diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/ioport.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 6 |
2 files changed, 15 insertions, 4 deletions
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index 6290dd120f5e..ff40f09ad911 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -33,8 +33,9 @@ void io_bitmap_share(struct task_struct *tsk) set_tsk_thread_flag(tsk, TIF_IO_BITMAP); } -static void task_update_io_bitmap(struct task_struct *tsk) +static void task_update_io_bitmap(void) { + struct task_struct *tsk = current; struct thread_struct *t = &tsk->thread; if (t->iopl_emul == 3 || t->io_bitmap) { @@ -54,7 +55,12 @@ void io_bitmap_exit(struct task_struct *tsk) struct io_bitmap *iobm = tsk->thread.io_bitmap; tsk->thread.io_bitmap = NULL; - task_update_io_bitmap(tsk); + /* + * Don't touch the TSS when invoked on a failed fork(). TSS + * reflects the state of @current and not the state of @tsk. + */ + if (tsk == current) + task_update_io_bitmap(); if (iobm && refcount_dec_and_test(&iobm->refcnt)) kfree(iobm); } @@ -192,8 +198,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level) } t->iopl_emul = level; - task_update_io_bitmap(current); - + task_update_io_bitmap(); return 0; } diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c1d2dac72b9c..704883c21f3a 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -176,6 +176,7 @@ 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)); @@ -464,6 +465,11 @@ 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. |