Skip to content

C
clone-Linux

gsplhtlxg / clone-Linux

通知 2
Star 0
Fork 1
C
clone-Linux

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 27 4月, 2009 1 次提交
  3. 22 4月, 2009 2 次提交
  5. 21 4月, 2009 1 次提交
  7. 17 4月, 2009 2 次提交
  9. 15 4月, 2009 3 次提交
  11. 14 4月, 2009 1 次提交
  13. 08 4月, 2009 5 次提交
  15. 03 4月, 2009 3 次提交
  17. 01 4月, 2009 2 次提交
  19. 31 3月, 2009 1 次提交
    • A
      proc 2/2: remove struct proc_dir_entry::owner · 99b76233
      由 Alexey Dobriyan 提交于 
      Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
      99b76233
  21. 30 3月, 2009 4 次提交
  23. 28 3月, 2009 1 次提交
  25. 27 3月, 2009 2 次提交
    • D
      sparc64: Fix MM refcount check in smp_flush_tlb_pending(). · f9384d41
      由 David S. Miller 提交于 
      As explained by Benjamin Herrenschmidt:

> CPU 0 is running the context, task->mm == task->active_mm == your
> context. The CPU is in userspace happily churning things.
>
> CPU 1 used to run it, not anymore, it's now running fancyfsd which
> is a kernel thread, but current->active_mm still points to that
> same context.
>
> Because there's only one "real" user, mm_users is 1 (but mm_count is
> elevated, it's just that the presence on CPU 1 as active_mm has no
> effect on mm_count().
>
> At this point, fancyfsd decides to invalidate a mapping currently mapped
> by that context, for example because a networked file has changed
> remotely or something like that, using unmap_mapping_ranges().
>
> So CPU 1 goes into the zapping code, which eventually ends up calling
> flush_tlb_pending(). Your test will succeed, as current->active_mm is
> indeed the target mm for the flush, and mm_users is indeed 1. So you
> will -not- send an IPI to the other CPU, and CPU 0 will continue happily
> accessing the pages that should have been unmapped.

To fix this problem, check ->mm instead of ->active_mm, and this
means:

> So if you test current->mm, you effectively account for mm_users == 1,
> so the only way the mm can be active on another processor is as a lazy
> mm for a kernel thread. So your test should work properly as long
> as you don't have a HW that will do speculative TLB reloads into the
> TLB on that other CPU (and even if you do, you flush-on-switch-in should
> get rid of any crap here).

And therefore we should be OK.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f9384d41
    • D
      sparc64: Fix build of timer_interrupt(). · e2ab3dff
      由 David Miller 提交于 
      arch/sparc/kernel/time_64.c: In function ‘timer_interrupt’:
  arch/sparc/kernel/time_64.c:732: error: ‘struct kernel_stat’ has no member named ‘irqs’
  make[1]: *** [arch/sparc/kernel/time_64.o] Error 1
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e2ab3dff
  27. 26 3月, 2009 1 次提交
  29. 19 3月, 2009 3 次提交
  31. 16 3月, 2009 8 次提交