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 0E4A22D9EE5; Sat, 14 Jun 2025 13:49:03 +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=1749908943; cv=none; b=m3XCahc44k1rPJb5xuqf1+HgW2EYABKI3Ksrx/D+HgoszFoQlX7aTOGYuJOv6w3RWT3qC/utnrD7phfEhjZanWNA/NU8hk+7ezN8PtbFj5nmfmkVsAfsifv6Pq/LGeOLYA5iBpiDswvFukwOTUm5X9quy9KsZyCk205r/dqttBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749908943; c=relaxed/simple; bh=BUrldnQPJ42xUrag3Jg1xnpVhRl3Q67bMpKOc+Wgtbs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fkB6StdTLki959HlSXVChaFoPTgf8nFtfEgengSUoVLMon0plMQ2oA7t+rsGR5II4ZPxj0CXy1qTPu1zXiHk7sz5ZZFrKb2TwyhiCDUthRR56d4NHTKhl+TIYFHmRxdnCx865IA23/58PxtHmXQuOgmC7h0kVQoQMy5FDQmgPd4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CmZVLvre; 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="CmZVLvre" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40041C4CEF0; Sat, 14 Jun 2025 13:49:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749908942; bh=BUrldnQPJ42xUrag3Jg1xnpVhRl3Q67bMpKOc+Wgtbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CmZVLvreLZ7ZPfep9/dudxMmrWK4WXhVHYZNeVNro1rbdVt+FztARkn49hP8NU1Ri 7nKa+pBUDdJnOvnv40X48Y6ekIvf3YKIsMHz33MH5WwaU6x1yDLpB2DZLE1YQwuMsK 6RBAqXs72GojYZIAi3zn0/dPHQwihhKV6YNLVguSWEtsTxkb6HeJJkTvWaGQB8/Fdw ZuAedZweI+wuKXlVoDjB31p0TsbhIpaSZfFvDjVFy/TdsOfrfzi4YEkJyRmrc/Yxe+ dY/8QDClcThvtvs2UPB56W5Yijh7Tpy4j+I11lvAmjqDFgiEtqU+ceZdslMcpLj+3Q 1pF+Xc5M4XpSQ== From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: linux-api@vger.kernel.org, workflows@vger.kernel.org, tools@kernel.org, Sasha Levin Subject: [RFC 02/19] eventpoll: add API specification for epoll_create1 Date: Sat, 14 Jun 2025 09:48:41 -0400 Message-Id: <20250614134858.790460-3-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250614134858.790460-1-sashal@kernel.org> References: <20250614134858.790460-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add kernel API specification for the epoll_create1() system call. Signed-off-by: Sasha Levin --- fs/eventpoll.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index d4dbffdedd08e..8f8a64ebbaef6 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -2265,6 +2266,91 @@ static int do_epoll_create(int flags) return error; } + +/* Valid values for epoll_create1 flags parameter */ +static const s64 epoll_create1_valid_values[] = { 0, EPOLL_CLOEXEC }; + +DEFINE_KERNEL_API_SPEC(sys_epoll_create1) + KAPI_DESCRIPTION("Create an epoll instance") + KAPI_LONG_DESC("Creates a new epoll instance and returns a file descriptor " + "referring to that instance. The file descriptor is used for all " + "subsequent calls to the epoll interface.") + KAPI_CONTEXT(KAPI_CTX_PROCESS | KAPI_CTX_SLEEPABLE) + + KAPI_PARAM(0, "flags", "int", "Creation flags for the epoll instance") + KAPI_PARAM_FLAGS(KAPI_PARAM_IN) + .constraint_type = KAPI_CONSTRAINT_ENUM, + .enum_values = epoll_create1_valid_values, + .enum_count = ARRAY_SIZE(epoll_create1_valid_values), + .constraints = "Must be 0 or EPOLL_CLOEXEC", + KAPI_PARAM_END + + KAPI_RETURN("long", "File descriptor on success, negative error code on failure") + .type = KAPI_TYPE_INT, + .check_type = KAPI_RETURN_FD, + KAPI_RETURN_END + + KAPI_ERROR(0, -EINVAL, "EINVAL", "Invalid flags specified", + "The flags parameter contains invalid values. Only EPOLL_CLOEXEC is allowed.") + KAPI_ERROR(1, -EMFILE, "EMFILE", "Per-process file descriptor limit reached", + "The per-process limit on the number of open file descriptors has been reached.") + KAPI_ERROR(2, -ENFILE, "ENFILE", "System file table overflow", + "The system-wide limit on the total number of open files has been reached.") + KAPI_ERROR(3, -ENOMEM, "ENOMEM", "Insufficient kernel memory", + "There was insufficient kernel memory to create the epoll instance.") + KAPI_ERROR(4, -EINTR, "EINTR", "Interrupted by signal", + "The system call was interrupted by a signal before the epoll instance could be created.") + + .error_count = 5, + .param_count = 1, + .since_version = "2.6.27", + .examples = "int epfd = epoll_create1(EPOLL_CLOEXEC);", + .notes = "EPOLL_CLOEXEC sets the close-on-exec (FD_CLOEXEC) flag on the new file descriptor. " + "When all file descriptors referring to an epoll instance are closed, the kernel " + "destroys the instance and releases associated resources.", + + /* Side effects */ + KAPI_SIDE_EFFECT(0, KAPI_EFFECT_RESOURCE_CREATE | KAPI_EFFECT_ALLOC_MEMORY, + "epoll instance", + "Creates a new epoll instance and allocates kernel memory for it") + KAPI_EFFECT_REVERSIBLE + KAPI_SIDE_EFFECT_END + + KAPI_SIDE_EFFECT(1, KAPI_EFFECT_RESOURCE_CREATE, + "file descriptor", + "Allocates a new file descriptor in the process's file descriptor table") + KAPI_EFFECT_REVERSIBLE + KAPI_SIDE_EFFECT_END + + KAPI_SIDE_EFFECT_COUNT(2) + + /* State transitions */ + KAPI_STATE_TRANS(0, "epoll instance", "non-existent", "created and empty", + "A new epoll instance is created with no monitored file descriptors") + KAPI_STATE_TRANS_END + + KAPI_STATE_TRANS_COUNT(1) + + /* Signal specifications */ + KAPI_SIGNAL(0, SIGINT, "SIGINT", KAPI_SIGNAL_RECEIVE, KAPI_SIGNAL_ACTION_RETURN) + KAPI_SIGNAL_CONDITION("During creation if process receives SIGINT") + KAPI_SIGNAL_DESC("If interrupted during kernel memory allocation, returns -EINTR") + KAPI_SIGNAL_RESTARTABLE + KAPI_SIGNAL_END + + KAPI_SIGNAL(1, SIGTERM, "SIGTERM", KAPI_SIGNAL_RECEIVE, KAPI_SIGNAL_ACTION_RETURN) + KAPI_SIGNAL_CONDITION("During creation if process receives SIGTERM") + KAPI_SIGNAL_DESC("If interrupted during kernel memory allocation, returns -EINTR") + KAPI_SIGNAL_RESTARTABLE + KAPI_SIGNAL_END + + KAPI_SIGNAL(2, SIGKILL, "SIGKILL", KAPI_SIGNAL_RECEIVE, KAPI_SIGNAL_ACTION_TERMINATE) + KAPI_SIGNAL_CONDITION("At any point during the syscall") + KAPI_SIGNAL_DESC("Process is terminated immediately, epoll instance creation may be incomplete") + KAPI_SIGNAL_END + + .signal_count = 3, +KAPI_END_SPEC; SYSCALL_DEFINE1(epoll_create1, int, flags) { return do_epoll_create(flags); -- 2.39.5