From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07373224AF9; Thu, 3 Apr 2025 19:17:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743707881; cv=none; b=GVEFWXwZXAF2I8cPhU+vgzaAOvt/UbGL/UgqWH9pOzxqzOuJDHWBWh2v2hBEBFw2LtsOmdVbhw9HrBPGtINARLHdQ/a50HzyMKCZeUoL0Tnc/WRZRl/TW9ItZxK3/vYwd1vz7p6lAFWZcb3vteSwM7fJg/GegP0kGdm/dNLCxPg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743707881; c=relaxed/simple; bh=X4xFh0c3hoeQlHdQxeeQPYkoirMgwJJycyh1alAO5As=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hmMAagbWXnUDIrZKKJuGFVF3tmupcy12fHmR9hK+ueMXdZiHwfT3EoC2kNJ5jgh2AUy8Y1wQAmMer+gJIyocA8nkjyuEq9kCrzE16kcsOHw2N6a4OGgBRdU4a98ErADsIF/6tOvUlKOPlJ1ie2aZG1UmmQhGvgMAzmplWcmDOGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d8hokcfl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d8hokcfl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36B22C4CEE9; Thu, 3 Apr 2025 19:17:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743707879; bh=X4xFh0c3hoeQlHdQxeeQPYkoirMgwJJycyh1alAO5As=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d8hokcflZtluLoGVzTZN5qV0Vr62iStR7cGeDDXNI4X7hq+W7SFdFBCY03re1Z+on BS2MvvsEsgQugAmm5YYMNG8bEq/H82S28inabrK+PaMDCaLnVgyxJemJlGkJrhOV6H tLxC8BBXXy3yHYf2VaYwdmKo2u6uAF6pznl1B4HvaiYsKRJBdmdaqgwBCyubpQROJY NKsxsXOO94mkXLitO3dNvEM0UK0iAN3heThfS/aVVwq6dexzahEVL/ZrEvYsO86+Wx Uq8QpTJ/N41dOb6RZUsvyuhAw6s3L+/N8sxd4ZlSDYdoacd3cIFdnUIpcGjQqR03tI Y/ENKVi1QIeVA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Emily Deng , Felix Kuehling , Alex Deucher , Sasha Levin , Felix.Kuehling@amd.com, christian.koenig@amd.com, airlied@gmail.com, simona@ffwll.ch, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.12 25/33] drm/amdgpu: Fix the race condition for draining retry fault Date: Thu, 3 Apr 2025 15:16:48 -0400 Message-Id: <20250403191656.2680995-25-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250403191656.2680995-1-sashal@kernel.org> References: <20250403191656.2680995-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.21 Content-Transfer-Encoding: 8bit From: Emily Deng [ Upstream commit f844732e3ad9c4b78df7436232949b8d2096d1a6 ] Issue: In the scenario where svm_range_restore_pages is called, but svm->checkpoint_ts has not been set and the retry fault has not been drained, svm_range_unmap_from_cpu is triggered and calls svm_range_free. Meanwhile, svm_range_restore_pages continues execution and reaches svm_range_from_addr. This results in a "failed to find prange..." error, causing the page recovery to fail. How to fix: Move the timestamp check code under the protection of svm->lock. v2: Make sure all right locks are released before go out. v3: Directly goto out_unlock_svms, and return -EAGAIN. v4: Refine code. Signed-off-by: Emily Deng Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 31 +++++++++++++++------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 8c61dee5ca0db..b50283864dcd2 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2992,19 +2992,6 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid, goto out; } - /* check if this page fault time stamp is before svms->checkpoint_ts */ - if (svms->checkpoint_ts[gpuidx] != 0) { - if (amdgpu_ih_ts_after(ts, svms->checkpoint_ts[gpuidx])) { - pr_debug("draining retry fault, drop fault 0x%llx\n", addr); - r = 0; - goto out; - } else - /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts - * to zero to avoid following ts wrap around give wrong comparing - */ - svms->checkpoint_ts[gpuidx] = 0; - } - if (!p->xnack_enabled) { pr_debug("XNACK not enabled for pasid 0x%x\n", pasid); r = -EFAULT; @@ -3024,6 +3011,21 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid, mmap_read_lock(mm); retry_write_locked: mutex_lock(&svms->lock); + + /* check if this page fault time stamp is before svms->checkpoint_ts */ + if (svms->checkpoint_ts[gpuidx] != 0) { + if (amdgpu_ih_ts_after(ts, svms->checkpoint_ts[gpuidx])) { + pr_debug("draining retry fault, drop fault 0x%llx\n", addr); + r = -EAGAIN; + goto out_unlock_svms; + } else { + /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts + * to zero to avoid following ts wrap around give wrong comparing + */ + svms->checkpoint_ts[gpuidx] = 0; + } + } + prange = svm_range_from_addr(svms, addr, NULL); if (!prange) { pr_debug("failed to find prange svms 0x%p address [0x%llx]\n", @@ -3148,7 +3150,8 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid, mutex_unlock(&svms->lock); mmap_read_unlock(mm); - svm_range_count_fault(node, p, gpuidx); + if (r != -EAGAIN) + svm_range_count_fault(node, p, gpuidx); mmput(mm); out: -- 2.39.5