From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D37F551FCBE; Mon, 31 Aug 2026 13:43:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788183838; cv=none; b=LLj7VMyd9POFAjBHCczcaezsuwwPoqJpMqrwOcCe5XoQ5gzimNVeCtznnTqNUKaMiPpFf//UdTJtX4akdmWfjH3cnAXrfv1tTKOl91OJ/jmWEH4S0B737XOGn65GSfxhQdj82X+ioP303aQA3EM5eIeQGkzISaJ5ZuC6GkvCoII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788183838; c=relaxed/simple; bh=FI6rnRQL1RPq+b/IB0heVFq0dV8yLFc5DhImLuGqhsQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OdsFwpzSYZyDDkTDWQn/f6UvB8iE4Wz0sCP4yXQig8bYHiC7fGLdSFpQHjCoEv89GUSO/b/ZKX+xJANonEUg1Rs0IDV2yIK34G2wRDM2uxwCc7lndgc8QQAMgJlWc11Gw0GhJeT8qQ+FhZWX0r+ipHY+/nGFAU0ZEK3Ot2ICOlo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FYRr0pkI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FYRr0pkI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C90E21F00A3E; Mon, 31 Aug 2026 13:43:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788183836; bh=ke4fPPgc4vuBUVflpSPOKOMERn+UVXGL4IbkQRINdlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FYRr0pkIGHRk8SaXZEs3ya23HIOO1kGiPhtGeOeTXFNTj75VxsStI8MU858vf/0ey DS5En34aC5ifKpajRvhAw7CPPWjPgqeCJu+4uCrpuAaxr3dDbPd6nVP7bo8+C1WATk 5F36HWmik3VsD9fbzcQcrt7nyKWaHo3DPUgZclbE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Biggers , Dmitry Baryshkov , Herbert Xu Subject: [PATCH 7.1 58/76] crypto: qcom-rng - Remove crypto_rng interface Date: Mon, 31 Aug 2026 15:34:30 +0200 Message-ID: <20260831133402.450619795@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.185608553@linuxfoundation.org> References: <20260831133359.185608553@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 2ecdf5c9910e20f73639bc322f0518a3439d17c0 upstream. qcom-rng.c exposes the same hardware through two completely separate interfaces, crypto_rng and hwrng. However, the implementation of this is buggy because it permits generation operations from these interfaces to run concurrently with each other, accessing the same registers. That is, qcom_rng_generate() synchronizes with itself but not with qcom_hwrng_read(). This results in potential repetition of output from the RNG, output of non-random values, etc. Fortunately, there's actually no point in hardware RNG drivers implementing the crypto_rng interface. It's not actually used by anything besides the "rng" algorithm type of AF_ALG, which in turn is not actually used in practice. Other crypto_rng hardware drivers are likewise being phased out, leaving just the hwrng support. Thus, remove it to simplify the code and avoid conflict (and confusion) with the hwrng interface which is the one that actually matters. Fixes: f29cd5bb64c2 ("crypto: qcom-rng - Add hw_random interface support") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Reviewed-by: Dmitry Baryshkov Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- drivers/crypto/Kconfig | 1 drivers/crypto/qcom-rng.c | 158 +++++----------------------------------------- 2 files changed, 19 insertions(+), 140 deletions(-) --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -659,7 +659,6 @@ config CRYPTO_DEV_QCOM_RNG tristate "Qualcomm Random Number Generator Driver" depends on ARCH_QCOM || COMPILE_TEST depends on HW_RANDOM - select CRYPTO_RNG help This driver provides support for the Random Number Generator hardware found on Qualcomm SoCs. --- a/drivers/crypto/qcom-rng.c +++ b/drivers/crypto/qcom-rng.c @@ -3,10 +3,8 @@ // // Based on msm-rng.c and downstream driver -#include #include #include -#include #include #include #include @@ -32,24 +30,15 @@ #define QCOM_TRNG_QUALITY 1024 struct qcom_rng { - struct mutex lock; void __iomem *base; struct clk *clk; struct hwrng hwrng; - struct qcom_rng_match_data *match_data; -}; - -struct qcom_rng_ctx { - struct qcom_rng *rng; }; struct qcom_rng_match_data { - bool skip_init; bool hwrng_support; }; -static struct qcom_rng *qcom_rng_dev; - static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max) { unsigned int currsize = 0; @@ -82,37 +71,6 @@ static int qcom_rng_read(struct qcom_rng return currsize; } -static int qcom_rng_generate(struct crypto_rng *tfm, - const u8 *src, unsigned int slen, - u8 *dstn, unsigned int dlen) -{ - struct qcom_rng_ctx *ctx = crypto_rng_ctx(tfm); - struct qcom_rng *rng = ctx->rng; - int ret; - - ret = clk_prepare_enable(rng->clk); - if (ret) - return ret; - - mutex_lock(&rng->lock); - - ret = qcom_rng_read(rng, dstn, dlen); - - mutex_unlock(&rng->lock); - clk_disable_unprepare(rng->clk); - - if (ret >= 0) - ret = 0; - - return ret; -} - -static int qcom_rng_seed(struct crypto_rng *tfm, const u8 *seed, - unsigned int slen) -{ - return 0; -} - static int qcom_hwrng_init(struct hwrng *hwrng) { struct qcom_rng *qrng = container_of(hwrng, struct qcom_rng, hwrng); @@ -134,74 +92,26 @@ static void qcom_hwrng_cleanup(struct hw clk_disable_unprepare(qrng->clk); } -static int qcom_rng_enable(struct qcom_rng *rng) -{ - u32 val; - int ret; - - ret = clk_prepare_enable(rng->clk); - if (ret) - return ret; - - /* Enable PRNG only if it is not already enabled */ - val = readl_relaxed(rng->base + PRNG_CONFIG); - if (val & PRNG_CONFIG_HW_ENABLE) - goto already_enabled; - - val = readl_relaxed(rng->base + PRNG_LFSR_CFG); - val &= ~PRNG_LFSR_CFG_MASK; - val |= PRNG_LFSR_CFG_CLOCKS; - writel(val, rng->base + PRNG_LFSR_CFG); - - val = readl_relaxed(rng->base + PRNG_CONFIG); - val |= PRNG_CONFIG_HW_ENABLE; - writel(val, rng->base + PRNG_CONFIG); - -already_enabled: - clk_disable_unprepare(rng->clk); - - return 0; -} - -static int qcom_rng_init(struct crypto_tfm *tfm) -{ - struct qcom_rng_ctx *ctx = crypto_tfm_ctx(tfm); - - ctx->rng = qcom_rng_dev; - - if (!ctx->rng->match_data->skip_init) - return qcom_rng_enable(ctx->rng); - - return 0; -} - -static struct rng_alg qcom_rng_alg = { - .generate = qcom_rng_generate, - .seed = qcom_rng_seed, - .seedsize = 0, - .base = { - .cra_name = "stdrng", - .cra_driver_name = "qcom-rng", - .cra_flags = CRYPTO_ALG_TYPE_RNG, - .cra_priority = 300, - .cra_ctxsize = sizeof(struct qcom_rng_ctx), - .cra_module = THIS_MODULE, - .cra_init = qcom_rng_init, - } -}; - static int qcom_rng_probe(struct platform_device *pdev) { + const struct qcom_rng_match_data *match_data; struct qcom_rng *rng; int ret; + match_data = device_get_match_data(&pdev->dev); + if (match_data == NULL || !match_data->hwrng_support) { + dev_info(&pdev->dev, "TRNG support not detected\n"); + /* + * In this case the driver does nothing except the dev_info(), + * but bind the device anyway to avoid effects on GCC state. + */ + return 0; + } + rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); if (!rng) return -ENOMEM; - platform_set_drvdata(pdev, rng); - mutex_init(&rng->lock); - rng->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(rng->base)) return PTR_ERR(rng->base); @@ -210,55 +120,26 @@ static int qcom_rng_probe(struct platfor if (IS_ERR(rng->clk)) return PTR_ERR(rng->clk); - rng->match_data = (struct qcom_rng_match_data *)device_get_match_data(&pdev->dev); - - qcom_rng_dev = rng; - ret = crypto_register_rng(&qcom_rng_alg); - if (ret) { - dev_err(&pdev->dev, "Register crypto rng failed: %d\n", ret); - qcom_rng_dev = NULL; - return ret; - } - - if (rng->match_data->hwrng_support) { - rng->hwrng.name = "qcom_hwrng"; - rng->hwrng.init = qcom_hwrng_init; - rng->hwrng.read = qcom_hwrng_read; - rng->hwrng.cleanup = qcom_hwrng_cleanup; - rng->hwrng.quality = QCOM_TRNG_QUALITY; - ret = devm_hwrng_register(&pdev->dev, &rng->hwrng); - if (ret) { - dev_err(&pdev->dev, "Register hwrng failed: %d\n", ret); - qcom_rng_dev = NULL; - goto fail; - } - } - - return ret; -fail: - crypto_unregister_rng(&qcom_rng_alg); + rng->hwrng.name = "qcom_hwrng"; + rng->hwrng.init = qcom_hwrng_init; + rng->hwrng.read = qcom_hwrng_read; + rng->hwrng.cleanup = qcom_hwrng_cleanup; + rng->hwrng.quality = QCOM_TRNG_QUALITY; + ret = devm_hwrng_register(&pdev->dev, &rng->hwrng); + if (ret) + dev_err(&pdev->dev, "Register hwrng failed: %d\n", ret); return ret; } -static void qcom_rng_remove(struct platform_device *pdev) -{ - crypto_unregister_rng(&qcom_rng_alg); - - qcom_rng_dev = NULL; -} - static struct qcom_rng_match_data qcom_prng_match_data = { - .skip_init = false, .hwrng_support = false, }; static struct qcom_rng_match_data qcom_prng_ee_match_data = { - .skip_init = true, .hwrng_support = false, }; static struct qcom_rng_match_data qcom_trng_match_data = { - .skip_init = true, .hwrng_support = true, }; @@ -278,7 +159,6 @@ MODULE_DEVICE_TABLE(of, qcom_rng_of_matc static struct platform_driver qcom_rng_driver = { .probe = qcom_rng_probe, - .remove = qcom_rng_remove, .driver = { .name = KBUILD_MODNAME, .of_match_table = of_match_ptr(qcom_rng_of_match),