linux/include
Xunlei Pang 9b492cf580 kexec: introduce a protection mechanism for the crashkernel reserved memory
For the cases that some kernel (module) path stamps the crash reserved
memory(already mapped by the kernel) where has been loaded the second
kernel data, the kdump kernel will probably fail to boot when panic
happens (or even not happens) leaving the culprit at large, this is
unacceptable.

The patch introduces a mechanism for detecting such cases:

1) After each crash kexec loading, it simply marks the reserved memory
   regions readonly since we no longer access it after that.  When someone
   stamps the region, the first kernel will panic and trigger the kdump.
   The weak arch_kexec_protect_crashkres() is introduced to do the actual
   protection.

2) To allow multiple loading, once 1) was done we also need to remark
   the reserved memory to readwrite each time a system call related to
   kdump is made.  The weak arch_kexec_unprotect_crashkres() is introduced
   to do the actual protection.

The architecture can make its specific implementation by overriding
arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres().

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
..
acpi Merge branches 'acpi-pci', 'acpi-misc' and 'acpi-tools' 2016-05-16 16:45:48 +02:00
asm-generic locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait() 2016-05-20 19:30:32 -07:00
clocksource clocksource: arm_arch_timer: Remove arch_timer_get_timecounter 2016-05-03 12:54:21 +02:00
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
drm
dt-bindings Staging and IIO driver update for 4.7-rc1 2016-05-20 22:20:48 -07:00
keys
kvm KVM: arm/arm64: vgic: Rely on the GIC driver to parse the firmware tables 2016-05-03 12:54:21 +02:00
linux kexec: introduce a protection mechanism for the crashkernel reserved memory 2016-05-23 17:04:14 -07:00
math-emu
media [media] media: rc: reduce size of struct ir_raw_event 2016-05-07 10:34:17 -03:00
memory
misc cxl: Add kernel API to allow a context to operate with relocate disabled 2016-05-11 21:54:10 +10:00
net net: sock: move ->sk_shutdown out of bitfields. 2016-05-20 18:05:32 -04:00
pcmcia
ras
rdma Merge branches 'cxgb4-2', 'i40iw-2', 'ipoib', 'misc-4.7' and 'mlx5-fcs' into k.o/for-4.7 2016-05-13 19:40:38 -04:00
rxrpc
scsi
soc ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
sound ASoC: Updates for v4.7 2016-05-16 14:59:00 +02:00
target target: enhance and export target_alloc_sgl/target_free_sgl 2016-05-13 13:37:19 -04:00
trace Enhancement 2016-05-21 18:25:28 -07:00
uapi Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2016-05-21 10:49:22 -07:00
video fbdev: sh_mipi_dsi: remove driver 2016-05-10 11:53:38 +03:00
xen
Kbuild