diff options
| -rw-r--r-- | arch/x86/kernel/process.c | 52 |
1 files changed, 26 insertions, 26 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index bd2a11ca5dd6..61e93a318983 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -377,37 +377,37 @@ static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm) void tss_update_io_bitmap(void) { struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); + struct thread_struct *t = ¤t->thread; u16 *base = &tss->x86_tss.io_bitmap_base; - if (test_thread_flag(TIF_IO_BITMAP)) { - struct thread_struct *t = ¤t->thread; - - if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) { - *base = IO_BITMAP_OFFSET_VALID_ALL; - } else { - struct io_bitmap *iobm = t->io_bitmap; - /* - * Only copy bitmap data when the sequence number - * differs. The update time is accounted to the - * incoming task. - */ - if (tss->io_bitmap.prev_sequence != iobm->sequence) - tss_copy_io_bitmap(tss, iobm); - - /* Enable the bitmap */ - *base = IO_BITMAP_OFFSET_VALID_MAP; - } + if (!test_thread_flag(TIF_IO_BITMAP)) { + tss_invalidate_io_bitmap(tss); + return; + } + + if (IS_ENABLED(CONFIG_X86_IOPL_IOPERM) && t->iopl_emul == 3) { + *base = IO_BITMAP_OFFSET_VALID_ALL; + } else { + struct io_bitmap *iobm = t->io_bitmap; + /* - * Make sure that the TSS limit is covering the io bitmap. - * It might have been cut down by a VMEXIT to 0x67 which - * would cause a subsequent I/O access from user space to - * trigger a #GP because tbe bitmap is outside the TSS - * limit. + * Only copy bitmap data when the sequence number differs. The + * update time is accounted to the incoming task. */ - refresh_tss_limit(); - } else { - tss_invalidate_io_bitmap(tss); + if (tss->io_bitmap.prev_sequence != iobm->sequence) + tss_copy_io_bitmap(tss, iobm); + + /* Enable the bitmap */ + *base = IO_BITMAP_OFFSET_VALID_MAP; } + + /* + * Make sure that the TSS limit is covering the IO bitmap. It might have + * been cut down by a VMEXIT to 0x67 which would cause a subsequent I/O + * access from user space to trigger a #GP because tbe bitmap is outside + * the TSS limit. + */ + refresh_tss_limit(); } #else /* CONFIG_X86_IOPL_IOPERM */ static inline void switch_to_bitmap(unsigned long tifp) { } |