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    SubjectRe: [RFC/RFT PATCH 2/5] memblock: introduce generic memblock_setup_resources()
    On Wed, Jun 02, 2021 at 09:15:02PM +0100, Russell King (Oracle) wrote:
    > On Wed, Jun 02, 2021 at 09:43:32PM +0300, Mike Rapoport wrote:
    > > Back then when __ex_table was moved from .data section, _sdata and _edata
    > > were part of the .data section. Today they are not. So something like the
    > > patch below will ensure for instance that __ex_table would be a part of
    > > "Kernel data" in /proc/iomem without moving it to the .data section:
    > >
    > This example has undesirable security implications. It moves the
    > exception table out of the read-only mappings into the read-write
    > mappings, thereby providing a way for an attacker to bypass the
    > read-only protection on the kernel and manipulate code pointers at
    > potentially known addresses for distro built kernels.

    My point was that __ex_table can be in "Kernel data" or "Kernel rodata"
    without loosing the ability to sort it.

    > You seem to be missing the point I've tried to make. The areas in
    > memblock that are marked "reserved" are the areas of reserved memory
    > from the firmware _plus_ the areas that the kernel has made during
    > boot which are of no consequence to userspace.

    I know what areas are marked "reserved" in memblock.
    I never suggested to report "ficticious" reserved areas in /proc/iomem
    unless an architecture already reports them there, like arm64 for example.

    You are right I should have described better the overall objective, but
    sill I feel that we keep missing each other points.

    I'll update the descriptions for the next repost, hopefully it'll help.

    --
    Sincerely yours,
    Mike.

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