[PATCH] linux-user/hppa: Fix segfaults on page zero

[Helge Deller]

This program:

    int main(void) { asm("bv %r0(%r0)"); return 0; }

produces on real hardware the expected segfault:

--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x3} ---
+++ killed by SIGSEGV +++
Segmentation fault

But when run on linux-user you get instead internal qemu errors:

ERROR: linux-user/hppa/cpu_loop.c:172:cpu_loop: code should not be reached
Bail out! ERROR: linux-user/hppa/cpu_loop.c:172:cpu_loop: code should not be 
reached
ERROR: accel/tcg/cpu-exec.c:933:cpu_exec: assertion failed: (cpu == current_cpu)
Bail out! ERROR: accel/tcg/cpu-exec.c:933:cpu_exec: assertion failed: (cpu == 
current_cpu)

Fix it by adding the missing case for the EXCP_IMP trap in
cpu_loop() and raise a segfault.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c
index a576d1a249..8f374aeef6 100644
--- a/linux-user/hppa/cpu_loop.c
+++ b/linux-user/hppa/cpu_loop.c
@@ -143,6 +143,9 @@ void cpu_loop(CPUHPPAState *env)
             env->iaoq_f = env->gr[31];
             env->iaoq_b = env->gr[31] + 4;
             break;
+        case EXCP_IMP:
+            force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, env->iaoq_f);
+            break;
         case EXCP_ILL:
             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPN, env->iaoq_f);
             break;