diff options
Diffstat (limited to 'meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/fvp-base/0001-virtio-rng-Workaround-for-FVP-returning-zero-size-bu.patch')
| -rw-r--r-- | meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/fvp-base/0001-virtio-rng-Workaround-for-FVP-returning-zero-size-bu.patch | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/fvp-base/0001-virtio-rng-Workaround-for-FVP-returning-zero-size-bu.patch b/meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/fvp-base/0001-virtio-rng-Workaround-for-FVP-returning-zero-size-bu.patch new file mode 100644 index 0000000000..689361d1d3 --- /dev/null +++ b/meta-arm/meta-arm-bsp/recipes-bsp/u-boot/u-boot/fvp-base/0001-virtio-rng-Workaround-for-FVP-returning-zero-size-bu.patch @@ -0,0 +1,49 @@ +From 3ab73b453016d91b9f942a7c12173854135530a4 Mon Sep 17 00:00:00 2001 +From: Peter Hoyes <Peter.Hoyes@arm.com> +Date: Wed, 23 Aug 2023 21:17:17 +0100 +Subject: [PATCH] virtio: rng: Workaround for FVP returning zero-size buffer + +The FVP virtio-rng device is observed to always 8 fewer bytes of random +data than requested. When 8 of fewer bytes are requested, the FVP +returns 0 bytes. This causes U-Boot to hang upon attempting to fill the +last 8 bytes of the input buffer. + +The virtio spec states than entropy devices must always return at least +1 byte of random data. + +To workaround this, always request exactly 16 bytes from the virtio +device, discarding any unused data. + +Upstream-Status: Inappropriate [Temporary workaround] +Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com> +--- + drivers/virtio/virtio_rng.c | 6 +++--- + 1 file changed, 3 insertions(+), 3 deletions(-) + +diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c +index b85545c2ee5..1e4fc342406 100644 +--- a/drivers/virtio/virtio_rng.c ++++ b/drivers/virtio/virtio_rng.c +@@ -29,7 +29,7 @@ static int virtio_rng_read(struct udevice *dev, void *data, size_t len) + + while (len) { + sg.addr = buf; +- sg.length = min(len, sizeof(buf)); ++ sg.length = sizeof(buf); + sgs[0] = &sg; + + ret = virtqueue_add(priv->rng_vq, sgs, 0, 1); +@@ -44,8 +44,8 @@ static int virtio_rng_read(struct udevice *dev, void *data, size_t len) + if (rsize > sg.length) + return -EIO; + +- memcpy(ptr, buf, rsize); +- len -= rsize; ++ memcpy(ptr, buf, min(len, (size_t)rsize)); ++ len -= min(len, (size_t)rsize); + ptr += rsize; + } + +-- +2.34.1 + |