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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-06-03 08:41:43 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-17 00:09:08 +1000 |
| commit | 6b4d630068b0c5cdd6d8e599182b131448e0cb06 (patch) | |
| tree | 4a1ceca50d4db3cb5dd4c5e0e0abdd68ff525b71 /arch/powerpc/mm | |
| parent | 50d2f104cd9572af476579eae9aa1b38de602ec7 (diff) | |
| download | linux-6b4d630068b0c5cdd6d8e599182b131448e0cb06.tar.gz linux-6b4d630068b0c5cdd6d8e599182b131448e0cb06.tar.bz2 linux-6b4d630068b0c5cdd6d8e599182b131448e0cb06.zip | |
powerpc/32s: Allow disabling KUAP at boot time
PPC64 uses MMU features to enable/disable KUAP at boot time.
But feature fixups are applied way too early on PPC32.
Now that all KUAP related actions are in C following the
conversion of KUAP initial setup and context switch in C,
static branches can be used to enable/disable KUAP.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Export disable_kuap_key to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cd79e8008455fba5395d099f9bb1305c039b931c.1622708530.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/book3s32/kuap.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c index 5533ed92ab3d..0e59c8b32c4f 100644 --- a/arch/powerpc/mm/book3s32/kuap.c +++ b/arch/powerpc/mm/book3s32/kuap.c @@ -3,15 +3,19 @@ #include <asm/kup.h> #include <asm/smp.h> +struct static_key_false disable_kuap_key; +EXPORT_SYMBOL(disable_kuap_key); + void __init setup_kuap(bool disabled) { - kuap_update_sr(mfsr(0) | SR_KS, 0, TASK_SIZE); + if (!disabled) + kuap_update_sr(mfsr(0) | SR_KS, 0, TASK_SIZE); if (smp_processor_id() != boot_cpuid) return; - pr_info("Activating Kernel Userspace Access Protection\n"); - if (disabled) - pr_warn("KUAP cannot be disabled yet on 6xx when compiled in\n"); + static_branch_enable(&disable_kuap_key); + else + pr_info("Activating Kernel Userspace Access Protection\n"); } |