Hello Thomas, On 07/11/2020 10:40, Thomas Bogendoerfer wrote: >> Linux doesn't own the memory immediately after the kernel image. On Octeon >> bootloader places a shared structure right close after the kernel _end, >> refer to "struct cvmx_bootinfo *octeon_bootinfo" in cavium-octeon/setup.c. >> >> If check_kernel_sections_mem() rounds the PFNs up, first memblock_alloc() >> inside early_init_dt_alloc_memory_arch() <= device_tree_init() returns >> memory block overlapping with the above octeon_bootinfo structure, which >> is being overwritten afterwards. > as this special for Octeon how about added the memblock_reserve > in octen specific code ?
while the shared structure which is being corrupted is indeed Octeon-specific, the wrong assumption that the memory right after the kernel can be allocated by memblock allocator and re-used somewhere in Linux is in MIPS-generic check_kernel_sections_mem(). I personally will be fine with repairing Octeon only as I don't have other MIPS targets to care about, but maybe someone else in the MIPS community will find this fix useful... -- Best regards, Alexander Sverdlin.
