diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c7ce3655b707..1dbd7a34645c 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -180,6 +180,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) frame->ret_addr = (unsigned long) ret_from_fork_asm; p->thread.sp = (unsigned long) fork_frame; p->thread.io_bitmap = NULL; + clear_tsk_thread_flag(p, TIF_IO_BITMAP); p->thread.iopl_warn = 0; memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); @@ -468,6 +469,11 @@ void native_tss_update_io_bitmap(void) } else { struct io_bitmap *iobm = t->io_bitmap; + if (WARN_ON_ONCE(!iobm)) { + clear_thread_flag(TIF_IO_BITMAP); + native_tss_invalidate_io_bitmap(); + } + /* * Only copy bitmap data when the sequence number differs. The * update time is accounted to the incoming task. @@ -906,13 +912,10 @@ static __init bool prefer_mwait_c1_over_halt(void) static __cpuidle void mwait_idle(void) { if (!current_set_polling_and_test()) { - if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) { - mb(); /* quirk */ - clflush((void *)¤t_thread_info()->flags); - mb(); /* quirk */ - } + const void *addr = ¤t_thread_info()->flags; - __monitor((void *)¤t_thread_info()->flags, 0, 0); + alternative_input("", "clflush (%[addr])", X86_BUG_CLFLUSH_MONITOR, [addr] "a" (addr)); + __monitor(addr, 0, 0); if (!need_resched()) { __sti_mwait(0, 0); raw_local_irq_disable(); |