[PATCH v2 0/6] powerpc/32s: Allocate modules outside of vmalloc space for STRICT_KERNEL_RWX

From: Christophe Leroy
Date: Mon Jun 29 2020 - 17:23:52 EST


On book3s32 (hash), exec protection is set per 256Mb segments with NX bit.
Instead of clearing NX bit on vmalloc space when CONFIG_MODULES is selected,
allocate modules in a dedicated segment (0xb0000000-0xbfffffff by default).
This allows to keep exec protection on vmalloc space while allowing exec
on modules.

v2:
- Removed the two patches that fix ptdump. Will submitted independently
- Only changing the user/kernel boundary for PPC32 now.
- Reordered the patches inside the series.

Christophe Leroy (6):
powerpc/lib: Prepare code-patching for modules allocated outside
vmalloc space
powerpc: Use MODULES_VADDR if defined
powerpc/32s: Only leave NX unset on segments used for modules
powerpc/32: Set user/kernel boundary at TASK_SIZE instead of
PAGE_OFFSET
powerpc/32s: Kernel space starts at TASK_SIZE
powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX

arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/book3s/32/pgtable.h | 15 +++++----------
arch/powerpc/include/asm/page.h | 4 +++-
arch/powerpc/kernel/head_32.S | 12 ++++++------
arch/powerpc/kernel/module.c | 11 +++++++++++
arch/powerpc/lib/code-patching.c | 2 +-
arch/powerpc/mm/book3s32/hash_low.S | 2 +-
arch/powerpc/mm/book3s32/mmu.c | 17 ++++++++++++++---
arch/powerpc/mm/kasan/kasan_init_32.c | 6 ++++++
arch/powerpc/mm/ptdump/ptdump.c | 16 ++++++++++++++--
10 files changed, 62 insertions(+), 24 deletions(-)

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2.25.0