From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-by2nam03on0090.outbound.protection.outlook.com ([104.47.42.90]:61856 "EHLO NAM03-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032188AbeCAPfF (ORCPT ); Thu, 1 Mar 2018 10:35:05 -0500 From: Sasha Levin To: "stable@vger.kernel.org" , "stable-commits@vger.kernel.org" CC: Max Filippov , Sasha Levin Subject: [added to the 4.1 stable tree] xtensa: fix futex_atomic_cmpxchg_inatomic Date: Thu, 1 Mar 2018 15:26:17 +0000 Message-ID: <20180301152116.1486-351-alexander.levin@microsoft.com> References: <20180301152116.1486-1-alexander.levin@microsoft.com> In-Reply-To: <20180301152116.1486-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Max Filippov This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ Upstream commit ca47480921587ae30417dd234a9f79af188e3666 ] Return 0 if the operation was successful, not the userspace memory value. Check that userspace value equals passed oldval, not itself. Don't update *uval if the value wasn't read from userspace memory. This fixes process hang due to infinite loop in futex_lock_pi. It also fixes a bunch of glibc tests nptl/tst-mutexpi*. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov Signed-off-by: Sasha Levin --- arch/xtensa/include/asm/futex.h | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff --git a/arch/xtensa/include/asm/futex.h b/arch/xtensa/include/asm/fute= x.h index b39531babec0..72bfc1cbc2b5 100644 --- a/arch/xtensa/include/asm/futex.h +++ b/arch/xtensa/include/asm/futex.h @@ -109,7 +109,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *ua= ddr, u32 oldval, u32 newval) { int ret =3D 0; - u32 prev; =20 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; @@ -120,26 +119,24 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *= uaddr, =20 __asm__ __volatile__ ( " # futex_atomic_cmpxchg_inatomic\n" - "1: l32i %1, %3, 0\n" - " mov %0, %5\n" - " wsr %1, scompare1\n" - "2: s32c1i %0, %3, 0\n" - "3:\n" + " wsr %5, scompare1\n" + "1: s32c1i %1, %4, 0\n" + " s32i %1, %6, 0\n" + "2:\n" " .section .fixup,\"ax\"\n" " .align 4\n" - "4: .long 3b\n" - "5: l32r %1, 4b\n" - " movi %0, %6\n" + "3: .long 2b\n" + "4: l32r %1, 3b\n" + " movi %0, %7\n" " jx %1\n" " .previous\n" " .section __ex_table,\"a\"\n" - " .long 1b,5b,2b,5b\n" + " .long 1b,4b\n" " .previous\n" - : "+r" (ret), "=3D&r" (prev), "+m" (*uaddr) - : "r" (uaddr), "r" (oldval), "r" (newval), "I" (-EFAULT) + : "+r" (ret), "+r" (newval), "+m" (*uaddr), "+m" (*uval) + : "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT) : "memory"); =20 - *uval =3D prev; return ret; } =20 --=20 2.14.1