Merge tag 'drm-fixes-2024-03-30' of https://gitlab.freedesktop.org/drm/kernel

Pull drm fixes from Dave Airlie:
 "Regular fixes for rc2, quite a few i915/amdgpu as usual, some xe, and
  then mostly scattered around. rc3 might be quieter with the holidays
  but we shall see.

  bridge:
   - select DRM_KMS_HELPER

  dma-buf:
   - fix NULL-pointer deref

  dp:
   - fix div-by-zero in DP MST unplug code

  fbdev:
   - select FB_IOMEM_FOPS for SBus

  sched:
   - fix NULL-pointer deref

  xe:
   - Fix build on mips
   - Fix wrong bound checks
   - Fix use of msec rather than jiffies
   - Remove dead code

  amdgpu:
   - SMU 14.0.1 updates
   - DCN 3.5.x updates
   - VPE fix
   - eDP panel flickering fix
   - Suspend fix
   - PSR fix
   - DCN 3.0+ fix
   - VCN 4.0.6 updates
   - debugfs fix

  amdkfd:
   - DMA-Buf fix
   - GFX 9.4.2 TLB flush fix
   - CP interrupt fix

  i915:
   - Fix for BUG_ON/BUILD_BUG_ON IN I915_memcpy.c
   - Update a MTL workaround
   - Fix locking inversion in hwmon's sysfs
   - Remove a bogus error message around PXP
   - Fix UAF on VMA
   - Reset queue_priority_hint on parking
   - Display Fixes:
   - Remove duplicated audio enable/disable on SDVO and DP
   - Disable AuxCCS for Xe driver
   - Revert init order of MIPI DSI
   - DRRS debugfs fix with an extra refactor patch
   - VRR related fixes
   - Fix a JSL eDP corruption
   - Fix the cursor physical dma address
   - BIOS VBT related fix

  nouveau:
   - dmem: handle kcalloc() allocation failures

  qxl:
   - remove unused variables

  rockchip:
   - vop2: remove support for AR30 and AB30 formats

  vmwgfx:
   - debugfs: create ttm_resource_manager entry only if needed"

* tag 'drm-fixes-2024-03-30' of https://gitlab.freedesktop.org/drm/kernel: (55 commits)
  drm/i915/bios: Tolerate devdata==NULL in intel_bios_encoder_supports_dp_dual_mode()
  drm/i915: Pre-populate the cursor physical dma address
  drm/i915/gt: Reset queue_priority_hint on parking
  drm/i915/vma: Fix UAF on destroy against retire race
  drm/i915: Do not print 'pxp init failed with 0' when it succeed
  drm/i915: Do not match JSL in ehl_combo_pll_div_frac_wa_needed()
  drm/i915/hwmon: Fix locking inversion in sysfs getter
  drm/i915/dsb: Fix DSB vblank waits when using VRR
  drm/i915/vrr: Generate VRR "safe window" for DSB
  drm/i915/display/debugfs: Fix duplicate checks in i915_drrs_status
  drm/i915/drrs: Refactor CPU transcoder DRRS check
  drm/i915/mtl: Update workaround 14018575942
  drm/i915/dsi: Go back to the previous INIT_OTP/DISPLAY_ON order, mostly
  drm/i915/display: Disable AuxCCS framebuffers if built for Xe
  drm/i915: Stop doing double audio enable/disable on SDVO and g4x+ DP
  drm/i915: Add includes for BUG_ON/BUILD_BUG_ON in i915_memcpy.c
  drm/qxl: remove unused variable from `qxl_process_single_command()`
  drm/qxl: remove unused `count` variable from `qxl_surface_id_alloc()`
  drm/i915: add bug.h include to i915_memcpy.c
  drm/vmwgfx: Create debugfs ttm_resource_manager entry only if needed
  ...

1 files changed, 29 insertions, 17 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 5505d646f43a..06f0a6534a94 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -524,46 +524,58 @@ static ssize_t amdgpu_debugfs_mqd_read(struct file *f, char __user *buf,
 {
 	struct amdgpu_ring *ring = file_inode(f)->i_private;
 	volatile u32 *mqd;
-	int r;
+	u32 *kbuf;
+	int r, i;
 	uint32_t value, result;
 
 	if (*pos & 3 || size & 3)
 		return -EINVAL;
 
-	result = 0;
+	kbuf = kmalloc(ring->mqd_size, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
 
 	r = amdgpu_bo_reserve(ring->mqd_obj, false);
 	if (unlikely(r != 0))
-		return r;
+		goto err_free;
 
 	r = amdgpu_bo_kmap(ring->mqd_obj, (void **)&mqd);
-	if (r) {
-		amdgpu_bo_unreserve(ring->mqd_obj);
-		return r;
-	}
+	if (r)
+		goto err_unreserve;
 
+	/*
+	 * Copy to local buffer to avoid put_user(), which might fault
+	 * and acquire mmap_sem, under reservation_ww_class_mutex.
+	 */
+	for (i = 0; i < ring->mqd_size/sizeof(u32); i++)
+		kbuf[i] = mqd[i];
+
+	amdgpu_bo_kunmap(ring->mqd_obj);
+	amdgpu_bo_unreserve(ring->mqd_obj);
+
+	result = 0;
 	while (size) {
 		if (*pos >= ring->mqd_size)
-			goto done;
+			break;
 
-		value = mqd[*pos/4];
+		value = kbuf[*pos/4];
 		r = put_user(value, (uint32_t *)buf);
 		if (r)
-			goto done;
+			goto err_free;
 		buf += 4;
 		result += 4;
 		size -= 4;
 		*pos += 4;
 	}
 
-done:
-	amdgpu_bo_kunmap(ring->mqd_obj);
-	mqd = NULL;
-	amdgpu_bo_unreserve(ring->mqd_obj);
-	if (r)
-		return r;
-
+	kfree(kbuf);
 	return result;
+
+err_unreserve:
+	amdgpu_bo_unreserve(ring->mqd_obj);
+err_free:
+	kfree(kbuf);
+	return r;
 }
 
 static const struct file_operations amdgpu_debugfs_mqd_fops = {