From 3eb1a3a04056ba3df3205e169b8acc9da0c65a94 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 7 Jun 2023 01:41:22 -0500 Subject: drm/amd: Make sure image is written to trigger VBIOS image update flow The VBIOS image update flow requires userspace to: 1) Write the image to `psp_vbflash` 2) Read `psp_vbflash` 3) Poll `psp_vbflash_status` to check for completion If userspace reads `psp_vbflash` before writing an image, it's possible that it causes problems that can put the dGPU into an invalid state. Explicitly check that an image has been written before letting a read succeed. Cc: stable@vger.kernel.org Fixes: 8424f2ccb3c0 ("drm/amdgpu/psp: Add vbflash sysfs interface support") Reviewed-by: Alex Deucher Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c') diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c index 9d7e6e0e73ed..cf2ffe6fe4a2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c @@ -3548,6 +3548,9 @@ static ssize_t amdgpu_psp_vbflash_read(struct file *filp, struct kobject *kobj, void *fw_pri_cpu_addr; int ret; + if (adev->psp.vbflash_image_size == 0) + return -EINVAL; + dev_info(adev->dev, "VBIOS flash to PSP started"); ret = amdgpu_bo_create_kernel(adev, adev->psp.vbflash_image_size, -- cgit v1.2.3 From 7ab1a4913d0051cf5196ef7987b5fa42c25e13b6 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 7 Jun 2023 01:45:20 -0500 Subject: drm/amd: Tighten permissions on VBIOS flashing attributes Non-root users shouldn't be able to try to trigger a VBIOS flash or query the flashing status. This should be reserved for users with the appropriate permissions. Cc: stable@vger.kernel.org Fixes: 8424f2ccb3c0 ("drm/amdgpu/psp: Add vbflash sysfs interface support") Reviewed-by: Alex Deucher Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c') diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c index cf2ffe6fe4a2..a150b7a4b4aa 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c @@ -3602,13 +3602,13 @@ static ssize_t amdgpu_psp_vbflash_status(struct device *dev, } static const struct bin_attribute psp_vbflash_bin_attr = { - .attr = {.name = "psp_vbflash", .mode = 0664}, + .attr = {.name = "psp_vbflash", .mode = 0660}, .size = 0, .write = amdgpu_psp_vbflash_write, .read = amdgpu_psp_vbflash_read, }; -static DEVICE_ATTR(psp_vbflash_status, 0444, amdgpu_psp_vbflash_status, NULL); +static DEVICE_ATTR(psp_vbflash_status, 0440, amdgpu_psp_vbflash_status, NULL); int amdgpu_psp_sysfs_init(struct amdgpu_device *adev) { -- cgit v1.2.3