Messages in this thread | | | Date | Fri, 22 Mar 2019 06:21:27 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH 1/4] arm64, mm: Move generic mmap layout functions to mm |
| |
> It then introduces a new define ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT > that can be defined by other architectures to benefit from those functions.
Can you make this a Kconfig option defined in arch/Kconfig or mm/Kconfig and selected by the architectures?
> -#ifndef STACK_RND_MASK > -#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ > -#endif > - > -static unsigned long randomize_stack_top(unsigned long stack_top) > -{ > - unsigned long random_variable = 0; > - > - if (current->flags & PF_RANDOMIZE) { > - random_variable = get_random_long(); > - random_variable &= STACK_RND_MASK; > - random_variable <<= PAGE_SHIFT; > - } > -#ifdef CONFIG_STACK_GROWSUP > - return PAGE_ALIGN(stack_top) + random_variable; > -#else > - return PAGE_ALIGN(stack_top) - random_variable; > -#endif > -} > -
Maybe the move of this function can be split into another prep patch, as it is only very lightly related?
> +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ > + defined(ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
Not sure if it is wrіtten down somehwere or just convention, but I general see cpp defined statements aligned with spaces to the one on the previous line.
Except for these nitpicks this looks very nice to me, thanks for doing this work!
| |