Commit eb52f66f authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/kuap: KUAP enabling/disabling functions must be __always_inline 



Objtool reports following warnings:

  arch/powerpc/kernel/signal_32.o: warning: objtool:
    __prevent_user_access.constprop.0+0x4 (.text+0x4):
    redundant UACCESS disable

  arch/powerpc/kernel/signal_32.o: warning: objtool: user_access_begin+0x2c
    (.text+0x4c): return with UACCESS enabled

  arch/powerpc/kernel/signal_32.o: warning: objtool: handle_rt_signal32+0x188
    (.text+0x360): call to __prevent_user_access.constprop.0() with UACCESS enabled

  arch/powerpc/kernel/signal_32.o: warning: objtool: handle_signal32+0x150
    (.text+0x4d4): call to __prevent_user_access.constprop.0() with UACCESS enabled

This is due to some KUAP enabling/disabling functions being outline
allthough they are marked inline. Use __always_inline instead.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/ca5e50ddbec3867db5146ebddbc9a1dc0e443bc8.1689091022.git.christophe.leroy@csgroup.eu
parent 5222a1d5

arch/powerpc/include/asm/book3s/32/kup.h

+9 −9
Original line number Diff line number Diff line
@@ -15,19 +15,19 @@ 


#define KUAP_NONE	(~0UL)



static inline void kuap_lock_one(unsigned long addr)

static __always_inline void kuap_lock_one(unsigned long addr)

{

	mtsr(mfsr(addr) | SR_KS, addr);

	isync();	/* Context sync required after mtsr() */

}



static inline void kuap_unlock_one(unsigned long addr)

static __always_inline void kuap_unlock_one(unsigned long addr)

{

	mtsr(mfsr(addr) & ~SR_KS, addr);

	isync();	/* Context sync required after mtsr() */

}



static inline void __kuap_save_and_lock(struct pt_regs *regs)

static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)

{

	unsigned long kuap = current->thread.kuap;
@@ -40,11 +40,11 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs) 
}

#define __kuap_save_and_lock __kuap_save_and_lock



static inline void kuap_user_restore(struct pt_regs *regs)

static __always_inline void kuap_user_restore(struct pt_regs *regs)

{

}



static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

{

	if (unlikely(kuap != KUAP_NONE)) {

		current->thread.kuap = KUAP_NONE;
@@ -59,7 +59,7 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kua 
	kuap_unlock_one(regs->kuap);

}



static inline unsigned long __kuap_get_and_assert_locked(void)

static __always_inline unsigned long __kuap_get_and_assert_locked(void)

{

	unsigned long kuap = current->thread.kuap;
@@ -94,7 +94,7 @@ static __always_inline void __prevent_user_access(unsigned long dir) 
	kuap_lock_one(kuap);

}



static inline unsigned long __prevent_user_access_return(void)

static __always_inline unsigned long __prevent_user_access_return(void)

{

	unsigned long flags = current->thread.kuap;
@@ -106,7 +106,7 @@ static inline unsigned long __prevent_user_access_return(void) 
	return flags;

}



static inline void __restore_user_access(unsigned long flags)

static __always_inline void __restore_user_access(unsigned long flags)

{

	if (flags != KUAP_NONE) {

		current->thread.kuap = flags;
@@ -114,7 +114,7 @@ static inline void __restore_user_access(unsigned long flags) 
	}

}



static inline bool

static __always_inline bool

__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

{

	unsigned long kuap = regs->kuap;

arch/powerpc/include/asm/book3s/64/kup.h

+12 −11
Original line number Diff line number Diff line
@@ -213,14 +213,14 @@ extern u64 __ro_after_init default_iamr; 
 * access restrictions. Because of this ignore AMR value when accessing

 * userspace via kernel thread.

 */

static inline u64 current_thread_amr(void)

static __always_inline u64 current_thread_amr(void)

{

	if (current->thread.regs)

		return current->thread.regs->amr;

	return default_amr;

}



static inline u64 current_thread_iamr(void)

static __always_inline u64 current_thread_iamr(void)

{

	if (current->thread.regs)

		return current->thread.regs->iamr;
@@ -230,7 +230,7 @@ static inline u64 current_thread_iamr(void) 


#ifdef CONFIG_PPC_KUAP



static inline void kuap_user_restore(struct pt_regs *regs)

static __always_inline void kuap_user_restore(struct pt_regs *regs)

{

	bool restore_amr = false, restore_iamr = false;

	unsigned long amr, iamr;
@@ -269,7 +269,7 @@ static inline void kuap_user_restore(struct pt_regs *regs) 
	 */

}



static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)

static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)

{

	if (likely(regs->amr == amr))

		return;
@@ -285,7 +285,7 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr 
	 */

}



static inline unsigned long __kuap_get_and_assert_locked(void)

static __always_inline unsigned long __kuap_get_and_assert_locked(void)

{

	unsigned long amr = mfspr(SPRN_AMR);
@@ -302,7 +302,7 @@ static inline unsigned long __kuap_get_and_assert_locked(void) 
 * because that would require an expensive read/modify write of the AMR.

 */



static inline unsigned long get_kuap(void)

static __always_inline unsigned long get_kuap(void)

{

	/*

	 * We return AMR_KUAP_BLOCKED when we don't support KUAP because
@@ -332,7 +332,8 @@ static __always_inline void set_kuap(unsigned long value) 
	isync();

}



static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

static __always_inline bool

__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

{

	/*

	 * For radix this will be a storage protection fault (DSISR_PROTFAULT).
@@ -375,12 +376,12 @@ static __always_inline void allow_user_access(void __user *to, const void __user 


#else /* CONFIG_PPC_KUAP */



static inline unsigned long get_kuap(void)

static __always_inline unsigned long get_kuap(void)

{

	return AMR_KUAP_BLOCKED;

}



static inline void set_kuap(unsigned long value) { }

static __always_inline void set_kuap(unsigned long value) { }



static __always_inline void allow_user_access(void __user *to, const void __user *from,

					      unsigned long size, unsigned long dir)
@@ -395,7 +396,7 @@ static __always_inline void prevent_user_access(unsigned long dir) 
		do_uaccess_flush();

}



static inline unsigned long prevent_user_access_return(void)

static __always_inline unsigned long prevent_user_access_return(void)

{

	unsigned long flags = get_kuap();
@@ -406,7 +407,7 @@ static inline unsigned long prevent_user_access_return(void) 
	return flags;

}



static inline void restore_user_access(unsigned long flags)

static __always_inline void restore_user_access(unsigned long flags)

{

	set_kuap(flags);

	if (static_branch_unlikely(&uaccess_flush_key) && flags == AMR_KUAP_BLOCKED)

arch/powerpc/include/asm/kup.h

+8 −8
Original line number Diff line number Diff line
@@ -57,14 +57,14 @@ static inline void setup_kuap(bool disabled) { } 


static __always_inline bool kuap_is_disabled(void) { return true; }



static inline bool

static __always_inline bool

__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

{

	return false;

}



static inline void kuap_user_restore(struct pt_regs *regs) { }

static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }

static __always_inline void kuap_user_restore(struct pt_regs *regs) { }

static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }



/*

 * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
@@ -72,11 +72,11 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr 
 * platforms.

 */

#ifndef CONFIG_PPC_BOOK3S_64

static inline void __allow_user_access(void __user *to, const void __user *from,

static __always_inline void __allow_user_access(void __user *to, const void __user *from,

						unsigned long size, unsigned long dir) { }

static inline void __prevent_user_access(unsigned long dir) { }

static inline unsigned long __prevent_user_access_return(void) { return 0UL; }

static inline void __restore_user_access(unsigned long flags) { }

static __always_inline void __prevent_user_access(unsigned long dir) { }

static __always_inline unsigned long __prevent_user_access_return(void) { return 0UL; }

static __always_inline void __restore_user_access(unsigned long flags) { }

#endif /* CONFIG_PPC_BOOK3S_64 */

#endif /* CONFIG_PPC_KUAP */

arch/powerpc/include/asm/nohash/32/kup-8xx.h

+10 −10
Original line number Diff line number Diff line
@@ -11,24 +11,24 @@ 


#include <asm/reg.h>



static inline void __kuap_save_and_lock(struct pt_regs *regs)

static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)

{

	regs->kuap = mfspr(SPRN_MD_AP);

	mtspr(SPRN_MD_AP, MD_APG_KUAP);

}

#define __kuap_save_and_lock __kuap_save_and_lock



static inline void kuap_user_restore(struct pt_regs *regs)

static __always_inline void kuap_user_restore(struct pt_regs *regs)

{

}



static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

{

	mtspr(SPRN_MD_AP, regs->kuap);

}



#ifdef CONFIG_PPC_KUAP_DEBUG

static inline unsigned long __kuap_get_and_assert_locked(void)

static __always_inline unsigned long __kuap_get_and_assert_locked(void)

{

	WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16);
@@ -37,18 +37,18 @@ static inline unsigned long __kuap_get_and_assert_locked(void) 
#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked

#endif



static inline void __allow_user_access(void __user *to, const void __user *from,

static __always_inline void __allow_user_access(void __user *to, const void __user *from,

						unsigned long size, unsigned long dir)

{

	mtspr(SPRN_MD_AP, MD_APG_INIT);

}



static inline void __prevent_user_access(unsigned long dir)

static __always_inline void __prevent_user_access(unsigned long dir)

{

	mtspr(SPRN_MD_AP, MD_APG_KUAP);

}



static inline unsigned long __prevent_user_access_return(void)

static __always_inline unsigned long __prevent_user_access_return(void)

{

	unsigned long flags;
@@ -59,12 +59,12 @@ static inline unsigned long __prevent_user_access_return(void) 
	return flags;

}



static inline void __restore_user_access(unsigned long flags)

static __always_inline void __restore_user_access(unsigned long flags)

{

	mtspr(SPRN_MD_AP, flags);

}



static inline bool

static __always_inline bool

__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

{

	return !((regs->kuap ^ MD_APG_KUAP) & 0xff000000);

arch/powerpc/include/asm/nohash/kup-booke.h

+11 −11
Original line number Diff line number Diff line
@@ -17,14 +17,14 @@ 


#include <asm/reg.h>



static inline void __kuap_lock(void)

static __always_inline void __kuap_lock(void)

{

	mtspr(SPRN_PID, 0);

	isync();

}

#define __kuap_lock __kuap_lock



static inline void __kuap_save_and_lock(struct pt_regs *regs)

static __always_inline void __kuap_save_and_lock(struct pt_regs *regs)

{

	regs->kuap = mfspr(SPRN_PID);

	mtspr(SPRN_PID, 0);
@@ -32,7 +32,7 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs) 
}

#define __kuap_save_and_lock __kuap_save_and_lock



static inline void kuap_user_restore(struct pt_regs *regs)

static __always_inline void kuap_user_restore(struct pt_regs *regs)

{

	if (kuap_is_disabled())

		return;
@@ -42,7 +42,7 @@ static inline void kuap_user_restore(struct pt_regs *regs) 
	/* Context synchronisation is performed by rfi */

}



static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

static __always_inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)

{

	if (regs->kuap)

		mtspr(SPRN_PID, current->thread.pid);
@@ -51,7 +51,7 @@ static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kua 
}



#ifdef CONFIG_PPC_KUAP_DEBUG

static inline unsigned long __kuap_get_and_assert_locked(void)

static __always_inline unsigned long __kuap_get_and_assert_locked(void)

{

	WARN_ON_ONCE(mfspr(SPRN_PID));
@@ -60,20 +60,20 @@ static inline unsigned long __kuap_get_and_assert_locked(void) 
#define __kuap_get_and_assert_locked __kuap_get_and_assert_locked

#endif



static inline void __allow_user_access(void __user *to, const void __user *from,

static __always_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)

static __always_inline void __prevent_user_access(unsigned long dir)

{

	mtspr(SPRN_PID, 0);

	isync();

}



static inline unsigned long __prevent_user_access_return(void)

static __always_inline unsigned long __prevent_user_access_return(void)

{

	unsigned long flags = mfspr(SPRN_PID);
@@ -83,7 +83,7 @@ static inline unsigned long __prevent_user_access_return(void) 
	return flags;

}



static inline void __restore_user_access(unsigned long flags)

static __always_inline void __restore_user_access(unsigned long flags)

{

	if (flags) {

		mtspr(SPRN_PID, current->thread.pid);
@@ -91,7 +91,7 @@ static inline void __restore_user_access(unsigned long flags) 
	}

}



static inline bool

static __always_inline bool

__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)

{

	return !regs->kuap;