powerpc/mm: Warn if W+X pages found on boot

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Implement code to walk all pages and warn if any are found to be both
writable and executable.  Depends on STRICT_KERNEL_RWX enabled, and is
behind the DEBUG_WX config option.

This only runs on boot and has no runtime performance implications.

Very heavily influenced (and in some cases copied verbatim) from the
ARM64 code written by Laura Abbott (thanks!), since our ptdump
infrastructure is similar.

Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Fixup build error when disabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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This commit is contained in:

Russell Currey 2019-05-02 17:39:47 +10:00 • committed by Michael Ellerman

parent 5f18cbdbdd

commit 453d87f6a8

5 changed files with 73 additions and 1 deletions

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19

arch/powerpc/Kconfig.debug

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6

arch/powerpc/include/asm/pgtable.h

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3

arch/powerpc/mm/pgtable_32.c

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3

arch/powerpc/mm/pgtable_64.c

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43

arch/powerpc/mm/ptdump/ptdump.c

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