Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754852AbbFEOAH (ORCPT ); Fri, 5 Jun 2015 10:00:07 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59942 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754807AbbFEN74 (ORCPT ); Fri, 5 Jun 2015 09:59:56 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Russell King , Luis Henriques Subject: [PATCH 3.16.y-ckt 087/110] ARM: fix missing syscall trace exit Date: Fri, 5 Jun 2015 14:58:10 +0100 Message-Id: <1433512713-22984-88-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433512713-22984-1-git-send-email-luis.henriques@canonical.com> References: <1433512713-22984-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1673 Lines: 45 3.16.7-ckt13 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit 1b97937246d8b97c0760d16d8992c7937bdf5e6a upstream. Josh Stone reports: I've discovered a case where both arm and arm64 will miss a ptrace syscall-exit that they should report. If the syscall is entered without TIF_SYSCALL_TRACE set, then it goes on the fast path. It's then possible to have TIF_SYSCALL_TRACE added in the middle of the syscall, but ret_fast_syscall doesn't check this flag again. Fix this by always checking for a syscall trace in the fast exit path. Reported-by: Josh Stone Signed-off-by: Russell King Signed-off-by: Luis Henriques --- arch/arm/kernel/entry-common.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 7139d4a7dea7..29b81fc959fe 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -32,7 +32,9 @@ ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) disable_irq @ disable interrupts - ldr r1, [tsk, #TI_FLAGS] + ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing + tst r1, #_TIF_SYSCALL_WORK + bne __sys_trace_return tst r1, #_TIF_WORK_MASK bne fast_work_pending asm_trace_hardirqs_on -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/