linux_dsm_epyc7002/arch
Baoquan He c05cd79750 x86/boot/KASLR: Prefer mirrored memory regions for the kernel physical address
Currently KASLR will parse all e820 entries of RAM type and add all
candidate positions into the slots array. After that we choose one slot
randomly as the new position which the kernel will be decompressed into
and run at.

On systems with EFI enabled, e820 memory regions are coming from EFI
memory regions by combining adjacent regions.

These EFI memory regions have various attributes, and the "mirrored"
attribute is one of them. The physical memory region whose descriptors
in EFI memory map has EFI_MEMORY_MORE_RELIABLE attribute (bit: 16) are
mirrored. The address range mirroring feature of the kernel arranges such
mirrored regions into normal zones and other regions into movable zones.

With the mirroring feature enabled, the code and data of the kernel can only
be located in the more reliable mirrored regions. However, the current KASLR
code doesn't check EFI memory entries, and could choose a new kernel position
in non-mirrored regions. This will break the intended functionality of the
address range mirroring feature.

To fix this, if EFI is detected, iterate EFI memory map and pick the mirrored
region to process for adding candidate of randomization slot. If EFI is disabled
or no mirrored region found, still process the e820 memory map.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ard.biesheuvel@linaro.org
Cc: fanc.fnst@cn.fujitsu.com
Cc: izumi.taku@jp.fujitsu.com
Cc: keescook@chromium.org
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: n-horiguchi@ah.jp.nec.com
Cc: thgarnie@google.com
Link: http://lkml.kernel.org/r/1502722464-20614-3-git-send-email-bhe@redhat.com
[ Rewrote most of the text. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-17 10:51:35 +02:00
..
alpha tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
arc dma-coherent: introduce interface for default DMA pool 2017-07-20 16:09:10 +02:00
arm mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
arm64 KVM fixes for v4.13-rc4 2017-08-04 15:18:27 -07:00
blackfin Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
c6x Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
cris Kbuild updates for v4.13 (2nd) 2017-07-13 13:37:57 -07:00
frv FRV: tlbflush: move asmlinkage before return type 2017-07-12 16:26:04 -07:00
h8300 h8300: Add missing closing parenthesis in flat_get_addr_from_rp() 2017-07-16 09:24:06 -07:00
hexagon hexagon: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:26 +09:00
ia64 mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
m32r Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m68k blackfin, m68k: Fix flat_set_persistent() for unsigned long to u32 changes 2017-07-16 09:24:06 -07:00
metag metag: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:30 +09:00
microblaze Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-08-13 15:34:28 -07:00
mn10300 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
nios2 nios2: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:43 +09:00
openrisc openrisc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:50 +09:00
parisc parisc: Define CONFIG_CPU_BIG_ENDIAN 2017-07-31 17:51:27 +02:00
powerpc powerpc fixes for 4.13 #6 2017-08-11 08:56:01 -07:00
s390 mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
score Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
sh mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
sparc sparc64: Increase max_phys_bits to 51 and VA bits to 53 for M8. 2017-08-04 11:08:53 -07:00
tile Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
um mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
unicore32 unicore32: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:52 +09:00
x86 x86/boot/KASLR: Prefer mirrored memory regions for the kernel physical address 2017-08-17 10:51:35 +02:00
xtensa Xtensa fixes for v4.13-rc4 2017-08-07 18:58:10 -07:00
.gitignore
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00