[PATCH v4 06/23] powerpc/32s: Create C version of kuap_user/kernel_restore() and friends
From: Christophe Leroy <hidden>
Date: 2021-01-25 14:55:30
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_user_restore() and kuap_kernel_restore() and kuap_check() and kuap_get_and_check() on book3s/32. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/book3s/32/kup.h | 33 ++++++++++++++++++++++++ 1 file changed, 33 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index a0117a9d5b06..a3e72e1141c5 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h@@ -103,6 +103,39 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end) isync(); /* Context sync required after mtsrin() */ } +static inline void kuap_user_restore(struct pt_regs *regs) +{ +} + +static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap) +{ + u32 addr = kuap & 0xf0000000; + u32 end = kuap << 28; + + if (unlikely(!kuap)) + return; + + current->thread.kuap = 0; + kuap_update_sr(mfsrin(addr) & ~SR_KS, addr, end); /* Clear Ks */ +} + +static inline void kuap_check(void) +{ + if (!IS_ENABLED(CONFIG_PPC_KUAP_DEBUG)) + return; + + WARN_ON_ONCE(current->thread.kuap != 0); +} + +static inline unsigned long kuap_get_and_check(void) +{ + unsigned long kuap = current->thread.kuap; + + WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != 0); + + return kuap; +} + static __always_inline void allow_user_access(void __user *to, const void __user *from, u32 size, unsigned long dir) {
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2.25.0