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 0CF991FDE14; Wed, 5 Feb 2025 14:41:43 +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=1738766504; cv=none; b=gjGiY3GJCq5seMIUJ7GbvpZGbzxxoTEFBT5bfIjRPDupHIUIoOcqe8mn5b9K5Hufa+/nBo3w3Zwe7SKXn5P0FlKhSvF9ZI8Xza9w0g4diPmec31/wcMs3a0jQroQxcpGjXKDKr/XqIa3b0FIZ0QSFmzT7KBRVFS/3YqpV0Bu78g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766504; c=relaxed/simple; bh=OKSLxRZYrKlzFz+AAMcS3v+ZH4y5Mk9lBX7tRFniT+g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=atrd6WzdfSjd5EkoLBSnBo0SjC2804BMNKnHB5A7XhgA3mUI4YX2Ks9PxqrA4mFS32UIWDuNIGNi1Z0TfGyNVAQCipFsZMpxxQwSn30jDQFZugCZX2EkkW9i54AjNDb6S0FQJpihFa7dIjo3d5Cij5KaoBkEK3yF4+JCmUIRk3g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ywtx6uW0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ywtx6uW0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 54585C4CEDD; Wed, 5 Feb 2025 14:41:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1738766503; bh=OKSLxRZYrKlzFz+AAMcS3v+ZH4y5Mk9lBX7tRFniT+g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ywtx6uW0V0/b/9yyw3aNiPlt4KZddQShDbCA+BqvK1LoOHVp4SzQ76/uUvjaFTAvt wqk9xrDDZ6t3reSKkAxIptVxh9vsCPO2u2H7e11j6uCq2THGFAlTpnJHMb1oJ0/ryE M2Wqa6yAQGj11zqxz9ojOh/7jFLSV2CcVlXB85lE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, kernel test robot , Pei Xiao , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.13 282/623] bpf: Use refcount_t instead of atomic_t for mmap_count Date: Wed, 5 Feb 2025 14:40:24 +0100 Message-ID: <20250205134507.019607953@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250205134456.221272033@linuxfoundation.org> References: <20250205134456.221272033@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pei Xiao [ Upstream commit dfa94ce54f4139c893b9c4ec17df6f7c6a7515d3 ] Use an API that resembles more the actual use of mmap_count. Found by cocci: kernel/bpf/arena.c:245:6-25: WARNING: atomic_dec_and_test variation before object free at line 249. Fixes: b90d77e5fd78 ("bpf: Fix remap of arena.") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202412292037.LXlYSHKl-lkp@intel.com/ Signed-off-by: Pei Xiao Link: https://lore.kernel.org/r/6ecce439a6bc81adb85d5080908ea8959b792a50.1735542814.git.xiaopei01@kylinos.cn Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/arena.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index 945a5680f6a54..8caf56a308d96 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -218,7 +218,7 @@ static u64 arena_map_mem_usage(const struct bpf_map *map) struct vma_list { struct vm_area_struct *vma; struct list_head head; - atomic_t mmap_count; + refcount_t mmap_count; }; static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma) @@ -228,7 +228,7 @@ static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma) vml = kmalloc(sizeof(*vml), GFP_KERNEL); if (!vml) return -ENOMEM; - atomic_set(&vml->mmap_count, 1); + refcount_set(&vml->mmap_count, 1); vma->vm_private_data = vml; vml->vma = vma; list_add(&vml->head, &arena->vma_list); @@ -239,7 +239,7 @@ static void arena_vm_open(struct vm_area_struct *vma) { struct vma_list *vml = vma->vm_private_data; - atomic_inc(&vml->mmap_count); + refcount_inc(&vml->mmap_count); } static void arena_vm_close(struct vm_area_struct *vma) @@ -248,7 +248,7 @@ static void arena_vm_close(struct vm_area_struct *vma) struct bpf_arena *arena = container_of(map, struct bpf_arena, map); struct vma_list *vml = vma->vm_private_data; - if (!atomic_dec_and_test(&vml->mmap_count)) + if (!refcount_dec_and_test(&vml->mmap_count)) return; guard(mutex)(&arena->lock); /* update link list under lock */ -- 2.39.5