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-rw-r--r--arch/powerpc/include/asm/kup.h4
-rw-r--r--arch/powerpc/include/asm/nohash/kup-booke.h110
-rw-r--r--arch/powerpc/include/asm/processor.h3
-rw-r--r--arch/powerpc/kernel/process.c3
-rw-r--r--arch/powerpc/mm/mmu_context.c6
-rw-r--r--arch/powerpc/mm/nohash/mmu_context.c6
6 files changed, 131 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 656e6f1d6b6f..fb2237809d63 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -14,6 +14,10 @@
#include <asm/nohash/32/kup-8xx.h>
#endif
+#ifdef CONFIG_BOOKE_OR_40x
+#include <asm/nohash/kup-booke.h>
+#endif
+
#ifdef CONFIG_PPC_BOOK3S_32
#include <asm/book3s/32/kup.h>
#endif
diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h
new file mode 100644
index 000000000000..49bb41ed0816
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/kup-booke.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KUP_BOOKE_H_
+#define _ASM_POWERPC_KUP_BOOKE_H_
+
+#include <asm/bug.h>
+
+#ifdef CONFIG_PPC_KUAP
+
+#ifdef __ASSEMBLY__
+
+.macro kuap_check_amr gpr1, gpr2
+.endm
+
+#else
+
+#include <linux/jump_label.h>
+#include <linux/sched.h>
+
+#include <asm/reg.h>
+
+extern struct static_key_false disable_kuap_key;
+
+static __always_inline bool kuap_is_disabled(void)
+{
+ return static_branch_unlikely(&disable_kuap_key);
+}
+
+static inline void __kuap_lock(void)
+{
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline void __kuap_save_and_lock(struct pt_regs *regs)
+{
+ regs->kuap = mfspr(SPRN_PID);
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+ if (kuap_is_disabled())
+ return;
+
+ mtspr(SPRN_PID, current->thread.pid);
+
+ /* Context synchronisation is performed by rfi */
+}
+
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+ if (regs->kuap)
+ mtspr(SPRN_PID, current->thread.pid);
+
+ /* Context synchronisation is performed by rfi */
+}
+
+static inline unsigned long __kuap_get_and_assert_locked(void)
+{
+ unsigned long kuap = mfspr(SPRN_PID);
+
+ if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+ WARN_ON_ONCE(kuap);
+
+ return kuap;
+}
+
+static inline void __allow_user_access(void __user *to, const void __user *from,
+ unsigned long size, unsigned long dir)
+{
+ mtspr(SPRN_PID, current->thread.pid);
+ isync();
+}
+
+static inline void __prevent_user_access(unsigned long dir)
+{
+ mtspr(SPRN_PID, 0);
+ isync();
+}
+
+static inline unsigned long __prevent_user_access_return(void)
+{
+ unsigned long flags = mfspr(SPRN_PID);
+
+ mtspr(SPRN_PID, 0);
+ isync();
+
+ return flags;
+}
+
+static inline void __restore_user_access(unsigned long flags)
+{
+ if (flags) {
+ mtspr(SPRN_PID, current->thread.pid);
+ isync();
+ }
+}
+
+static inline bool
+__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+ return !regs->kuap;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* CONFIG_PPC_KUAP */
+
+#endif /* _ASM_POWERPC_KUP_BOOKE_H_ */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index fe1ef1d7523b..2c8686d9e964 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -160,6 +160,9 @@ struct thread_struct {
unsigned long sr0;
#endif
#endif /* CONFIG_PPC32 */
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+ unsigned long pid; /* value written in PID reg. at interrupt exit */
+#endif
/* Debug Registers */
struct debug_reg debug;
#ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index afdcc2d3d470..790790dfb390 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1803,6 +1803,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
p->thread.kuap = KUAP_NONE;
#endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+ p->thread.pid = MMU_NO_CONTEXT;
+#endif
setup_ksp_vsid(p, sp);
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index e618d5442a28..735c36f26388 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -21,6 +21,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
#ifdef CONFIG_PPC_BOOK3S_32
tsk->thread.sr0 = mm->context.sr0;
#endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+ tsk->thread.pid = mm->context.id;
+#endif
}
#elif defined(CONFIG_PPC_BOOK3E_64)
static inline void switch_mm_pgdir(struct task_struct *tsk,
@@ -28,6 +31,9 @@ static inline void switch_mm_pgdir(struct task_struct *tsk,
{
/* 64-bit Book3E keeps track of current PGD in the PACA */
get_paca()->pgd = mm->pgd;
+#ifdef CONFIG_PPC_KUAP
+ tsk->thread.pid = mm->context.id;
+#endif
}
#else
static inline void switch_mm_pgdir(struct task_struct *tsk,
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index 44b2b5e7cabe..85b048f04c56 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -33,6 +33,7 @@
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/smp.h>
+#include <asm/kup.h>
#include <mm/mmu_decl.h>
@@ -217,7 +218,7 @@ static void set_context(unsigned long id, pgd_t *pgd)
/* sync */
mb();
- } else {
+ } else if (kuap_is_disabled()) {
if (IS_ENABLED(CONFIG_40x))
mb(); /* sync */
@@ -305,6 +306,9 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
if (IS_ENABLED(CONFIG_BDI_SWITCH))
abatron_pteptrs[1] = next->pgd;
set_context(id, next->pgd);
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+ tsk->thread.pid = id;
+#endif
raw_spin_unlock(&context_lock);
}