[PATCH v3 10/10] powerpc/fsl_booke: Enable STRICT_KERNEL_RWX
From: Christophe Leroy <hidden>
Date: 2021-10-25 21:50:05
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Enable STRICT_KERNEL_RWX on fsl_booke. For that, we need additional TLBCAMs dedicated to linear mapping, based on the alignment of _sinittext. By default, up to 768 Mbytes of memory are mapped. It uses 3 TLBCAMs of size 256 Mbytes. With a data alignment of 16, we need up to 9 TLBCAMs: 16/16/16/16/64/64/64/256/256 With a data alignment of 4, we need up to 12 TLBCAMs: 4/4/4/4/16/16/16/64/64/64/256/256 With a data alignment of 1, we need up to 15 TLBCAMs: 1/1/1/1/4/4/4/16/16/16/64/64/64/256/256 By default, set a 16 Mbytes alignment as a compromise between memory usage and number of TLBCAMs. This can be adjusted manually when needed. For the time being, it doens't work when the base is randomised. Signed-off-by: Christophe Leroy <redacted> --- v3: No change v2: No change --- arch/powerpc/Kconfig | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6b9f523882c5..939a47642a9c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -139,6 +139,7 @@ config PPC select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64 select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION + select ARCH_HAS_STRICT_KERNEL_RWX if FSL_BOOKE && !HIBERNATION && !RANDOMIZE_BASE select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX && !PPC_BOOK3S_32 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UACCESS_FLUSHCACHE
@@ -778,7 +779,8 @@ config DATA_SHIFT_BOOL bool "Set custom data alignment" depends on ADVANCED_OPTIONS depends on STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE - depends on PPC_BOOK3S_32 || (PPC_8xx && !PIN_TLB_DATA && !STRICT_KERNEL_RWX) + depends on PPC_BOOK3S_32 || (PPC_8xx && !PIN_TLB_DATA && !STRICT_KERNEL_RWX) || \ + FSL_BOOKE help This option allows you to set the kernel data alignment. When RAM is mapped by blocks, the alignment needs to fit the size and
@@ -791,11 +793,13 @@ config DATA_SHIFT default 24 if STRICT_KERNEL_RWX && PPC64 range 17 28 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE) && PPC_BOOK3S_32 range 19 23 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE) && PPC_8xx + range 20 24 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE) && PPC_FSL_BOOKE default 22 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default 18 if (DEBUG_PAGEALLOC || KFENCE) && PPC_BOOK3S_32 default 23 if STRICT_KERNEL_RWX && PPC_8xx default 23 if (DEBUG_PAGEALLOC || KFENCE) && PPC_8xx && PIN_TLB_DATA default 19 if (DEBUG_PAGEALLOC || KFENCE) && PPC_8xx + default 24 if STRICT_KERNEL_RWX && FSL_BOOKE default PPC_PAGE_SHIFT help On Book3S 32 (603+), DBATs are used to map kernel text and rodata RO.
@@ -1123,7 +1127,10 @@ config LOWMEM_CAM_NUM_BOOL config LOWMEM_CAM_NUM depends on FSL_BOOKE int "Number of CAMs to use to map low memory" if LOWMEM_CAM_NUM_BOOL - default 3 + default 3 if !STRICT_KERNEL_RWX + default 9 if DATA_SHIFT >= 24 + default 12 if DATA_SHIFT >= 22 + default 15 config DYNAMIC_MEMSTART bool "Enable page aligned dynamic load address for kernel"
--
2.31.1