From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 4539A41B346 for ; Wed, 29 Apr 2026 18:20:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486803; cv=none; b=NwLiBtSeJcZ/HuNlT1SEj2vKS1b79qCRxaBYjdk/ArY1mww87uzWk6WWZvMDgyYEPChTPMx+0vaYZumcA4KsUOM9HpC7Tx6S+WjMAvwH1SewPQ0KTUw677y65+LF6u5S2rDTJuxlIcdw7kbS7mugCy4zMpYXSHplvdZbVZj0pQk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486803; c=relaxed/simple; bh=+sJGsZ4/2gGZtmGKtRdP26CBc6vMMZiB8DZRyd6JjHk=; h=Subject:To:Cc:From:Date:References:In-Reply-To:Message-Id; b=jNABVH8nX6KwxY6oAxr7Tznxu/QFizRsshgkRN8U+7/7v7slLNpcac6IRH/wAc07VZ9os7/d9iKJ00ADNgTc5uAgVFWgRbc+EfQaGlNNBg1Yn+WMtWpUlJ/ivfIVxtiCxwOpg9EPj7ioYtXy6kVuGbz6Svhw/7UbqEyUD5NZH0E= 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=MfCgKhyv; arc=none smtp.client-ip=192.198.163.8 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="MfCgKhyv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777486802; x=1809022802; h=subject:to:cc:from:date:references:in-reply-to: message-id; bh=+sJGsZ4/2gGZtmGKtRdP26CBc6vMMZiB8DZRyd6JjHk=; b=MfCgKhyvwe4nNSaeYKB/PpYVz6YvHnN8tsTkUJ9W8Ntjr4+PUREKko+Y yPAV4/DgLkKIwQy1ftM6I/PjpBCblSc+sLrDHxY78Rg+gv5NGJ9+GwfrB P0bkcuYYVWAKCQnYVwY1Vbn0/XNtQpXjtyqkBW3SupZEuXs+wh0weF1NQ maFjPrglWvmqilj7pEXwOol59k7UbPfBNJsFt9pbztkDCe7FyqNqo7XZ/ mx1O0/FMeWEi7hGP4mQlLzPq1ZorMkCC0uC/SqgZZzDzvLZcJ7pbZCxDu /YSHY7/B1P3ZDF98ZviVGLzyxQfsFGPW6h1Yz4jEAZ5TuheXCqyGFM1aM g==; X-CSE-ConnectionGUID: Ewx7aZOxSuG0yTf2bPvubQ== X-CSE-MsgGUID: slSN5/JaRA6Tm4swWB+kHg== X-IronPort-AV: E=McAfee;i="6800,10657,11771"; a="95990120" X-IronPort-AV: E=Sophos;i="6.23,206,1770624000"; d="scan'208";a="95990120" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2026 11:20:01 -0700 X-CSE-ConnectionGUID: gncUGFtqT9GLDg0YFldOQA== X-CSE-MsgGUID: 9ZVGbQVnSfWkW5U9dFOILg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,206,1770624000"; d="scan'208";a="239336412" Received: from davehans-spike.ostc.intel.com (HELO localhost.localdomain) ([10.165.164.11]) by fmviesa005.fm.intel.com with ESMTP; 29 Apr 2026 11:20:01 -0700 Subject: [PATCH 4/6] binder: Remove mmap_lock fallback To: linux-kernel@vger.kernel.org Cc: Dave Hansen , Andrew Morton , "Liam R. Howlett" , linux-mm@kvack.org, Lorenzo Stoakes , Shakeel Butt , Suren Baghdasaryan , Vlastimil Babka From: Dave Hansen Date: Wed, 29 Apr 2026 11:20:00 -0700 References: <20260429181954.F50224AE@davehans-spike.ostc.intel.com> In-Reply-To: <20260429181954.F50224AE@davehans-spike.ostc.intel.com> Message-Id: <20260429182000.93887DFB@davehans-spike.ostc.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: From: Dave Hansen Previously, the per-VMA locking could fail in the face of writers which necessitate a fallback to mmap_lock. The new lock_vma_under_rcu_wait() will wait for writers instead of failing. Use the new helper. Wait for writers. Remove the fallback to mmap_lock. Signed-off-by: Dave Hansen Cc: Suren Baghdasaryan Cc: Andrew Morton Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: Vlastimil Babka Cc: Shakeel Butt Cc: linux-mm@kvack.org --- b/drivers/android/binder_alloc.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff -puN drivers/android/binder_alloc.c~binder-vma-waiter drivers/android/binder_alloc.c --- a/drivers/android/binder_alloc.c~binder-vma-waiter 2026-04-29 11:18:51.307654829 -0700 +++ b/drivers/android/binder_alloc.c 2026-04-29 11:18:51.310654944 -0700 @@ -259,21 +259,14 @@ static int binder_page_insert(struct bin struct vm_area_struct *vma; int ret = -ESRCH; - /* attempt per-vma lock first */ - vma = lock_vma_under_rcu(mm, addr); - if (vma) { - if (binder_alloc_is_mapped(alloc)) - ret = vm_insert_page(vma, addr, page); - vma_end_read(vma); + vma = lock_vma_under_rcu_wait(mm, addr); + if (!vma) return ret; - } - /* fall back to mmap_lock */ - mmap_read_lock(mm); - vma = vma_lookup(mm, addr); - if (vma && binder_alloc_is_mapped(alloc)) + if (binder_alloc_is_mapped(alloc)) ret = vm_insert_page(vma, addr, page); - mmap_read_unlock(mm); + + vma_end_read(vma); return ret; } _