Re: [RFC WIP PATCH] powerpc/32: system call implement entry/exit logic in C

From: Christophe Leroy <hidden>
Date: 2020-04-01 11:48:21
Also in: lkml


Le 31/03/2020 à 17:22, Christophe Leroy a écrit :

That's first try to port PPC64 syscall entry/exit logic in C to PPC32.
I've do the minimum to get it work. I have not reworked calls
to sys_fork() and friends for instance.

For the time being, it seems to work more or less but:
- ping reports EINVAL on recvfrom
- strace shows NULL instead of strings in call like open() for instance.

For the two above problems, that's because system_call_exception() 
doesn't set orig_gpr3 whereas DoSycall() does in entry_32.S . Is that 
only done on PPC32 ?

With the following line at the begining of system_call_exception(), it 
works perfectly:

	regs->orig_gpr3 = r3;

I will now focus on performance to see if we can do something about it.

Christophe

quoted hunk ↗ jump to hunk

- the performance is definitively bad

On an 8xx, null_syscall test is about 30% slower after this patch:
- Without the patch: 284 cycles
- With the patch: 371 cycles

@nick and others, any suggestion to fix and improve ?

Signed-off-by: Christophe Leroy <redacted>
---
  arch/powerpc/include/asm/book3s/32/kup.h      |  21 ++
  .../powerpc/include/asm/book3s/64/kup-radix.h |  12 +-
  arch/powerpc/include/asm/hw_irq.h             |  15 +
  arch/powerpc/include/asm/kup.h                |   2 +
  arch/powerpc/include/asm/nohash/32/kup-8xx.h  |  13 +
  arch/powerpc/kernel/Makefile                  |   5 +-
  arch/powerpc/kernel/entry_32.S                | 259 ++----------------
  arch/powerpc/kernel/head_32.h                 |   3 +-
  .../kernel/{syscall_64.c => syscall.c}        |  25 +-
  9 files changed, 102 insertions(+), 253 deletions(-)
  rename arch/powerpc/kernel/{syscall_64.c => syscall.c} (97%)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 3c0ba22dc360..c85bc5b56366 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h

@@ -102,6 +102,27 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
  	isync();	/* Context sync required after mtsrin() */
  }
  
+static inline void kuap_restore(struct pt_regs *regs)
+{
+	u32 kuap = current->thread.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 __always_inline void allow_user_access(void __user *to, const void __user *from,
  					      u32 size, unsigned long dir)
  {

diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h
index 3bcef989a35d..1f2716a0dcd8 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h

@@ -60,13 +60,13 @@
  #include <asm/mmu.h>
  #include <asm/ptrace.h>
  
-static inline void kuap_restore_amr(struct pt_regs *regs)
+static inline void kuap_restore(struct pt_regs *regs)
  {
  	if (mmu_has_feature(MMU_FTR_RADIX_KUAP))
  		mtspr(SPRN_AMR, regs->kuap);
  }
  
-static inline void kuap_check_amr(void)
+static inline void kuap_check(void)
  {
  	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_RADIX_KUAP))
  		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);

@@ -141,14 +141,6 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
  		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
  }
-#else /* CONFIG_PPC_KUAP */
-static inline void kuap_restore_amr(struct pt_regs *regs)
-{
-}
-
-static inline void kuap_check_amr(void)
-{
-}
  #endif /* CONFIG_PPC_KUAP */
  
  #endif /* __ASSEMBLY__ */

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index e0e71777961f..6ccf07de6665 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h

@@ -321,6 +321,16 @@ static inline void arch_local_irq_disable(void)
  		mtmsr(mfmsr() & ~MSR_EE);
  }
  
+static inline void arch_local_recovery_disable(void)
+{
+	if (IS_ENABLED(CONFIG_BOOKE))
+		wrtee(0);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		wrtspr(SPRN_NRI);
+	else
+		mtmsr(mfmsr() & ~(MSR_EE | MSR_RI));
+}
+
  static inline void arch_local_irq_enable(void)
  {
  	if (IS_ENABLED(CONFIG_BOOKE))

@@ -343,6 +353,11 @@ static inline bool arch_irqs_disabled(void)
  
  #define hard_irq_disable()		arch_local_irq_disable()
  
+#define __hard_irq_enable()		arch_local_irq_enable()
+#define __hard_irq_disable()		arch_local_irq_disable()
+#define __hard_EE_RI_disable()		arch_local_recovery_disable()
+#define __hard_RI_enable()		arch_local_irq_disable()
+
  static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
  {
  	return !(regs->msr & MSR_EE);

diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 92bcd1a26d73..1100c13b6d9e 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h

@@ -62,6 +62,8 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  {
  	return false;
  }
+static inline void kuap_restore(struct pt_regs *regs) { }
+static inline void kuap_check(void) { }
  #endif /* CONFIG_PPC_KUAP */
  
  static inline void allow_read_from_user(const void __user *from, unsigned long size)

diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 85ed2390fb99..1918d2e55da3 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h

@@ -34,6 +34,19 @@
  
  #include <asm/reg.h>
  
+static inline void kuap_restore(struct pt_regs *regs)
+{
+	mtspr(SPRN_MD_AP, regs->kuap);
+}
+
+static inline void kuap_check(void)
+{
+	if (!IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		return;
+
+	WARN_ON_ONCE((mfspr(SPRN_MD_AP) & 0xffff0000) != (MD_APG_KUAP & 0xffff0000));
+}
+
  static inline void allow_user_access(void __user *to, const void __user *from,
  				     unsigned long size, unsigned long dir)
  {

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 570660efbb3d..e4be425b7718 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile

@@ -45,11 +45,10 @@ obj-y				:= cputable.o syscalls.o \
  				   signal.o sysfs.o cacheinfo.o time.o \
  				   prom.o traps.o setup-common.o \
  				   udbg.o misc.o io.o misc_$(BITS).o \
-				   of_platform.o prom_parse.o
+				   of_platform.o prom_parse.o syscall.o
  obj-y				+= ptrace/
  obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o signal_64.o \
-				   paca.o nvram_64.o firmware.o note.o \
-				   syscall_64.o
+				   paca.o nvram_64.o firmware.o note.o
  obj-$(CONFIG_VDSO32)		+= vdso32/
  obj-$(CONFIG_PPC_WATCHDOG)	+= watchdog.o
  obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index a6371fb8f761..103f5158bc44 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S

@@ -315,162 +315,37 @@ stack_ovf:
  	RFI
  #endif
  
-#ifdef CONFIG_TRACE_IRQFLAGS
-trace_syscall_entry_irq_off:
-	/*
-	 * Syscall shouldn't happen while interrupts are disabled,
-	 * so let's do a warning here.
-	 */
-0:	trap
-	EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
-	bl	trace_hardirqs_on
-
-	/* Now enable for real */
-	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
-	mtmsr	r10
-
-	REST_GPR(0, r1)
-	REST_4GPRS(3, r1)
-	REST_2GPRS(7, r1)
-	b	DoSyscall
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
  	.globl	transfer_to_syscall
  transfer_to_syscall:
-#ifdef CONFIG_TRACE_IRQFLAGS
-	andi.	r12,r9,MSR_EE
-	beq-	trace_syscall_entry_irq_off
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
-/*
- * Handle a system call.
- */
-	.stabs	"arch/powerpc/kernel/",N_SO,0,0,0f
-	.stabs	"entry_32.S",N_SO,0,0,0f
-0:
-
-_GLOBAL(DoSyscall)
-	stw	r3,ORIG_GPR3(r1)
-	li	r12,0
-	stw	r12,RESULT(r1)
-#ifdef CONFIG_TRACE_IRQFLAGS
-	/* Make sure interrupts are enabled */
-	mfmsr	r11
-	andi.	r12,r11,MSR_EE
-	/* We came in with interrupts disabled, we WARN and mark them enabled
-	 * for lockdep now */
-0:	tweqi	r12, 0
-	EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
-#endif /* CONFIG_TRACE_IRQFLAGS */
-	lwz	r11,TI_FLAGS(r2)
-	andi.	r11,r11,_TIF_SYSCALL_DOTRACE
-	bne-	syscall_dotrace
-syscall_dotrace_cont:
-	cmplwi	0,r0,NR_syscalls
-	lis	r10,sys_call_table@h
-	ori	r10,r10,sys_call_table@l
-	slwi	r0,r0,2
-	bge-	66f
-
-	barrier_nospec_asm
-	/*
-	 * Prevent the load of the handler below (based on the user-passed
-	 * system call number) being speculatively executed until the test
-	 * against NR_syscalls and branch to .66f above has
-	 * committed.
-	 */
-
-	lwzx	r10,r10,r0	/* Fetch system call handler [ptr] */
-	mtlr	r10
-	addi	r9,r1,STACK_FRAME_OVERHEAD
-	PPC440EP_ERR42
-	blrl			/* Call handler */
-	.globl	ret_from_syscall
+	mr	r9, r0
+	addi	r10, r1, STACK_FRAME_OVERHEAD
+	bl	system_call_exception
  ret_from_syscall:
-#ifdef CONFIG_DEBUG_RSEQ
-	/* Check whether the syscall is issued inside a restartable sequence */
-	stw	r3,GPR3(r1)
-	addi    r3,r1,STACK_FRAME_OVERHEAD
-	bl      rseq_syscall
-	lwz	r3,GPR3(r1)
-#endif
-	mr	r6,r3
-	/* disable interrupts so current_thread_info()->flags can't change */
-	LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)	/* doesn't include MSR_EE */
-	/* Note: We don't bother telling lockdep about it */
-	SYNC
-	mtmsr	r10
-	lwz	r9,TI_FLAGS(r2)
-	li	r8,-MAX_ERRNO
-	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
-	bne-	syscall_exit_work
-	cmplw	0,r3,r8
-	blt+	syscall_exit_cont
-	lwz	r11,_CCR(r1)			/* Load CR */
-	neg	r3,r3
-	oris	r11,r11,0x1000	/* Set SO bit in CR */
-	stw	r11,_CCR(r1)
-syscall_exit_cont:
-	lwz	r8,_MSR(r1)
-#ifdef CONFIG_TRACE_IRQFLAGS
-	/* If we are going to return from the syscall with interrupts
-	 * off, we trace that here. It shouldn't normally happen.
-	 */
-	andi.	r10,r8,MSR_EE
-	bne+	1f
-	stw	r3,GPR3(r1)
-	bl      trace_hardirqs_off
-	lwz	r3,GPR3(r1)
-1:
-#endif /* CONFIG_TRACE_IRQFLAGS */
-#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-	/* If the process has its own DBCR0 value, load it up.  The internal
-	   debug mode bit tells us that dbcr0 should be loaded. */
-	lwz	r0,THREAD+THREAD_DBCR0(r2)
-	andis.	r10,r0,DBCR0_IDM@h
-	bnel-	load_dbcr0
-#endif
-#ifdef CONFIG_44x
-BEGIN_MMU_FTR_SECTION
-	lis	r4,icache_44x_need_flush@ha
-	lwz	r5,icache_44x_need_flush@l(r4)
-	cmplwi	cr0,r5,0
-	bne-	2f
-1:
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x)
-#endif /* CONFIG_44x */
-BEGIN_FTR_SECTION
-	lwarx	r7,0,r1
-END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
-	stwcx.	r0,0,r1			/* to clear the reservation */
-	ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
-#ifdef CONFIG_PPC_BOOK3S_32
-	kuep_unlock r5, r7
-#endif
-	kuap_check r2, r4
-	lwz	r4,_LINK(r1)
-	lwz	r5,_CCR(r1)
-	mtlr	r4
-	mtcr	r5
-	lwz	r7,_NIP(r1)
-	lwz	r2,GPR2(r1)
-	lwz	r1,GPR1(r1)
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
-	mtspr	SPRN_NRI, r0
-#endif
-	mtspr	SPRN_SRR0,r7
-	mtspr	SPRN_SRR1,r8
-	SYNC
-	RFI
-#ifdef CONFIG_44x
-2:	li	r7,0
-	iccci	r0,r0
-	stw	r7,icache_44x_need_flush@l(r4)
+	addi    r4, r1, STACK_FRAME_OVERHEAD
+	bl	syscall_exit_prepare
+	lwz	r2, _CCR(r1)
+	lwz	r4, _NIP(r1)
+	lwz	r5, _MSR(r1)
+	lwz	r6, _LINK(r1)
+	mtspr	SPRN_SRR0, r4
+	mtspr	SPRN_SRR1, r5
+	mtlr	r6
+	cmpwi	r3, 0
+	bne	2f
+1:	mtcr	r2
+	REST_GPR(2, r1)
+	REST_GPR(3, r1)
+	REST_GPR(1, r1)
+	rfi
+2:	lwz	r3, _CTR(r1)
+	lwz	r4, _XER(r1)
+	REST_NVGPRS(r1)
+	mtctr	r3
+	mtspr	SPRN_XER, r4
+	REST_GPR(0, r1)
+	REST_8GPRS(4, r1)
+	REST_GPR(12, r1)
  	b	1b
-#endif  /* CONFIG_44x */
-
-66:	li	r3,-ENOSYS
-	b	ret_from_syscall
  
  	.globl	ret_from_fork
  ret_from_fork:

@@ -490,86 +365,6 @@ ret_from_kernel_thread:
  	li	r3,0
  	b	ret_from_syscall
  
-/* Traced system call support */
-syscall_dotrace:
-	SAVE_NVGPRS(r1)
-	li	r0,0xc00
-	stw	r0,_TRAP(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_syscall_trace_enter
-	/*
-	 * Restore argument registers possibly just changed.
-	 * We use the return value of do_syscall_trace_enter
-	 * for call number to look up in the table (r0).
-	 */
-	mr	r0,r3
-	lwz	r3,GPR3(r1)
-	lwz	r4,GPR4(r1)
-	lwz	r5,GPR5(r1)
-	lwz	r6,GPR6(r1)
-	lwz	r7,GPR7(r1)
-	lwz	r8,GPR8(r1)
-	REST_NVGPRS(r1)
-
-	cmplwi	r0,NR_syscalls
-	/* Return code is already in r3 thanks to do_syscall_trace_enter() */
-	bge-	ret_from_syscall
-	b	syscall_dotrace_cont
-
-syscall_exit_work:
-	andi.	r0,r9,_TIF_RESTOREALL
-	beq+	0f
-	REST_NVGPRS(r1)
-	b	2f
-0:	cmplw	0,r3,r8
-	blt+	1f
-	andi.	r0,r9,_TIF_NOERROR
-	bne-	1f
-	lwz	r11,_CCR(r1)			/* Load CR */
-	neg	r3,r3
-	oris	r11,r11,0x1000	/* Set SO bit in CR */
-	stw	r11,_CCR(r1)
-
-1:	stw	r6,RESULT(r1)	/* Save result */
-	stw	r3,GPR3(r1)	/* Update return value */
-2:	andi.	r0,r9,(_TIF_PERSYSCALL_MASK)
-	beq	4f
-
-	/* Clear per-syscall TIF flags if any are set.  */
-
-	li	r11,_TIF_PERSYSCALL_MASK
-	addi	r12,r2,TI_FLAGS
-3:	lwarx	r8,0,r12
-	andc	r8,r8,r11
-#ifdef CONFIG_IBM405_ERR77
-	dcbt	0,r12
-#endif
-	stwcx.	r8,0,r12
-	bne-	3b
-	
-4:	/* Anything which requires enabling interrupts? */
-	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
-	beq	ret_from_except
-
-	/* Re-enable interrupts. There is no need to trace that with
-	 * lockdep as we are supposed to have IRQs on at this point
-	 */
-	ori	r10,r10,MSR_EE
-	SYNC
-	mtmsr	r10
-
-	/* Save NVGPRS if they're not saved already */
-	lwz	r4,_TRAP(r1)
-	andi.	r4,r4,1
-	beq	5f
-	SAVE_NVGPRS(r1)
-	li	r4,0xc00
-	stw	r4,_TRAP(r1)
-5:
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_syscall_trace_leave
-	b	ret_from_except_full
-
  	/*
  	 * System call was called from kernel. We get here with SRR1 in r9.
  	 * Mark the exception as recoverable once we have retrieved SRR0,

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 9abec6cd099c..97691931a306 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h

@@ -174,12 +174,13 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
  	stw	r2,GPR2(r11)
  	addi	r10,r10,STACK_FRAME_REGS_MARKER@l
  	stw	r9,_MSR(r11)
-	li	r2, \trapno + 1
+	li	r2, \trapno
  	stw	r10,8(r11)
  	stw	r2,_TRAP(r11)
  	SAVE_GPR(0, r11)
  	SAVE_4GPRS(3, r11)
  	SAVE_2GPRS(7, r11)
+	SAVE_NVGPRS(r11)
  	addi	r11,r1,STACK_FRAME_OVERHEAD
  	addi	r2,r12,-THREAD
  	stw	r11,PT_REGS(r12)

diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall.c
similarity index 97%
rename from arch/powerpc/kernel/syscall_64.c
rename to arch/powerpc/kernel/syscall.c
index cf06eb443a80..a07702a85f81 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall.c

@@ -1,8 +1,9 @@
  // SPDX-License-Identifier: GPL-2.0-or-later
  
  #include <linux/err.h>
+#include <linux/compat.h>
+
  #include <asm/asm-prototypes.h>
-#include <asm/book3s/64/kup-radix.h>
  #include <asm/cputime.h>
  #include <asm/hw_irq.h>
  #include <asm/kprobes.h>

@@ -25,16 +26,20 @@ notrace long system_call_exception(long r3, long r4, long r5,
  	unsigned long ti_flags;
  	syscall_fn f;
  
+#ifdef CONFIG_PPC64
  	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
  		BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
+#endif
  
  	trace_hardirqs_off(); /* finish reconciling */
  
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S))
+	if (!IS_ENABLED(CONFIG_PPC_BOOK3E))
  		BUG_ON(!(regs->msr & MSR_RI));
  	BUG_ON(!(regs->msr & MSR_PR));
  	BUG_ON(!FULL_REGS(regs));
+#ifdef CONFIG_PPC64
  	BUG_ON(regs->softe != IRQS_ENABLED);
+#endif
  
  	account_cpu_user_entry();

@@ -48,7 +53,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
  	}
  #endif
  
-	kuap_check_amr();
+	kuap_check();
  
  	/*
  	 * This is not required for the syscall exit path, but makes the

@@ -56,7 +61,9 @@ notrace long system_call_exception(long r3, long r4, long r5,
  	 * frame, or if the unwinder was taught the first stack frame always
  	 * returns to user with IRQS_ENABLED, this store could be avoided!
  	 */
+#ifdef CONFIG_PPC64
  	regs->softe = IRQS_ENABLED;
+#endif
  
  	local_irq_enable();

@@ -86,7 +93,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
  	/* May be faster to do array_index_nospec? */
  	barrier_nospec();
  
-	if (unlikely(ti_flags & _TIF_32BIT)) {
+	if (is_compat_task()) {
  		f = (void *)compat_sys_call_table[r0];
  
  		r3 &= 0x00000000ffffffffULL;

@@ -148,7 +155,9 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
  		ret |= _TIF_RESTOREALL;
  	}
  
+#ifdef CONFIG_PPC64
  again:
+#endif
  	local_irq_disable();
  	ti_flags = READ_ONCE(*ti_flagsp);
  	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {

@@ -191,6 +200,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
  
  	/* This pattern matches prep_irq_for_idle */
  	__hard_EE_RI_disable();
+#ifdef CONFIG_PPC64
  	if (unlikely(lazy_irq_pending())) {
  		__hard_RI_enable();
  		trace_hardirqs_off();

@@ -201,12 +211,13 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
  	}
  	local_paca->irq_happened = 0;
  	irq_soft_mask_set(IRQS_ENABLED);
+#endif
  
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  	local_paca->tm_scratch = regs->msr;
  #endif
  
-	kuap_check_amr();
+	kuap_check();
  
  	account_cpu_user_exit();

@@ -294,7 +305,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
  	local_paca->tm_scratch = regs->msr;
  #endif
  
-	kuap_check_amr();
+	kuap_check();
  
  	account_cpu_user_exit();

@@ -372,7 +383,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
  	 * We don't need to restore AMR on the way back to userspace for KUAP.
  	 * The value of AMR only matters while we're in the kernel.
  	 */
-	kuap_restore_amr(regs);
+	kuap_restore(regs);
  
  	return ret;
  }

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