From: Laurent Vivier <laur...@vivier.eu>
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 <h...@tuxfamily.org>
Signed-off-by: Laurent Vivier <laur...@vivier.eu>
Signed-off-by: Riku Voipio <riku.voi...@linaro.org>
---
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
