Commit Graph

6 Commits

Author SHA1 Message Date
Matt Redfearn
ec62a3bd84 MIPS: KASLR: Add missing header files
After the split of linux/sched.h, KASLR stopped building.

Fix this by including the correct header file for init_thread_union

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Steven J. Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15849/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-12 17:02:04 +02:00
Marcin Nowakowski
4c9fff3622 MIPS: relocate: Optionally relocate the DTB
If the DTB is located in the target memory area for the relocated kernel
it needs to be relocated as well before kernel relocation takes place.

After copying the DTB use the new plat_fdt_relocated() API from the
relocated kernel to ensure the relocated kernel updates any information
that it may have cached about the location of the DTB.

plat_fdt_relocated is declared as a weak symbol so that platforms that
do not require it do not need to implement the method.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14616/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03 16:34:45 +01:00
Steven J. Hill
8cc709d7d4 MIPS: Relocatable: Provide plat_post_relocation hook
This hook provides the platform the chance to perform any required
setup before the boot processor switches to the relocated kernel.
The relocated kernel has been copied and fixed up ready for execution
at this point. Secondary CPUs may wish to switch to it early. There
is also the opportunity for the platform to abort jumping to the
relocated kernel if there is anything wrong with the chosen offset.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: Steven J. Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14651/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03 16:34:36 +01:00
Matt Redfearn
4736697963 MIPS: KASLR: Fix handling of NULL FDT
If platform code returns a NULL pointer to the FDT, initial_boot_params
will not get set to a valid pointer and attempting to find the /chosen
node in it will cause a NULL pointer dereference and the kernel to crash
immediately on startup - with no output to the console.

Fix this by checking that initial_boot_params is valid before using it.

Fixes: 405bc8fd12 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14414/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04 00:30:49 +01:00
Matt Redfearn
405bc8fd12 MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE
This patch adds KASLR to the MIPS kernel.

Entropy is derived from the banner, which will change every build and
random_get_entropy() which should provide additional runtime entropy.
Additionally the bootloader may pass entropy via the /chosen/kaslr-seed
node in device tree.

The kernel is relocated by up to RANDOMIZE_BASE_MAX_OFFSET bytes from
its link address (PHYSICAL_START). Because relocation happens so early
in the kernel boot, the amount of physical memory has not yet been
determined. This means the only way to limit relocation within the
available memory is via Kconfig.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12990/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:03 +02:00
Matt Redfearn
279b991b24 MIPS: Kernel: Add relocate.c
arch/mips/kernel/relocate.c contains the functions necessary to relocate
the kernel elsewhere in memory

The kernel makes a copy of itself at the new address. It uses the
relocation table inserted by the relocs tool to fix symbol references
within the new image.

If copy/relocation is sucessful then the entry point of the new kernel
is returned, otherwise fall back to starting the kernel in place.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12985/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:02 +02:00