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powerpc/book3e: Activate KUEP at all time

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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 <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e376b114283fb94504e2aa2de846780063252cde.1634627931.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-10-19 09:29:15 +02:00 committed by Michael Ellerman
parent ee2631603f
commit dc3a0e5b83
2 changed files with 3 additions and 0 deletions
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1
arch/powerpc/kernel/head_fsl_booke.S
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@ -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

2
arch/powerpc/platforms/Kconfig.cputype
View File

@ -299,6 +299,8 @@ 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