[PATCH v3 04/22] powerpc/book3e: Activate KUEP at all time
From: Christophe Leroy <hidden>
Date: 2021-10-19 07:30:08
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
On book3e, - When using 64 bits PTE: User pages don't have the SX bit defined so KUEP is always active. - When using 32 bits PTE: Implement KUEP by clearing SX bit during TLB miss for user pages. The impact is minimal and worth neither boot time nor build time selection. Activate it at all time. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/kernel/head_fsl_booke.S | 1 + arch/powerpc/platforms/Kconfig.cputype | 2 ++ 2 files changed, 3 insertions(+)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 0a9a0f301474..4622b50a5208 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S@@ -777,6 +777,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS) andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */ slwi r10, r12, 1 or r10, r10, r12 + rlwinm r10, r10, 0, ~_PAGE_EXEC /* Clear SX on user pages */ iseleq r12, r12, r10 rlwimi r13, r12, 0, 20, 31 /* Get RPN from PTE, merge w/ perms */ mtspr SPRN_MAS3, r13
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 6f2e8a4026ff..68361ab7078d 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype@@ -292,6 +292,8 @@ config PPC_FSL_BOOK3E select FSL_EMB_PERFMON select PPC_SMP_MUXED_IPI select PPC_DOORBELL + select PPC_HAVE_KUEP + select PPC_KUEP default y if FSL_BOOKE config PTE_64BIT
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2.31.1