Messages in this thread | | | From | Daniel Axtens <> | Subject | Re: [PATCH v3 2/4] mm: Make generic arch_is_kernel_initmem_freed() do what it says | Date | Fri, 01 Oct 2021 17:14:41 +1000 |
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> #ifdef __KERNEL__ > +/* > + * Check if an address is part of freed initmem. After initmem is freed, > + * memory can be allocated from it, and such allocations would then have > + * addresses within the range [_stext, _end]. > + */ > +#ifndef arch_is_kernel_initmem_freed > +static int arch_is_kernel_initmem_freed(unsigned long addr) > +{ > + if (system_state < SYSTEM_FREEING_INITMEM) > + return 0; > + > + return init_section_contains((void *)addr, 1);
Is init_section_contains sufficient here?
include/asm-generic/sections.h says: * [__init_begin, __init_end]: contains .init.* sections, but .init.text.* * may be out of this range on some architectures. * [_sinittext, _einittext]: contains .init.text.* sections
init_section_contains only checks __init_*: static inline bool init_section_contains(void *virt, size_t size) { return memory_contains(__init_begin, __init_end, virt, size); }
Do we need to check against _sinittext and _einittext?
Your proposed generic code will work for powerpc and s390 because those archs only test against __init_* anyway. I don't know if any platform actually does place .init.text outside of __init_begin=>__init_end, but the comment seems to suggest that they could.
Kind regards, Daniel
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