From patchwork Fri Sep 18 12:45:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11784793 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 003AB618 for ; Fri, 18 Sep 2020 12:45:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A715E21D24 for ; Fri, 18 Sep 2020 12:45:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="s9ZOEgea" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726635AbgIRMpr (ORCPT ); Fri, 18 Sep 2020 08:45:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbgIRMpr (ORCPT ); Fri, 18 Sep 2020 08:45:47 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 341F5C06174A; Fri, 18 Sep 2020 05:45:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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; bh=9yRRDQwct1JF6ZjH1ZNHGCkZ32QJgvqPcvKB0dar+RA=; b=s9ZOEgeausCRzTAIKECqvkUxtU mBy6UNf6RRm6AlyFjmIkQ3cVDdDYzfwSdhLijuDrQUI+A78+ZqGwh62ALTJTxP+Hb8b83fxY6Qyi6 isvS5QdYE1J4kBdCQWs+MMQ4aSFmky4TbtL3CMmkNu1/mGKdA0TuWf6yx7Uk0Ps1g7r1gKN2xuwhK HRHNr25lHpABcK0AvSVrpaODyp1+JRO4exW0ZmPuLFmNoS3AjrOgbDe3M4ZooZEY0dg3iws/po7YP mnoC1b0zsP8OSDeJX3yk3JwikUwzt2CQzpFw1N1+BKD+glSDIGYYTqxd9FdthshAjsDRO8EDuc8gB 68Zuo9Zg==; Received: from [80.122.85.238] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJFlh-0008Sq-JK; Fri, 18 Sep 2020 12:45:37 +0000 From: Christoph Hellwig To: Alexander Viro Cc: Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Date: Fri, 18 Sep 2020 14:45:25 +0200 Message-Id: <20200918124533.3487701-2-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200918124533.3487701-1-hch@lst.de> References: <20200918124533.3487701-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org Add a flag to force processing a syscall as a compat syscall. This is required so that in_compat_syscall() works for I/O submitted by io_uring helper threads on behalf of compat syscalls. Signed-off-by: Christoph Hellwig --- arch/sparc/include/asm/compat.h | 3 ++- arch/x86/include/asm/compat.h | 2 +- fs/io_uring.c | 9 +++++++++ include/linux/compat.h | 5 ++++- include/linux/sched.h | 1 + 5 files changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h index 40a267b3bd5208..fee6c51d36e869 100644 --- a/arch/sparc/include/asm/compat.h +++ b/arch/sparc/include/asm/compat.h @@ -211,7 +211,8 @@ static inline int is_compat_task(void) static inline bool in_compat_syscall(void) { /* Vector 0x110 is LINUX_32BIT_SYSCALL_TRAP */ - return pt_regs_trap_type(current_pt_regs()) == 0x110; + return pt_regs_trap_type(current_pt_regs()) == 0x110 || + (current->flags & PF_FORCE_COMPAT); } #define in_compat_syscall in_compat_syscall #endif diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index d4edf281fff49d..fbab072d4e5b31 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -208,7 +208,7 @@ static inline bool in_32bit_syscall(void) #ifdef CONFIG_COMPAT static inline bool in_compat_syscall(void) { - return in_32bit_syscall(); + return in_32bit_syscall() || (current->flags & PF_FORCE_COMPAT); } #define in_compat_syscall in_compat_syscall /* override the generic impl */ #endif diff --git a/fs/io_uring.c b/fs/io_uring.c index 3790c7fe9fee22..5755d557c3f7bc 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5449,6 +5449,9 @@ static int io_req_defer_prep(struct io_kiocb *req, if (unlikely(ret)) return ret; + if (req->ctx->compat) + current->flags |= PF_FORCE_COMPAT; + switch (req->opcode) { case IORING_OP_NOP: break; @@ -5546,6 +5549,7 @@ static int io_req_defer_prep(struct io_kiocb *req, break; } + current->flags &= ~PF_FORCE_COMPAT; return ret; } @@ -5669,6 +5673,9 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, struct io_ring_ctx *ctx = req->ctx; int ret; + if (ctx->compat) + current->flags |= PF_FORCE_COMPAT; + switch (req->opcode) { case IORING_OP_NOP: ret = io_nop(req, cs); @@ -5898,6 +5905,8 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, break; } + current->flags &= ~PF_FORCE_COMPAT; + if (ret) return ret; diff --git a/include/linux/compat.h b/include/linux/compat.h index b354ce58966e2d..685066f7ad325f 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -891,7 +891,10 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args); */ #ifndef in_compat_syscall -static inline bool in_compat_syscall(void) { return is_compat_task(); } +static inline bool in_compat_syscall(void) +{ + return is_compat_task() || (current->flags & PF_FORCE_COMPAT); +} #endif /** diff --git a/include/linux/sched.h b/include/linux/sched.h index afe01e232935fa..c8b183b5655a1e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1491,6 +1491,7 @@ extern struct pid *cad_pid; */ #define PF_IDLE 0x00000002 /* I am an IDLE thread */ #define PF_EXITING 0x00000004 /* Getting shut down */ +#define PF_FORCE_COMPAT 0x00000008 /* acting as compat task */ #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */