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  1. 24 Feb, 2010 2 commits
  3. 23 Feb, 2010 2 commits
  5. 21 Feb, 2010 1 commit
  7. 20 Feb, 2010 9 commits
  9. 19 Feb, 2010 2 commits
    • Brandon Philips's avatar
      x86, irq: Keep chip_data in create_irq_nr and destroy_irq · eb5b3794
      Brandon Philips authored 
      Version 4: use get_irq_chip_data() in destroy_irq() to get rid of some
local vars.

When two drivers are setting up MSI-X at the same time via
pci_enable_msix() there is a race.  See this dmesg excerpt:

[   85.170610] ixgbe 0000:02:00.1: irq 97 for MSI/MSI-X
[   85.170611]   alloc irq_desc for 99 on node -1
[   85.170613] igb 0000:08:00.1: irq 98 for MSI/MSI-X
[   85.170614]   alloc kstat_irqs on node -1
[   85.170616] alloc irq_2_iommu on node -1
[   85.170617]   alloc irq_desc for 100 on node -1
[   85.170619]   alloc kstat_irqs on node -1
[   85.170621] alloc irq_2_iommu on node -1
[   85.170625] ixgbe 0000:02:00.1: irq 99 for MSI/MSI-X
[   85.170626]   alloc irq_desc for 101 on node -1
[   85.170628] igb 0000:08:00.1: irq 100 for MSI/MSI-X
[   85.170630]   alloc kstat_irqs on node -1
[   85.170631] alloc irq_2_iommu on node -1
[   85.170635]   alloc irq_desc for 102 on node -1
[   85.170636]   alloc kstat_irqs on node -1
[   85.170639] alloc irq_2_iommu on node -1
[   85.170646] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000088

As you can see igb and ixgbe are both alternating on create_irq_nr()
via pci_enable_msix() in their probe function.

ixgbe: While looping through irq_desc_ptrs[] via create_irq_nr() ixgbe
choses irq_desc_ptrs[102] and exits the loop, drops vector_lock and
calls dynamic_irq_init. Then it sets irq_desc_ptrs[102]->chip_data =
NULL via dynamic_irq_init().

igb: Grabs the vector_lock now and starts looping over irq_desc_ptrs[]
via create_irq_nr(). It gets to irq_desc_ptrs[102] and does this:

	cfg_new = irq_desc_ptrs[102]->chip_data;
	if (cfg_new->vector != 0)
		continue;

This hits the NULL deref.

Another possible race exists via pci_disable_msix() in a driver or in
the number of error paths that call free_msi_irqs():

destroy_irq()
dynamic_irq_cleanup() which sets desc->chip_data = NULL
...race window...
desc->chip_data = cfg;

Remove the save and restore code for cfg in create_irq_nr() and
destroy_irq() and take the desc->lock when checking the irq_cfg.
Reported-and-analyzed-by: default avatarBrandon Philips <bphilips@suse.de>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
LKML-Reference: <20100207210250.GB8256@jenkins.home.ifup.org>
Signed-off-by: default avatarBrandon Phiilps <bphilips@suse.de>
Cc: stable@kernel.org
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      eb5b3794
    • Eric W. Biederman's avatar
      xen: Remove unnecessary arch specific xen irq functions. · ca4dbc66
      Eric W. Biederman authored 
      Right now xen's use of the x86 and ia64 handle_irq is just bizarre and very
fragile as it is very non-obvious the function exists and is is used by
code out in drivers/....  Luckily using handle_irq is completely unnecessary,
and we can just use the generic irq apis instead.

This still leaves drivers/xen/events.c as a problematic user of the generic
irq apis it has "static struct irq_info irq_info[NR_IRQS]" but that can be
fixed some other time.
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <4B7CAAD2.10803@kernel.org>
Acked-by: default avatarJeremy Fitzhardinge <jeremy@goop.org>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      ca4dbc66
  11. 18 Feb, 2010 6 commits
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  19. 11 Feb, 2010 2 commits