[PATCH v3 40/41] powerpc/8xx: Create C version of kuap save/restore/check helpers
From: Christophe Leroy <hidden>
Date: 2021-03-12 12:52:18
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
In preparation of porting PPC32 to C syscall entry/exit, create C version of kuap_save_and_lock() and kuap_user_restore() and kuap_kernel_restore() and kuap_assert_locked() and kuap_get_and_assert_locked() on 8xx. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/nohash/32/kup-8xx.h | 31 ++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 17a4a616436f..e6b5ebca47e5 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h@@ -34,6 +34,37 @@ #include <asm/reg.h> +static inline void kuap_save_and_lock(struct pt_regs *regs) +{ + regs->kuap = mfspr(SPRN_MD_AP); + mtspr(SPRN_MD_AP, MD_APG_KUAP); +} + +static inline void kuap_user_restore(struct pt_regs *regs) +{ +} + +static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap) +{ + mtspr(SPRN_MD_AP, regs->kuap); +} + +static inline unsigned long kuap_get_and_assert_locked(void) +{ + unsigned long kuap = mfspr(SPRN_MD_AP); + + if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) + WARN_ON_ONCE(kuap >> 16 != MD_APG_KUAP >> 16); + + return kuap; +} + +static inline void kuap_assert_locked(void) +{ + if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) + kuap_get_and_assert_locked(); +} + static inline void allow_user_access(void __user *to, const void __user *from, unsigned long size, unsigned long dir) {
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2.25.0