From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 6F50B3FD131; Mon, 11 May 2026 17:30:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778520657; cv=none; b=oqOq/F3DZn0DnSuqwbvImcQLiaeYSHgtsoM2E47wdvOygzQniOyawWXI6Ir45b1yPAchv99NKixyCdKTHCMCSTRJvZEGITodCJFgISNP/YC4t/HdXWhMfsGjD1tC+CUvR7D+74mmJXhDfB8wqkuZGceCSkckZj3GoaP2F90nOt4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778520657; c=relaxed/simple; bh=Z5tnKsqQw7EiBeSDr2ywtUGax4C0M+Mxkthf6nfbtWw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Cv750ScBUK+71UQL1coRQ622hWFPS4gYI349OWdthYxtMfmzNhUiSlJ6JKz+XHFWd7rUujCKyAvtHpYWx2T6ppthpkX+JMNiH+58IVGXi1Yxg98Vk7RCHuSZ/3pjfKuNGBpHCFpSyUh6d216kzmZz/D8TZYKgQ8EJTg+yGwhiyE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=hE4ZFYc/; arc=none smtp.client-ip=198.175.65.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="hE4ZFYc/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1778520655; x=1810056655; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Z5tnKsqQw7EiBeSDr2ywtUGax4C0M+Mxkthf6nfbtWw=; b=hE4ZFYc/2/nB0/Y+xi27khGjg96mQK1WGrvduCh+zcRdasiKIJGF/ZLk ppc9Quq/yAidwJkXtWU1g/MpnXxWAspoEk7f8GPP/eI//s5LaEs8bd2EP DXoBPg82KaxfDoIhb1HKPfdxpRXc97eZWQxHJgJSBePWAlURix2jltFTa PCd5n4oebSyT/bR9KiSPpPXz+QuUlnUMyqhtFCDeheLEmvR7shhLzgaKJ S8eZGePWsFKtXr3T3WfR0LcDzK+QOmGuDaJBk9ql/pPZLK2ED70C9kHji RrpLs2rKpEjmSJ7sglvx764sYZCRAUSNAnicqH2EGn9I8iFCUp5A4gK76 w==; X-CSE-ConnectionGUID: lzDWTOeLQw2U91JTJuLDrQ== X-CSE-MsgGUID: iXZh2kymReGM5jjDpkLnPQ== X-IronPort-AV: E=McAfee;i="6800,10657,11783"; a="79314118" X-IronPort-AV: E=Sophos;i="6.23,229,1770624000"; d="scan'208";a="79314118" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2026 10:30:45 -0700 X-CSE-ConnectionGUID: cQZX9EhnR/iT6c7D0YB+FQ== X-CSE-MsgGUID: RVLexnFOSyCbdPBgRcYhSg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,229,1770624000"; d="scan'208";a="261000339" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO fedora) ([10.245.244.248]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2026 10:30:39 -0700 From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= To: intel-xe@lists.freedesktop.org Cc: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Sashiko-bot , Friedrich Vock , Maarten Lankhorst , Tejun Heo , Maxime Ripard , =?UTF-8?q?Christian=20K=C3=B6nig?= , Alex Deucher , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, stable@vger.kernel.org, Natalie Vock , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , cgroups@vger.kernel.org, Huang Rui , Matthew Brost , Matthew Auld , Maarten Lankhorst , Thomas Zimmermann , Simona Vetter , David Airlie , Rodrigo Vivi , linux-kernel@vger.kernel.org Subject: [PATCH v3 1/5] drm/amdgpu: Fix init ordering in amdgpu_vram_mgr_init() Date: Mon, 11 May 2026 19:30:04 +0200 Message-ID: <20260511173008.36526-2-thomas.hellstrom@linux.intel.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260511173008.36526-1-thomas.hellstrom@linux.intel.com> References: <20260511173008.36526-1-thomas.hellstrom@linux.intel.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit drmm_cgroup_register_region() is called before INIT_LIST_HEAD() and gpu_buddy_init() in amdgpu_vram_mgr_init(). If it fails, the function returns early and bypasses those initializations. Since adev->mman.initialized is set to true before amdgpu_vram_mgr_init() is called, a failure triggers amdgpu_ttm_fini(), which calls amdgpu_vram_mgr_fini(), which then: - Calls list_for_each_entry_safe() on reservations_pending and reserved_pages, whose list_head::next pointers are zero-initialized (NULL). The loop does not recognize them as empty and dereferences NULL. - Calls gpu_buddy_fini(), which iterates free_trees[] unconditionally via for_each_free_tree(). Since mm->free_trees is NULL (never allocated), this dereferences NULL. Both result in a kernel panic on the module load error path. Fix by moving drmm_cgroup_register_region() to after the list and buddy allocator are fully initialized, so the teardown path is safe to run. Reported-by: Sashiko-bot Closes: https://sashiko.dev/#/patchset/20260428073116.15687-1-thomas.hellstrom@linux.intel.com?part=4 Fixes: 2b624a2c1865 ("drm/ttm: Handle cgroup based eviction in TTM") Cc: Friedrich Vock Cc: Maarten Lankhorst Cc: Tejun Heo Cc: Maxime Ripard Cc: Christian König Cc: Alex Deucher Cc: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: # v6.14+ Assisted-by: GitHub_Copilot:claude-sonnet-4.6 Signed-off-by: Thomas Hellström --- drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c index 2a241a5b12c4..ac3f71d77140 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -918,9 +918,6 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev) struct ttm_resource_manager *man = &mgr->manager; int err; - man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram", adev->gmc.real_vram_size); - if (IS_ERR(man->cg)) - return PTR_ERR(man->cg); ttm_resource_manager_init(man, &adev->mman.bdev, adev->gmc.real_vram_size); @@ -935,6 +932,10 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev) if (err) return err; + man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram", adev->gmc.real_vram_size); + if (IS_ERR(man->cg)) + return PTR_ERR(man->cg); + ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager); ttm_resource_manager_set_used(man, true); return 0; -- 2.54.0