8 files changed, 33 insertions, 14 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e2f7ccc13edb..7be27862329f 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -175,9 +175,14 @@ struct hash_pte {
 
 typedef struct {
 	unsigned long id;
+	unsigned long sr0;
 	void __user *vdso;
 } mm_context_t;
 
+#ifdef CONFIG_PPC_KUEP
+#define INIT_MM_CONTEXT(mm) .context.sr0 = SR_NX
+#endif
+
 void update_bats(void);
 static inline void cleanup_cpu_mmu_context(void) { }
 
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 978a80308466..fe1ef1d7523b 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -157,6 +157,7 @@ struct thread_struct {
 #ifdef CONFIG_PPC_BOOK3S_32
 	unsigned long	r0, r3, r4, r5, r6, r8, r9, r11;
 	unsigned long	lr, ctr;
+	unsigned long	sr0;
 #endif
 #endif /* CONFIG_PPC32 */
 	/* Debug Registers */
@@ -278,6 +279,12 @@ struct thread_struct {
 #define SPEFSCR_INIT
 #endif
 
+#ifdef CONFIG_PPC_BOOK3S_32
+#define SR0_INIT	.sr0 = IS_ENABLED(CONFIG_PPC_KUEP) ? SR_NX : 0,
+#else
+#define SR0_INIT
+#endif
+
 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
 #define INIT_THREAD { \
 	.ksp = INIT_SP, \
@@ -285,6 +292,7 @@ struct thread_struct {
 	.kuap = ~0UL, /* KUAP_NONE */ \
 	.fpexc_mode = MSR_FE0 | MSR_FE1, \
 	SPEFSCR_INIT \
+	SR0_INIT \
 }
 #elif defined(CONFIG_PPC32)
 #define INIT_THREAD { \
@@ -292,6 +300,7 @@ struct thread_struct {
 	.pgdir = swapper_pg_dir, \
 	.fpexc_mode = MSR_FE0 | MSR_FE1, \
 	SPEFSCR_INIT \
+	SR0_INIT \
 }
 #else
 #define INIT_THREAD  { \
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b823f484c640..cf3436b7b166 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -139,6 +139,7 @@ int main(void)
 	OFFSET(THR11, thread_struct, r11);
 	OFFSET(THLR, thread_struct, lr);
 	OFFSET(THCTR, thread_struct, ctr);
+	OFFSET(THSR0, thread_struct, sr0);
 #endif
 #ifdef CONFIG_SPE
 	OFFSET(THREAD_EVR0, thread_struct, evr[0]);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0756829b2f7f..035bf4f3eb5d 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -76,15 +76,13 @@ _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)
 #if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
 	.globl	__kuep_lock
 __kuep_lock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,3
-	oris    r9,r9,SR_NX@h
+	lwz	r9, THREAD+THSR0(r2)
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
 
 __kuep_unlock:
-	mfsr    r9,0
-	rlwinm  r9,r9,0,8,2
+	lwz	r9, THREAD+THSR0(r2)
+	rlwinm  r9,r9,0,~SR_NX
 	update_user_segments_by_4 r9, r10, r11, r12
 	blr
 
diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c
index 0f920f09af57..28676cabb005 100644
--- a/arch/powerpc/mm/book3s32/kuap.c
+++ b/arch/powerpc/mm/book3s32/kuap.c
@@ -20,8 +20,11 @@ EXPORT_SYMBOL(kuap_unlock_all_ool);
 
 void setup_kuap(bool disabled)
 {
-	if (!disabled)
+	if (!disabled) {
 		kuap_lock_all_ool();
+		init_mm.context.sr0 |= SR_KS;
+		current->thread.sr0 |= SR_KS;
+	}
 
 	if (smp_processor_id() != boot_cpuid)
 		return;
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index bac1420d028b..78fc48eee510 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <asm/code-patching.h>
 #include <asm/kup.h>
 #include <asm/smp.h>
 
diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c
index e2708e387dc3..269a3eb25a73 100644
--- a/arch/powerpc/mm/book3s32/mmu_context.c
+++ b/arch/powerpc/mm/book3s32/mmu_context.c
@@ -69,6 +69,12 @@ EXPORT_SYMBOL_GPL(__init_new_context);
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
 	mm->context.id = __init_new_context();
+	mm->context.sr0 = CTX_TO_VSID(mm->context.id, 0);
+
+	if (!kuep_is_disabled())
+		mm->context.sr0 |= SR_NX;
+	if (!kuap_is_disabled())
+		mm->context.sr0 |= SR_KS;
 
 	return 0;
 }
@@ -108,20 +114,13 @@ void __init mmu_context_init(void)
 void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
 {
 	long id = next->context.id;
-	unsigned long val;
 
 	if (id < 0)
 		panic("mm_struct %p has no context ID", next);
 
 	isync();
 
-	val = CTX_TO_VSID(id, 0);
-	if (!kuep_is_disabled())
-		val |= SR_NX;
-	if (!kuap_is_disabled())
-		val |= SR_KS;
-
-	update_user_segments(val);
+	update_user_segments(next->context.sr0);
 
 	if (IS_ENABLED(CONFIG_BDI_SWITCH))
 		abatron_pteptrs[1] = next->pgd;
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 74246536b832..e618d5442a28 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -18,6 +18,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
 {
 	/* 32-bit keeps track of the current PGDIR in the thread struct */
 	tsk->thread.pgdir = mm->pgd;
+#ifdef CONFIG_PPC_BOOK3S_32
+	tsk->thread.sr0 = mm->context.sr0;
+#endif
 }
 #elif defined(CONFIG_PPC_BOOK3E_64)
 static inline void switch_mm_pgdir(struct task_struct *tsk,