Skip to content

K
Kernel

openeuler / Kernel
大约 1 年 前同步成功

通知 5
Star 0
Fork 0
K
Kernel

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 20 10月, 2005 3 次提交
    • H
      [PATCH] mm: hugetlb truncation fixes · 1c59827d
      由 Hugh Dickins 提交于 
      hugetlbfs allows truncation of its files (should it?), but hugetlb.c often
forgets that: crashes and misaccounting ensue.

copy_hugetlb_page_range better grab the src page_table_lock since we don't
want to guess what happens if concurrently truncated.  unmap_hugepage_range
rss accounting must not assume the full range was mapped.  follow_hugetlb_page
must guard with page_table_lock and be prepared to exit early.

Restyle copy_hugetlb_page_range with a for loop like the others there.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      1c59827d
    • R
      [PATCH] Fix cpu timers exit deadlock and races · e03d13e9
      由 Roland McGrath 提交于 
      Oleg Nesterov reported an SMP deadlock.  If there is a running timer
tracking a different process's CPU time clock when the process owning
the timer exits, we deadlock on tasklist_lock in posix_cpu_timer_del via
exit_itimers.

That code was using tasklist_lock to check for a race with __exit_signal
being called on the timer-target task and clearing its ->signal.
However, there is actually no such race.  __exit_signal will have called
posix_cpu_timers_exit and posix_cpu_timers_exit_group before it does
that.  Those will clear those k_itimer's association with the dying
task, so posix_cpu_timer_del will return early and never reach the code
in question.

In addition, posix_cpu_timer_del called from exit_itimers during execve
or directly from timer_delete in the process owning the timer can race
with an exiting timer-target task to cause a double put on timer-target
task struct.  Make sure we always access cpu_timers lists with sighand
lock held.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NChris Wright <chrisw@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e03d13e9
    • S
      [PATCH] Handle spurious page fault for hugetlb region · 3359b54c
      由 Seth, Rohit 提交于 
      The hugetlb pages are currently pre-faulted.  At the time of mmap of
hugepages, we populate the new PTEs.  It is possible that HW has already
cached some of the unused PTEs internally.  These stale entries never
get a chance to be purged in existing control flow.

This patch extends the check in page fault code for hugepages.  Check if
a faulted address falls with in size for the hugetlb file backing it.
We return VM_FAULT_MINOR for these cases (assuming that the arch
specific page-faulting code purges the stale entry for the archs that
need it).
Signed-off-by: NRohit Seth <rohit.seth@intel.com>

[ This is apparently arguably an ia64 port bug. But the code won't
  hurt, and for now it fixes a real problem on some ia64 machines ]
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3359b54c
  3. 18 10月, 2005 22 次提交
  5. 17 10月, 2005 5 次提交
    • R
      [PATCH] fix black/white-only svideo input in vpx3220 decoder · de21eb63
      由 Ronald S. Bultje 提交于 
      Fix the fact that the svideo input will only give input in black/white in
some circumstances.  Reason is that in the PCI controller driver (zr36067),
after setting input, we reset norm, which overwrites the input register
with the default.  This patch makes it always set the correct value for the
input when changing norm.
Signed-off-by: NRonald S. Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      de21eb63
    • R
      [PATCH] fix vpx3220 offset issue in SECAM · 9b3acc21
      由 Ronald S. Bultje 提交于 
      Fix bug #5404 in kernel bugzilla.

It basically updates the vpx3220 initialization tables with some newer
values that we've had in CVS for a while (and that, for some reason, never
ended up in the kernel...  must've gotten lost).  Those fix a ~16 pixels
noise at the top of the picture in at least SECAM, although (now that I
think about it) PAL was probably affected, also.
Signed-off-by: NRonald S. Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9b3acc21
    • S
      [PATCH] SVGATextMode fix · 0aec4867
      由 Samuel Thibault 提交于 
      Fix bug 5441.

I didn't know about messy programs like svgatextmode...  Couldn't this be
integrated in some linux/drivers/video/console/svgacon.c ?...  So because
of the existence of the svgatextmode program, the kernel is not supposed to
touch to CRT_OVERFLOW/SYNC_END/DISP/DISP_END/OFFSET ?

Disabling the check in vgacon_resize() might help indeed, but I'm really
not sure whether it will work for any chipset: in my patch, CRT registers
are set at each console switch, since stty rows/cols apply to consoles
separately...

The attached solution is to keep the test, but if it fails, we assume that
the caller knows what it does (i.e.  it is svgatextmode) and then disable
any further call to vgacon_doresize.  Svgatextmode is usually used to
_expand_ the display, not to shrink it.  And it is harmless in the case of
a too big stty rows/cols: the display will just be cropped.  I tested it on
my laptop, and it works fine with svgatextmode.

A better solution would be that svgatextmode explicitely tells the kernel
not to care about video timing, but for this an interface needs be defined
and svgatextmode be patched.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0aec4867
    • H
      [PATCH] list: add missing rcu_dereference on first element · b24d18aa
      由 Herbert Xu 提交于 
      It seems that all the list_*_rcu primitives are missing a memory barrier
on the very first dereference.  For example,

#define list_for_each_rcu(pos, head) \
	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
		pos = rcu_dereference(pos->next))

It will go something like:

	pos = (head)->next

	prefetch(pos->next)

	pos != (head)

	do stuff

We're missing a barrier here.

	pos = rcu_dereference(pos->next)

		fetch pos->next

		barrier given by rcu_dereference(pos->next)

		store pos

Without the missing barrier, the pos->next value may turn out to be stale.
In fact, if "do stuff" were also dereferencing pos and relying on
list_for_each_rcu to provide the barrier then it may also break.

So here is a patch to make sure that we have a barrier for the first
element in the list.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b24d18aa
    • L
      Fix memory ordering bug in page reclaim · 3d80636a
      由 Linus Torvalds 提交于 
      As noticed by Nick Piggin, we need to make sure that we check the page
count before we check for PageDirty, since the dirty check is only valid
if the count implies that we're the only possible ones holding the page.

We always did do this, but the code needs a read-memory-barrier to make
sure that the orderign is also honored by the CPU.

(The writer side is ordered due to the atomic decrement and test on the
page count, see the discussion on linux-kernel)
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3d80636a
  7. 16 10月, 2005 2 次提交
  9. 15 10月, 2005 8 次提交