From patchwork Tue May 4 05:52:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1473618 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=201602 header.b=kdtkbdHD; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FZ8kk0vv0z9sCD for ; Tue, 4 May 2021 16:17:02 +1000 (AEST) Received: from localhost ([::1]:56298 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ldoMd-0005cw-To for incoming@patchwork.ozlabs.org; Tue, 04 May 2021 02:16:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60554) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ldo06-0005JS-DV; Tue, 04 May 2021 01:53:43 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:34629) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ldo02-0004mm-M7; Tue, 04 May 2021 01:53:40 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4FZ8CK6LJLz9sXN; Tue, 4 May 2021 15:53:17 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1620107597; bh=6Z6jyo3bzAclzYab342gMCr7M/a/GiGYHd806MpvsQw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kdtkbdHDsnqI4XUrnOnqBteRDvuttHL3b14s3mSU/7UfgOPrGjoCs2YI7HzkodiS9 8N7Io1PFS+i5uZQ60d8HaQ6Pu2+0aDNkm7vpRncRQN/pn4e312bhR1UhRgjZ6viYT/ fEKzeAboAzneRalwUmgzHNEYm0W1cvt7/RjUDqiY= From: David Gibson To: peter.maydell@linaro.org, groug@kaod.org Subject: [PULL 18/46] linux-user/ppc: Fix msr updates for signal handling Date: Tue, 4 May 2021 15:52:44 +1000 Message-Id: <20210504055312.306823-19-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210504055312.306823-1-david@gibson.dropbear.id.au> References: <20210504055312.306823-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Richard Henderson , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson In save_user_regs, there are two bugs where we OR in a bit number instead of the bit, clobbering the low bits of MSR. However: The MSR_VR and MSR_SPE bits control the availability of the insns. If the bits were not already set in MSR, then any attempt to access those registers would result in SIGILL. For linux-user, we always initialize MSR to the capabilities of the cpu. We *could* add checks vs MSR where we currently check insn_flags and insn_flags2, but we know they match. Also, there's a stray cut-and-paste comment in restore. Then, do not force little-endian binaries into big-endian mode. Finally, use ppc_store_msr for the update to affect hflags. Which is the reason none of these bugs were previously noticed. Signed-off-by: Richard Henderson Message-Id: <20210323184340.619757-10-richard.henderson@linaro.org> Signed-off-by: David Gibson --- linux-user/ppc/cpu_loop.c | 5 +++-- linux-user/ppc/signal.c | 23 +++++++++++------------ 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/linux-user/ppc/cpu_loop.c b/linux-user/ppc/cpu_loop.c index df71e15a25..4a0f6c8dc2 100644 --- a/linux-user/ppc/cpu_loop.c +++ b/linux-user/ppc/cpu_loop.c @@ -492,11 +492,12 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs) #if defined(TARGET_PPC64) int flag = (env->insns_flags2 & PPC2_BOOKE206) ? MSR_CM : MSR_SF; #if defined(TARGET_ABI32) - env->msr &= ~((target_ulong)1 << flag); + ppc_store_msr(env, env->msr & ~((target_ulong)1 << flag)); #else - env->msr |= (target_ulong)1 << flag; + ppc_store_msr(env, env->msr | (target_ulong)1 << flag); #endif #endif + env->nip = regs->nip; for(i = 0; i < 32; i++) { env->gpr[i] = regs->gpr[i]; diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c index b78613f7c8..bad38f8ed9 100644 --- a/linux-user/ppc/signal.c +++ b/linux-user/ppc/signal.c @@ -261,9 +261,6 @@ static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame) __put_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]); __put_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]); } - /* Set MSR_VR in the saved MSR value to indicate that - frame->mc_vregs contains valid data. */ - msr |= MSR_VR; #if defined(TARGET_PPC64) vrsave = (uint32_t *)&frame->mc_vregs.altivec[33]; /* 64-bit needs to put a pointer to the vectors in the frame */ @@ -300,9 +297,6 @@ static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame) for (i = 0; i < ARRAY_SIZE(env->gprh); i++) { __put_user(env->gprh[i], &frame->mc_vregs.spe[i]); } - /* Set MSR_SPE in the saved MSR value to indicate that - frame->mc_vregs contains valid data. */ - msr |= MSR_SPE; __put_user(env->spe_fscr, &frame->mc_vregs.spe[32]); } #endif @@ -354,8 +348,10 @@ static void restore_user_regs(CPUPPCState *env, __get_user(msr, &frame->mc_gregs[TARGET_PT_MSR]); /* If doing signal return, restore the previous little-endian mode. */ - if (sig) - env->msr = (env->msr & ~(1ull << MSR_LE)) | (msr & (1ull << MSR_LE)); + if (sig) { + ppc_store_msr(env, ((env->msr & ~(1ull << MSR_LE)) | + (msr & (1ull << MSR_LE)))); + } /* Restore Altivec registers if necessary. */ if (env->insns_flags & PPC_ALTIVEC) { @@ -376,8 +372,6 @@ static void restore_user_regs(CPUPPCState *env, __get_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]); __get_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]); } - /* Set MSR_VEC in the saved MSR value to indicate that - frame->mc_vregs contains valid data. */ #if defined(TARGET_PPC64) vrsave = (uint32_t *)&v_regs[33]; #else @@ -468,7 +462,7 @@ void setup_frame(int sig, struct target_sigaction *ka, env->nip = (target_ulong) ka->_sa_handler; /* Signal handlers are entered in big-endian mode. */ - env->msr &= ~(1ull << MSR_LE); + ppc_store_msr(env, env->msr & ~(1ull << MSR_LE)); unlock_user_struct(frame, frame_addr, 1); return; @@ -563,8 +557,13 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, env->nip = (target_ulong) ka->_sa_handler; #endif +#ifdef TARGET_WORDS_BIGENDIAN /* Signal handlers are entered in big-endian mode. */ - env->msr &= ~(1ull << MSR_LE); + ppc_store_msr(env, env->msr & ~(1ull << MSR_LE)); +#else + /* Signal handlers are entered in little-endian mode. */ + ppc_store_msr(env, env->msr | (1ull << MSR_LE)); +#endif unlock_user_struct(rt_sf, rt_sf_addr, 1); return;