From patchwork Fri Dec 13 19:34:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elizabeth Figura X-Patchwork-Id: 850603 Received: from mail.codeweavers.com (mail.codeweavers.com [4.36.192.163]) (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 03EE01F4729; Fri, 13 Dec 2024 19:35:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=4.36.192.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734118552; cv=none; b=M5I4t+B3Th3MOnoPW9COvdBvhrjBmzETpoVrODX3QorINLJntPJcgTGnctgEMejLCmwk1WEc6SugnQwAh5Geh5ZIAQjm99JbZ3r+Gv2SJP74NQ/9ED/F9H9fQIkLJGF8iiLjxm/VFAGlYO6036m3DerzMEFqSmoJZLlDgzsSVB4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734118552; c=relaxed/simple; bh=5h+5UjohCgzdnl9DSCo9wwirEU1Tt2y322Mj4DZbPQ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LZVeZgMCeZU4hbB+hB7AzmDpfDZ0wAyWQLxs/2xsFFjj9UT9oVZQymfgQia1CInFIkvlS3w3SVo8T61oVcAHMkqNuoAah5w95IEB/uO91bDbkPrLq83fz8naW3gdtDyS2l++6gE/0EzWFScImJto276/KVN/bOlmdPEpWvfEjbQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeweavers.com; spf=pass smtp.mailfrom=codeweavers.com; dkim=pass (2048-bit key) header.d=codeweavers.com header.i=@codeweavers.com header.b=V5lYtcAf; arc=none smtp.client-ip=4.36.192.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeweavers.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codeweavers.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=codeweavers.com header.i=@codeweavers.com header.b="V5lYtcAf" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=codeweavers.com; s=s1; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=rOOqXVw4GjnuvQPRYC3b5xDammu80OMek3a+hWg9yIE=; b=V5lYtcAfK2KRhY0v0tl8eKRNTf IWekpePwmseIvE+Es3eTBch5zdkTahOjpkkiPapRe7E2dCIN1pnxrKLhfPChPScJ7sT4UDyXCV+2p GTv+V7J1SfS7GIsmKssh+m4SVLdZTLku/0/9/rbiT6M42ynTLTz2q0ZhF84bgY88F+3n1lsFhUkZl xrQ1NKISvBgRO6ja1+VnC/m7TszV9M6wkTMxWo4L48JBqkLBjXvbYKIJCwMzB/xs65ak9SE1dQkeH 1U9xrmCspOcVyuQze+NSDNK8Ch0Litkno414YHwbvRsouAgvYsgLxdO9+NyZyy3QP3FGUbQNGOF4I aoOxjuJQ==; Received: from cw137ip160.mn.codeweavers.com ([10.69.137.160] helo=camazotz.mn.codeweavers.com) by mail.codeweavers.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tMBRy-00ASsZ-10; Fri, 13 Dec 2024 13:35:46 -0600 From: Elizabeth Figura To: Arnd Bergmann , Greg Kroah-Hartman , Jonathan Corbet , Shuah Khan Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, wine-devel@winehq.org, =?utf-8?q?Andr=C3=A9_Almeida?= , Wolfram Sang , Arkadiusz Hiler , Peter Zijlstra , Andy Lutomirski , linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Randy Dunlap , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , Elizabeth Figura Subject: [PATCH v7 15/30] ntsync: Introduce alertable waits. Date: Fri, 13 Dec 2024 13:34:56 -0600 Message-ID: <20241213193511.457338-16-zfigura@codeweavers.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241213193511.457338-1-zfigura@codeweavers.com> References: <20241213193511.457338-1-zfigura@codeweavers.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 NT waits can optionally be made "alertable". This is a special channel for thread wakeup that is mildly similar to SIGIO. A thread has an internal single bit of "alerted" state, and if a thread is alerted while an alertable wait, the wait will return a special value, consume the "alerted" state, and will not consume any of its objects. Alerts are implemented using events; the user-space NT emulator is expected to create an internal ntsync event for each thread and pass that event to wait functions. Signed-off-by: Elizabeth Figura --- drivers/misc/ntsync.c | 70 ++++++++++++++++++++++++++++++++----- include/uapi/linux/ntsync.h | 3 +- 2 files changed, 63 insertions(+), 10 deletions(-) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 78dc405bb759..457ff28b789f 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -869,22 +869,29 @@ static int setup_wait(struct ntsync_device *dev, const struct ntsync_wait_args *args, bool all, struct ntsync_q **ret_q) { + int fds[NTSYNC_MAX_WAIT_COUNT + 1]; const __u32 count = args->count; - int fds[NTSYNC_MAX_WAIT_COUNT]; struct ntsync_q *q; + __u32 total_count; __u32 i, j; - if (args->pad[0] || args->pad[1] || (args->flags & ~NTSYNC_WAIT_REALTIME)) + if (args->pad || (args->flags & ~NTSYNC_WAIT_REALTIME)) return -EINVAL; if (args->count > NTSYNC_MAX_WAIT_COUNT) return -EINVAL; + total_count = count; + if (args->alert) + total_count++; + if (copy_from_user(fds, u64_to_user_ptr(args->objs), array_size(count, sizeof(*fds)))) return -EFAULT; + if (args->alert) + fds[count] = args->alert; - q = kmalloc(struct_size(q, entries, count), GFP_KERNEL); + q = kmalloc(struct_size(q, entries, total_count), GFP_KERNEL); if (!q) return -ENOMEM; q->task = current; @@ -894,7 +901,7 @@ static int setup_wait(struct ntsync_device *dev, q->ownerdead = false; q->count = count; - for (i = 0; i < count; i++) { + for (i = 0; i < total_count; i++) { struct ntsync_q_entry *entry = &q->entries[i]; struct ntsync_obj *obj = get_obj(dev, fds[i]); @@ -944,10 +951,10 @@ static void try_wake_any_obj(struct ntsync_obj *obj) static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) { struct ntsync_wait_args args; + __u32 i, total_count; struct ntsync_q *q; int signaled; bool all; - __u32 i; int ret; if (copy_from_user(&args, argp, sizeof(args))) @@ -957,9 +964,13 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) if (ret < 0) return ret; + total_count = args.count; + if (args.alert) + total_count++; + /* queue ourselves */ - for (i = 0; i < args.count; i++) { + for (i = 0; i < total_count; i++) { struct ntsync_q_entry *entry = &q->entries[i]; struct ntsync_obj *obj = entry->obj; @@ -968,9 +979,15 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) ntsync_unlock_obj(dev, obj, all); } - /* check if we are already signaled */ + /* + * Check if we are already signaled. + * + * Note that the API requires that normal objects are checked before + * the alert event. Hence we queue the alert event last, and check + * objects in order. + */ - for (i = 0; i < args.count; i++) { + for (i = 0; i < total_count; i++) { struct ntsync_obj *obj = q->entries[i].obj; if (atomic_read(&q->signaled) != -1) @@ -987,7 +1004,7 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) /* and finally, unqueue */ - for (i = 0; i < args.count; i++) { + for (i = 0; i < total_count; i++) { struct ntsync_q_entry *entry = &q->entries[i]; struct ntsync_obj *obj = entry->obj; @@ -1047,6 +1064,14 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) */ list_add_tail(&entry->node, &obj->all_waiters); } + if (args.alert) { + struct ntsync_q_entry *entry = &q->entries[args.count]; + struct ntsync_obj *obj = entry->obj; + + dev_lock_obj(dev, obj); + list_add_tail(&entry->node, &obj->any_waiters); + dev_unlock_obj(dev, obj); + } /* check if we are already signaled */ @@ -1054,6 +1079,21 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) mutex_unlock(&dev->wait_all_lock); + /* + * Check if the alert event is signaled, making sure to do so only + * after checking if the other objects are signaled. + */ + + if (args.alert) { + struct ntsync_obj *obj = q->entries[args.count].obj; + + if (atomic_read(&q->signaled) == -1) { + bool all = ntsync_lock_obj(dev, obj); + try_wake_any_obj(obj); + ntsync_unlock_obj(dev, obj, all); + } + } + /* sleep */ ret = ntsync_schedule(q, &args); @@ -1079,6 +1119,18 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) mutex_unlock(&dev->wait_all_lock); + if (args.alert) { + struct ntsync_q_entry *entry = &q->entries[args.count]; + struct ntsync_obj *obj = entry->obj; + bool all; + + all = ntsync_lock_obj(dev, obj); + list_del(&entry->node); + ntsync_unlock_obj(dev, obj, all); + + put_obj(obj); + } + signaled = atomic_read(&q->signaled); if (signaled != -1) { struct ntsync_wait_args __user *user_args = argp; diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index b9d208a8c00f..6d06793512b1 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -34,7 +34,8 @@ struct ntsync_wait_args { __u32 index; __u32 flags; __u32 owner; - __u32 pad[2]; + __u32 alert; + __u32 pad; }; #define NTSYNC_MAX_WAIT_COUNT 64