From patchwork Thu Feb 4 16:23:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Larsson X-Patchwork-Id: 1436079 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=sparclinux-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DWkRB3rj4z9sXV for ; Fri, 5 Feb 2021 03:24:54 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237000AbhBDQYg (ORCPT ); Thu, 4 Feb 2021 11:24:36 -0500 Received: from bin-mail-out-06.binero.net ([195.74.38.229]:37496 "EHLO bin-mail-out-06.binero.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237885AbhBDQY3 (ORCPT ); Thu, 4 Feb 2021 11:24:29 -0500 X-Halon-ID: 58f64f36-6705-11eb-a076-005056917f90 Authorized-sender: andreas@gaisler.com Received: from andreas.got.gaisler.com (h-98-128-223-123.na.cust.bahnhof.se [98.128.223.123]) by bin-vsp-out-02.atm.binero.net (Halon) with ESMTPA id 58f64f36-6705-11eb-a076-005056917f90; Thu, 04 Feb 2021 17:23:46 +0100 (CET) From: Andreas Larsson To: David Miller , sparclinux@vger.kernel.org Cc: Sam Ravnborg , linux-kernel@vger.kernel.org, software@gaisler.com Subject: [PATCH] sparc32: Preserve clone syscall flags argument for restarts due to signals Date: Thu, 4 Feb 2021 17:23:41 +0100 Message-Id: <20210204162341.4218-1-andreas@gaisler.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org This fixes a bug where a clone syscall that is restarted due to a pending signal is restarted with garbage in the register %o0 that holds the clone flags. This keep the original %i0 of a syscall (as seen from the trap handler) in %l6 rather than %l5. This is done because for clone (and also qfork) %l5 is used as a temporary variable in the same register window. Before this, that temporary value would be the value that was then incorrectly used as the orig_i0 argument to do_notify_resume. In order to preserve %l6, the temporary usage of %l6 in ret_sys_call is changed to use %l5 instead and the setting %l6 to 0 or 1 was removed. The use of that 0 or 1 value in %l6 was removed in commit 28e6103665301ce60634e8a77f0b657c6cc099de. Signed-off-by: Andreas Larsson --- arch/sparc/kernel/entry.S | 8 +++----- arch/sparc/kernel/rtrap_32.S | 2 +- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S index d58940280f8d..a269ad2fe6df 100644 --- a/arch/sparc/kernel/entry.S +++ b/arch/sparc/kernel/entry.S @@ -994,7 +994,7 @@ do_syscall: andcc %l5, _TIF_SYSCALL_TRACE, %g0 mov %i4, %o4 bne linux_syscall_trace - mov %i0, %l5 + mov %i0, %l6 2: call %l7 mov %i5, %o5 @@ -1003,16 +1003,15 @@ do_syscall: st %o0, [%sp + STACKFRAME_SZ + PT_I0] ret_sys_call: - ld [%curptr + TI_FLAGS], %l6 + ld [%curptr + TI_FLAGS], %l5 cmp %o0, -ERESTART_RESTARTBLOCK ld [%sp + STACKFRAME_SZ + PT_PSR], %g3 set PSR_C, %g2 bgeu 1f - andcc %l6, _TIF_SYSCALL_TRACE, %g0 + andcc %l5, _TIF_SYSCALL_TRACE, %g0 /* System call success, clear Carry condition code. */ andn %g3, %g2, %g3 - clr %l6 st %g3, [%sp + STACKFRAME_SZ + PT_PSR] bne linux_syscall_trace2 ld [%sp + STACKFRAME_SZ + PT_NPC], %l1 /* pc = npc */ @@ -1027,7 +1026,6 @@ ret_sys_call: sub %g0, %o0, %o0 or %g3, %g2, %g3 st %o0, [%sp + STACKFRAME_SZ + PT_I0] - mov 1, %l6 st %g3, [%sp + STACKFRAME_SZ + PT_PSR] bne linux_syscall_trace2 ld [%sp + STACKFRAME_SZ + PT_NPC], %l1 /* pc = npc */ diff --git a/arch/sparc/kernel/rtrap_32.S b/arch/sparc/kernel/rtrap_32.S index dca8ed810046..8931fe266346 100644 --- a/arch/sparc/kernel/rtrap_32.S +++ b/arch/sparc/kernel/rtrap_32.S @@ -75,7 +75,7 @@ signal_p: ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr mov %g2, %o2 - mov %l5, %o1 + mov %l6, %o1 call do_notify_resume add %sp, STACKFRAME_SZ, %o0 ! pt_regs ptr