| Message ID | 20180917163103.6113-2-cota@braap.org |
|---|---|
| State | New |
| Headers | show |
| Series | exec: drop BQL from interrupt handling | expand |
On 9/17/18 9:30 AM, Emilio G. Cota wrote: > 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. > > Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com> > Cc: Richard Henderson <rth@twiddle.net> > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- > accel/tcg/tcg-all.c | 2 +- > accel/tcg/translate-all.c | 2 +- > qom/cpu.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) Eh, sure, I guess. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index 56dbb56a16..3d25bdcc17 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -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) { diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 898c3bb3d1..f7784bbc2d 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -2352,7 +2352,7 @@ 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); } /* diff --git a/qom/cpu.c b/qom/cpu.c index 92599f3541..20ad54d43f 100644 --- a/qom/cpu.c +++ b/qom/cpu.c @@ -266,7 +266,7 @@ 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;
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. Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Emilio G. Cota <cota@braap.org> --- accel/tcg/tcg-all.c | 2 +- accel/tcg/translate-all.c | 2 +- qom/cpu.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)