Messages in this thread | | | From | pierre kuo <> | Date | Mon, 1 Apr 2019 22:59:53 +0800 | Subject | Re: [PATCH v2 1/1] initrd: move initrd_start calculate within linear mapping range check |
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hi Catalin:
> > With CONFIG_RANDOMIZE_BASE we can get a further change to memstart_addr > > after the place where you moved the initrd_{start,end} setting, which > > would result in a different value for __phys_to_virt(phys_initrd_start). > > I found what you mean, since __phys_to_virt will use PHYS_OFFSET > (memstart_addr) for calculating. > How about moving CONFIG_RANDOMIZE_BASE part of code ahead of > CONFIG_BLK_DEV_INITRD checking? > > That means below (d) moving ahead of (c) > prvious: > if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {} ---(a) > if (memory_limit != PHYS_ADDR_MAX) {} ---(b) > if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {} ---(c) > if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {} ---(d) > > now: > if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) { ---(a) > if (memory_limit != PHYS_ADDR_MAX) {} ----------------(b) > if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {} --------------(d) > if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {} ---(c) >
After tracing the kernel code, is it even possible to move CONFIG_RANDOMIZE_BASE part of code ahead of memory_limit?
that mean the flow may look like below: now2: if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {} ---(a) if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {} ---(d) if (memory_limit != PHYS_ADDR_MAX) {} ---(b) if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {} ---(c)
in (b), the result of __pa_symbol(_text), memory_limit, memblock_mem_limit_remove_map and memblock_add are not depended on memsart_addr. So the now2 flow can grouping modification of memstart_address, put (a) and (d) together.
Sincerely Appreciate your comment.
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