From: Eric Biggers Date: Sun, 31 May 2026 19:17:35 +0000 (-0700) Subject: crypto: xilinx-trng - Remove crypto_rng interface X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=32b4d29280ed2a991dc196d5845b892acedc63b8;p=thirdparty%2Flinux.git crypto: xilinx-trng - Remove crypto_rng interface Implementing the crypto_rng interface has no purpose, as it isn't used in practice. It's being removed from other drivers too. Just remove it. This leaves hwrng, which is actually used. Tagging with 'Cc stable' due to the bugs that this removes: - xtrng_trng_generate() sometimes returned success even when it didn't fill in all the bytes. - It was possible for xtrng_trng_generate() and xtrng_hwrng_trng_read() to run concurrently and interfere with each other, as the locking code in xtrng_hwrng_trng_read() was broken. Fixes: 8979744aca80 ("crypto: xilinx - Add TRNG driver for Versal") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 4c47ab6bb2679..851904fb9ba49 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -703,7 +703,6 @@ config CRYPTO_DEV_XILINX_TRNG tristate "Support for Xilinx True Random Generator" depends on ZYNQMP_FIRMWARE || COMPILE_TEST select CRYPTO_DF80090A - select CRYPTO_RNG select HW_RANDOM help Xilinx Versal SoC driver provides kernel-side support for True Random Number diff --git a/drivers/crypto/xilinx/xilinx-trng.c b/drivers/crypto/xilinx/xilinx-trng.c index 43a4832f07e7d..a35643baa4899 100644 --- a/drivers/crypto/xilinx/xilinx-trng.c +++ b/drivers/crypto/xilinx/xilinx-trng.c @@ -6,7 +6,6 @@ #include #include -#include #include #include #include @@ -14,13 +13,11 @@ #include #include #include -#include #include #include #include #include #include -#include /* TRNG Registers Offsets */ #define TRNG_STATUS_OFFSET 0x4U @@ -60,16 +57,9 @@ struct xilinx_rng { struct device *dev; unsigned char *scratchpadbuf; struct aes_enckey *aeskey; - struct mutex lock; /* Protect access to TRNG device */ struct hwrng trng; }; -struct xilinx_rng_ctx { - struct xilinx_rng *rng; -}; - -static struct xilinx_rng *xilinx_rng_dev; - static void xtrng_readwrite32(void __iomem *addr, u32 mask, u8 value) { u32 val; @@ -245,47 +235,6 @@ static int xtrng_random_bytes_generate(struct xilinx_rng *rng, u8 *rand_buf_ptr, return nbytes; } -static int xtrng_trng_generate(struct crypto_rng *tfm, const u8 *src, u32 slen, - u8 *dst, u32 dlen) -{ - struct xilinx_rng_ctx *ctx = crypto_rng_ctx(tfm); - int ret; - - mutex_lock(&ctx->rng->lock); - ret = xtrng_random_bytes_generate(ctx->rng, dst, dlen, true); - mutex_unlock(&ctx->rng->lock); - - return ret < 0 ? ret : 0; -} - -static int xtrng_trng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) -{ - return 0; -} - -static int xtrng_trng_init(struct crypto_tfm *rtfm) -{ - struct xilinx_rng_ctx *ctx = crypto_tfm_ctx(rtfm); - - ctx->rng = xilinx_rng_dev; - - return 0; -} - -static struct rng_alg xtrng_trng_alg = { - .generate = xtrng_trng_generate, - .seed = xtrng_trng_seed, - .seedsize = 0, - .base = { - .cra_name = "stdrng", - .cra_driver_name = "xilinx-trng", - .cra_priority = 300, - .cra_ctxsize = sizeof(struct xilinx_rng_ctx), - .cra_module = THIS_MODULE, - .cra_init = xtrng_trng_init, - }, -}; - static int xtrng_hwrng_trng_read(struct hwrng *hwrng, void *data, size_t max, bool wait) { u8 buf[TRNG_SEC_STRENGTH_BYTES]; @@ -293,12 +242,6 @@ static int xtrng_hwrng_trng_read(struct hwrng *hwrng, void *data, size_t max, bo int ret = -EINVAL, i = 0; rng = container_of(hwrng, struct xilinx_rng, trng); - /* Return in case wait not set and lock not available. */ - if (!mutex_trylock(&rng->lock) && !wait) - return 0; - else if (!mutex_is_locked(&rng->lock) && wait) - mutex_lock(&rng->lock); - while (i < max) { ret = xtrng_random_bytes_generate(rng, buf, TRNG_SEC_STRENGTH_BYTES, wait); if (ret < 0) @@ -307,8 +250,6 @@ static int xtrng_hwrng_trng_read(struct hwrng *hwrng, void *data, size_t max, bo memcpy(data + i, buf, min_t(int, ret, (max - i))); i += min_t(int, ret, (max - i)); } - mutex_unlock(&rng->lock); - return ret; } @@ -354,40 +295,24 @@ static int xtrng_probe(struct platform_device *pdev) sb_size = crypto_drbg_ctr_df_datalen(TRNG_SEED_LEN_BYTES, AES_BLOCK_SIZE); rng->scratchpadbuf = devm_kzalloc(&pdev->dev, sb_size, GFP_KERNEL); - if (!rng->scratchpadbuf) { - ret = -ENOMEM; - goto end; - } + if (!rng->scratchpadbuf) + return -ENOMEM; xtrng_trng_reset(rng->rng_base); ret = xtrng_reseed_internal(rng); if (ret) { dev_err(&pdev->dev, "TRNG Seed fail\n"); - goto end; - } - - xilinx_rng_dev = rng; - mutex_init(&rng->lock); - ret = crypto_register_rng(&xtrng_trng_alg); - if (ret) { - dev_err(&pdev->dev, "Crypto Random device registration failed: %d\n", ret); - goto end; + return ret; } ret = xtrng_hwrng_register(&rng->trng); if (ret) { dev_err(&pdev->dev, "HWRNG device registration failed: %d\n", ret); - goto crypto_rng_free; + return ret; } platform_set_drvdata(pdev, rng); return 0; - -crypto_rng_free: - crypto_unregister_rng(&xtrng_trng_alg); - -end: - return ret; } static void xtrng_remove(struct platform_device *pdev) @@ -397,13 +322,11 @@ static void xtrng_remove(struct platform_device *pdev) rng = platform_get_drvdata(pdev); xtrng_hwrng_unregister(&rng->trng); - crypto_unregister_rng(&xtrng_trng_alg); xtrng_write_multiple_registers(rng->rng_base + TRNG_EXT_SEED_OFFSET, zero, TRNG_NUM_INIT_REGS); xtrng_write_multiple_registers(rng->rng_base + TRNG_PER_STRNG_OFFSET, zero, TRNG_NUM_INIT_REGS); xtrng_hold_reset(rng->rng_base); - xilinx_rng_dev = NULL; } static const struct of_device_id xtrng_of_match[] = {