From: Zhen Lei <thunder.leizhen@xxxxxxxxxx> Unlike in the past, the low memory allocation direction of the crashkernel is changed from top-down to bottom-up. As long as the DMA zone has sufficient continuous free memory, the allocated crashkernel low memory must meet the requirements. The allocation direction of crashkernel high memory remains unchanged, that is, top-down. As long as the high memory(above DMA zone) has sufficient continuous free memory, the allocated crashkernel high memory must meet the requirements. In this way, with the restoration of the original page-level mapping and the implementation of the arch_kexec_protect_crashkres() function, write protection for the crashkernel memory region can be supported. Of course, if the high memory or low memory cannot meet the initial requirements, that is, fall back is required. In this case, write protection is not supported because the newly allocated memory is not page-level mapped. Because the original retry process is eliminated, the new process looks clearer and is a simple sequential flow. Zhen Lei (3): arm64: kdump: Allocate crash low memory in the bottom-up direction arm64: kdump: use page-level mapping for crashkernel region arm64: kdump: add support access protection for crashkernel region arch/arm64/include/asm/kexec.h | 8 ++ arch/arm64/kernel/machine_kexec.c | 26 ++++ arch/arm64/mm/init.c | 216 +++++++++++++++++++++++------- arch/arm64/mm/mmu.c | 21 +++ 4 files changed, 219 insertions(+), 52 deletions(-) -- 2.25.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
