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 C199E21D00D; Mon, 7 Apr 2025 19:25:53 +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=1744053953; cv=none; b=kAeH77UsQKoUOdnsVUlGPHuhDhHOKFZ6+OXwvJkCp4NQq+P+ISHhSow863tutSe18uYxQ3looEKPy46RNhqLbmS0HuDAnqfsAI0G0GiDjkPIEs/103PgWmacBKhCfX/Wun/+VSZipVfCwa3vTwAEFOsymXwNHtH8L+gPO9OLzVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744053953; c=relaxed/simple; bh=lCrDHc8UyV2gK3U9FDLItNUPzr/DmcFHZkzvakgFphw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Dw+jgu4U3s+5czKCra6XS9i7Ex7+9/or5AA80SCLHfIJaTtAsqtftuLS7g0irJZt5Qt1yYTdEifbrwZA+FdezzbSoaaF0zgnp/u4jtK2YdEQZM0x6LyqbPcECYelxch67yuK4TgMrQJoZ5tdCdDQT7xx2RuPE2y+NyEERmcEzPM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DB8CWYxQ; 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="DB8CWYxQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29CDDC4CEDD; Mon, 7 Apr 2025 19:25:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744053953; bh=lCrDHc8UyV2gK3U9FDLItNUPzr/DmcFHZkzvakgFphw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DB8CWYxQrmtcIVB/CFdNFSaBdScqNnjYgWr3xTAjDEdRcfNAIP+ThOl/ObYpo3G8c zjc669wPFW2B3eW2s42QUijDjGBUpZzGGEVMtcfqetJvG1ywHBkYc7h/RlBsF6l8bQ kvNkaXliBrfMxRUhR63rQzc7SexCwcd4ANfR0jDmCERSpP+N5LWzfhKUyP1cZzAz64 QMHojQbzkS244JlyBi7OfQAm7TWSrf2DlJOu72oETaWII8eLoYgoCs/sAZ7bBjoZVz ryhdljLx0iHReMb550o2HmXzN26wKl6GZwt5KwDIusJFWnFMDYd9mxzEk9iftr5wPY z8SSRuGl9GaJQ== Date: Mon, 7 Apr 2025 12:25:50 -0700 From: Kees Cook To: "Gustavo A. R. Silva" Cc: Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] drm/nouveau: svm: Avoid -Wflex-array-member-not-at-end warning Message-ID: <202504071225.6AB490E7@keescook> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Apr 02, 2025 at 03:39:07PM -0600, Gustavo A. R. Silva wrote: > -Wflex-array-member-not-at-end was introduced in GCC-14, and we are > getting ready to enable it, globally. > > Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of > a flexible structure where the size of the flexible-array member > is known at compile-time, and refactor the rest of the code, > accordingly. > > So, with these changes, fix the following warning: > > drivers/gpu/drm/nouveau/nouveau_svm.c:724:44: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/gpu/drm/nouveau/nouveau_svm.c | 39 +++++++++++++-------------- > 1 file changed, 18 insertions(+), 21 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c > index e12e2596ed84..6fa387da0637 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_svm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c > @@ -720,10 +720,7 @@ nouveau_svm_fault(struct work_struct *work) > struct nouveau_svm *svm = container_of(buffer, typeof(*svm), buffer[buffer->id]); > struct nvif_object *device = &svm->drm->client.device.object; > struct nouveau_svmm *svmm; > - struct { > - struct nouveau_pfnmap_args i; > - u64 phys[1]; > - } args; > + DEFINE_RAW_FLEX(struct nouveau_pfnmap_args, args, p.phys, 1); > unsigned long hmm_flags; > u64 inst, start, limit; > int fi, fn; > @@ -772,11 +769,11 @@ nouveau_svm_fault(struct work_struct *work) > mutex_unlock(&svm->mutex); > > /* Process list of faults. */ > - args.i.i.version = 0; > - args.i.i.type = NVIF_IOCTL_V0_MTHD; > - args.i.m.version = 0; > - args.i.m.method = NVIF_VMM_V0_PFNMAP; > - args.i.p.version = 0; > + args->i.version = 0; > + args->i.type = NVIF_IOCTL_V0_MTHD; > + args->m.version = 0; > + args->m.method = NVIF_VMM_V0_PFNMAP; > + args->p.version = 0; > > for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) { > struct svm_notifier notifier; > @@ -802,9 +799,9 @@ nouveau_svm_fault(struct work_struct *work) > * fault window, determining required pages and access > * permissions based on pending faults. > */ > - args.i.p.addr = start; > - args.i.p.page = PAGE_SHIFT; > - args.i.p.size = PAGE_SIZE; > + args->p.addr = start; > + args->p.page = PAGE_SHIFT; > + args->p.size = PAGE_SIZE; > /* > * Determine required permissions based on GPU fault > * access flags. > @@ -832,16 +829,16 @@ nouveau_svm_fault(struct work_struct *work) > > notifier.svmm = svmm; > if (atomic) > - ret = nouveau_atomic_range_fault(svmm, svm->drm, > - &args.i, sizeof(args), > + ret = nouveau_atomic_range_fault(svmm, svm->drm, args, > + __struct_size(args), > ¬ifier); > else > - ret = nouveau_range_fault(svmm, svm->drm, &args.i, > - sizeof(args), hmm_flags, > - ¬ifier); > + ret = nouveau_range_fault(svmm, svm->drm, args, > + __struct_size(args), > + hmm_flags, ¬ifier); > mmput(mm); > > - limit = args.i.p.addr + args.i.p.size; > + limit = args->p.addr + args->p.size; > for (fn = fi; ++fn < buffer->fault_nr; ) { > /* It's okay to skip over duplicate addresses from the > * same SVMM as faults are ordered by access type such > @@ -855,14 +852,14 @@ nouveau_svm_fault(struct work_struct *work) > if (buffer->fault[fn]->svmm != svmm || > buffer->fault[fn]->addr >= limit || > (buffer->fault[fi]->access == FAULT_ACCESS_READ && > - !(args.phys[0] & NVIF_VMM_PFNMAP_V0_V)) || > + !(args->p.phys[0] & NVIF_VMM_PFNMAP_V0_V)) || > (buffer->fault[fi]->access != FAULT_ACCESS_READ && > buffer->fault[fi]->access != FAULT_ACCESS_PREFETCH && > - !(args.phys[0] & NVIF_VMM_PFNMAP_V0_W)) || > + !(args->p.phys[0] & NVIF_VMM_PFNMAP_V0_W)) || > (buffer->fault[fi]->access != FAULT_ACCESS_READ && > buffer->fault[fi]->access != FAULT_ACCESS_WRITE && > buffer->fault[fi]->access != FAULT_ACCESS_PREFETCH && > - !(args.phys[0] & NVIF_VMM_PFNMAP_V0_A))) > + !(args->p.phys[0] & NVIF_VMM_PFNMAP_V0_A))) > break; > } > LGTM, including the __struct_size() usage. Reviewed-by: Kees Cook -- Kees Cook