[PATCH v1 0/8] powerpc/32s: Allocate modules outside of vmalloc space for STRICT_KERNEL_RWX

From: Christophe Leroy
Date: Fri Jun 19 2020 - 11:07:09 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.

Christophe Leroy (8):
powerpc/ptdump: Refactor update of st->last_pa
powerpc/ptdump: Refactor update of pg_state
powerpc: Set user/kernel boundary at TASK_SIZE instead of PAGE_OFFSET
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/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 | 2 +-
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 | 53 ++++++++++++--------
10 files changed, 78 insertions(+), 43 deletions(-)

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2.25.0