linux/arch/x86
Bryan O'Donoghue dd71a17b11 x86/platform/intel/quark: Change the kernel's IMR lock bit to false
Currently when setting up an IMR around the kernel's .text section we lock
that IMR, preventing further modification. While superficially this appears
to be the right thing to do, in fact this doesn't account for a legitimate
change in the memory map such as when executing a new kernel via kexec.

In such a scenario a second kernel can have a different size and location
to it's predecessor and can view some of the memory occupied by it's
predecessor as legitimately usable DMA RAM. If this RAM were then
subsequently allocated to DMA agents within the system it could conceivably
trigger an IMR violation.

This patch fixes the this potential situation by keeping the kernel's .text
section IMR lock bit false by default.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boon.leong.ong@intel.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/1456190999-12685-2-git-send-email-pure.logic@nexus-software.ie
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-23 07:35:53 +01:00
..
boot UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
configs Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
crypto crypto: chacha20-ssse3 - Align stack pointer to 64 bytes 2016-01-25 21:47:45 +08:00
entry UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
ia32 Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
include Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2016-02-18 16:34:15 -08:00
kernel perf/x86/amd/uncore: Plug reference leak 2016-02-17 08:36:09 +01:00
kvm kvm: rename pfn_t to kvm_pfn_t 2016-01-15 17:56:32 -08:00
lguest Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-11 16:26:03 -08:00
lib x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache() 2016-02-17 09:10:23 +01:00
math-emu Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 21:05:40 -08:00
mm Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-02-20 09:32:40 -08:00
net bpf, x86: detect/optimize loading 0 immediates 2015-12-18 16:04:51 -05:00
oprofile
pci PCI changes for the v4.5 merge window: 2016-01-21 11:52:16 -08:00
platform x86/platform/intel/quark: Change the kernel's IMR lock bit to false 2016-02-23 07:35:53 +01:00
power x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume 2015-11-26 10:04:53 +01:00
purgatory
ras x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC 2015-10-12 16:15:48 +02:00
realmode UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
tools
um virtio: barrier rework+fixes 2016-01-18 16:44:24 -08:00
video
xen xen: features and fixes for 4.5-rc0 2016-01-12 13:05:36 -08:00
.gitignore
Kbuild
Kconfig hpet: Drop stale URLs 2016-02-17 09:39:56 +01:00
Kconfig.cpu x86/Kconfig/cpus: Fix/complete CPU type help texts 2015-10-21 11:12:56 +02:00
Kconfig.debug libnvdimm for 4.5 2016-01-13 19:15:14 -08:00
Makefile Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-11-04 09:11:12 -08:00
Makefile_32.cpu
Makefile.um