enable the TrustZone memory allocator\n"); + if (ret) { + dev_err_probe(__scm->dev, ret, + "Failed to enable the TrustZone memory allocator\n"); + goto err; + } memset(&pool_config, 0, sizeof(pool_config)); pool_config.initial_size = 0; @@ -2078,9 +2086,11 @@ static int qcom_scm_probe(struct platform_device *pdev) pool_config.max_size = SZ_256K; __scm->mempool = devm_qcom_tzmem_pool_new(__scm->dev, &pool_config); - if (IS_ERR(__scm->mempool)) - return dev_err_probe(__scm->dev, PTR_ERR(__scm->mempool), - "Failed to create the SCM memory pool\n"); + if (IS_ERR(__scm->mempool)) { + dev_err_probe(__scm->dev, PTR_ERR(__scm->mempool), + "Failed to create the SCM memory pool\n"); + goto err; + } /* * Initialize the QSEECOM interface. @@ -2096,6 +2106,12 @@ static int qcom_scm_probe(struct platform_device *pdev) WARN(ret < 0, "failed to initialize qseecom: %d\n", ret); return 0; + +err: + /* Paired with smp_load_acquire() in qcom_scm_is_available(). */ + smp_store_release(&__scm, NULL); + + return ret; } static void qcom_scm_shutdown(struct platform_device *pdev) |