On Wed, Jun 12, 2002 at 01:04:09PM -0700, Linus Torvalds wrote:
> Why do you introduce a arch_dispose_thread_struct(), instead of just
> making the x86 exit_thread() do it?
That makes much more sense. Below is an updated patch against cset
1.479 that allocs in sys_ioperm() and copy_thread() and frees in
exit_thread(). It also gets rid of the IO_BITMAP_SIZE+1 crap, as
only the tss actually needs the tail long, and we weren't copying
it into the bitmap anyways. There is a test program at
http://www.kvack.org/~blah/iobitmap.c . Side note: double kfree()
does not trigger a BUG()...
-ben
-- "You will be reincarnated as a toad; and you will be much happier.":r ~/patches/v2.5/v2.5.21.5-io_bitmap-B0.diff diff -urN linus-2.5/arch/i386/kernel/ioport.c work-2.5.diff/arch/i386/kernel/ioport.c --- linus-2.5/arch/i386/kernel/ioport.c Wed Jun 12 20:59:11 2002 +++ work-2.5.diff/arch/i386/kernel/ioport.c Thu Jun 13 02:10:59 2002 @@ -10,10 +10,10 @@ #include <linux/errno.h> #include <linux/types.h> #include <linux/ioport.h> -#include <linux/mm.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/stddef.h> +#include <linux/slab.h> /* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */ static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value) @@ -66,12 +66,16 @@ * IO bitmap up. ioperm() is much less timing critical than clone(), * this is why we delay this operation until now: */ - if (!t->ioperm) { + if (!t->ts_io_bitmap) { + unsigned long *bitmap; + bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); + if (!bitmap) + return -ENOMEM; /* * just in case ... */ - memset(t->io_bitmap,0xff,(IO_BITMAP_SIZE+1)*4); - t->ioperm = 1; + memset(bitmap, 0xff, IO_BITMAP_BYTES); + t->ts_io_bitmap = bitmap; /* * this activates it in the TSS */ @@ -81,7 +85,7 @@ /* * do it in the per-thread copy and in the TSS ... */ - set_bitmap(t->io_bitmap, from, num, !turn_on); + set_bitmap(t->ts_io_bitmap, from, num, !turn_on); set_bitmap(tss->io_bitmap, from, num, !turn_on); return 0; diff -urN linus-2.5/arch/i386/kernel/process.c work-2.5.diff/arch/i386/kernel/process.c --- linus-2.5/arch/i386/kernel/process.c Wed Jun 12 20:59:11 2002 +++ work-2.5.diff/arch/i386/kernel/process.c Thu Jun 13 02:03:36 2002 @@ -509,7 +509,13 @@ */ void exit_thread(void) { - /* nothing to do ... */ + struct task_struct *tsk = current; + + /* The process may have allocated an io port bitmap... nuke it. */ + if (unlikely(NULL != tsk->thread.ts_io_bitmap)) { + kfree(tsk->thread.ts_io_bitmap); + tsk->thread.ts_io_bitmap = NULL; + } } void flush_thread(void) @@ -549,6 +555,7 @@ struct task_struct * p, struct pt_regs * regs) { struct pt_regs * childregs; + struct task_struct *tsk; childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1; struct_cpy(childregs, regs); @@ -563,8 +570,17 @@ savesegment(fs,p->thread.fs); savesegment(gs,p->thread.gs); - unlazy_fpu(current); - struct_cpy(&p->thread.i387, ¤t->thread.i387); + tsk = current; + unlazy_fpu(tsk); + struct_cpy(&p->thread.i387, &tsk->thread.i387); + + if (unlikely(NULL != tsk->thread.ts_io_bitmap)) { + p->thread.ts_io_bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); + if (!p->thread.ts_io_bitmap) + return -ENOMEM; + memcpy(p->thread.ts_io_bitmap, tsk->thread.ts_io_bitmap, + IO_BITMAP_BYTES); + } return 0; } @@ -685,8 +701,8 @@ loaddebug(next, 7); } - if (unlikely(prev->ioperm || next->ioperm)) { - if (next->ioperm) { + if (unlikely(prev->ts_io_bitmap || next->ts_io_bitmap)) { + if (next->ts_io_bitmap) { /* * 4 cachelines copy ... not good, but not that * bad either. Anyone got something better? @@ -695,8 +711,8 @@ * and playing VM tricks to switch the IO bitmap * is not really acceptable.] */ - memcpy(tss->io_bitmap, next->io_bitmap, - IO_BITMAP_SIZE*sizeof(unsigned long)); + memcpy(tss->io_bitmap, next->ts_io_bitmap, + IO_BITMAP_BYTES); tss->bitmap = IO_BITMAP_OFFSET; } else /* diff -urN linus-2.5/include/asm-i386/processor.h work-2.5.diff/include/asm-i386/processor.h --- linus-2.5/include/asm-i386/processor.h Wed Jun 12 20:59:17 2002 +++ work-2.5.diff/include/asm-i386/processor.h Thu Jun 13 02:02:30 2002 @@ -267,6 +267,7 @@ * Size of io_bitmap in longwords: 32 is ports 0-0x3ff. */ #define IO_BITMAP_SIZE 32 +#define IO_BITMAP_BYTES (IO_BITMAP_SIZE * 4) #define IO_BITMAP_OFFSET offsetof(struct tss_struct,io_bitmap) #define INVALID_IO_BITMAP_OFFSET 0x8000 @@ -370,8 +371,7 @@ unsigned long screen_bitmap; unsigned long v86flags, v86mask, v86mode, saved_esp0; /* IO permissions */ - int ioperm; - unsigned long io_bitmap[IO_BITMAP_SIZE+1]; + unsigned long *ts_io_bitmap; }; #define INIT_THREAD { \ @@ -381,7 +381,7 @@ 0, 0, 0, \ { { 0, }, }, /* 387 state */ \ 0,0,0,0,0,0, \ - 0,{~0,} /* io permissions */ \ + NULL, /* io permissions */ \ } #define INIT_TSS { \ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jun 15 2002 - 22:00:27 EST