Commit 49e55cba authored by Laurent Vivier's avatar Laurent Vivier Committed by Riku Voipio
Browse files

linux-user,target-ppc: fix use of MSR_LE 



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: default avatarThomas Huth <huth@tuxfamily.org>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
Signed-off-by: default avatarRiku Voipio <riku.voipio@linaro.org>
parent 5b1d59d0

linux-user/signal.c

+3 −3
Original line number Diff line number Diff line
@@ -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;