linux-user: Clean up nios2 main loop signal handling

The nios2 main loop code's code does some odd
things with gdb_handlesig() that no other target
CPU does: it has some signals that are delivered
to gdb and only to gdb. Stop doing this, and instead
behave like all the other targets:
 * a trap instruction becomes a SIGTRAP
 * an unhandled exception type returned from cpu_exec()
   causes us to abort(), not to try to hand gdb a SIGILL

This fixes in passing Coverity issue CID 1390853,
which was a complaint that the old code failed to
check the return value from gdb_handlesig().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20181019174958.26616-3-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[lv: removed gdbsig unused variable]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
master
Peter Maydell 2018-10-19 18:49:58 +01:00 committed by Laurent Vivier
parent b10089a14c
commit 9f214bd390
1 changed files with 6 additions and 11 deletions

View File

@ -26,13 +26,12 @@ void cpu_loop(CPUNios2State *env)
CPUState *cs = ENV_GET_CPU(env);
Nios2CPU *cpu = NIOS2_CPU(cs);
target_siginfo_t info;
int trapnr, gdbsig, ret;
int trapnr, ret;
for (;;) {
cpu_exec_start(cs);
trapnr = cpu_exec(cs);
cpu_exec_end(cs);
gdbsig = 0;
switch (trapnr) {
case EXCP_INTERRUPT:
@ -68,7 +67,10 @@ void cpu_loop(CPUNios2State *env)
env->regs[R_EA] = env->regs[R_PC] + 4;
env->regs[R_PC] = cpu->exception_addr;
gdbsig = TARGET_SIGTRAP;
info.si_signo = TARGET_SIGTRAP;
info.si_errno = 0;
info.si_code = TARGET_TRAP_BRKPT;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
}
case 0xaa:
@ -106,14 +108,7 @@ kuser_fail:
default:
EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
trapnr);
gdbsig = TARGET_SIGILL;
break;
}
if (gdbsig) {
gdb_handlesig(cs, gdbsig);
if (gdbsig != TARGET_SIGTRAP) {
exit(EXIT_FAILURE);
}
abort();
}
process_pending_signals(env);