diff options
Diffstat (limited to 'arch/x86/kernel/ioport.c')
| -rw-r--r-- | arch/x86/kernel/ioport.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index 198beadb3732..f9fc69aeb033 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -16,6 +16,18 @@ static atomic64_t io_bitmap_sequence; +void io_bitmap_exit(void) +{ + struct io_bitmap *iobm = current->thread.io_bitmap; + + current->thread.io_bitmap = NULL; + clear_thread_flag(TIF_IO_BITMAP); + preempt_disable(); + tss_update_io_bitmap(); + preempt_enable(); + kfree(iobm); +} + /* * this changes the io permissions bitmap in the current task. */ @@ -61,11 +73,16 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) * Search for a (possibly new) maximum. This is simple and stupid, * to keep it obviously correct: */ - max_long = 0; + max_long = UINT_MAX; for (i = 0; i < IO_BITMAP_LONGS; i++) { if (iobm->bitmap[i] != ~0UL) max_long = i; } + /* All permissions dropped? */ + if (max_long == UINT_MAX) { + io_bitmap_exit(); + return 0; + } iobm->max = (max_long + 1) * sizeof(unsigned long); |