With hash translation, the kernel will use key 3 for implementing KUAP feature. Hence the default UAMOR value depends on what other keys are marked reserved. Move the UAMOR initialization to pkeys init.
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> --- arch/powerpc/include/asm/book3s/64/kup.h | 2 ++ arch/powerpc/kernel/smp.c | 5 +++++ arch/powerpc/mm/book3s64/pkeys.c | 25 +++++++++++++++++++----- 3 files changed, 27 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h index f4fb651f5850..1b350bf781ec 100644 --- a/arch/powerpc/include/asm/book3s/64/kup.h +++ b/arch/powerpc/include/asm/book3s/64/kup.h @@ -67,6 +67,8 @@ #include <asm/mmu.h> #include <asm/ptrace.h> +extern u64 default_uamor; + static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { if (mmu_has_feature(MMU_FTR_KUAP)) { diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 6d2a3a3666f0..4cd5b620c08c 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -59,6 +59,7 @@ #include <asm/asm-prototypes.h> #include <asm/cpu_has_feature.h> #include <asm/ftrace.h> +#include <asm/kup.h> #ifdef DEBUG #include <asm/udbg.h> @@ -1256,6 +1257,10 @@ void start_secondary(void *unused) mmgrab(&init_mm); current->active_mm = &init_mm; +#ifdef CONFIG_PPC_MEM_KEYS + mtspr(SPRN_UAMOR, default_uamor); +#endif + smp_store_cpu_info(cpu); set_dec(tb_ticks_per_jiffy); preempt_disable(); diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index 7498c9a8ef74..12a9ac169f5d 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -23,7 +23,7 @@ static u32 initial_allocation_mask; /* Bits set for the initially allocated k static u64 default_amr; static u64 default_iamr; /* Allow all keys to be modified by default */ -static u64 default_uamor = ~0x0UL; +u64 default_uamor = ~0x0UL; /* * Key used to implement PROT_EXEC mmap. Denies READ/WRITE * We pick key 2 because 0 is special key and 1 is reserved as per ISA. @@ -112,8 +112,16 @@ void __init pkey_early_init_devtree(void) /* scan the device tree for pkey feature */ pkeys_total = scan_pkey_feature(); if (!pkeys_total) { - /* No support for pkey. Mark it disabled */ - return; + /* + * No key support but on radix we can use key 0 + * to implement kuap. + */ + if (early_radix_enabled()) + /* + * Make sure userspace can't change the AMR + */ + default_uamor = 0; + goto err_out; } cur_cpu_spec->mmu_features |= MMU_FTR_PKEY; @@ -195,6 +203,12 @@ void __init pkey_early_init_devtree(void) */ initial_allocation_mask |= reserved_allocation_mask; +err_out: + /* + * Setup uamor on boot cpu + */ + mtspr(SPRN_UAMOR, default_uamor); + return; } @@ -230,8 +244,9 @@ void __init setup_kuap(bool disabled) cur_cpu_spec->mmu_features |= MMU_FTR_KUAP; } - /* Make sure userspace can't change the AMR */ - mtspr(SPRN_UAMOR, 0); + /* + * Set the default kernel AMR values on all cpus. + */ mtspr(SPRN_AMR, AMR_KUAP_BLOCKED); isync(); } -- 2.26.2