Commit fff42f18 authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

tcg: access cpu->icount_decr.u16.high with atomics 



Consistently access u16.high with atomics to avoid
undefined behaviour in MTTCG.

Note that icount_decr.u16.low is only used in icount mode,
so regular accesses to it are OK.

Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Message-Id: <20181010144853.13005-2-cota@braap.org>
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
parent d7f425fd

accel/tcg/tcg-all.c

+1 −1
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ static void tcg_handle_interrupt(CPUState *cpu, int mask) 
    if (!qemu_cpu_is_self(cpu)) {

        qemu_cpu_kick(cpu);

    } else {

        cpu->icount_decr.u16.high = -1;

        atomic_set(&cpu->icount_decr.u16.high, -1);

        if (use_icount &&

            !cpu->can_do_io

            && (mask & ~old_mask) != 0) {

accel/tcg/translate-all.c

+1 −1
Original line number Diff line number Diff line
@@ -2341,7 +2341,7 @@ void cpu_interrupt(CPUState *cpu, int mask) 
{

    g_assert(qemu_mutex_iothread_locked());

    cpu->interrupt_request |= mask;

    cpu->icount_decr.u16.high = -1;

    atomic_set(&cpu->icount_decr.u16.high, -1);

}



/*

qom/cpu.c

+1 −1
Original line number Diff line number Diff line
@@ -265,7 +265,7 @@ static void cpu_common_reset(CPUState *cpu) 
    cpu->mem_io_pc = 0;

    cpu->mem_io_vaddr = 0;

    cpu->icount_extra = 0;

    cpu->icount_decr.u32 = 0;

    atomic_set(&cpu->icount_decr.u32, 0);

    cpu->can_do_io = 1;

    cpu->exception_index = -1;

    cpu->crash_occurred = false;