From: Bart Van Assche <bvanassche@acm.org>
Date: Fri, 27 Feb 2026 16:55:01 +0000 (-0800)
Subject: dma-buf: Suppress a thread-safety complaint
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=01086b97dcc92799bd03cd243ed6061fd21db7a6;p=thirdparty%2Fkernel%2Flinux.git

dma-buf: Suppress a thread-safety complaint

Handle all possible dma_resv_lock() return values. This patch prepares
for enabling compile-time thread-safety analysis. This will cause the
compiler to check whether all dma_resv_lock() return values are handled.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20260227165501.2062829-1-bvanassche@acm.org
---

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index bea3e9858aca5..ce9e6c04897ff 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -790,8 +790,11 @@ static int __init dma_resv_lockdep(void)
 	mmap_read_lock(mm);
 	ww_acquire_init(&ctx, &reservation_ww_class);
 	ret = dma_resv_lock(&obj, &ctx);
-	if (ret == -EDEADLK)
+	if (ret) {
+		/* Only EDEADLK from the error injection is possible here */
+		WARN_ON(ret != -EDEADLK);
 		dma_resv_lock_slow(&obj, &ctx);
+	}
 	fs_reclaim_acquire(GFP_KERNEL);
 	/* for unmap_mapping_range on trylocked buffer objects in shrinkers */
 	i_mmap_lock_write(&mapping);