From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b6HOH-00080Y-W4 for qemu-devel@nongnu.org; Fri, 27 May 2016 09:01:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b6HOD-0001OE-6k for qemu-devel@nongnu.org; Fri, 27 May 2016 09:01:25 -0400 Received: from mail-lf0-x230.google.com ([2a00:1450:4010:c07::230]:33390) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b6HOC-0001O7-Up for qemu-devel@nongnu.org; Fri, 27 May 2016 09:01:21 -0400 Received: by mail-lf0-x230.google.com with SMTP id s64so21627128lfe.0 for ; Fri, 27 May 2016 06:01:20 -0700 (PDT) From: riku.voipio@linaro.org Date: Fri, 27 May 2016 16:00:29 +0300 Message-Id: <49e55cbacf4ad08f831b9f3f9cb0f3082883a3a1.1464353863.git.riku.voipio@linaro.org> In-Reply-To: References: Subject: [Qemu-devel] [PULL v2 38/38] linux-user, target-ppc: fix use of MSR_LE List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Laurent Vivier From: Laurent Vivier setup_frame()/setup_rt_frame()/restore_user_regs() are using MSR_LE as the similar kernel functions do: as a bitmask. But in QEMU, MSR_LE is a bit position, so change this accordingly. The previous code was doing nothing as MSR_LE is 0, and "env->msr &= ~MSR_LE" doesn't change the value of msr. And yes, a user process can change its endianness, see linux kernel commit: fab5db9 [PATCH] powerpc: Implement support for setting little-endian mode via prctl and prctl(2): PR_SET_ENDIAN, PR_GET_ENDIAN Reviewed-by: Thomas Huth Signed-off-by: Laurent Vivier Signed-off-by: Riku Voipio --- linux-user/signal.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/linux-user/signal.c b/linux-user/signal.c index 28ce921..8090b4d 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -4632,7 +4632,7 @@ static void restore_user_regs(CPUPPCState *env, /* If doing signal return, restore the previous little-endian mode. */ if (sig) - env->msr = (env->msr & ~MSR_LE) | (msr & MSR_LE); + env->msr = (env->msr & ~(1ull << MSR_LE)) | (msr & (1ull << MSR_LE)); /* Restore Altivec registers if necessary. */ if (env->insns_flags & PPC_ALTIVEC) { @@ -4747,7 +4747,7 @@ static void setup_frame(int sig, struct target_sigaction *ka, #endif /* Signal handlers are entered in big-endian mode. */ - env->msr &= ~MSR_LE; + env->msr &= ~(1ull << MSR_LE); unlock_user_struct(frame, frame_addr, 1); return; @@ -4842,7 +4842,7 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, #endif /* Signal handlers are entered in big-endian mode. */ - env->msr &= ~MSR_LE; + env->msr &= ~(1ull << MSR_LE); unlock_user_struct(rt_sf, rt_sf_addr, 1); return; -- 2.1.4