linux-user/s390x: Use the guest pointer for the sigreturn stub

When setting up the pointer for the sigreturn stub in the return
address register (r14) we currently use the host frame address instead
of the guest frame address.

Note: This only caused problems if Qemu has been built with
--disable-pie (as it is in distros nowadays). Otherwise guest_base
defaults to 0 hiding the actual problem.

Signed-off-by: Andreas Krebbel <krebbel@linux.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210324185128.63971-1-krebbel@linux.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c
index ecfa2a14a9827fc2928f560642a46e98247e6f85..7107c5fb533521666e339c08d61da2d4e46e026b 100644 (file)
--- a/linux-user/s390x/signal.c
+++ b/linux-user/s390x/signal.c
@@ -211,9 +211,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     /* Set up to return from userspace.  If provided, use a stub
        already in userspace.  */
     if (ka->sa_flags & TARGET_SA_RESTORER) {
-        env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE;
+        env->regs[14] = ka->sa_restorer | PSW_ADDR_AMODE;
     } else {
-        env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE;
+        env->regs[14] = (frame_addr + offsetof(typeof(*frame), retcode))
+                        | PSW_ADDR_AMODE;
         __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
                    (uint16_t *)(frame->retcode));
     }