Messages in this thread Patch in this message | | | Date | Mon, 1 Apr 2019 16:38:10 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v2 1/1] initrd: move initrd_start calculate within linear mapping range check |
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[+Ard in case I'm missing something]
On Mon, Apr 01, 2019 at 10:59:53PM +0800, pierre kuo wrote: > > > 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.
I'm afraid that you've lost me with this. Why isn't it just as simple as the diff below?
Will
--->8
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index c29b17b520cd..ec3487c94b10 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -377,7 +377,7 @@ void __init arm64_memblock_init(void) base + size > memblock_start_of_DRAM() + linear_region_size, "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) { - initrd_start = 0; + phys_initrd_size = 0; } else { memblock_remove(base, size); /* clear MEMBLOCK_ flags */ memblock_add(base, size);
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