When handling a signal, the signal handler may have clobbered the condition code set by the interrupted thread.
Signed-off-by: Jonathan Albrecht <jonathan.albre...@linux.vnet.ibm.com> Buglink: https://bugs.launchpad.net/qemu/+bug/1886793 Buglink: https://bugs.launchpad.net/qemu/+bug/1893040 --- linux-user/s390x/signal.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c index ef136dae33..03cacb2829 100644 --- a/linux-user/s390x/signal.c +++ b/linux-user/s390x/signal.c @@ -65,6 +65,10 @@ typedef struct { uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; target_sigcontext sc; target_sigregs sregs; + uint32_t scc_op; + uint64_t scc_src; + uint64_t scc_dst; + uint64_t scc_vr; int signo; target_sigregs_ext sregs_ext; uint16_t retcode; @@ -86,6 +90,10 @@ typedef struct { uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; uint16_t retcode; struct target_siginfo info; + uint32_t scc_op; + uint64_t scc_src; + uint64_t scc_dst; + uint64_t scc_vr; struct target_ucontext uc; } rt_sigframe; @@ -224,6 +232,12 @@ void setup_frame(int sig, struct target_sigaction *ka, env->regs[5] = 0; /* FIXME: regs->int_parm_long */ env->regs[6] = 0; /* FIXME: current->thread.last_break */ + /* Some programs could clobber the condition code, so save it here */ + __put_user(env->cc_op, &frame->scc_op); + __put_user(env->cc_src, &frame->scc_src); + __put_user(env->cc_dst, &frame->scc_dst); + __put_user(env->cc_vr, &frame->scc_vr); + unlock_user_struct(frame, frame_addr, 1); } @@ -273,6 +287,12 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, save_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); tswap_sigset(&frame->uc.tuc_sigmask, set); + /* Some programs could clobber the condition code, so save it here */ + __put_user(env->cc_op, &frame->scc_op); + __put_user(env->cc_src, &frame->scc_src); + __put_user(env->cc_dst, &frame->scc_dst); + __put_user(env->cc_vr, &frame->scc_vr); + /* Set up registers for signal handler */ env->regs[14] = restorer; env->regs[15] = frame_addr; @@ -285,6 +305,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, env->regs[3] = frame_addr + offsetof(typeof(*frame), info); env->regs[4] = frame_addr + offsetof(typeof(*frame), uc); env->regs[5] = 0; /* FIXME: current->thread.last_break */ + + /* QUESTION: Was there a missing unlock user struct here? */ + unlock_user_struct(frame, frame_addr, 1); + return; } static void restore_sigregs(CPUS390XState *env, target_sigregs *sc) @@ -350,6 +374,12 @@ long do_sigreturn(CPUS390XState *env) restore_sigregs(env, &frame->sregs); restore_sigregs_ext(env, &frame->sregs_ext); + /* restore the condition code */ + __get_user(env->cc_op, &frame->scc_op); + __get_user(env->cc_src, &frame->scc_src); + __get_user(env->cc_dst, &frame->scc_dst); + __get_user(env->cc_vr, &frame->scc_vr); + unlock_user_struct(frame, frame_addr, 0); return -TARGET_QEMU_ESIGRETURN; } @@ -372,6 +402,11 @@ long do_rt_sigreturn(CPUS390XState *env) restore_sigregs(env, &frame->uc.tuc_mcontext); restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); + /* restore the condition code */ + __get_user(env->cc_op, &frame->scc_op); + __get_user(env->cc_src, &frame->scc_src); + __get_user(env->cc_dst, &frame->scc_dst); + __get_user(env->cc_vr, &frame->scc_vr); target_restore_altstack(&frame->uc.tuc_stack, env); unlock_user_struct(frame, frame_addr, 0); -- 2.31.1
