linux-kernel - [PATCH 0/2] cpumask fallout: Initialize irq_default

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <496CE153.5010802@caviumnetworks.com>
Date:	Tue, 13 Jan 2009 10:45:39 -0800
From:	David Daney <ddaney@...iumnetworks.com>
To:	Andrew Morton <akpm@...ux-foundation.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Linus Torvalds <torvalds@...ux-foundation.org>
CC:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-mips <linux-mips@...ux-mips.org>,
	Mike Travis <travis@....com>
Subject: [PATCH 0/2] cpumask fallout: Initialize irq_default_affinity earlier
 et al. (v3)

Now that mips/OCTEON support has been merged, this patch set has 
slightly more urgency.

The interrupt affinity on OCTEON is determined by irq_default_affinity,
because that is what the code in kernel/irq/manage.c uses to set 
affinity.  Since for the majority of devices (Serial, Compact Flash,
Network...) we want interrupts to be handled on a single CPU, we set
irq_default_affinity to the boot CPU in init_IRQ().  The problem we
have is that with the new cpumask infrastructure, irq_default_affinity
is being initialized in core_initcall which undoes our initialization.

As I said in 2/2:

     Move the initialization of irq_default_affinity to early_irq_init
     as core_initcall is too late.

     irq_default_affinity can be used in init_IRQ and potentially timer
     and SMP init as well.  All of these happen before core_initcall.
     Moving the initialization to early_irq_init ensures that it is
     initialized before it is used.

Mike Travis pointed out that irq_default_affinity depends on
CONFIG_GENERIC_HARDIRQS in addition to CONFIG_SMP.  So to make things
consistent, I added 1/2 so that the irq_*_affinity functions and
irq_default_affinity are defined for the same conditions that they are
declared.

I Took Linus' suggestion to move init_irq_default_affinity over to
kernel/irq/handle.c, however due to the way that cpumask_*() are
defined, it is still necessary to have the ugly ifdefs, but now they
are localized to init_irq_default_affinity.

Mike Travis also suggested that alloc_bootmem_cpumask_var() be used in
preference to alloc_cpumask_var, so I incorporated that suggestion as
well.

I tested both with and without CONFIG_SMP, on mips/cavium_octeon, Mike
tested a similar(but not identical patch) on x86_64.

Changes from v2 of this set are just a small rearrangement of the
#ifdefs suggested by Ihar Hrachyshka that make the code look a bit
cleaner.

I will reply with the two patches.

David Daney (2):
   Make irq_*_affinity depend on CONFIG_GENERIC_HARDIRQS too.
   cpumask fallout: Initialize irq_default_affinity earlier (v3).

  kernel/irq/handle.c |   16 ++++++++++++++++
  kernel/irq/manage.c |   10 +---------
  2 files changed, 17 insertions(+), 9 deletions(-)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/