On 19/10/2018 19:49, Peter Maydell wrote:
> 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.mayd...@linaro.org>
> ---
> Disclaimer: compile tested, and the change makes conceptual
> sense, but I have no nios2 test environment.
I'll push a slightly modified version of this patch: gdbsig is now
unused and my compiler complains about that.
Thanks,
Laurent
> ---
> linux-user/nios2/cpu_loop.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c
> index dac7a061813..973dd54d791 100644
> --- a/linux-user/nios2/cpu_loop.c
> +++ b/linux-user/nios2/cpu_loop.c
> @@ -68,7 +68,10 @@ 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 +109,7 @@ 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);
>
