From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753031AbeC2L0f (ORCPT ); Thu, 29 Mar 2018 07:26:35 -0400 Received: from isilmar-4.linta.de ([136.243.71.142]:59048 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752950AbeC2L02 (ORCPT ); Thu, 29 Mar 2018 07:26:28 -0400 From: Dominik Brodowski To: linux-kernel@vger.kernel.org Cc: viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org, arnd@arndb.de, linux-arch@vger.kernel.org, "Eric W. Biederman" , Al Viro , Andrew Morton Subject: [PATCH 041/109] kernel: add do_compat_sigaltstack() helper; remove in-kernel call to compat syscall Date: Thu, 29 Mar 2018 13:23:18 +0200 Message-Id: <20180329112426.23043-42-linux@dominikbrodowski.net> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180329112426.23043-1-linux@dominikbrodowski.net> References: <20180329112426.23043-1-linux@dominikbrodowski.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Using this helper allows us to avoid the in-kernel call to the compat_sys_sigaltstack() syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: "Eric W. Biederman" Cc: Al Viro Cc: Andrew Morton Signed-off-by: Dominik Brodowski --- kernel/signal.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 985c61749bcf..f04466655238 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3573,9 +3573,8 @@ int __save_altstack(stack_t __user *uss, unsigned long sp) } #ifdef CONFIG_COMPAT -COMPAT_SYSCALL_DEFINE2(sigaltstack, - const compat_stack_t __user *, uss_ptr, - compat_stack_t __user *, uoss_ptr) +static int do_compat_sigaltstack(const compat_stack_t __user *uss_ptr, + compat_stack_t __user *uoss_ptr) { stack_t uss, uoss; int ret; @@ -3602,9 +3601,16 @@ COMPAT_SYSCALL_DEFINE2(sigaltstack, return ret; } +COMPAT_SYSCALL_DEFINE2(sigaltstack, + const compat_stack_t __user *, uss_ptr, + compat_stack_t __user *, uoss_ptr) +{ + return do_compat_sigaltstack(uss_ptr, uoss_ptr); +} + int compat_restore_altstack(const compat_stack_t __user *uss) { - int err = compat_sys_sigaltstack(uss, NULL); + int err = do_compat_sigaltstack(uss, NULL); /* squash all but -EFAULT for now */ return err == -EFAULT ? err : 0; } -- 2.16.3