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* [RFC PATCH 8/9] powerpc/64s: interrupt soft-enable race fix
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

Prevent interrupt restore from allowing racing hard interrupts going
ahead of previous soft-pending ones, by using the soft-masked restart
handler to allow a store to clear the soft-mask while knowing nothing
is soft-pending.

This probably doesn't matter much in practice, but it's a simple
demonstrator / test case to exercise the restart table logic.

XXX: 64e can't do this unless it adds restart table support

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/irq.c | 79 +++++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c8185f709d26..9671468b2c51 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -317,52 +317,73 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	unsigned char irq_happened;
 
 	/* Write the new soft-enabled value */
-	irq_soft_mask_set(mask);
-	if (mask)
+	if (mask) {
+		irq_soft_mask_set(mask);
 		return;
+	}
 
 	/*
-	 * From this point onward, we can take interrupts, preempt,
-	 * etc... unless we got hard-disabled. We check if an event
-	 * happened. If none happened, we know we can just return.
-	 *
-	 * We may have preempted before the check below, in which case
-	 * we are checking the "new" CPU instead of the old one. This
-	 * is only a problem if an event happened on the "old" CPU.
+	 * After the stb, interrupts are unmasked and there are no interrupts
+	 * pending replay. The restart sequence makes this atomic with
+	 * respect to soft-masked interrupts. If this was just a simple code
+	 * sequence, a soft-masked interrupt could become pending right after
+	 * the comparison and before the stb.
 	 *
-	 * External interrupt events will have caused interrupts to
-	 * be hard-disabled, so there is no problem, we
-	 * cannot have preempted.
+	 * This allows interrupts to be unmasked without hard disabling, and
+	 * also without new hard interrupts coming in ahead of pending ones.
 	 */
+	asm_volatile_goto(
+"1:					\n"
+"		lbz	9,%0(13)	\n"
+"		cmpwi	9,0		\n"
+"		bne	%l[happened]	\n"
+"		stb	9,%1(13)	\n"
+"2:					\n"
+		RESTART_TABLE(1b, 2b, 1b)
+	: : "i" (offsetof(struct paca_struct, irq_happened)),
+	    "i" (offsetof(struct paca_struct, irq_soft_mask))
+	: "cr0", "r9"
+	: happened);
+
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(!(mfmsr() & MSR_EE));
+
+	return;
+
+happened:
 	irq_happened = get_irq_happened();
-	if (!irq_happened) {
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(!irq_happened);
+
+	if (irq_happened == PACA_IRQ_HARD_DIS) {
 		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-			WARN_ON_ONCE(!(mfmsr() & MSR_EE));
+			WARN_ON_ONCE(mfmsr() & MSR_EE);
+		irq_soft_mask_set(IRQS_ENABLED);
+		local_paca->irq_happened = 0;
+		__hard_irq_enable();
 		return;
 	}
 
-	/* We need to hard disable to replay. */
+	/* Have interrupts to replay, need to hard disable first */
 	if (!(irq_happened & PACA_IRQ_HARD_DIS)) {
-		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
-			WARN_ON_ONCE(!(mfmsr() & MSR_EE));
+		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+			if (!(mfmsr() & MSR_EE)) {
+				/*
+				 * An interrupt could have come in and cleared
+				 * MSR[EE] and set IRQ_HARD_DIS, so check
+				 * IRQ_HARD_DIS again and warn if it is still
+				 * clear.
+				 */
+				irq_happened = get_irq_happened();
+				WARN_ON_ONCE(!(irq_happened & PACA_IRQ_HARD_DIS));
+			}
+		}
 		__hard_irq_disable();
 	} else {
-		/*
-		 * We should already be hard disabled here. We had bugs
-		 * where that wasn't the case so let's dbl check it and
-		 * warn if we are wrong. Only do that when IRQ tracing
-		 * is enabled as mfmsr() can be costly.
-		 */
 		if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
 			if (WARN_ON_ONCE(mfmsr() & MSR_EE))
 				__hard_irq_disable();
 		}
-
-		if (irq_happened == PACA_IRQ_HARD_DIS) {
-			local_paca->irq_happened = 0;
-			__hard_irq_enable();
-			return;
-		}
 	}
 
 	/*
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 7/9] powerpc/64s: allow alternate return locations for soft-masked interrupts
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

This is a variation of the exception table code which adjusts a failed
page fault return location if it was taken at an address specified in
an exception table, to a corresponding fixup handler address.

This patch adds a similar masked interrupt restart table that is checked
when when an asynchronous interrupt is taken while soft-masked.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/interrupt.h | 18 ++++++++++++++
 arch/powerpc/include/asm/ppc_asm.h   |  8 +++++++
 arch/powerpc/kernel/exceptions-64s.S | 36 +++++++++++++++++++++++++++-
 arch/powerpc/kernel/interrupt_64.S   |  3 +++
 arch/powerpc/kernel/vmlinux.lds.S    | 10 ++++++++
 arch/powerpc/lib/Makefile            |  2 +-
 arch/powerpc/lib/restart_table.c     | 26 ++++++++++++++++++++
 arch/powerpc/perf/core-book3s.c      | 19 ++++++++++++---
 8 files changed, 117 insertions(+), 5 deletions(-)
 create mode 100644 arch/powerpc/lib/restart_table.c

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 1aeb9a841cc6..5d68c510e5e0 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -18,6 +18,11 @@ static inline void nap_adjust_return(struct pt_regs *regs)
 #endif
 }
 
+#ifdef CONFIG_PPC_BOOK3S_64
+extern char __end_soft_masked[];
+unsigned long search_kernel_restart_table(unsigned long addr);
+#endif
+
 struct interrupt_state {
 #ifdef CONFIG_PPC_BOOK3E_64
 	enum ctx_state ctx_state;
@@ -47,6 +52,9 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 		 */
 		if (TRAP(regs) != 0x700)
 			CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
+		BUG_ON(regs->nip < (unsigned long)__end_soft_masked));
+		if (arch_irq_disabled_regs(regs))
+			BUG_ON(search_kernel_restart_table(regs->nip));
 	}
 #endif
 
@@ -126,6 +134,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
 {
 #ifdef CONFIG_PPC64
 #ifdef CONFIG_PPC_BOOK3S_64
+	if (!(regs->msr & MSR_PR) && regs->nip < (unsigned long)__end_soft_masked)
+		regs->softe = IRQS_ALL_DISABLED;
 	state->irq_soft_mask = local_paca->irq_soft_mask;
 	state->irq_happened = local_paca->irq_happened;
 
@@ -163,6 +173,14 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
 
 	nap_adjust_return(regs);
 
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (arch_irq_disabled_regs(regs)) {
+		unsigned long rst = search_kernel_restart_table(regs->nip);
+		if (rst)
+			regs_set_return_ip(regs, rst);
+	}
+#endif
+
 #ifdef CONFIG_PPC64
 	this_cpu_set_ftrace_enabled(state->ftrace_enabled);
 
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index c1199f6c75a3..da084d695cfe 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -791,6 +791,14 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
 	stringify_in_c(.long (_target) - . ;)	\
 	stringify_in_c(.previous)
 
+#define RESTART_TABLE(_start, _end, _target)	\
+	stringify_in_c(.section __restart_table,"a";)\
+	stringify_in_c(.balign 8;)		\
+	stringify_in_c(.llong (_start);)	\
+	stringify_in_c(.llong (_end);)		\
+	stringify_in_c(.llong (_target);)	\
+	stringify_in_c(.previous)
+
 #ifdef CONFIG_PPC_FSL_BOOK3E
 #define BTB_FLUSH(reg)			\
 	lis reg,BUCSR_INIT@h;		\
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a01f69e774b5..0615c2e724ea 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -514,8 +514,9 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 
 		/* Kernel code running below __end_interrupts is implicitly
 		 * soft-masked */
-		LOAD_HANDLER(r10, __end_interrupts)
+		LOAD_HANDLER(r10, __end_soft_masked)
 		cmpld	r11,r10
+
 		li	r10,IMASK
 		blt-	1f
 
@@ -673,6 +674,28 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 	__GEN_COMMON_BODY \name
 .endm
 
+.macro SEARCH_RESTART_TABLE
+	LOAD_REG_IMMEDIATE_SYM(r9, r12, __start___restart_table)
+	LOAD_REG_IMMEDIATE_SYM(r10, r12, __stop___restart_table)
+300:
+	cmpd	r9,r10
+	beq	302f
+	ld	r12,0(r9)
+	cmpld	r11,r12
+	blt	301f
+	ld	r12,8(r9)
+	cmpld	r11,r12
+	bge	301f
+	ld	r12,16(r9)
+	b	303f
+301:
+	addi	r9,r9,24
+	b	300b
+302:
+	li	r12,0
+303:
+.endm
+
 /*
  * Restore all registers including H/SRR0/1 saved in a stack frame of a
  * standard exception.
@@ -2758,6 +2781,7 @@ EXC_COMMON_BEGIN(soft_nmi_common)
 	mtmsrd	r9,1
 
 	kuap_restore_amr r9, r10
+
 	EXCEPTION_RESTORE_REGS hsrr=0
 	RFI_TO_KERNEL
 
@@ -2815,6 +2839,16 @@ masked_interrupt:
 	stb	r9,PACASRR_VALID(r13)
 	.endif
 
+	SEARCH_RESTART_TABLE
+	cmpdi	r12,0
+	beq	3f
+	.if \hsrr
+	mtspr	SPRN_HSRR0,r12
+	.else
+	mtspr	SPRN_SRR0,r12
+	.endif
+3:
+
 	ld	r9,PACA_EXGEN+EX_CTR(r13)
 	mtctr	r9
 	lwz	r9,PACA_EXGEN+EX_CCR(r13)
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index e121829ef717..9b44f6d3463b 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -605,4 +605,7 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 interrupt_return_macro srr
 interrupt_return_macro hsrr
 
+	.globl __end_soft_masked
+__end_soft_masked:
+DEFINE_FIXED_SYMBOL(__end_soft_masked)
 #endif /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index e0548b4950de..211c82e96420 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -9,6 +9,14 @@
 #define EMITS_PT_NOTE
 #define RO_EXCEPTION_TABLE_ALIGN	0
 
+#define RESTART_TABLE(align)						\
+	. = ALIGN(align);						\
+	__restart_table : AT(ADDR(__restart_table) - LOAD_OFFSET) {	\
+		__start___restart_table = .;				\
+		KEEP(*(__restart_table))				\
+		__stop___restart_table = .;				\
+	}
+
 #include <asm/page.h>
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/cache.h>
@@ -124,6 +132,8 @@ SECTIONS
 	RO_DATA(PAGE_SIZE)
 
 #ifdef CONFIG_PPC64
+	RESTART_TABLE(8)
+
 	. = ALIGN(8);
 	__stf_entry_barrier_fixup : AT(ADDR(__stf_entry_barrier_fixup) - LOAD_OFFSET) {
 		__start___stf_entry_barrier_fixup = .;
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 69a91b571845..5d90bebcf9cf 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -36,7 +36,7 @@ extra-$(CONFIG_PPC64)	+= crtsavres.o
 endif
 
 obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
-			       memcpy_power7.o
+			       memcpy_power7.o restart_table.o
 
 obj64-y	+= copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
 	   memcpy_64.o copy_mc_64.o
diff --git a/arch/powerpc/lib/restart_table.c b/arch/powerpc/lib/restart_table.c
new file mode 100644
index 000000000000..f2df84c46f24
--- /dev/null
+++ b/arch/powerpc/lib/restart_table.c
@@ -0,0 +1,26 @@
+struct restart_table_entry {
+	unsigned long start;
+	unsigned long end;
+	unsigned long fixup;
+};
+
+extern struct restart_table_entry __start___restart_table[];
+extern struct restart_table_entry __stop___restart_table[];
+
+/* Given an address, look for it in the kernel exception table */
+unsigned long search_kernel_restart_table(unsigned long addr)
+{
+	struct restart_table_entry *rte = __start___restart_table;
+
+	while (rte < __stop___restart_table) {
+		unsigned long start = rte->start;
+		unsigned long end = rte->end;
+		unsigned long fixup = rte->fixup;
+
+		if (addr >= start && addr < end)
+			return fixup;
+
+		rte++;
+	}
+	return 0;
+}
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 08643cba1494..4afd292a7a5e 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -332,9 +332,15 @@ static inline void perf_read_regs(struct pt_regs *regs)
  * If interrupts were soft-disabled when a PMU interrupt occurs, treat
  * it as an NMI.
  */
+extern char __end_soft_masked[];
 static inline int perf_intr_is_nmi(struct pt_regs *regs)
 {
-	return (regs->softe & IRQS_DISABLED);
+	if (regs->softe & IRQS_DISABLED)
+		return true;
+
+	if (!(regs->msr & MSR_PR) && regs->nip < (unsigned long)__end_soft_masked)
+		return true;
+	return false;
 }
 
 /*
@@ -2214,6 +2220,8 @@ static bool pmc_overflow(unsigned long val)
 	return false;
 }
 
+unsigned long search_kernel_restart_table(unsigned long addr);
+
 /*
  * Performance monitor interrupt stuff
  */
@@ -2301,10 +2309,15 @@ static void __perf_event_interrupt(struct pt_regs *regs)
 	 */
 	write_mmcr0(cpuhw, cpuhw->mmcr.mmcr0);
 
-	if (nmi)
+	if (nmi) {
+		unsigned long rst = search_kernel_restart_table(regs->nip);
+		if (rst)
+			regs_set_return_ip(regs, rst);
+
 		nmi_exit();
-	else
+	} else {
 		irq_exit();
+	}
 }
 
 static void perf_event_interrupt(struct pt_regs *regs)
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 6/9] powerpc/64s: save one more register in the masked interrupt handler
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

This frees up one more register (and takes advantage of that to
clean things up a little bit).

This register will be used in the following patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 34 ++++++++++++++++------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b370a5f334fc..a01f69e774b5 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2745,7 +2745,6 @@ INT_DEFINE_END(soft_nmi)
  * and run it entirely with interrupts hard disabled.
  */
 EXC_COMMON_BEGIN(soft_nmi_common)
-	mfspr	r11,SPRN_SRR0
 	mr	r10,r1
 	ld	r1,PACAEMERGSP(r13)
 	subi	r1,r1,INT_FRAME_SIZE
@@ -2780,19 +2779,24 @@ masked_Hinterrupt:
 	.else
 masked_interrupt:
 	.endif
-	lbz	r11,PACAIRQHAPPENED(r13)
-	or	r11,r11,r10
-	stb	r11,PACAIRQHAPPENED(r13)
+	stw	r9,PACA_EXGEN+EX_CCR(r13)
+	lbz	r9,PACAIRQHAPPENED(r13)
+	or	r9,r9,r10
+	stb	r9,PACAIRQHAPPENED(r13)
+
+	.if ! \hsrr
 	cmpwi	r10,PACA_IRQ_DEC
 	bne	1f
-	lis	r10,0x7fff
-	ori	r10,r10,0xffff
-	mtspr	SPRN_DEC,r10
+	LOAD_REG_IMMEDIATE(r9, 0x7fffffff)
+	mtspr	SPRN_DEC,r9
 #ifdef CONFIG_PPC_WATCHDOG
+	lwz	r9,PACA_EXGEN+EX_CCR(r13)
 	b	soft_nmi_common
 #else
 	b	2f
 #endif
+	.endif
+
 1:	andi.	r10,r10,PACA_IRQ_MUST_HARD_MASK
 	beq	2f
 	xori	r12,r12,MSR_EE	/* clear MSR_EE */
@@ -2801,17 +2805,19 @@ masked_interrupt:
 	.else
 	mtspr	SPRN_SRR1,r12
 	.endif
-	ori	r11,r11,PACA_IRQ_HARD_DIS
-	stb	r11,PACAIRQHAPPENED(r13)
+	ori	r9,r9,PACA_IRQ_HARD_DIS
+	stb	r9,PACAIRQHAPPENED(r13)
 2:	/* done */
-	li	r10,0
+	li	r9,0
 	.if \hsrr
-	stb	r10,PACAHSRR_VALID(r13)
+	stb	r9,PACAHSRR_VALID(r13)
 	.else
-	stb	r10,PACASRR_VALID(r13)
+	stb	r9,PACASRR_VALID(r13)
 	.endif
-	ld	r10,PACA_EXGEN+EX_CTR(r13)
-	mtctr	r10
+
+	ld	r9,PACA_EXGEN+EX_CTR(r13)
+	mtctr	r9
+	lwz	r9,PACA_EXGEN+EX_CCR(r13)
 	mtcrf	0x80,r9
 	std	r1,PACAR1(r13)
 	ld	r9,PACA_EXGEN+EX_R9(r13)
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 5/9] powerpc/64: move interrupt return asm to interrupt_64.S
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

The next patch would like to move interrupt return assembly code to a low
location before general text, so move it into its own file and include via
head_64.S

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/head-64.h |   2 +-
 arch/powerpc/kernel/entry_64.S     | 601 ----------------------------
 arch/powerpc/kernel/head_64.S      |   5 +-
 arch/powerpc/kernel/interrupt_64.S | 608 +++++++++++++++++++++++++++++
 4 files changed, 613 insertions(+), 603 deletions(-)
 create mode 100644 arch/powerpc/kernel/interrupt_64.S

diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index 4cb9efa2eb21..242204e12993 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -16,7 +16,7 @@
 	.section ".head.data.\name\()","a",@progbits
 .endm
 .macro use_ftsec name
-	.section ".head.text.\name\()"
+	.section ".head.text.\name\()","ax",@progbits
 .endm
 
 /*
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6236a88a592f..65ddd159974b 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -32,7 +32,6 @@
 #include <asm/irqflags.h>
 #include <asm/hw_irq.h>
 #include <asm/context_tracking.h>
-#include <asm/tm.h>
 #include <asm/ppc-opcode.h>
 #include <asm/barrier.h>
 #include <asm/export.h>
@@ -48,411 +47,7 @@
 /*
  * System calls.
  */
-	.section	".toc","aw"
-SYS_CALL_TABLE:
-	.tc sys_call_table[TC],sys_call_table
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYS_CALL_TABLE:
-	.tc compat_sys_call_table[TC],compat_sys_call_table
-#endif
-
-/* This value is used to mark exception frames on the stack. */
-exception_marker:
-	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
-
 	.section	".text"
-	.align 7
-
-#ifdef CONFIG_PPC_BOOK3S
-.macro DEBUG_SRR_VALID srr
-#ifdef CONFIG_PPC_RFI_SRR_DEBUG
-	.ifc \srr,srr
-	mfspr	r11,SPRN_SRR0
-	ld	r12,_NIP(r1)
-100:	tdne	r11,r12
-	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
-	mfspr	r11,SPRN_SRR1
-	ld	r12,_MSR(r1)
-100:	tdne	r11,r12
-	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
-	.else
-	mfspr	r11,SPRN_HSRR0
-	ld	r12,_NIP(r1)
-100:	tdne	r11,r12
-	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
-	mfspr	r11,SPRN_HSRR1
-	ld	r12,_MSR(r1)
-100:	tdne	r11,r12
-	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
-	.endif
-#endif
-.endm
-
-.macro system_call_vectored name trapnr
-	.globl system_call_vectored_\name
-system_call_vectored_\name:
-_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
-	extrdi.	r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
-	bne	.Ltabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
-	INTERRUPT_TO_KERNEL
-	mr	r10,r1
-	ld	r1,PACAKSAVE(r13)
-	std	r10,0(r1)
-	std	r11,_NIP(r1)
-	std	r12,_MSR(r1)
-	std	r0,GPR0(r1)
-	std	r10,GPR1(r1)
-	std	r2,GPR2(r1)
-	ld	r2,PACATOC(r13)
-	mfcr	r12
-	li	r11,0
-	/* Can we avoid saving r3-r8 in common case? */
-	std	r3,GPR3(r1)
-	std	r4,GPR4(r1)
-	std	r5,GPR5(r1)
-	std	r6,GPR6(r1)
-	std	r7,GPR7(r1)
-	std	r8,GPR8(r1)
-	/* Zero r9-r12, this should only be required when restoring all GPRs */
-	std	r11,GPR9(r1)
-	std	r11,GPR10(r1)
-	std	r11,GPR11(r1)
-	std	r11,GPR12(r1)
-	std	r9,GPR13(r1)
-	SAVE_NVGPRS(r1)
-	std	r11,_XER(r1)
-	std	r11,_LINK(r1)
-	std	r11,_CTR(r1)
-
-	li	r11,\trapnr
-	std	r11,_TRAP(r1)
-	std	r12,_CCR(r1)
-	std	r3,ORIG_GPR3(r1)
-	addi	r10,r1,STACK_FRAME_OVERHEAD
-	ld	r11,exception_marker@toc(r2)
-	std	r11,-16(r10)		/* "regshere" marker */
-
-BEGIN_FTR_SECTION
-	HMT_MEDIUM
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
-	/*
-	 * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
-	 * would clobber syscall parameters. Also we always enter with IRQs
-	 * enabled and nothing pending. system_call_exception() will call
-	 * trace_hardirqs_off().
-	 *
-	 * scv enters with MSR[EE]=1, so don't set PACA_IRQ_HARD_DIS. The
-	 * entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED.
-	 */
-
-	/* Calling convention has r9 = orig r0, r10 = regs */
-	mr	r9,r0
-	bl	system_call_exception
-
-.Lsyscall_vectored_\name\()_exit:
-	addi    r4,r1,STACK_FRAME_OVERHEAD
-	li	r5,1 /* scv */
-	bl	syscall_exit_prepare
-
-	ld	r2,_CCR(r1)
-	ld	r4,_NIP(r1)
-	ld	r5,_MSR(r1)
-
-BEGIN_FTR_SECTION
-	stdcx.	r0,0,r1			/* to clear the reservation */
-END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
-BEGIN_FTR_SECTION
-	HMT_MEDIUM_LOW
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
-	cmpdi	r3,0
-	bne	.Lsyscall_vectored_\name\()_restore_regs
-
-	/* rfscv returns with LR->NIA and CTR->MSR */
-	mtlr	r4
-	mtctr	r5
-
-	/* Could zero these as per ABI, but we may consider a stricter ABI
-	 * which preserves these if libc implementations can benefit, so
-	 * restore them for now until further measurement is done. */
-	ld	r0,GPR0(r1)
-	ld	r4,GPR4(r1)
-	ld	r5,GPR5(r1)
-	ld	r6,GPR6(r1)
-	ld	r7,GPR7(r1)
-	ld	r8,GPR8(r1)
-	/* Zero volatile regs that may contain sensitive kernel data */
-	li	r9,0
-	li	r10,0
-	li	r11,0
-	li	r12,0
-	mtspr	SPRN_XER,r0
-
-	/*
-	 * 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.
-	 */
-	mtcr	r2
-	ld	r2,GPR2(r1)
-	ld	r3,GPR3(r1)
-	ld	r13,GPR13(r1)
-	ld	r1,GPR1(r1)
-	RFSCV_TO_USER
-	b	.	/* prevent speculative execution */
-
-.Lsyscall_vectored_\name\()_restore_regs:
-	li	r3,0
-	mtmsrd	r3,1
-	mtspr	SPRN_SRR0,r4
-	mtspr	SPRN_SRR1,r5
-
-	ld	r3,_CTR(r1)
-	ld	r4,_LINK(r1)
-	ld	r5,_XER(r1)
-
-	REST_NVGPRS(r1)
-	ld	r0,GPR0(r1)
-	mtcr	r2
-	mtctr	r3
-	mtlr	r4
-	mtspr	SPRN_XER,r5
-	REST_10GPRS(2, r1)
-	REST_2GPRS(12, r1)
-	ld	r1,GPR1(r1)
-	RFI_TO_USER
-.endm
-
-system_call_vectored common 0x3000
-/*
- * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
- * which is tested by system_call_exception when r0 is -1 (as set by vector
- * entry code).
- */
-system_call_vectored sigill 0x7ff0
-
-
-/*
- * Entered via kernel return set up by kernel/sstep.c, must match entry regs
- */
-	.globl system_call_vectored_emulate
-system_call_vectored_emulate:
-_ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
-	li	r10,IRQS_ALL_DISABLED
-	stb	r10,PACAIRQSOFTMASK(r13)
-	b	system_call_vectored_common
-#endif
-
-	.balign IFETCH_ALIGN_BYTES
-	.globl system_call_common_real
-system_call_common_real:
-	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
-	mtmsrd	r10
-
-	.balign IFETCH_ALIGN_BYTES
-	.globl system_call_common
-system_call_common:
-_ASM_NOKPROBE_SYMBOL(system_call_common)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
-	extrdi.	r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
-	bne	.Ltabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
-	mr	r10,r1
-	ld	r1,PACAKSAVE(r13)
-	std	r10,0(r1)
-	std	r11,_NIP(r1)
-	std	r12,_MSR(r1)
-	std	r0,GPR0(r1)
-	std	r10,GPR1(r1)
-	std	r2,GPR2(r1)
-#ifdef CONFIG_PPC_FSL_BOOK3E
-START_BTB_FLUSH_SECTION
-	BTB_FLUSH(r10)
-END_BTB_FLUSH_SECTION
-#endif
-	ld	r2,PACATOC(r13)
-	mfcr	r12
-	li	r11,0
-	/* Can we avoid saving r3-r8 in common case? */
-	std	r3,GPR3(r1)
-	std	r4,GPR4(r1)
-	std	r5,GPR5(r1)
-	std	r6,GPR6(r1)
-	std	r7,GPR7(r1)
-	std	r8,GPR8(r1)
-	/* Zero r9-r12, this should only be required when restoring all GPRs */
-	std	r11,GPR9(r1)
-	std	r11,GPR10(r1)
-	std	r11,GPR11(r1)
-	std	r11,GPR12(r1)
-	std	r9,GPR13(r1)
-	SAVE_NVGPRS(r1)
-	std	r11,_XER(r1)
-	std	r11,_CTR(r1)
-	mflr	r10
-
-	/*
-	 * This clears CR0.SO (bit 28), which is the error indication on
-	 * return from this system call.
-	 */
-	rldimi	r12,r11,28,(63-28)
-	li	r11,0xc00
-	std	r10,_LINK(r1)
-	std	r11,_TRAP(r1)
-	std	r12,_CCR(r1)
-	std	r3,ORIG_GPR3(r1)
-	addi	r10,r1,STACK_FRAME_OVERHEAD
-	ld	r11,exception_marker@toc(r2)
-	std	r11,-16(r10)		/* "regshere" marker */
-
-	li	r11,1
-	stb	r11,PACASRR_VALID(r13)
-
-	/*
-	 * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
-	 * would clobber syscall parameters. Also we always enter with IRQs
-	 * enabled and nothing pending. system_call_exception() will call
-	 * trace_hardirqs_off().
-	 */
-	li	r11,IRQS_ALL_DISABLED
-	li	r12,PACA_IRQ_HARD_DIS
-	stb	r11,PACAIRQSOFTMASK(r13)
-	stb	r12,PACAIRQHAPPENED(r13)
-
-	/* Calling convention has r9 = orig r0, r10 = regs */
-	mr	r9,r0
-	bl	system_call_exception
-
-.Lsyscall_exit:
-	addi    r4,r1,STACK_FRAME_OVERHEAD
-	li	r5,0 /* !scv */
-	bl	syscall_exit_prepare
-
-	ld	r2,_CCR(r1)
-	ld	r6,_LINK(r1)
-	mtlr	r6
-
-	lbz	r4,PACASRR_VALID(r13)
-	cmpdi	r4,0
-	bne	1f
-	li	r4,0
-	stb	r4,PACASRR_VALID(r13)
-	ld	r4,_NIP(r1)
-	ld	r5,_MSR(r1)
-	mtspr	SPRN_SRR0,r4
-	mtspr	SPRN_SRR1,r5
-1:
-	DEBUG_SRR_VALID srr
-
-BEGIN_FTR_SECTION
-	stdcx.	r0,0,r1			/* to clear the reservation */
-END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
-	cmpdi	r3,0
-	bne	.Lsyscall_restore_regs
-	/* Zero volatile regs that may contain sensitive kernel data */
-	li	r0,0
-	li	r4,0
-	li	r5,0
-	li	r6,0
-	li	r7,0
-	li	r8,0
-	li	r9,0
-	li	r10,0
-	li	r11,0
-	li	r12,0
-	mtctr	r0
-	mtspr	SPRN_XER,r0
-.Lsyscall_restore_regs_cont:
-
-BEGIN_FTR_SECTION
-	HMT_MEDIUM_LOW
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
-	/*
-	 * 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.
-	 */
-	mtcr	r2
-	ld	r2,GPR2(r1)
-	ld	r3,GPR3(r1)
-	ld	r13,GPR13(r1)
-	ld	r1,GPR1(r1)
-	RFI_TO_USER
-	b	.	/* prevent speculative execution */
-
-.Lsyscall_restore_regs:
-	ld	r3,_CTR(r1)
-	ld	r4,_XER(r1)
-	REST_NVGPRS(r1)
-	mtctr	r3
-	mtspr	SPRN_XER,r4
-	ld	r0,GPR0(r1)
-	REST_8GPRS(4, r1)
-	ld	r12,GPR12(r1)
-	b	.Lsyscall_restore_regs_cont
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-.Ltabort_syscall:
-	/* Firstly we need to enable TM in the kernel */
-	mfmsr	r10
-	li	r9, 1
-	rldimi	r10, r9, MSR_TM_LG, 63-MSR_TM_LG
-	mtmsrd	r10, 0
-
-	/* tabort, this dooms the transaction, nothing else */
-	li	r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
-	TABORT(R9)
-
-	/*
-	 * Return directly to userspace. We have corrupted user register state,
-	 * but userspace will never see that register state. Execution will
-	 * resume after the tbegin of the aborted transaction with the
-	 * checkpointed register state.
-	 */
-	li	r9, MSR_RI
-	andc	r10, r10, r9
-	mtmsrd	r10, 1
-	mtspr	SPRN_SRR0, r11
-	mtspr	SPRN_SRR1, r12
-	RFI_TO_USER
-	b	.	/* prevent speculative execution */
-#endif
-
-#ifdef CONFIG_PPC_BOOK3S
-_GLOBAL(ret_from_fork_scv)
-	bl	schedule_tail
-	REST_NVGPRS(r1)
-	li	r3,0	/* fork() return value */
-	b	.Lsyscall_vectored_common_exit
-#endif
-
-_GLOBAL(ret_from_fork)
-	bl	schedule_tail
-	REST_NVGPRS(r1)
-	li	r3,0	/* fork() return value */
-	b	.Lsyscall_exit
-
-_GLOBAL(ret_from_kernel_thread)
-	bl	schedule_tail
-	REST_NVGPRS(r1)
-	mtctr	r14
-	mr	r3,r15
-#ifdef PPC64_ELF_ABI_v2
-	mr	r12,r14
-#endif
-	bctrl
-	li	r3,0
-	b	.Lsyscall_exit
-
 #ifdef CONFIG_PPC_BOOK3E
 /* Save non-volatile GPRs, if not already saved. */
 _GLOBAL(save_nvgprs)
@@ -681,202 +276,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	addi	r1,r1,SWITCH_FRAME_SIZE
 	blr
 
-#ifdef CONFIG_PPC_BOOK3S
-	/*
-	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
-	 * touched, no exit work created, then this can be used.
-	 */
-	.balign IFETCH_ALIGN_BYTES
-	.globl fast_interrupt_return_srr
-fast_interrupt_return_srr:
-_ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr)
-	kuap_check_amr r3, r4
-	ld	r5,_MSR(r1)
-	andi.	r0,r5,MSR_PR
-	bne	.Lfast_user_interrupt_return_srr
-	kuap_restore_amr r3, r4
-	andi.	r0,r5,MSR_RI
-	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
-	bne+	.Lfast_kernel_interrupt_return_srr
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	unrecoverable_exception
-	b	. /* should not get here */
-
-.macro interrupt_return_macro srr
-	.balign IFETCH_ALIGN_BYTES
-	.globl interrupt_return_\srr
-interrupt_return_\srr\():
-_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
-	ld	r4,_MSR(r1)
-	andi.	r0,r4,MSR_PR
-	beq	.Lkernel_interrupt_return_\srr
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	interrupt_exit_user_prepare
-	cmpdi	r3,0
-	bne-	.Lrestore_nvgprs_\srr
-
-.Lfast_user_interrupt_return_\srr:
-BEGIN_FTR_SECTION
-	ld	r10,_PPR(r1)
-	mtspr	SPRN_PPR,r10
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	.ifc \srr,srr
-	lbz	r4,PACASRR_VALID(r13)
-	.else
-	lbz	r4,PACAHSRR_VALID(r13)
-	.endif
-	cmpdi	r4,0
-	li	r4,0
-	bne	1f
-	ld	r11,_NIP(r1)
-	ld	r12,_MSR(r1)
-	.ifc \srr,srr
-	mtspr	SPRN_SRR0,r11
-	mtspr	SPRN_SRR1,r12
-1:
-	stb	r4,PACASRR_VALID(r13)
-	.else
-	mtspr	SPRN_HSRR0,r11
-	mtspr	SPRN_HSRR1,r12
-1:
-	stb	r4,PACAHSRR_VALID(r13)
-	.endif
-	DEBUG_SRR_VALID \srr
-
-BEGIN_FTR_SECTION
-	stdcx.	r0,0,r1		/* to clear the reservation */
-FTR_SECTION_ELSE
-	ldarx	r0,0,r1
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
-	ld	r3,_CCR(r1)
-	ld	r4,_LINK(r1)
-	ld	r5,_CTR(r1)
-	ld	r6,_XER(r1)
-	li	r0,0
-
-	REST_4GPRS(7, r1)
-	REST_2GPRS(11, r1)
-	REST_GPR(13, r1)
-
-	mtcr	r3
-	mtlr	r4
-	mtctr	r5
-	mtspr	SPRN_XER,r6
-
-	REST_4GPRS(2, r1)
-	REST_GPR(6, r1)
-	REST_GPR(0, r1)
-	REST_GPR(1, r1)
-	.ifc \srr,srr
-	RFI_TO_USER
-	.else
-	HRFI_TO_USER
-	.endif
-	b	.	/* prevent speculative execution */
-
-.Lrestore_nvgprs_\srr\():
-	REST_NVGPRS(r1)
-	b	.Lfast_user_interrupt_return_\srr
-
-	.balign IFETCH_ALIGN_BYTES
-.Lkernel_interrupt_return_\srr\():
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	interrupt_exit_kernel_prepare
-
-.Lfast_kernel_interrupt_return_\srr\():
-	cmpdi	cr1,r3,0
-	.ifc \srr,srr
-	lbz	r4,PACASRR_VALID(r13)
-	.else
-	lbz	r4,PACAHSRR_VALID(r13)
-	.endif
-	cmpdi	r4,0
-	li	r4,0
-	bne	1f
-	ld	r11,_NIP(r1)
-	ld	r12,_MSR(r1)
-	.ifc \srr,srr
-	mtspr	SPRN_SRR0,r11
-	mtspr	SPRN_SRR1,r12
-1:
-	stb	r4,PACASRR_VALID(r13)
-	.else
-	mtspr	SPRN_HSRR0,r11
-	mtspr	SPRN_HSRR1,r12
-1:
-	stb	r4,PACAHSRR_VALID(r13)
-	.endif
-	DEBUG_SRR_VALID \srr
-
-BEGIN_FTR_SECTION
-	stdcx.	r0,0,r1		/* to clear the reservation */
-FTR_SECTION_ELSE
-	ldarx	r0,0,r1
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
-	ld	r3,_LINK(r1)
-	ld	r4,_CTR(r1)
-	ld	r5,_XER(r1)
-	ld	r6,_CCR(r1)
-	li	r0,0
-
-	REST_4GPRS(7, r1)
-	REST_2GPRS(11, r1)
-
-	mtlr	r3
-	mtctr	r4
-	mtspr	SPRN_XER,r5
-
-	/*
-	 * Leaving a stale exception_marker on the stack can confuse
-	 * the reliable stack unwinder later on. Clear it.
-	 */
-	std	r0,STACK_FRAME_OVERHEAD-16(r1)
-
-	REST_4GPRS(2, r1)
-
-	bne-	cr1,1f /* emulate stack store */
-	mtcr	r6
-	REST_GPR(6, r1)
-	REST_GPR(0, r1)
-	REST_GPR(1, r1)
-	.ifc \srr,srr
-	RFI_TO_KERNEL
-	.else
-	HRFI_TO_KERNEL
-	.endif
-	b	.	/* prevent speculative execution */
-
-1:	/*
-	 * Emulate stack store with update. New r1 value was already calculated
-	 * and updated in our interrupt regs by emulate_loadstore, but we can't
-	 * store the previous value of r1 to the stack before re-loading our
-	 * registers from it, otherwise they could be clobbered.  Use
-	 * PACA_EXGEN as temporary storage to hold the store data, as
-	 * interrupts are disabled here so it won't be clobbered.
-	 */
-	mtcr	r6
-	std	r9,PACA_EXGEN+0(r13)
-	addi	r9,r1,INT_FRAME_SIZE /* get original r1 */
-	REST_GPR(6, r1)
-	REST_GPR(0, r1)
-	REST_GPR(1, r1)
-	std	r9,0(r1) /* perform store component of stdu */
-	ld	r9,PACA_EXGEN+0(r13)
-
-	.ifc \srr,srr
-	RFI_TO_KERNEL
-	.else
-	HRFI_TO_KERNEL
-	.endif
-	b	.	/* prevent speculative execution */
-.endm
-
-interrupt_return_macro srr
-interrupt_return_macro hsrr
-#endif /* CONFIG_PPC_BOOK3S */
-
 #ifdef CONFIG_PPC_RTAS
 /*
  * On CHRP, the Run-Time Abstraction Services (RTAS) have to be
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 4e2591cb4bd1..b13a2d79dfb4 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -189,8 +189,9 @@ CLOSE_FIXED_SECTION(first_256B)
 
 /* This value is used to mark exception frames on the stack. */
 	.section ".toc","aw"
+/* This value is used to mark exception frames on the stack. */
 exception_marker:
-	.tc	ID_72656773_68657265[TC],0x7265677368657265
+	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
 	.previous
 
 /*
@@ -206,6 +207,8 @@ OPEN_TEXT_SECTION(0x100)
 
 USE_TEXT_SECTION()
 
+#include "interrupt_64.S"
+
 #ifdef CONFIG_PPC_BOOK3E
 /*
  * The booting_thread_hwid holds the thread id we want to boot in cpu
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
new file mode 100644
index 000000000000..e121829ef717
--- /dev/null
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -0,0 +1,608 @@
+#include <asm/ppc_asm.h>
+#include <asm/head-64.h>
+#include <asm/bug.h>
+#include <asm/hw_irq.h>
+#include <asm/tm.h>
+#include <asm/mmu.h>
+#include <asm/asm-offsets.h>
+#include <asm/exception-64s.h>
+#include <asm/ptrace.h>
+#include <asm/head-64.h>
+#include <asm/feature-fixups.h>
+#include <asm/kup.h>
+
+	.section	".toc","aw"
+SYS_CALL_TABLE:
+	.tc sys_call_table[TC],sys_call_table
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYS_CALL_TABLE:
+	.tc compat_sys_call_table[TC],compat_sys_call_table
+#endif
+	.previous
+
+#ifdef CONFIG_PPC_BOOK3S
+.macro DEBUG_SRR_VALID srr
+#ifdef CONFIG_PPC_RFI_SRR_DEBUG
+	.ifc \srr,srr
+	mfspr	r11,SPRN_SRR0
+	ld	r12,_NIP(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	mfspr	r11,SPRN_SRR1
+	ld	r12,_MSR(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	.else
+	mfspr	r11,SPRN_HSRR0
+	ld	r12,_NIP(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	mfspr	r11,SPRN_HSRR1
+	ld	r12,_MSR(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	.endif
+#endif
+.endm
+
+.macro system_call_vectored name trapnr
+	.globl system_call_vectored_\name
+system_call_vectored_\name:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+BEGIN_FTR_SECTION
+	extrdi.	r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
+	bne	.Ltabort_syscall
+END_FTR_SECTION_IFSET(CPU_FTR_TM)
+#endif
+	INTERRUPT_TO_KERNEL
+	mr	r10,r1
+	ld	r1,PACAKSAVE(r13)
+	std	r10,0(r1)
+	std	r11,_NIP(r1)
+	std	r12,_MSR(r1)
+	std	r0,GPR0(r1)
+	std	r10,GPR1(r1)
+	std	r2,GPR2(r1)
+	ld	r2,PACATOC(r13)
+	mfcr	r12
+	li	r11,0
+	/* Can we avoid saving r3-r8 in common case? */
+	std	r3,GPR3(r1)
+	std	r4,GPR4(r1)
+	std	r5,GPR5(r1)
+	std	r6,GPR6(r1)
+	std	r7,GPR7(r1)
+	std	r8,GPR8(r1)
+	/* Zero r9-r12, this should only be required when restoring all GPRs */
+	std	r11,GPR9(r1)
+	std	r11,GPR10(r1)
+	std	r11,GPR11(r1)
+	std	r11,GPR12(r1)
+	std	r9,GPR13(r1)
+	SAVE_NVGPRS(r1)
+	std	r11,_XER(r1)
+	std	r11,_LINK(r1)
+	std	r11,_CTR(r1)
+
+	li	r11,\trapnr
+	std	r11,_TRAP(r1)
+	std	r12,_CCR(r1)
+	std	r3,ORIG_GPR3(r1)
+	addi	r10,r1,STACK_FRAME_OVERHEAD
+	ld	r11,exception_marker@toc(r2)
+	std	r11,-16(r10)		/* "regshere" marker */
+
+BEGIN_FTR_SECTION
+	HMT_MEDIUM
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	/*
+	 * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
+	 * would clobber syscall parameters. Also we always enter with IRQs
+	 * enabled and nothing pending. system_call_exception() will call
+	 * trace_hardirqs_off().
+	 *
+	 * scv enters with MSR[EE]=1, so don't set PACA_IRQ_HARD_DIS. The
+	 * entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED.
+	 */
+
+	/* Calling convention has r9 = orig r0, r10 = regs */
+	mr	r9,r0
+	bl	system_call_exception
+
+.Lsyscall_vectored_\name\()_exit:
+	addi    r4,r1,STACK_FRAME_OVERHEAD
+	li	r5,1 /* scv */
+	bl	syscall_exit_prepare
+
+	ld	r2,_CCR(r1)
+	ld	r4,_NIP(r1)
+	ld	r5,_MSR(r1)
+
+BEGIN_FTR_SECTION
+	stdcx.	r0,0,r1			/* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+BEGIN_FTR_SECTION
+	HMT_MEDIUM_LOW
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	cmpdi	r3,0
+	bne	.Lsyscall_vectored_\name\()_restore_regs
+
+	/* rfscv returns with LR->NIA and CTR->MSR */
+	mtlr	r4
+	mtctr	r5
+
+	/* Could zero these as per ABI, but we may consider a stricter ABI
+	 * which preserves these if libc implementations can benefit, so
+	 * restore them for now until further measurement is done. */
+	ld	r0,GPR0(r1)
+	ld	r4,GPR4(r1)
+	ld	r5,GPR5(r1)
+	ld	r6,GPR6(r1)
+	ld	r7,GPR7(r1)
+	ld	r8,GPR8(r1)
+	/* Zero volatile regs that may contain sensitive kernel data */
+	li	r9,0
+	li	r10,0
+	li	r11,0
+	li	r12,0
+	mtspr	SPRN_XER,r0
+
+	/*
+	 * 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.
+	 */
+	mtcr	r2
+	ld	r2,GPR2(r1)
+	ld	r3,GPR3(r1)
+	ld	r13,GPR13(r1)
+	ld	r1,GPR1(r1)
+	RFSCV_TO_USER
+	b	.	/* prevent speculative execution */
+
+.Lsyscall_vectored_\name\()_restore_regs:
+	li	r3,0
+	mtmsrd	r3,1
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r5
+
+	ld	r3,_CTR(r1)
+	ld	r4,_LINK(r1)
+	ld	r5,_XER(r1)
+
+	REST_NVGPRS(r1)
+	ld	r0,GPR0(r1)
+	mtcr	r2
+	mtctr	r3
+	mtlr	r4
+	mtspr	SPRN_XER,r5
+	REST_10GPRS(2, r1)
+	REST_2GPRS(12, r1)
+	ld	r1,GPR1(r1)
+	RFI_TO_USER
+.endm
+
+system_call_vectored common 0x3000
+/*
+ * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
+ * which is tested by system_call_exception when r0 is -1 (as set by vector
+ * entry code).
+ */
+system_call_vectored sigill 0x7ff0
+
+
+/*
+ * Entered via kernel return set up by kernel/sstep.c, must match entry regs
+ */
+	.globl system_call_vectored_emulate
+system_call_vectored_emulate:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
+	li	r10,IRQS_ALL_DISABLED
+	stb	r10,PACAIRQSOFTMASK(r13)
+	b	system_call_vectored_common
+#endif /* CONFIG_PPC_BOOK3S */
+
+	.balign IFETCH_ALIGN_BYTES
+	.globl system_call_common_real
+system_call_common_real:
+	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
+	mtmsrd	r10
+
+	.balign IFETCH_ALIGN_BYTES
+	.globl system_call_common
+system_call_common:
+_ASM_NOKPROBE_SYMBOL(system_call_common)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+BEGIN_FTR_SECTION
+	extrdi.	r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
+	bne	.Ltabort_syscall
+END_FTR_SECTION_IFSET(CPU_FTR_TM)
+#endif
+	mr	r10,r1
+	ld	r1,PACAKSAVE(r13)
+	std	r10,0(r1)
+	std	r11,_NIP(r1)
+	std	r12,_MSR(r1)
+	std	r0,GPR0(r1)
+	std	r10,GPR1(r1)
+	std	r2,GPR2(r1)
+#ifdef CONFIG_PPC_FSL_BOOK3E
+START_BTB_FLUSH_SECTION
+	BTB_FLUSH(r10)
+END_BTB_FLUSH_SECTION
+#endif
+	ld	r2,PACATOC(r13)
+	mfcr	r12
+	li	r11,0
+	/* Can we avoid saving r3-r8 in common case? */
+	std	r3,GPR3(r1)
+	std	r4,GPR4(r1)
+	std	r5,GPR5(r1)
+	std	r6,GPR6(r1)
+	std	r7,GPR7(r1)
+	std	r8,GPR8(r1)
+	/* Zero r9-r12, this should only be required when restoring all GPRs */
+	std	r11,GPR9(r1)
+	std	r11,GPR10(r1)
+	std	r11,GPR11(r1)
+	std	r11,GPR12(r1)
+	std	r9,GPR13(r1)
+	SAVE_NVGPRS(r1)
+	std	r11,_XER(r1)
+	std	r11,_CTR(r1)
+	mflr	r10
+
+	/*
+	 * This clears CR0.SO (bit 28), which is the error indication on
+	 * return from this system call.
+	 */
+	rldimi	r12,r11,28,(63-28)
+	li	r11,0xc00
+	std	r10,_LINK(r1)
+	std	r11,_TRAP(r1)
+	std	r12,_CCR(r1)
+	std	r3,ORIG_GPR3(r1)
+	addi	r10,r1,STACK_FRAME_OVERHEAD
+	ld	r11,exception_marker@toc(r2)
+	std	r11,-16(r10)		/* "regshere" marker */
+
+	li	r11,1
+	stb	r11,PACASRR_VALID(r13)
+
+	/*
+	 * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
+	 * would clobber syscall parameters. Also we always enter with IRQs
+	 * enabled and nothing pending. system_call_exception() will call
+	 * trace_hardirqs_off().
+	 */
+	li	r11,IRQS_ALL_DISABLED
+	li	r12,PACA_IRQ_HARD_DIS
+	stb	r11,PACAIRQSOFTMASK(r13)
+	stb	r12,PACAIRQHAPPENED(r13)
+
+	/* Calling convention has r9 = orig r0, r10 = regs */
+	mr	r9,r0
+	bl	system_call_exception
+
+.Lsyscall_exit:
+	addi    r4,r1,STACK_FRAME_OVERHEAD
+	li	r5,0 /* !scv */
+	bl	syscall_exit_prepare
+
+	ld	r2,_CCR(r1)
+	ld	r6,_LINK(r1)
+	mtlr	r6
+
+	lbz	r4,PACASRR_VALID(r13)
+	cmpdi	r4,0
+	bne	1f
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
+	ld	r4,_NIP(r1)
+	ld	r5,_MSR(r1)
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r5
+1:
+	DEBUG_SRR_VALID srr
+
+BEGIN_FTR_SECTION
+	stdcx.	r0,0,r1			/* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+	cmpdi	r3,0
+	bne	.Lsyscall_restore_regs
+	/* Zero volatile regs that may contain sensitive kernel data */
+	li	r0,0
+	li	r4,0
+	li	r5,0
+	li	r6,0
+	li	r7,0
+	li	r8,0
+	li	r9,0
+	li	r10,0
+	li	r11,0
+	li	r12,0
+	mtctr	r0
+	mtspr	SPRN_XER,r0
+.Lsyscall_restore_regs_cont:
+
+BEGIN_FTR_SECTION
+	HMT_MEDIUM_LOW
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	/*
+	 * 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.
+	 */
+	mtcr	r2
+	ld	r2,GPR2(r1)
+	ld	r3,GPR3(r1)
+	ld	r13,GPR13(r1)
+	ld	r1,GPR1(r1)
+	RFI_TO_USER
+	b	.	/* prevent speculative execution */
+
+.Lsyscall_restore_regs:
+	ld	r3,_CTR(r1)
+	ld	r4,_XER(r1)
+	REST_NVGPRS(r1)
+	mtctr	r3
+	mtspr	SPRN_XER,r4
+	ld	r0,GPR0(r1)
+	REST_8GPRS(4, r1)
+	ld	r12,GPR12(r1)
+	b	.Lsyscall_restore_regs_cont
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+.Ltabort_syscall:
+	/* Firstly we need to enable TM in the kernel */
+	mfmsr	r10
+	li	r9, 1
+	rldimi	r10, r9, MSR_TM_LG, 63-MSR_TM_LG
+	mtmsrd	r10, 0
+
+	/* tabort, this dooms the transaction, nothing else */
+	li	r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
+	TABORT(R9)
+
+	/*
+	 * Return directly to userspace. We have corrupted user register state,
+	 * but userspace will never see that register state. Execution will
+	 * resume after the tbegin of the aborted transaction with the
+	 * checkpointed register state.
+	 */
+	li	r9, MSR_RI
+	andc	r10, r10, r9
+	mtmsrd	r10, 1
+	mtspr	SPRN_SRR0, r11
+	mtspr	SPRN_SRR1, r12
+	RFI_TO_USER
+	b	.	/* prevent speculative execution */
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S
+_GLOBAL(ret_from_fork_scv)
+	bl	schedule_tail
+	REST_NVGPRS(r1)
+	li	r3,0	/* fork() return value */
+	b	.Lsyscall_vectored_common_exit
+#endif
+
+_GLOBAL(ret_from_fork)
+	bl	schedule_tail
+	REST_NVGPRS(r1)
+	li	r3,0	/* fork() return value */
+	b	.Lsyscall_exit
+
+_GLOBAL(ret_from_kernel_thread)
+	bl	schedule_tail
+	REST_NVGPRS(r1)
+	mtctr	r14
+	mr	r3,r15
+#ifdef PPC64_ELF_ABI_v2
+	mr	r12,r14
+#endif
+	bctrl
+	li	r3,0
+	b	.Lsyscall_exit
+
+#ifdef CONFIG_PPC_BOOK3S
+	/*
+	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
+	 * touched, no exit work created, then this can be used.
+	 */
+	.balign IFETCH_ALIGN_BYTES
+	.globl fast_interrupt_return_srr
+fast_interrupt_return_srr:
+_ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr)
+	kuap_check_amr r3, r4
+	ld	r5,_MSR(r1)
+	andi.	r0,r5,MSR_PR
+	bne	.Lfast_user_interrupt_return_srr
+	kuap_restore_amr r3, r4
+	andi.	r0,r5,MSR_RI
+	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
+	bne+	.Lfast_kernel_interrupt_return_srr
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	unrecoverable_exception
+	b	. /* should not get here */
+
+.macro interrupt_return_macro srr
+	.balign IFETCH_ALIGN_BYTES
+	.globl interrupt_return_\srr
+interrupt_return_\srr\():
+_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
+	ld	r4,_MSR(r1)
+	andi.	r0,r4,MSR_PR
+	beq	.Lkernel_interrupt_return_\srr
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	interrupt_exit_user_prepare
+	cmpdi	r3,0
+	bne-	.Lrestore_nvgprs_\srr
+
+.Lfast_user_interrupt_return_\srr:
+BEGIN_FTR_SECTION
+	ld	r10,_PPR(r1)
+	mtspr	SPRN_PPR,r10
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	.ifc \srr,srr
+	lbz	r4,PACASRR_VALID(r13)
+	.else
+	lbz	r4,PACAHSRR_VALID(r13)
+	.endif
+	cmpdi	r4,0
+	li	r4,0
+	bne	1f
+	ld	r11,_NIP(r1)
+	ld	r12,_MSR(r1)
+	.ifc \srr,srr
+	mtspr	SPRN_SRR0,r11
+	mtspr	SPRN_SRR1,r12
+1:
+	stb	r4,PACASRR_VALID(r13)
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+1:
+	stb	r4,PACAHSRR_VALID(r13)
+	.endif
+	DEBUG_SRR_VALID \srr
+
+BEGIN_FTR_SECTION
+	stdcx.	r0,0,r1		/* to clear the reservation */
+FTR_SECTION_ELSE
+	ldarx	r0,0,r1
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+	ld	r3,_CCR(r1)
+	ld	r4,_LINK(r1)
+	ld	r5,_CTR(r1)
+	ld	r6,_XER(r1)
+	li	r0,0
+
+	REST_4GPRS(7, r1)
+	REST_2GPRS(11, r1)
+	REST_GPR(13, r1)
+
+	mtcr	r3
+	mtlr	r4
+	mtctr	r5
+	mtspr	SPRN_XER,r6
+
+	REST_4GPRS(2, r1)
+	REST_GPR(6, r1)
+	REST_GPR(0, r1)
+	REST_GPR(1, r1)
+	.ifc \srr,srr
+	RFI_TO_USER
+	.else
+	HRFI_TO_USER
+	.endif
+	b	.	/* prevent speculative execution */
+
+.Lrestore_nvgprs_\srr\():
+	REST_NVGPRS(r1)
+	b	.Lfast_user_interrupt_return_\srr
+
+	.balign IFETCH_ALIGN_BYTES
+.Lkernel_interrupt_return_\srr\():
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	interrupt_exit_kernel_prepare
+
+.Lfast_kernel_interrupt_return_\srr\():
+	cmpdi	cr1,r3,0
+	.ifc \srr,srr
+	lbz	r4,PACASRR_VALID(r13)
+	.else
+	lbz	r4,PACAHSRR_VALID(r13)
+	.endif
+	cmpdi	r4,0
+	li	r4,0
+	bne	1f
+	ld	r11,_NIP(r1)
+	ld	r12,_MSR(r1)
+	.ifc \srr,srr
+	mtspr	SPRN_SRR0,r11
+	mtspr	SPRN_SRR1,r12
+1:
+	stb	r4,PACASRR_VALID(r13)
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+1:
+	stb	r4,PACAHSRR_VALID(r13)
+	.endif
+	DEBUG_SRR_VALID \srr
+
+BEGIN_FTR_SECTION
+	stdcx.	r0,0,r1		/* to clear the reservation */
+FTR_SECTION_ELSE
+	ldarx	r0,0,r1
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+	ld	r3,_LINK(r1)
+	ld	r4,_CTR(r1)
+	ld	r5,_XER(r1)
+	ld	r6,_CCR(r1)
+	li	r0,0
+
+	REST_4GPRS(7, r1)
+	REST_2GPRS(11, r1)
+
+	mtlr	r3
+	mtctr	r4
+	mtspr	SPRN_XER,r5
+
+	/*
+	 * Leaving a stale exception_marker on the stack can confuse
+	 * the reliable stack unwinder later on. Clear it.
+	 */
+	std	r0,STACK_FRAME_OVERHEAD-16(r1)
+
+	REST_4GPRS(2, r1)
+
+	bne-	cr1,1f /* emulate stack store */
+	mtcr	r6
+	REST_GPR(6, r1)
+	REST_GPR(0, r1)
+	REST_GPR(1, r1)
+	.ifc \srr,srr
+	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
+	b	.	/* prevent speculative execution */
+
+1:	/*
+	 * Emulate stack store with update. New r1 value was already calculated
+	 * and updated in our interrupt regs by emulate_loadstore, but we can't
+	 * store the previous value of r1 to the stack before re-loading our
+	 * registers from it, otherwise they could be clobbered.  Use
+	 * PACA_EXGEN as temporary storage to hold the store data, as
+	 * interrupts are disabled here so it won't be clobbered.
+	 */
+	mtcr	r6
+	std	r9,PACA_EXGEN+0(r13)
+	addi	r9,r1,INT_FRAME_SIZE /* get original r1 */
+	REST_GPR(6, r1)
+	REST_GPR(0, r1)
+	REST_GPR(1, r1)
+	std	r9,0(r1) /* perform store component of stdu */
+	ld	r9,PACA_EXGEN+0(r13)
+
+	.ifc \srr,srr
+	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
+	b	.	/* prevent speculative execution */
+.endm
+
+interrupt_return_macro srr
+interrupt_return_macro hsrr
+
+#endif /* CONFIG_PPC_BOOK3S */
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 4/9] powerpc/64s: avoid reloading (H)SRR registers if they are still valid
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

When an interrupt is taken, the SRR registers are set to return to
where it left off. Unless they are modified in the meantime, or the
return address or MSR are modified, there is no need to reload these
registers when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers, clear them when returning from interrupt, using the registers
for something else (e.g., OPAL calls), or adjusting return address or MSR.

This improves the performance of interrupt returns.

XXX: 64e build breaks

XXX: may not need to invalidate both hsrr and srr all the time

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/Kconfig.debug                 |  5 ++
 arch/powerpc/include/asm/paca.h            |  2 +
 arch/powerpc/include/asm/ptrace.h          | 15 +++++
 arch/powerpc/kernel/asm-offsets.c          |  2 +
 arch/powerpc/kernel/entry_64.S             | 75 +++++++++++++++++++---
 arch/powerpc/kernel/exceptions-64s.S       | 27 ++++++++
 arch/powerpc/kernel/fpu.S                  |  2 +
 arch/powerpc/kernel/kgdb.c                 |  2 +-
 arch/powerpc/kernel/kprobes-ftrace.c       |  2 +-
 arch/powerpc/kernel/kprobes.c              | 10 +--
 arch/powerpc/kernel/process.c              | 21 +++++-
 arch/powerpc/kernel/rtas.c                 | 13 +++-
 arch/powerpc/kernel/signal.c               |  2 +-
 arch/powerpc/kernel/signal_64.c            | 14 ++++
 arch/powerpc/kernel/syscalls.c             |  2 +
 arch/powerpc/kernel/traps.c                | 18 +++---
 arch/powerpc/kernel/vector.S               |  4 ++
 arch/powerpc/lib/sstep.c                   |  5 +-
 arch/powerpc/math-emu/math.c               |  2 +-
 arch/powerpc/mm/fault.c                    |  2 +-
 arch/powerpc/platforms/powernv/opal-call.c |  3 +
 arch/powerpc/sysdev/fsl_pci.c              |  2 +-
 22 files changed, 197 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index b88900f4832f..ad1f5bf6ab3d 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -84,6 +84,11 @@ config MSI_BITMAP_SELFTEST
 
 config PPC_IRQ_SOFT_MASK_DEBUG
 	bool "Include extra checks for powerpc irq soft masking"
+	depends on PPC64
+
+config PPC_RFI_SRR_DEBUG
+	bool "Include extra checks for RFI SRR register validity"
+	depends on PPC_BOOK3S_64
 
 config XMON
 	bool "Include xmon kernel debugger"
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 9454d29ff4b4..58e9995c3184 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -170,6 +170,8 @@ struct paca_struct {
 #ifdef CONFIG_PPC_BOOK3E
 	u16 trap_save;			/* Used when bad stack is encountered */
 #endif
+	u8 hsrr_valid;			/* HSRRs set for HRFID */
+	u8 srr_valid;			/* SRRs set for RFID */
 	u8 irq_soft_mask;		/* mask for irq soft masking */
 	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 irq_work_pending;		/* IRQ_WORK interrupt while soft-disable */
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index e2c778c176a3..2c3e773ce292 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -110,6 +110,7 @@ struct pt_regs
 #endif /* __powerpc64__ */
 
 #ifndef __ASSEMBLY__
+#include <asm/paca.h>
 
 static inline unsigned long instruction_pointer(struct pt_regs *regs)
 {
@@ -160,6 +161,20 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 	regs->gpr[3] = rc;
 }
 
+static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip)
+{
+	regs->nip = ip;
+#ifdef CONFIG_PPC_BOOK3S
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void regs_add_return_ip(struct pt_regs *regs, long offset)
+{
+	regs_set_return_ip(regs, regs->nip + offset);
+}
+
 #ifdef __powerpc64__
 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
 #else
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index c2722ff36e98..ea13e35dd511 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -210,6 +210,8 @@ int main(void)
 	OFFSET(PACATOC, paca_struct, kernel_toc);
 	OFFSET(PACAKBASE, paca_struct, kernelbase);
 	OFFSET(PACAKMSR, paca_struct, kernel_msr);
+	OFFSET(PACAHSRR_VALID, paca_struct, hsrr_valid);
+	OFFSET(PACASRR_VALID, paca_struct, srr_valid);
 	OFFSET(PACAIRQSOFTMASK, paca_struct, irq_soft_mask);
 	OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
 	OFFSET(PACA_FTRACE_ENABLED, paca_struct, ftrace_enabled);
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 53027fc9cd31..6236a88a592f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -65,6 +65,30 @@ exception_marker:
 	.align 7
 
 #ifdef CONFIG_PPC_BOOK3S
+.macro DEBUG_SRR_VALID srr
+#ifdef CONFIG_PPC_RFI_SRR_DEBUG
+	.ifc \srr,srr
+	mfspr	r11,SPRN_SRR0
+	ld	r12,_NIP(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	mfspr	r11,SPRN_SRR1
+	ld	r12,_MSR(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	.else
+	mfspr	r11,SPRN_HSRR0
+	ld	r12,_NIP(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	mfspr	r11,SPRN_HSRR1
+	ld	r12,_MSR(r1)
+100:	tdne	r11,r12
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+	.endif
+#endif
+.endm
+
 .macro system_call_vectored name trapnr
 	.globl system_call_vectored_\name
 system_call_vectored_\name:
@@ -289,6 +313,9 @@ END_BTB_FLUSH_SECTION
 	ld	r11,exception_marker@toc(r2)
 	std	r11,-16(r10)		/* "regshere" marker */
 
+	li	r11,1
+	stb	r11,PACASRR_VALID(r13)
+
 	/*
 	 * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
 	 * would clobber syscall parameters. Also we always enter with IRQs
@@ -310,18 +337,25 @@ END_BTB_FLUSH_SECTION
 	bl	syscall_exit_prepare
 
 	ld	r2,_CCR(r1)
+	ld	r6,_LINK(r1)
+	mtlr	r6
+
+	lbz	r4,PACASRR_VALID(r13)
+	cmpdi	r4,0
+	bne	1f
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
 	ld	r4,_NIP(r1)
 	ld	r5,_MSR(r1)
-	ld	r6,_LINK(r1)
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r5
+1:
+	DEBUG_SRR_VALID srr
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1			/* to clear the reservation */
 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 
-	mtspr	SPRN_SRR0,r4
-	mtspr	SPRN_SRR1,r5
-	mtlr	r6
-
 	cmpdi	r3,0
 	bne	.Lsyscall_restore_regs
 	/* Zero volatile regs that may contain sensitive kernel data */
@@ -648,7 +682,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	blr
 
 #ifdef CONFIG_PPC_BOOK3S
-
 	/*
 	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
 	 * touched, no exit work created, then this can be used.
@@ -683,19 +716,32 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
 	bne-	.Lrestore_nvgprs_\srr
 
 .Lfast_user_interrupt_return_\srr:
-	ld	r11,_NIP(r1)
-	ld	r12,_MSR(r1)
 BEGIN_FTR_SECTION
 	ld	r10,_PPR(r1)
 	mtspr	SPRN_PPR,r10
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	.ifc \srr,srr
+	lbz	r4,PACASRR_VALID(r13)
+	.else
+	lbz	r4,PACAHSRR_VALID(r13)
+	.endif
+	cmpdi	r4,0
+	li	r4,0
+	bne	1f
+	ld	r11,_NIP(r1)
+	ld	r12,_MSR(r1)
 	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+1:
+	stb	r4,PACASRR_VALID(r13)
 	.else
 	mtspr	SPRN_HSRR0,r11
 	mtspr	SPRN_HSRR1,r12
+1:
+	stb	r4,PACAHSRR_VALID(r13)
 	.endif
+	DEBUG_SRR_VALID \srr
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
@@ -740,15 +786,28 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 
 .Lfast_kernel_interrupt_return_\srr\():
 	cmpdi	cr1,r3,0
+	.ifc \srr,srr
+	lbz	r4,PACASRR_VALID(r13)
+	.else
+	lbz	r4,PACAHSRR_VALID(r13)
+	.endif
+	cmpdi	r4,0
+	li	r4,0
+	bne	1f
 	ld	r11,_NIP(r1)
 	ld	r12,_MSR(r1)
 	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+1:
+	stb	r4,PACASRR_VALID(r13)
 	.else
 	mtspr	SPRN_HSRR0,r11
 	mtspr	SPRN_HSRR1,r12
+1:
+	stb	r4,PACAHSRR_VALID(r13)
 	.endif
+	DEBUG_SRR_VALID \srr
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1f725a3ac2f3..b370a5f334fc 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -567,6 +567,20 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 	std	r0,GPR0(r1)		/* save r0 in stackframe	*/
 	std	r10,GPR1(r1)		/* save r1 in stackframe	*/
 
+	/* Mark our [H]SRRs valid for return */
+	li	r10,1
+	.if IHSRR_IF_HVMODE
+	BEGIN_FTR_SECTION
+	stb	r10,PACAHSRR_VALID(r13)
+	FTR_SECTION_ELSE
+	stb	r10,PACASRR_VALID(r13)
+	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+	.elseif IHSRR
+	stb	r10,PACAHSRR_VALID(r13)
+	.else
+	stb	r10,PACASRR_VALID(r13)
+	.endif
+
 	.if ISET_RI
 	li	r10,MSR_RI
 	mtmsrd	r10,1			/* Set MSR_RI */
@@ -666,10 +680,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 .macro EXCEPTION_RESTORE_REGS hsrr=0
 	/* Move original SRR0 and SRR1 into the respective regs */
 	ld	r9,_MSR(r1)
+	li	r10,0
 	.if \hsrr
 	mtspr	SPRN_HSRR1,r9
+	stb	r10,PACAHSRR_VALID(r13)
 	.else
 	mtspr	SPRN_SRR1,r9
+	stb	r10,PACASRR_VALID(r13)
 	.endif
 	ld	r9,_NIP(r1)
 	.if \hsrr
@@ -1781,6 +1798,8 @@ EXC_COMMON_BEGIN(hdecrementer_common)
 	 *
 	 * Be careful to avoid touching the kernel stack.
 	 */
+	li	r10,0
+	stb	r10,PACAHSRR_VALID(r13)
 	ld	r10,PACA_EXGEN+EX_CTR(r13)
 	mtctr	r10
 	mtcrf	0x80,r9
@@ -2611,6 +2630,8 @@ BEGIN_FTR_SECTION
 	ld	r10,PACA_EXGEN+EX_CFAR(r13)
 	mtspr	SPRN_CFAR,r10
 END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+	li	r10,0
+	stb	r10,PACAHSRR_VALID(r13)
 	ld	r10,PACA_EXGEN+EX_R10(r13)
 	ld	r11,PACA_EXGEN+EX_R11(r13)
 	ld	r12,PACA_EXGEN+EX_R12(r13)
@@ -2783,6 +2804,12 @@ masked_interrupt:
 	ori	r11,r11,PACA_IRQ_HARD_DIS
 	stb	r11,PACAIRQHAPPENED(r13)
 2:	/* done */
+	li	r10,0
+	.if \hsrr
+	stb	r10,PACAHSRR_VALID(r13)
+	.else
+	stb	r10,PACASRR_VALID(r13)
+	.endif
 	ld	r10,PACA_EXGEN+EX_CTR(r13)
 	mtctr	r10
 	mtcrf	0x80,r9
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 3ff9a8fafa46..ae80b4a3da48 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -105,6 +105,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	ori	r12,r12,MSR_FP
 	or	r12,r12,r4
 	std	r12,_MSR(r1)
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
 #endif
 	li	r4,1
 	stb	r4,THREAD_LOAD_FP(r5)
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 409080208a6c..dcac6c74a93c 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -147,7 +147,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 		return 0;
 
 	if (*(u32 *)regs->nip == BREAK_INSTR)
-		regs->nip += BREAK_INSTR_SIZE;
+		regs_add_return_ip(regs, BREAK_INSTR_SIZE);
 
 	return 1;
 }
diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c
index 972cb28174b2..dc35d4f5564f 100644
--- a/arch/powerpc/kernel/kprobes-ftrace.c
+++ b/arch/powerpc/kernel/kprobes-ftrace.c
@@ -40,7 +40,7 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
 			 * Emulate singlestep (and also recover regs->nip)
 			 * as if there is a nop
 			 */
-			regs->nip += MCOUNT_INSN_SIZE;
+			regs_add_return_ip(regs, MCOUNT_INSN_SIZE);
 			if (unlikely(p->post_handler)) {
 				kcb->kprobe_status = KPROBE_HIT_SSDONE;
 				p->post_handler(p, regs, 0);
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..8165ed71ab51 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -178,7 +178,7 @@ static nokprobe_inline void prepare_singlestep(struct kprobe *p, struct pt_regs
 	 * variant as values in regs could play a part in
 	 * if the trap is taken or not
 	 */
-	regs->nip = (unsigned long)p->ainsn.insn;
+	regs_set_return_ip(regs, (unsigned long)p->ainsn.insn);
 }
 
 static nokprobe_inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -415,7 +415,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
 	 * we end up emulating it in kprobe_handler(), which increments the nip
 	 * again.
 	 */
-	regs->nip = orig_ret_address - 4;
+	regs_set_return_ip(regs, orig_ret_address - 4);
 	regs->link = orig_ret_address;
 
 	return 0;
@@ -450,7 +450,7 @@ int kprobe_post_handler(struct pt_regs *regs)
 	}
 
 	/* Adjust nip to after the single-stepped instruction */
-	regs->nip = (unsigned long)cur->addr + len;
+	regs_set_return_ip(regs, (unsigned long)cur->addr + len);
 	regs->msr |= kcb->kprobe_saved_msr;
 
 	/*Restore back the original saved kprobes variables and continue. */
@@ -490,7 +490,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 		 * and allow the page fault handler to continue as a
 		 * normal page fault.
 		 */
-		regs->nip = (unsigned long)cur->addr;
+		regs_set_return_ip(regs, (unsigned long)cur->addr);
 		regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
 		regs->msr |= kcb->kprobe_saved_msr;
 		if (kcb->kprobe_status == KPROBE_REENTER)
@@ -523,7 +523,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 		 * zero, try to fix up.
 		 */
 		if ((entry = search_exception_tables(regs->nip)) != NULL) {
-			regs->nip = extable_fixup(entry);
+			regs_set_return_ip(regs, extable_fixup(entry));
 			return 1;
 		}
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0bdd3ed653df..ea36a29c8b01 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -97,6 +97,8 @@ static void check_if_tm_restore_required(struct task_struct *tsk)
 	    !test_thread_flag(TIF_RESTORE_TM)) {
 		tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
 		set_thread_flag(TIF_RESTORE_TM);
+		local_paca->hsrr_valid = 0;
+		local_paca->srr_valid = 0;
 	}
 }
 
@@ -161,6 +163,8 @@ static void __giveup_fpu(struct task_struct *tsk)
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr &= ~MSR_VSX;
 	tsk->thread.regs->msr = msr;
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 }
 
 void giveup_fpu(struct task_struct *tsk)
@@ -244,6 +248,8 @@ static void __giveup_altivec(struct task_struct *tsk)
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr &= ~MSR_VSX;
 	tsk->thread.regs->msr = msr;
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 }
 
 void giveup_altivec(struct task_struct *tsk)
@@ -559,6 +565,8 @@ void notrace restore_math(struct pt_regs *regs)
 		msr_check_and_clear(new_msr);
 
 		regs->msr |= new_msr | fpexc_mode;
+		local_paca->hsrr_valid = 0;
+		local_paca->srr_valid = 0;
 	}
 }
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -1295,6 +1303,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
 			atomic_read(&current->mm->context.vas_windows)))
 			asm volatile(PPC_CP_ABORT);
 	}
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
 	return last;
@@ -1878,6 +1888,9 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 	thread_pkey_regs_init(&current->thread);
+
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 }
 EXPORT_SYMBOL(start_thread);
 
@@ -1925,9 +1938,12 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
 	if (val > PR_FP_EXC_PRECISE)
 		return -EINVAL;
 	tsk->thread.fpexc_mode = __pack_fe01(val);
-	if (regs != NULL && (regs->msr & MSR_FP) != 0)
+	if (regs != NULL && (regs->msr & MSR_FP) != 0) {
 		regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
 			| tsk->thread.fpexc_mode;
+		local_paca->hsrr_valid = 0;
+		local_paca->srr_valid = 0;
+	}
 	return 0;
 }
 
@@ -1979,6 +1995,9 @@ int set_endian(struct task_struct *tsk, unsigned int val)
 	else
 		return -EINVAL;
 
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	return 0;
 }
 
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 954f41676f69..85b5541a24f7 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -46,6 +46,13 @@
 /* This is here deliberately so it's only used in this file */
 void enter_rtas(unsigned long);
 
+static inline void do_enter_rtas(unsigned long args)
+{
+	enter_rtas(args);
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+}
+
 struct rtas_t rtas = {
 	.lock = __ARCH_SPIN_LOCK_UNLOCKED
 };
@@ -384,7 +391,7 @@ static char *__fetch_rtas_last_error(char *altbuf)
 	save_args = rtas.args;
 	rtas.args = err_args;
 
-	enter_rtas(__pa(&rtas.args));
+	do_enter_rtas(__pa(&rtas.args));
 
 	err_args = rtas.args;
 	rtas.args = save_args;
@@ -430,7 +437,7 @@ va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
 	for (i = 0; i < nret; ++i)
 		args->rets[i] = 0;
 
-	enter_rtas(__pa(args));
+	do_enter_rtas(__pa(args));
 }
 
 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
@@ -1198,7 +1205,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
 	flags = lock_rtas();
 
 	rtas.args = args;
-	enter_rtas(__pa(&rtas.args));
+	do_enter_rtas(__pa(&rtas.args));
 	args = rtas.args;
 
 	/* A -1 return code indicates that the last command couldn't
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 44ec7b34b27e..ca1a504d442d 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -242,7 +242,7 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
 			regs->gpr[0] = __NR_restart_syscall;
 		else
 			regs->gpr[3] = regs->orig_gpr3;
-		regs->nip -= 4;
+		regs_add_return_ip(regs, - 4);
 		regs->result = 0;
 	} else {
 		if (trap_is_scv(regs)) {
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index bfc939360bad..8e60c89dcc87 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -693,6 +693,10 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 
 	/* This returns like rt_sigreturn */
 	set_thread_flag(TIF_RESTOREALL);
+
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	return 0;
 }
 
@@ -798,6 +802,10 @@ SYSCALL_DEFINE0(rt_sigreturn)
 		goto badframe;
 
 	set_thread_flag(TIF_RESTOREALL);
+
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	return 0;
 
 badframe:
@@ -878,6 +886,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
 
 	/* Set up "regs" so we "return" to the signal handler. */
+	/* XXX: use set return IP */
 	if (is_elf2_task()) {
 		regs->ctr = (unsigned long) ksig->ka.sa.sa_handler;
 		regs->gpr[12] = regs->ctr;
@@ -910,6 +919,9 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	if (err)
 		goto badframe;
 
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	return 0;
 
 badframe:
@@ -917,6 +929,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
 				   tsk->comm, tsk->pid, "setup_rt_frame",
 				   (long)frame, regs->nip, regs->link);
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 
 	return 1;
 }
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index 078608ec2e92..13bf62ccfa18 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -123,6 +123,8 @@ SYSCALL_DEFINE0(switch_endian)
 	struct thread_info *ti;
 
 	current->thread.regs->msr ^= MSR_LE;
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
 
 	/*
 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 95f84c542523..0796391edd16 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1049,7 +1049,7 @@ static void p9_hmi_special_emu(struct pt_regs *regs)
 #endif /* !__LITTLE_ENDIAN__ */
 
 	/* Go to next instruction */
-	regs->nip += 4;
+	regs_add_return_ip(regs, 4);
 }
 #endif /* CONFIG_VSX */
 
@@ -1487,7 +1487,7 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 
 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
 		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
-			regs->nip += 4;
+			regs_add_return_ip(regs, 4);
 			return;
 		}
 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
@@ -1549,7 +1549,7 @@ DEFINE_INTERRUPT_HANDLER(program_check_exception)
 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
 		switch (emulate_instruction(regs)) {
 		case 0:
-			regs->nip += 4;
+			regs_add_return_ip(regs, 4);
 			emulate_single_step(regs);
 			return;
 		case -EFAULT:
@@ -1600,7 +1600,7 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
 
 	if (fixed == 1) {
 		/* skip over emulated instruction */
-		regs->nip += inst_length(reason);
+		regs_add_return_ip(regs, inst_length(reason));
 		emulate_single_step(regs);
 		return;
 	}
@@ -1767,7 +1767,7 @@ DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
 				pr_err("DSCR based mfspr emulation failed\n");
 				return;
 			}
-			regs->nip += 4;
+			regs_add_return_ip(regs, 4);
 			emulate_single_step(regs);
 		}
 		return;
@@ -2030,7 +2030,7 @@ DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)
 	PPC_WARN_EMULATED(altivec, regs);
 	err = emulate_altivec(regs);
 	if (err == 0) {
-		regs->nip += 4;		/* skip emulated instruction */
+		regs_add_return_ip(regs, 4); /* skip emulated instruction */
 		emulate_single_step(regs);
 		return;
 	}
@@ -2094,7 +2094,7 @@ void SPEFloatingPointException(struct pt_regs *regs)
 
 	err = do_spe_mathemu(regs);
 	if (err == 0) {
-		regs->nip += 4;		/* skip emulated instruction */
+		regs_add_return_ip(regs, 4); /* skip emulated instruction */
 		emulate_single_step(regs);
 		return;
 	}
@@ -2125,10 +2125,10 @@ void SPEFloatingPointRoundException(struct pt_regs *regs)
 		giveup_spe(current);
 	preempt_enable();
 
-	regs->nip -= 4;
+	regs_add_return_ip(regs, - 4);
 	err = speround_handler(regs);
 	if (err == 0) {
-		regs->nip += 4;		/* skip emulated instruction */
+		regs_add_return_ip(regs, 4); /* skip emulated instruction */
 		emulate_single_step(regs);
 		return;
 	}
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 2c948e7b0d00..609e3526a66f 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -75,6 +75,8 @@ _GLOBAL(load_up_altivec)
 	addi	r5,r4,THREAD		/* Get THREAD */
 	oris	r12,r12,MSR_VEC@h
 	std	r12,_MSR(r1)
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
 #endif
 	li	r4,1
 	stb	r4,THREAD_LOAD_VEC(r5)
@@ -133,6 +135,8 @@ _GLOBAL(load_up_vsx)
 	/* enable use of VSX after return */
 	oris	r12,r12,MSR_VSX@h
 	std	r12,_MSR(r1)
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
 	b	fast_interrupt_return_srr
 
 #endif /* CONFIG_VSX */
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 855457ed09b5..6c2d6a3c9c8a 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3033,7 +3033,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op)
 	default:
 		WARN_ON_ONCE(1);
 	}
-	regs->nip = next_pc;
+	regs_set_return_ip(regs, next_pc);
 }
 NOKPROBE_SYMBOL(emulate_update_regs);
 
@@ -3310,6 +3310,9 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr)
 	unsigned long val;
 	unsigned long ea;
 
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	r = analyse_instr(&op, regs, instr);
 	if (r < 0)
 		return r;
diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 30b4b69c6941..d92416d78aee 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c
@@ -453,7 +453,7 @@ do_mathemu(struct pt_regs *regs)
 		break;
 	}
 
-	regs->nip += 4;
+	regs_add_return_ip(regs, 4);
 	return 0;
 
 illegal:
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 1999982200ab..1d82dc53386f 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -615,7 +615,7 @@ void bad_page_fault(struct pt_regs *regs, int sig)
 
 	/* Are we prepared to handle this fault?  */
 	if ((entry = search_exception_tables(regs->nip)) != NULL) {
-		regs->nip = extable_fixup(entry);
+		regs_set_return_ip(regs, extable_fixup(entry));
 		return;
 	}
 
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 5cd0f52d258f..1a7bc261d156 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -100,6 +100,9 @@ static int64_t opal_call(int64_t a0, int64_t a1, int64_t a2, int64_t a3,
 	bool mmu = (msr & (MSR_IR|MSR_DR));
 	int64_t ret;
 
+	local_paca->hsrr_valid = 0;
+	local_paca->srr_valid = 0;
+
 	msr &= ~MSR_EE;
 
 	if (unlikely(!mmu))
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 040b9d01c079..af78e7c3108f 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1072,7 +1072,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
 			ret = get_kernel_nofault(inst, (void *)regs->nip);
 
 		if (!ret && mcheck_handle_load(regs, inst)) {
-			regs->nip += 4;
+			regs_add_return_ip(regs, 4);
 			return 1;
 		}
 	}
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 3/9] powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

This makes no real difference yet except that HSRR type interrupts will
use hrfid to return. This is important for the next patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/entry_64.S       | 58 +++++++++++++++------
 arch/powerpc/kernel/exceptions-64s.S | 78 +++++++++++++++-------------
 arch/powerpc/kernel/vector.S         |  2 +-
 3 files changed, 85 insertions(+), 53 deletions(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index bd8cc7a214d3..53027fc9cd31 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -648,47 +648,54 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	blr
 
 #ifdef CONFIG_PPC_BOOK3S
+
 	/*
 	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
 	 * touched, no exit work created, then this can be used.
 	 */
 	.balign IFETCH_ALIGN_BYTES
-	.globl fast_interrupt_return
-fast_interrupt_return:
-_ASM_NOKPROBE_SYMBOL(fast_interrupt_return)
+	.globl fast_interrupt_return_srr
+fast_interrupt_return_srr:
+_ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr)
 	kuap_check_amr r3, r4
 	ld	r5,_MSR(r1)
 	andi.	r0,r5,MSR_PR
-	bne	.Lfast_user_interrupt_return
+	bne	.Lfast_user_interrupt_return_srr
 	kuap_restore_amr r3, r4
 	andi.	r0,r5,MSR_RI
 	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
-	bne+	.Lfast_kernel_interrupt_return
+	bne+	.Lfast_kernel_interrupt_return_srr
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unrecoverable_exception
 	b	. /* should not get here */
 
+.macro interrupt_return_macro srr
 	.balign IFETCH_ALIGN_BYTES
-	.globl interrupt_return
-interrupt_return:
-_ASM_NOKPROBE_SYMBOL(interrupt_return)
+	.globl interrupt_return_\srr
+interrupt_return_\srr\():
+_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
 	ld	r4,_MSR(r1)
 	andi.	r0,r4,MSR_PR
-	beq	.Lkernel_interrupt_return
+	beq	.Lkernel_interrupt_return_\srr
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	interrupt_exit_user_prepare
 	cmpdi	r3,0
-	bne-	.Lrestore_nvgprs
+	bne-	.Lrestore_nvgprs_\srr
 
-.Lfast_user_interrupt_return:
+.Lfast_user_interrupt_return_\srr:
 	ld	r11,_NIP(r1)
 	ld	r12,_MSR(r1)
 BEGIN_FTR_SECTION
 	ld	r10,_PPR(r1)
 	mtspr	SPRN_PPR,r10
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+	.endif
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
@@ -715,24 +722,33 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	REST_GPR(6, r1)
 	REST_GPR(0, r1)
 	REST_GPR(1, r1)
+	.ifc \srr,srr
 	RFI_TO_USER
+	.else
+	HRFI_TO_USER
+	.endif
 	b	.	/* prevent speculative execution */
 
-.Lrestore_nvgprs:
+.Lrestore_nvgprs_\srr\():
 	REST_NVGPRS(r1)
-	b	.Lfast_user_interrupt_return
+	b	.Lfast_user_interrupt_return_\srr
 
 	.balign IFETCH_ALIGN_BYTES
-.Lkernel_interrupt_return:
+.Lkernel_interrupt_return_\srr\():
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	interrupt_exit_kernel_prepare
 
-.Lfast_kernel_interrupt_return:
+.Lfast_kernel_interrupt_return_\srr\():
 	cmpdi	cr1,r3,0
 	ld	r11,_NIP(r1)
 	ld	r12,_MSR(r1)
+	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+	.endif
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
@@ -766,7 +782,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	REST_GPR(6, r1)
 	REST_GPR(0, r1)
 	REST_GPR(1, r1)
+	.ifc \srr,srr
 	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
 	b	.	/* prevent speculative execution */
 
 1:	/*
@@ -786,8 +806,16 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	std	r9,0(r1) /* perform store component of stdu */
 	ld	r9,PACA_EXGEN+0(r13)
 
+	.ifc \srr,srr
 	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
 	b	.	/* prevent speculative execution */
+.endm
+
+interrupt_return_macro srr
+interrupt_return_macro hsrr
 #endif /* CONFIG_PPC_BOOK3S */
 
 #ifdef CONFIG_PPC_RTAS
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ad9f51e49806..1f725a3ac2f3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1236,7 +1236,7 @@ EXC_COMMON_BEGIN(machine_check_common)
 	mtmsrd 	r10,1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	machine_check_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM machine_check
 
@@ -1360,10 +1360,10 @@ MMU_FTR_SECTION_ELSE
 	bl	do_page_fault
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
         cmpdi	r3,0
-	beq+	interrupt_return
+	beq+	interrupt_return_srr
 	/* We need to restore NVGPRS */
 	REST_NVGPRS(r1)
-	b       interrupt_return
+	b       interrupt_return_srr
 
 	GEN_KVM data_access
 
@@ -1410,7 +1410,7 @@ BEGIN_MMU_FTR_SECTION
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 1:	/* Error case */
 MMU_FTR_SECTION_ELSE
 	/* Radix case, access is outside page table range */
@@ -1419,7 +1419,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	std	r3,RESULT(r1)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_bad_slb_fault
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM data_access_slb
 
@@ -1458,10 +1458,10 @@ MMU_FTR_SECTION_ELSE
 	bl	do_page_fault
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
         cmpdi	r3,0
-	beq+	interrupt_return
+	beq+	interrupt_return_srr
 	/* We need to restore NVGPRS */
 	REST_NVGPRS(r1)
-	b       interrupt_return
+	b       interrupt_return_srr
 
 	GEN_KVM instruction_access
 
@@ -1499,7 +1499,7 @@ BEGIN_MMU_FTR_SECTION
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 1:	/* Error case */
 MMU_FTR_SECTION_ELSE
 	/* Radix case, access is outside page table range */
@@ -1508,7 +1508,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	std	r3,RESULT(r1)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_bad_slb_fault
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM instruction_access_slb
 
@@ -1554,7 +1554,11 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
 	GEN_COMMON hardware_interrupt
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_IRQ
-	b	interrupt_return
+	BEGIN_FTR_SECTION
+	b	interrupt_return_hsrr
+	FTR_SECTION_ELSE
+	b	interrupt_return_srr
+	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 
 	GEN_KVM hardware_interrupt
 
@@ -1583,7 +1587,7 @@ EXC_COMMON_BEGIN(alignment_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	alignment_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM alignment
 
@@ -1647,7 +1651,7 @@ EXC_COMMON_BEGIN(program_check_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	program_check_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM program_check
 
@@ -1692,12 +1696,12 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_TM)
 #endif
 	bl	load_up_fpu
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	fp_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 
 	GEN_KVM fp_unavailable
@@ -1738,7 +1742,7 @@ EXC_COMMON_BEGIN(decrementer_common)
 	GEN_COMMON decrementer
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	timer_interrupt
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM decrementer
 
@@ -1826,7 +1830,7 @@ EXC_COMMON_BEGIN(doorbell_super_common)
 #else
 	bl	unknown_async_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM doorbell_super
 
@@ -1995,7 +1999,7 @@ EXC_COMMON_BEGIN(single_step_common)
 	GEN_COMMON single_step
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	single_step_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM single_step
 
@@ -2036,7 +2040,7 @@ BEGIN_MMU_FTR_SECTION
 MMU_FTR_SECTION_ELSE
 	bl      unknown_exception
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
-	b       interrupt_return
+	b       interrupt_return_hsrr
 
 	GEN_KVM h_data_storage
 
@@ -2063,7 +2067,7 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
 	GEN_COMMON h_instr_storage
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unknown_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM h_instr_storage
 
@@ -2089,7 +2093,7 @@ EXC_COMMON_BEGIN(emulation_assist_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	emulation_assist_interrupt
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM emulation_assist
 
@@ -2170,7 +2174,7 @@ EXC_COMMON_BEGIN(hmi_exception_common)
 	GEN_COMMON hmi_exception
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	handle_hmi_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM hmi_exception
 
@@ -2202,7 +2206,7 @@ EXC_COMMON_BEGIN(h_doorbell_common)
 #else
 	bl	unknown_async_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM h_doorbell
 
@@ -2230,7 +2234,7 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
 	GEN_COMMON h_virt_irq
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_IRQ
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM h_virt_irq
 
@@ -2275,7 +2279,7 @@ EXC_COMMON_BEGIN(performance_monitor_common)
 	GEN_COMMON performance_monitor
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	performance_monitor_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM performance_monitor
 
@@ -2314,19 +2318,19 @@ BEGIN_FTR_SECTION
   END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
 #endif
 	bl	load_up_altivec
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	altivec_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	altivec_unavailable_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM altivec_unavailable
 
@@ -2369,14 +2373,14 @@ BEGIN_FTR_SECTION
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	vsx_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	vsx_unavailable_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM vsx_unavailable
 
@@ -2406,7 +2410,7 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM facility_unavailable
 
@@ -2436,7 +2440,7 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM h_facility_unavailable
 
@@ -2469,7 +2473,7 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
 	GEN_COMMON cbe_system_error
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_system_error_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM cbe_system_error
 
@@ -2497,7 +2501,7 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
 	GEN_COMMON instruction_breakpoint
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	instruction_breakpoint_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM instruction_breakpoint
 
@@ -2619,7 +2623,7 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 	GEN_COMMON denorm_exception
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unknown_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM denorm_exception
 
@@ -2640,7 +2644,7 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
 	GEN_COMMON cbe_maintenance
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_maintenance_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM cbe_maintenance
 
@@ -2672,7 +2676,7 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 #else
 	bl	unknown_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_srr
 
 	GEN_KVM altivec_assist
 
@@ -2693,7 +2697,7 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
 	GEN_COMMON cbe_thermal
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_thermal_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 	GEN_KVM cbe_thermal
 
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 801dc28fdcca..2c948e7b0d00 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -133,7 +133,7 @@ _GLOBAL(load_up_vsx)
 	/* enable use of VSX after return */
 	oris	r12,r12,MSR_VSX@h
 	std	r12,_MSR(r1)
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 
 #endif /* CONFIG_VSX */
 
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 2/9] powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

This extends the MSR[RI]=0 window a little further into the system
call in order to pair RI and EE enabling with a single mtmsrd.

XXX: May need to make this radix-only opt. - might take SLB or HPT faults
on the context tracking, etc.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ea7bb7cc0db1..ad9f51e49806 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1905,8 +1905,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
 	mtctr	r10
 	bctr
 	.else
-	li	r10,MSR_RI
-	mtmsrd 	r10,1			/* Set RI (EE=0) */
 #ifdef CONFIG_RELOCATABLE
 	__LOAD_HANDLER(r10, system_call_common)
 	mtctr	r10
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 1/9] powerpc/64s: syscall real mode entry use mtmsrd rather than rfid
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin
In-Reply-To: <20201106155929.2246055-1-npiggin@gmail.com>

Have the real mode system call entry handler branch to the kernel
0xc000... address and then use mtmsrd to enable the MMU, rather than use
SRRs and rfid.

Commit 8729c26e675c ("powerpc/64s/exception: Move real to virt switch
into the common handler") implemented this style of real mode entry for
other interrupt handlers, so this brings system calls into line with
them, which is the main motivcation for the change.

This tends to be slightly faster due to avoiding the mtsprs, and it also
does not clobber the SRR registers, which becomes important in a
subsequent change. The real mode entry points don't tend to be too
important for performance these days, but it is possible for a
hypervisor to run guests in AIL=0 mode for certian reasons.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/entry_64.S       | 6 ++++++
 arch/powerpc/kernel/exceptions-64s.S | 9 +++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 479fb58844fa..bd8cc7a214d3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -225,6 +225,12 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
 	b	system_call_vectored_common
 #endif
 
+	.balign IFETCH_ALIGN_BYTES
+	.globl system_call_common_real
+system_call_common_real:
+	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
+	mtmsrd	r10
+
 	.balign IFETCH_ALIGN_BYTES
 	.globl system_call_common
 system_call_common:
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1db6b3438c88..ea7bb7cc0db1 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1901,12 +1901,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
 	HMT_MEDIUM
 
 	.if ! \virt
-	__LOAD_HANDLER(r10, system_call_common)
-	mtspr	SPRN_SRR0,r10
-	ld	r10,PACAKMSR(r13)
-	mtspr	SPRN_SRR1,r10
-	RFI_TO_KERNEL
-	b	.	/* prevent speculative execution */
+	__LOAD_HANDLER(r10, system_call_common_real)
+	mtctr	r10
+	bctr
 	.else
 	li	r10,MSR_RI
 	mtmsrd 	r10,1			/* Set RI (EE=0) */
-- 
2.23.0


^ permalink raw reply related

* [RFC PATCH 0/9] powerpc/64s: fast interrupt exit
From: Nicholas Piggin @ 2020-11-06 15:59 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Nicholas Piggin

This series attempts to improve the speed of interrupts and system calls
in two major ways.

Firstly, the SRR/HSRR registers do not need to be reloaded if they were
not used or clobbered fur the duration of the interrupt.

Secondly, an alternate return location facility is added for soft-masked
asynchronous interrupts and then that's used to set everything up for
return without having to disable MSR RI or EE.

After this series, the entire system call / interrupt handler fast path
executes no mtsprs and one mtmsrd to enable interrupts initially, and
the system call vectored path doesn't even need to do that.

Thanks,
Nick

Nicholas Piggin (9):
  powerpc/64s: syscall real mode entry use mtmsrd rather than rfid
  powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]
  powerpc/64s: introduce different functions to return from SRR vs HSRR
    interrupts
  powerpc/64s: avoid reloading (H)SRR registers if they are still valid
  powerpc/64: move interrupt return asm to interrupt_64.S
  powerpc/64s: save one more register in the masked interrupt handler
  powerpc/64s: allow alternate return locations for soft-masked
    interrupts
  powerpc/64s: interrupt soft-enable race fix
  powerpc/64s: use interrupt restart table to speed up return from
    interrupt

 arch/powerpc/Kconfig.debug                 |   5 +
 arch/powerpc/include/asm/asm-prototypes.h  |   4 +-
 arch/powerpc/include/asm/head-64.h         |   2 +-
 arch/powerpc/include/asm/interrupt.h       |  18 +
 arch/powerpc/include/asm/paca.h            |   3 +
 arch/powerpc/include/asm/ppc_asm.h         |   8 +
 arch/powerpc/include/asm/ptrace.h          |  28 +-
 arch/powerpc/kernel/asm-offsets.c          |   5 +
 arch/powerpc/kernel/entry_64.S             | 508 ---------------
 arch/powerpc/kernel/exceptions-64s.S       | 180 ++++--
 arch/powerpc/kernel/fpu.S                  |   2 +
 arch/powerpc/kernel/head_64.S              |   5 +-
 arch/powerpc/kernel/interrupt_64.S         | 720 +++++++++++++++++++++
 arch/powerpc/kernel/irq.c                  |  79 ++-
 arch/powerpc/kernel/kgdb.c                 |   2 +-
 arch/powerpc/kernel/kprobes-ftrace.c       |   2 +-
 arch/powerpc/kernel/kprobes.c              |  10 +-
 arch/powerpc/kernel/process.c              |  21 +-
 arch/powerpc/kernel/rtas.c                 |  13 +-
 arch/powerpc/kernel/signal.c               |   2 +-
 arch/powerpc/kernel/signal_64.c            |  14 +
 arch/powerpc/kernel/syscall_64.c           | 242 ++++---
 arch/powerpc/kernel/syscalls.c             |   2 +
 arch/powerpc/kernel/traps.c                |  18 +-
 arch/powerpc/kernel/vector.S               |   6 +-
 arch/powerpc/kernel/vmlinux.lds.S          |  10 +
 arch/powerpc/lib/Makefile                  |   2 +-
 arch/powerpc/lib/restart_table.c           |  26 +
 arch/powerpc/lib/sstep.c                   |   5 +-
 arch/powerpc/math-emu/math.c               |   2 +-
 arch/powerpc/mm/fault.c                    |   2 +-
 arch/powerpc/perf/core-book3s.c            |  19 +-
 arch/powerpc/platforms/powernv/opal-call.c |   3 +
 arch/powerpc/sysdev/fsl_pci.c              |   2 +-
 34 files changed, 1244 insertions(+), 726 deletions(-)
 create mode 100644 arch/powerpc/kernel/interrupt_64.S
 create mode 100644 arch/powerpc/lib/restart_table.c

-- 
2.23.0


^ permalink raw reply

* Re: [PATCH 02/29] powerpc/rtas: prevent suspend-related sys_rtas use on LE
From: Andrew Donnellan @ 2020-11-06 14:59 UTC (permalink / raw)
  To: Nathan Lynch, linuxppc-dev; +Cc: tyreld, brking, mmc, cforno12, drt
In-Reply-To: <87r1pfkj7z.fsf@linux.ibm.com>

On 30/10/20 11:10 pm, Nathan Lynch wrote:
>> And there's a zero chance that drmgr will ever be fixed on LE?
> 
> It's always used the sysfs interface on LE, and the only way to provoke
> it to attempt the syscalls is by doing something like this before
> running the migration:
> 
> # echo 0 > /tmp/fake_api_version
> # mount -o bind,ro /tmp/fake_api_version /sys/kernel/mobility/api_version
> 
> So I'm not aware of any circumstance that would actually motivate
> someone to make it work on LE. I'd say it's more likely that drmgr will
> drop its support for using the syscall altogether.
> 

Okay. librtas should handle the error fine, so I don't have any huge 
objection to this, though perhaps a documentation patch to librtas to 
mention that these calls are BE-only would be in order.

-- 
Andrew Donnellan              OzLabs, ADL Canberra
ajd@linux.ibm.com             IBM Australia Limited

^ permalink raw reply

* Re: [PATCH 11/11 v3] ftrace: Add recording of functions that caused recursion
From: Petr Mladek @ 2020-11-06 14:27 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Anton Vorontsov, linux-doc, Peter Zijlstra,
	Sebastian Andrzej Siewior, Kamalesh Babulal, James E.J. Bottomley,
	Guo Ren, H. Peter Anvin, live-patching, Miroslav Benes,
	Ingo Molnar, linux-s390, Joe Lawrence, Jonathan Corbet,
	Mauro Carvalho Chehab, Helge Deller, x86, linux-csky,
	Christian Borntraeger, Kees Cook, Vasily Gorbik, Heiko Carstens,
	Jiri Kosina, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
	Tony Luck, linux-parisc, linux-kernel, Masami Hiramatsu,
	Colin Cross, Paul Mackerras, Andrew Morton, linuxppc-dev
In-Reply-To: <20201106084131.7dfc3a30@gandalf.local.home>

On Fri 2020-11-06 08:41:31, Steven Rostedt wrote:
> On Fri, 6 Nov 2020 14:13:17 +0100
> Petr Mladek <pmladek@suse.com> wrote:
> 
> > JFYI, the code reading and writing the cache looks good to me.
> > 
> > It is still possible that some entries might stay unused (filled
> > with zeroes) but it should be hard to hit in practice. It
> > is good enough from my POV.
> 
> You mean the part that was commented?

Yeah, it is the comment problem when nr_records is pushed forward.

> > 
> > I do not give Reviewed-by tag just because I somehow do not have power
> > to review the entire patch carefully enough at the moment.
> 
> No problem. Thanks for looking at it.
> 
> I'm adding a link to this thread, so if someone wants proof you helped out
> on this code, you can have them follow the links ;-)
> 
> Anyway, even if I push this to linux-next where I stop rebasing code
> (because of test coverage), I do rebase for adding tags. So if you ever get
> around at looking at this code, I can add that tag later (before the next
> merge window), or if you find something, I could fix it with a new patch and
> give you a Reported-by.

Good to know.

Best Regards,
Petr

^ permalink raw reply

* Re: [PATCH 11/11 v3] ftrace: Add recording of functions that caused recursion
From: Steven Rostedt @ 2020-11-06 13:41 UTC (permalink / raw)
  To: Petr Mladek
  Cc: Anton Vorontsov, linux-doc, Peter Zijlstra,
	Sebastian Andrzej Siewior, Kamalesh Babulal, James E.J. Bottomley,
	Guo Ren, H. Peter Anvin, live-patching, Miroslav Benes,
	Ingo Molnar, linux-s390, Joe Lawrence, Jonathan Corbet,
	Mauro Carvalho Chehab, Helge Deller, x86, linux-csky,
	Christian Borntraeger, Kees Cook, Vasily Gorbik, Heiko Carstens,
	Jiri Kosina, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
	Tony Luck, linux-parisc, linux-kernel, Masami Hiramatsu,
	Colin Cross, Paul Mackerras, Andrew Morton, linuxppc-dev
In-Reply-To: <20201106131317.GW20201@alley>

On Fri, 6 Nov 2020 14:13:17 +0100
Petr Mladek <pmladek@suse.com> wrote:

> JFYI, the code reading and writing the cache looks good to me.
> 
> It is still possible that some entries might stay unused (filled
> with zeroes) but it should be hard to hit in practice. It
> is good enough from my POV.

You mean the part that was commented?

> 
> I do not give Reviewed-by tag just because I somehow do not have power
> to review the entire patch carefully enough at the moment.

No problem. Thanks for looking at it.

I'm adding a link to this thread, so if someone wants proof you helped out
on this code, you can have them follow the links ;-)

Anyway, even if I push this to linux-next where I stop rebasing code
(because of test coverage), I do rebase for adding tags. So if you ever get
around at looking at this code, I can add that tag later (before the next
merge window), or if you find something, I could fix it with a new patch and
give you a Reported-by.

-- Steve

^ permalink raw reply

* [PATCH] powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functions
From: Christophe Leroy @ 2020-11-06 13:20 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel

All hugetlb range freeing functions have a verification like the following,
which only differs by the mask used, depending on the page table level.

	start &= MASK;
	if (start < floor)
		return;
	if (ceiling) {
		ceiling &= MASK;
		if (! ceiling)
			return;
		}
	if (end - 1 > ceiling - 1)
		return;

Refactor that into a helper function which takes the mask as
an argument, returning true when [start;end[ is not fully
contained inside [floor;ceiling[

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/hugetlbpage.c | 56 ++++++++++++-----------------------
 1 file changed, 19 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 36c3800769fb..f8d8a4988e15 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -294,6 +294,21 @@ static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
 static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {}
 #endif
 
+/* Return true when the entry to be freed maps more than the area being freed */
+static bool range_is_outside_limits(unsigned long start, unsigned long end,
+				    unsigned long floor, unsigned long ceiling,
+				    unsigned long mask)
+{
+	if ((start & mask) < floor)
+		return true;
+	if (ceiling) {
+		ceiling &= mask;
+		if (!ceiling)
+			return true;
+	}
+	return end - 1 > ceiling - 1;
+}
+
 static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
 			      unsigned long start, unsigned long end,
 			      unsigned long floor, unsigned long ceiling)
@@ -309,15 +324,7 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
 	if (shift > pdshift)
 		num_hugepd = 1 << (shift - pdshift);
 
-	start &= pdmask;
-	if (start < floor)
-		return;
-	if (ceiling) {
-		ceiling &= pdmask;
-		if (! ceiling)
-			return;
-	}
-	if (end - 1 > ceiling - 1)
+	if (range_is_outside_limits(start, end, floor, ceiling, pdmask))
 		return;
 
 	for (i = 0; i < num_hugepd; i++, hpdp++)
@@ -334,18 +341,9 @@ static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 				   unsigned long addr, unsigned long end,
 				   unsigned long floor, unsigned long ceiling)
 {
-	unsigned long start = addr;
 	pgtable_t token = pmd_pgtable(*pmd);
 
-	start &= PMD_MASK;
-	if (start < floor)
-		return;
-	if (ceiling) {
-		ceiling &= PMD_MASK;
-		if (!ceiling)
-			return;
-	}
-	if (end - 1 > ceiling - 1)
+	if (range_is_outside_limits(addr, end, floor, ceiling, PMD_MASK))
 		return;
 
 	pmd_clear(pmd);
@@ -395,15 +393,7 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 				  addr, next, floor, ceiling);
 	} while (addr = next, addr != end);
 
-	start &= PUD_MASK;
-	if (start < floor)
-		return;
-	if (ceiling) {
-		ceiling &= PUD_MASK;
-		if (!ceiling)
-			return;
-	}
-	if (end - 1 > ceiling - 1)
+	if (range_is_outside_limits(start, end, floor, ceiling, PUD_MASK))
 		return;
 
 	pmd = pmd_offset(pud, start);
@@ -446,15 +436,7 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
 		}
 	} while (addr = next, addr != end);
 
-	start &= PGDIR_MASK;
-	if (start < floor)
-		return;
-	if (ceiling) {
-		ceiling &= PGDIR_MASK;
-		if (!ceiling)
-			return;
-	}
-	if (end - 1 > ceiling - 1)
+	if (range_is_outside_limits(start, end, floor, ceiling, PGDIR_MASK))
 		return;
 
 	pud = pud_offset(p4d, start);
-- 
2.25.0


^ permalink raw reply related

* Re: [PATCH 11/11 v3] ftrace: Add recording of functions that caused recursion
From: Petr Mladek @ 2020-11-06 13:13 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Anton Vorontsov, linux-doc, Peter Zijlstra,
	Sebastian Andrzej Siewior, Kamalesh Babulal, James E.J. Bottomley,
	Guo Ren, H. Peter Anvin, live-patching, Miroslav Benes,
	Ingo Molnar, linux-s390, Joe Lawrence, Jonathan Corbet,
	Mauro Carvalho Chehab, Helge Deller, x86, linux-csky,
	Christian Borntraeger, Kees Cook, Vasily Gorbik, Heiko Carstens,
	Jiri Kosina, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
	Tony Luck, linux-parisc, linux-kernel, Masami Hiramatsu,
	Colin Cross, Paul Mackerras, Andrew Morton, linuxppc-dev
In-Reply-To: <20201106023548.102375687@goodmis.org>

On Thu 2020-11-05 21:32:46, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file
> "recursed_functions" all the functions that caused recursion while a
> callback to the function tracer was running.
> 
> Changes since v2:
> 
>  - Use trace_recursion flags in current for protecting recursion of recursion recording
>  - Make the recursion logic a little cleaner
>  - Export GPL the recursion recording

JFYI, the code reading and writing the cache looks good to me.

It is still possible that some entries might stay unused (filled
with zeroes) but it should be hard to hit in practice. It
is good enough from my POV.

I do not give Reviewed-by tag just because I somehow do not have power
to review the entire patch carefully enough at the moment.

Best Regards,
Petr

^ permalink raw reply

* Re: Kernel panic from malloc() on SUSE 15.1?
From: Michal Suchánek @ 2020-11-06 12:51 UTC (permalink / raw)
  To: Carl Jacobsen; +Cc: linuxppc-dev
In-Reply-To: <CAKkwB_S6Bs_+5At2aajbQbJg==WE_4NLdhSK=Bj+td67215Htg@mail.gmail.com>

On Mon, Nov 02, 2020 at 12:14:27PM -0800, Carl Jacobsen wrote:
> I've got a SUSE 15.1 install (on ppc64le) that kernel panics on a very
> simple
> test program, built in a slightly unusual way.
> 
> I'm compiling on SUSE 12, using gcc 4.8.3. I'm linking to a static
> copy of libcrypto.a (from openssl-1.1.1g), built without threads.
> I have a 10 line C test program that compiles and runs fine on the
> SUSE 12 system. If I compile the same program on SUSE 15.1 (with
> gcc 7.4.1), it runs fine on SUSE 15.1.
> 
> But, if I run the version that I compiled on SUSE 12, on the SUSE 15.1
> system, the call to RAND_status() gets to a malloc() and then panics.
> (And, of course, if I just compile a call to malloc(), that runs fine
> on both systems.) Here's the test program, it's really just a call to
> RAND_status():
> 
>     #include <stdio.h>
>     #include <openssl/rand.h>
> 
>     int main(int argc, char **argv)
>     {
>         int has_enough_data = RAND_status();
>         printf("The PRNG %s been seeded with enough data\n",
>                has_enough_data ? "HAS" : "has NOT");
>         return 0;
>     }
> 
> openssl is configured/built with:
>     ./config no-shared no-dso no-threads -fPIC -ggdb3 -debug -static
>     make
> 
> and the test program is compiled with:
>     gcc -ggdb3 -o rand_test rand_test.c libcrypto.a
> 
> The kernel on SUSE 12 is: 3.12.28-4-default
> And glibc is: 2.19
> 
> The kernel on SUSE 15.1 is: 4.12.14-197.18-default
> And glibc is: 2.26

SLE 12 SP5 has pretty much the same kernel as SLE 15 SP1 and pretty much
the same compiler as SLE 12 so it might be interesting data point to try
there.

Also I saw you are using very old VIOS (which should not make much of a
difference) but did not see what firmware version the machine has.

There have been cases of mysterious crashes solved by updating the
firmware.

Thanks

Michal

^ permalink raw reply

* Re: Kernel panic from malloc() on SUSE 15.1?
From: Michael Ellerman @ 2020-11-06 12:25 UTC (permalink / raw)
  To: Carl Jacobsen; +Cc: linuxppc-dev
In-Reply-To: <CAKkwB_TQJ=tg17SJd_s2SSXA7F3MeHmzjMC8f2uiV7yGvsLufg@mail.gmail.com>

Carl Jacobsen <cjacobsen@storix.com> writes:
> On Thu, Nov 5, 2020 at 2:19 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
>> Carl Jacobsen <cjacobsen@storix.com> writes:
>> > The panic (on a call to malloc from static linked libcrypto) looks like
>> > this:
>>
>> What hardware is this on?
>>
>
> Thank you for looking into this.
>
> The system that's panicking identifies like this:
>     # uname -a
>     Linux sl151pwr8 4.12.14-197.18-default #1 SMP Tue Sep 17 14:26:49 UTC
> 2019
>     (d75059b) ppc64le ppc64le ppc64le GNU/Linux
>     #
>     # cat /etc/os-release
>     NAME="SLES"
>     VERSION="15-SP1"
>     VERSION_ID="15.1"
>     PRETTY_NAME="SUSE Linux Enterprise Server 15 SP1"
>     ID="sles"
>     ID_LIKE="suse"
>     ANSI_COLOR="0;32"
>     CPE_NAME="cpe:/o:suse:sles:15:sp1"
>
> The system is an LPAR running under PowerVM vios version 2.2.3.4.
> The underlying hardware is machine type-model 8284-22A.

OK thanks. That's a Power8.

>> Can you try booting with ppc_tm=off on the kernel command line, and see
>> if that changes anything?
>
> Yes. Output is down below. Doesn't appear to change much, but I don't have
> the background to interpret the registers.

Yeah looks like that's not the problem.

>> Can you put your compiled test program up somewhere we can download it
>> and look at? Or post the disassembly?
>>
>
> Here's the source file:
>     https://www.storix.com/download/support/misc/rand_test.c
>
> Here's the resulting executable:
>     https://www.storix.com/download/support/misc/rand_test

Thanks.

So something seems to have gone wrong linking this, I see eg:

0000000010004a8c <syscall_random>:
    10004a8c:   2b 10 40 3c     lis     r2,4139
    10004a90:   88 f7 42 38     addi    r2,r2,-2168
    10004a94:   a6 02 08 7c     mflr    r0
    10004a98:   10 00 01 f8     std     r0,16(r1)
    10004a9c:   f8 ff e1 fb     std     r31,-8(r1)
    10004aa0:   81 ff 21 f8     stdu    r1,-128(r1)
    10004aa4:   78 0b 3f 7c     mr      r31,r1
    10004aa8:   60 00 7f f8     std     r3,96(r31)
    10004aac:   68 00 9f f8     std     r4,104(r31)
    10004ab0:   00 00 00 60     nop
    10004ab4:   30 80 22 e9     ld      r9,-32720(r2)
    10004ab8:   00 00 a9 2f     cmpdi   cr7,r9,0
    10004abc:   30 00 9e 41     beq     cr7,10004aec <syscall_random+0x60>
    10004ac0:   60 00 7f e8     ld      r3,96(r31)
    10004ac4:   68 00 9f e8     ld      r4,104(r31)
    10004ac8:   39 b5 ff 4b     bl      10000000 <_init-0x1f00>

Notice that last bl (branch and link) to 0x10000000. But there's no text
at 0x10000000, that's the start of the page which happens to be the ELF
magic.

I've seen something like this before, but I can't remember when/where so
I haven't been able to track down what the problem was.

Anyway hopefully someone on the list will know.

That still doesn't explain the kernel crash though.


> Executable is linked to libcrypto from openssl-1.1.1g, configured with:
>     ./config no-shared no-dso no-threads -fPIC -ggdb3 -debug -static
>
> Executable is built (on SUSE 12) with:
>     gcc -ggdb3 -o rand_test rand_test.c libcrypto.a


> And running the executable (on SUSE 15.1) through gdb goes like this:
>
>     # gdb --args ./rand_test
>     GNU gdb (GDB; SUSE Linux Enterprise 15) 8.3.1
>     << snip intro text >>
>     Reading symbols from ./rand_test...
>     (gdb) b main
>     Breakpoint 1 at 0x1000288c: file rand_test.c, line 6.
>     (gdb) r
>     Starting program: /tmp/ossl/rand_test
>
>     Breakpoint 1, main (argc=1, argv=0x7ffffffff798) at rand_test.c:6
>     6           int has_enough_data = RAND_status();
>     (gdb) s
>     RAND_status () at crypto/rand/rand_lib.c:958
>     958         const RAND_METHOD *meth = RAND_get_rand_method();
>     (gdb)
>     RAND_get_rand_method () at crypto/rand/rand_lib.c:844
>     844         const RAND_METHOD *tmp_meth = NULL;
>     (gdb)
>     846         if (!RUN_ONCE(&rand_init, do_rand_init))
>     (gdb)
>     CRYPTO_THREAD_run_once (once=0x102a7d88 <rand_init>, > init=0x10002f30 <do_rand_init_ossl_>) at crypto/threads_none.c:67
>     67          if (*once != 0)
>     (gdb)
>     70          init();
>     (gdb)
>     do_rand_init_ossl_ () at crypto/rand/rand_lib.c:306
>     306     DEFINE_RUN_ONCE_STATIC(do_rand_init)
>     (gdb)
>     do_rand_init () at crypto/rand/rand_lib.c:309
>     309         rand_engine_lock = CRYPTO_THREAD_lock_new();
>     (gdb)
>     CRYPTO_THREAD_lock_new () at crypto/threads_none.c:24
>     24          if ((lock = OPENSSL_zalloc(sizeof(unsigned int))) == NULL) {
>     (gdb)
>     CRYPTO_zalloc (num=4, file=0x1023a500 "crypto/threads_none.c", line=24) > at crypto/mem.c:230
>     230         void *ret = CRYPTO_malloc(num, file, line);
>     (gdb)
>     CRYPTO_malloc (num=4, file=0x1023a500 "crypto/threads_none.c", line=24) > at crypto/mem.c:194
>     194         void *ret = NULL;
>     (gdb)
>     197         if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)
>     (gdb)
>     200         if (num == 0)
>     (gdb)
>     204         if (allow_customize) {
>     (gdb)
>     210             allow_customize = 0;
>     (gdb)
>     222         ret = malloc(num);
>     (gdb)
>     Bad kernel stack pointer 7fffffffef20 at 700


On my machine it doesn't crash the kernel, so I can catch it later. For
me it's here:

Program received signal SIGILL, Illegal instruction.
0x0000000010000004 in ?? ()
(gdb) bt
#0  0x0000000010000004 in ?? ()
#1  0x0000000010004acc in syscall_random (buf=0x102b0730, buflen=32)
    at crypto/rand/rand_unix.c:371
#2  0x00000000100053fc in rand_pool_acquire_entropy (pool=0x102b06e0)
    at crypto/rand/rand_unix.c:636
#3  0x0000000010002b58 in rand_drbg_get_entropy (drbg=0x102b02e0, 
    pout=0x7ffffffff3f0, entropy=256, min_len=32, max_len=2147483647, 
    prediction_resistance=0) at crypto/rand/rand_lib.c:198
#4  0x000000001001ed9c in RAND_DRBG_instantiate (drbg=0x102b02e0, 
    pers=0x10248d00 <ossl_pers_string> "OpenSSL NIST SP 800-90A DRBG", 
    perslen=28) at crypto/rand/drbg_lib.c:338
#5  0x0000000010020300 in drbg_setup (parent=0x0) at crypto/rand/drbg_lib.c:895
#6  0x0000000010020414 in do_rand_drbg_init () at crypto/rand/drbg_lib.c:924
#7  0x000000001002034c in do_rand_drbg_init_ossl_ ()
    at crypto/rand/drbg_lib.c:909
#8  0x0000000010005d1c in CRYPTO_THREAD_run_once (
    once=0x102ab4d8 <rand_drbg_init>, 
    init=0x1002032c <do_rand_drbg_init_ossl_>) at crypto/threads_none.c:70
#9  0x00000000100209c4 in RAND_DRBG_get0_master ()
    at crypto/rand/drbg_lib.c:1102
#10 0x0000000010020914 in drbg_status () at crypto/rand/drbg_lib.c:1084
#11 0x0000000010004a58 in RAND_status () at crypto/rand/rand_lib.c:961
#12 0x0000000010002890 in main (argc=1, argv=0x7ffffffffa68) at rand_test.c:6
(gdb) 


ie. in the syscall_random() that I mentioned above.

You should be able to catch it there too if you do:

(gdb) b *0x10000000
(gdb) r

Hopefully it will stop without crashing the kernel, and then a `bt` will
show that you're in the same place as me.

If you can get that to work, when you're stopped there, can you do an
`info registers` and send us the output.

cheers

^ permalink raw reply

* Re: [PATCH v3 1/2] ASoC: dt-bindings: fsl_aud2htx: Add binding doc for aud2htx module
From: Mark Brown @ 2020-11-06 12:20 UTC (permalink / raw)
  To: Shengjiu Wang, perex, Xiubo.Lee, festevam, robh+dt, nicoleotsuka,
	timur, tiwai, devicetree, alsa-devel, lgirdwood
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <160466365499.22812.9217467877032314221.b4-ty@kernel.org>

[-- Attachment #1: Type: text/plain, Size: 485 bytes --]

On Fri, Nov 06, 2020 at 11:54:23AM +0000, Mark Brown wrote:
> On Mon, 2 Nov 2020 09:52:26 +0800, Shengjiu Wang wrote:
> > AUD2HTX (Audio Subsystem TO HDMI TX Subsystem) is a new
> > IP module found on i.MX8MP.
> 
> Applied to
> 
>    https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Sorry, looks like me queueing this raced with the review comments coming
in.  I think the review commments are small enough that it'll be OK to
fix incrementally?

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

^ permalink raw reply

* Re: [PATCH v3 1/2] ASoC: dt-bindings: fsl_aud2htx: Add binding doc for aud2htx module
From: Mark Brown @ 2020-11-06 11:54 UTC (permalink / raw)
  To: Shengjiu Wang, perex, Xiubo.Lee, festevam, robh+dt, nicoleotsuka,
	timur, tiwai, devicetree, alsa-devel, lgirdwood
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <1604281947-26874-1-git-send-email-shengjiu.wang@nxp.com>

On Mon, 2 Nov 2020 09:52:26 +0800, Shengjiu Wang wrote:
> AUD2HTX (Audio Subsystem TO HDMI TX Subsystem) is a new
> IP module found on i.MX8MP.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/2] ASoC: dt-bindings: fsl_aud2htx: Add binding doc for aud2htx module
      commit: 40f4c56d08f2a95f4f3b036987f171dde69ddd36
[2/2] ASoC: fsl_aud2htx: Add aud2htx module driver
      commit: 8a24c834c053ef1b0cdefbd9c5bcb487cbc5068f

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

^ permalink raw reply

* [PATCH] powerpc/64s: Remove RFI
From: Christophe Leroy @ 2020-11-06 11:36 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel

Last use of RFI on PPC64 was removed by
commit b8e90cb7bc04 ("powerpc/64: Convert the syscall exit path to
use RFI_TO_USER/KERNEL").

Remove the macro.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/ppc_asm.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 511786f0e40d..bedf3eb52ebc 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -495,7 +495,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
 #endif
 
 #ifdef CONFIG_PPC_BOOK3S_64
-#define RFI		rfid
 #define MTMSRD(r)	mtmsrd	r
 #define MTMSR_EERI(reg)	mtmsrd	reg,1
 #else
-- 
2.25.0


^ permalink raw reply related

* Re: [PATCH 05/11 v3] kprobes/ftrace: Add recursion protection to the ftrace callback
From: Masami Hiramatsu @ 2020-11-06 10:25 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: Peter Zijlstra, James E.J. Bottomley, Guo Ren, linux-csky,
	H. Peter Anvin, Miroslav Benes, Ingo Molnar, linux-s390,
	Helge Deller, x86, Anil S Keshavamurthy, Christian Borntraeger,
	Naveen N. Rao, Petr Mladek, Vasily Gorbik, Heiko Carstens,
	Jiri Kosina, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
	linux-parisc, linux-kernel, Masami Hiramatsu, Paul Mackerras,
	Andrew Morton, linuxppc-dev, David S. Miller
In-Reply-To: <20201106023546.944907560@goodmis.org>

On Thu, 05 Nov 2020 21:32:40 -0500
Steven Rostedt (VMware) <rostedt@goodmis.org> wrote:

> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> If a ftrace callback does not supply its own recursion protection and
> does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
> make a helper trampoline to do so before calling the callback instead of
> just calling the callback directly.
> 
> The default for ftrace_ops is going to change. It will expect that handlers
> provide their own recursion protection, unless its ftrace_ops states
> otherwise.
> 
> Link: https://lkml.kernel.org/r/20201028115613.140212174@goodmis.org
> 

Looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you!

> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Guo Ren <guoren@kernel.org>
> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> Cc: Helge Deller <deller@gmx.de>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: x86@kernel.org
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: linux-csky@vger.kernel.org
> Cc: linux-parisc@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-s390@vger.kernel.org
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> ---
> 
> Changes since v2:
> 
>  - Move get_kprobe() into preempt disabled sections for various archs
> 
> 
>  arch/csky/kernel/probes/ftrace.c     | 12 ++++++++++--
>  arch/parisc/kernel/ftrace.c          | 16 +++++++++++++---
>  arch/powerpc/kernel/kprobes-ftrace.c | 11 ++++++++++-
>  arch/s390/kernel/ftrace.c            | 16 +++++++++++++---
>  arch/x86/kernel/kprobes/ftrace.c     | 12 ++++++++++--
>  5 files changed, 56 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c
> index 5264763d05be..5eb2604fdf71 100644
> --- a/arch/csky/kernel/probes/ftrace.c
> +++ b/arch/csky/kernel/probes/ftrace.c
> @@ -13,16 +13,21 @@ int arch_check_ftrace_location(struct kprobe *p)
>  void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  			   struct ftrace_ops *ops, struct pt_regs *regs)
>  {
> +	int bit;
>  	bool lr_saver = false;
>  	struct kprobe *p;
>  	struct kprobe_ctlblk *kcb;
>  
> -	/* Preempt is disabled by ftrace */
> +	bit = ftrace_test_recursion_trylock();
> +	if (bit < 0)
> +		return;
> +
> +	preempt_disable_notrace();
>  	p = get_kprobe((kprobe_opcode_t *)ip);
>  	if (!p) {
>  		p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE));
>  		if (unlikely(!p) || kprobe_disabled(p))
> -			return;
> +			goto out;
>  		lr_saver = true;
>  	}
>  
> @@ -56,6 +61,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  		 */
>  		__this_cpu_write(current_kprobe, NULL);
>  	}
> +out:
> +	preempt_enable_notrace();
> +	ftrace_test_recursion_unlock(bit);
>  }
>  NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>  
> diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
> index 63e3ecb9da81..13d85042810a 100644
> --- a/arch/parisc/kernel/ftrace.c
> +++ b/arch/parisc/kernel/ftrace.c
> @@ -207,14 +207,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  			   struct ftrace_ops *ops, struct pt_regs *regs)
>  {
>  	struct kprobe_ctlblk *kcb;
> -	struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
> +	struct kprobe *p;
> +	int bit;
>  
> -	if (unlikely(!p) || kprobe_disabled(p))
> +	bit = ftrace_test_recursion_trylock();
> +	if (bit < 0)
>  		return;
>  
> +	preempt_disable_notrace();
> +	p = get_kprobe((kprobe_opcode_t *)ip);
> +	if (unlikely(!p) || kprobe_disabled(p))
> +		goto out;
> +
>  	if (kprobe_running()) {
>  		kprobes_inc_nmissed_count(p);
> -		return;
> +		goto out;
>  	}
>  
>  	__this_cpu_write(current_kprobe, p);
> @@ -235,6 +242,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  		}
>  	}
>  	__this_cpu_write(current_kprobe, NULL);
> +out:
> +	preempt_enable_notrace();
> +	ftrace_test_recursion_unlock(bit);
>  }
>  NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>  
> diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c
> index 972cb28174b2..5df8d50c65ae 100644
> --- a/arch/powerpc/kernel/kprobes-ftrace.c
> +++ b/arch/powerpc/kernel/kprobes-ftrace.c
> @@ -18,10 +18,16 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
>  {
>  	struct kprobe *p;
>  	struct kprobe_ctlblk *kcb;
> +	int bit;
>  
> +	bit = ftrace_test_recursion_trylock();
> +	if (bit < 0)
> +		return;
> +
> +	preempt_disable_notrace();
>  	p = get_kprobe((kprobe_opcode_t *)nip);
>  	if (unlikely(!p) || kprobe_disabled(p))
> -		return;
> +		goto out;
>  
>  	kcb = get_kprobe_ctlblk();
>  	if (kprobe_running()) {
> @@ -52,6 +58,9 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
>  		 */
>  		__this_cpu_write(current_kprobe, NULL);
>  	}
> +out:
> +	preempt_enable_notrace();
> +	ftrace_test_recursion_unlock(bit);
>  }
>  NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>  
> diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
> index b388e87a08bf..8f31c726537a 100644
> --- a/arch/s390/kernel/ftrace.c
> +++ b/arch/s390/kernel/ftrace.c
> @@ -201,14 +201,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  		struct ftrace_ops *ops, struct pt_regs *regs)
>  {
>  	struct kprobe_ctlblk *kcb;
> -	struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
> +	struct kprobe *p;
> +	int bit;
>  
> -	if (unlikely(!p) || kprobe_disabled(p))
> +	bit = ftrace_test_recursion_trylock();
> +	if (bit < 0)
>  		return;
>  
> +	preempt_disable_notrace();
> +	p = get_kprobe((kprobe_opcode_t *)ip);
> +	if (unlikely(!p) || kprobe_disabled(p))
> +		goto out;
> +
>  	if (kprobe_running()) {
>  		kprobes_inc_nmissed_count(p);
> -		return;
> +		goto out;
>  	}
>  
>  	__this_cpu_write(current_kprobe, p);
> @@ -228,6 +235,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  		}
>  	}
>  	__this_cpu_write(current_kprobe, NULL);
> +out:
> +	preempt_enable_notrace();
> +	ftrace_test_recursion_unlock(bit);
>  }
>  NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>  
> diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
> index 681a4b36e9bb..a40a6cdfcca3 100644
> --- a/arch/x86/kernel/kprobes/ftrace.c
> +++ b/arch/x86/kernel/kprobes/ftrace.c
> @@ -18,11 +18,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  {
>  	struct kprobe *p;
>  	struct kprobe_ctlblk *kcb;
> +	int bit;
>  
> -	/* Preempt is disabled by ftrace */
> +	bit = ftrace_test_recursion_trylock();
> +	if (bit < 0)
> +		return;
> +
> +	preempt_disable_notrace();
>  	p = get_kprobe((kprobe_opcode_t *)ip);
>  	if (unlikely(!p) || kprobe_disabled(p))
> -		return;
> +		goto out;
>  
>  	kcb = get_kprobe_ctlblk();
>  	if (kprobe_running()) {
> @@ -52,6 +57,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
>  		 */
>  		__this_cpu_write(current_kprobe, NULL);
>  	}
> +out:
> +	preempt_enable_notrace();
> +	ftrace_test_recursion_unlock(bit);
>  }
>  NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>  
> -- 
> 2.28.0
> 
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

^ permalink raw reply

* Re: [PATCH 00/36] Rid W=1 issues from TTY
From: Greg Kroah-Hartman @ 2020-11-06  9:54 UTC (permalink / raw)
  To: Lee Jones
  Cc: Robert Love, Nick Holloway, Russ Gorby, Kevin Wells, --,
	Andrew Morton, Laxman Dewangan, Paul Mackerras, David A. Hinds,
	linux-riscv, Jiri Slaby, linux-stm32, Bill Hawes, Roland Stigge,
	Rob Herring, Russell King, Michal Simek, Jonathan Hunter,
	Jan Dumon, Andy Gross, linux-serial, Sylvain Lemieux,
	Gerald Baeza, Sumit Semwal, Marko Kohtala, linux-media,
	Philipp Zabel, Alexandre Torgue, linux-arm-msm,
	Vladimir Zapolskiy, linaro-mm-sig, Stanislav Voronyi,
	C. Scott Ananian, Paul Walmsley, linux-tegra, Bjorn Andersson,
	Andrew J. Kroll, processes-Sapan Bhatia, Miloslav Trmac,
	Mike Hudson, Joseph Barrow, dri-devel, linux-kernel, paulkf,
	Filip Aben, Palmer Dabbelt, Maxime Coquelin, Thierry Reding,
	Colin Ian King, Jakub Jelinek, linuxppc-dev, Christian König,
	Russell King
In-Reply-To: <20201104193549.4026187-1-lee.jones@linaro.org>

On Wed, Nov 04, 2020 at 07:35:13PM +0000, Lee Jones wrote:
> This set is part of a larger effort attempting to clean-up W=1
> kernel builds, which are currently overwhelmingly riddled with
> niggly little warnings.

Many of these now applied, please update the series against my
tty-testing branch and resend the rest.

thanks,

greg k-h

^ permalink raw reply

* Re: [PATCH v2 00/16] PCI: dwc: Another round of clean-ups
From: Marek Szyprowski @ 2020-11-06  9:17 UTC (permalink / raw)
  To: Rob Herring, Lorenzo Pieralisi
  Cc: Kunihiko Hayashi, Neil Armstrong, linux-pci, Binghui Wang,
	Bjorn Andersson, linux-tegra, Thierry Reding, linux-arm-kernel,
	Thomas Petazzoni, Jonathan Chocron, Shawn Guo, Jonathan Hunter,
	Fabio Estevam, Jerome Brunet, Jesper Nilsson, linux-samsung-soc,
	Minghuan Lian, Kevin Hilman, Pratyush Anand, Krzysztof Kozlowski,
	Kishon Vijay Abraham I, Kukjin Kim, Mingkai Hu, Xiaowei Song,
	NXP Linux Team, Richard Zhu, Martin Blumenstingl, linux-arm-msm,
	Sascha Hauer, Yue Wang, Murali Karicheri, Bjorn Helgaas,
	linux-amlogic, linux-omap, linux-arm-kernel, Roy Zang,
	Masahiro Yamada, Jingoo Han, Andy Gross, Vidya Sagar,
	Stanimir Varbanov, Pengutronix Kernel Team, Gustavo Pimentel,
	linuxppc-dev, Lucas Stach
In-Reply-To: <20201105211159.1814485-1-robh@kernel.org>

Hi Rob,

On 05.11.2020 22:11, Rob Herring wrote:
> Here's another batch of DWC PCI host refactoring. This series primarily
> moves more of the MSI, link up, and resource handling to the core
> code. Beyond a couple of minor fixes, new in this version is runtime
> detection of iATU regions instead of using DT properties.

iATU detection seems to work fine with 
https://lore.kernel.org/linux-samsung-soc/20201029134017.27400-1-m.szyprowski@samsung.com/ 
on top of your patchset on Samsung Exynos5433 SoC:

exynos-pcie 15700000.pcie: host bridge /soc@0/pcie@15700000 ranges:
exynos-pcie 15700000.pcie:       IO 0x000c001000..0x000c010fff -> 
0x0000000000
exynos-pcie 15700000.pcie:      MEM 0x000c011000..0x000ffffffe -> 
0x000c011000
exynos-pcie 15700000.pcie: iATU unroll: disabled
exynos-pcie 15700000.pcie: Detected iATU regions: 3 outbound, 5 inbound
exynos-pcie 15700000.pcie: Link up
exynos-pcie 15700000.pcie: PCI host bridge to bus 0000:00

Fell free to add my:

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

> No doubt I've probably broken something. Please test. I've run this thru
> kernelci and checked boards with DWC PCI which currently is just
> Layerscape boards (hint: add boards and/or enable PCI). A git branch is
> here[1].
>
> This is dependent on "PCI: dwc: Restore ATU memory resource setup to use
> last entry" which will be in v5.10-rc3.
>
> Rob
>
> [1] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git pci-more-dwc-cleanup
>
> Rob Herring (16):
>    PCI: dwc: Support multiple ATU memory regions
>    PCI: dwc/intel-gw: Move ATU offset out of driver match data
>    PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into
>      common code
>    PCI: dwc/intel-gw: Remove some unneeded function wrappers
>    PCI: dwc: Ensure all outbound ATU windows are reset
>    PCI: dwc/dra7xx: Use the common MSI irq_chip
>    PCI: dwc: Drop the .set_num_vectors() host op
>    PCI: dwc: Move MSI interrupt setup into DWC common code
>    PCI: dwc: Rework MSI initialization
>    PCI: dwc: Move link handling into common code
>    PCI: dwc: Move dw_pcie_msi_init() into core
>    PCI: dwc: Move dw_pcie_setup_rc() to DWC common code
>    PCI: dwc: Remove unnecessary wrappers around dw_pcie_host_init()
>    Revert "PCI: dwc/keystone: Drop duplicated 'num-viewport'"
>    PCI: dwc: Move inbound and outbound windows to common struct
>    PCI: dwc: Detect number of iATU windows
>
>   drivers/pci/controller/dwc/pci-dra7xx.c       | 141 +-----------------
>   drivers/pci/controller/dwc/pci-exynos.c       |  50 ++-----
>   drivers/pci/controller/dwc/pci-imx6.c         |  39 +----
>   drivers/pci/controller/dwc/pci-keystone.c     |  79 ++--------
>   .../pci/controller/dwc/pci-layerscape-ep.c    |  37 +----
>   drivers/pci/controller/dwc/pci-layerscape.c   |  67 +--------
>   drivers/pci/controller/dwc/pci-meson.c        |  53 ++-----
>   drivers/pci/controller/dwc/pcie-al.c          |  29 +---
>   drivers/pci/controller/dwc/pcie-armada8k.c    |  37 ++---
>   drivers/pci/controller/dwc/pcie-artpec6.c     |  76 +---------
>   .../pci/controller/dwc/pcie-designware-ep.c   |  58 +++----
>   .../pci/controller/dwc/pcie-designware-host.c | 139 ++++++++++-------
>   .../pci/controller/dwc/pcie-designware-plat.c |  70 +--------
>   drivers/pci/controller/dwc/pcie-designware.c  |  93 +++++++++++-
>   drivers/pci/controller/dwc/pcie-designware.h  |  24 +--
>   drivers/pci/controller/dwc/pcie-histb.c       |  37 ++---
>   drivers/pci/controller/dwc/pcie-intel-gw.c    |  67 ++-------
>   drivers/pci/controller/dwc/pcie-kirin.c       |  62 +-------
>   drivers/pci/controller/dwc/pcie-qcom.c        |  38 +----
>   drivers/pci/controller/dwc/pcie-spear13xx.c   |  62 +++-----
>   drivers/pci/controller/dwc/pcie-tegra194.c    |  41 +----
>   drivers/pci/controller/dwc/pcie-uniphier-ep.c |  38 +----
>   drivers/pci/controller/dwc/pcie-uniphier.c    |  51 +------
>   23 files changed, 356 insertions(+), 1032 deletions(-)
>
> --
> 2.25.1
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


^ permalink raw reply

* Re: [PATCH 03/18] powerpc: bad_page_fault, do_break get registers from regs
From: Christophe Leroy @ 2020-11-06  8:14 UTC (permalink / raw)
  To: Nicholas Piggin, linuxppc-dev
In-Reply-To: <20201105143431.1874789-4-npiggin@gmail.com>



Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
> This also moves the 32s DABR match to C.

Is there a real benefit doing this ?

> 
> Similar to the previous patch this makes interrupt handler function
> types more regular so they can be wrapped with the next patch.
> 
> bad_page_fault and do_break are not performance critical.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>   arch/powerpc/include/asm/bug.h             |  2 +-
>   arch/powerpc/include/asm/debug.h           |  3 +--
>   arch/powerpc/kernel/entry_32.S             | 14 ++++----------
>   arch/powerpc/kernel/exceptions-64e.S       |  3 +--
>   arch/powerpc/kernel/exceptions-64s.S       |  3 +--
>   arch/powerpc/kernel/head_8xx.S             |  5 ++---
>   arch/powerpc/kernel/process.c              |  7 +++----
>   arch/powerpc/kernel/traps.c                |  2 +-
>   arch/powerpc/mm/book3s64/hash_utils.c      |  4 ++--
>   arch/powerpc/mm/book3s64/slb.c             |  2 +-
>   arch/powerpc/mm/fault.c                    | 14 +++++++-------
>   arch/powerpc/platforms/8xx/machine_check.c |  2 +-
>   12 files changed, 25 insertions(+), 36 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
> index 2fa0cf6c6011..4af6c3835eb2 100644
> --- a/arch/powerpc/include/asm/bug.h
> +++ b/arch/powerpc/include/asm/bug.h
> @@ -113,7 +113,7 @@
>   struct pt_regs;
>   extern long do_page_fault(struct pt_regs *);
>   extern long hash__do_page_fault(struct pt_regs *);
> -extern void bad_page_fault(struct pt_regs *, unsigned long, int);
> +extern void bad_page_fault(struct pt_regs *, int);

pointless extern

Christophe

>   extern void _exception(int, struct pt_regs *, int, unsigned long);
>   extern void _exception_pkey(struct pt_regs *, unsigned long, int);
>   extern void die(const char *, struct pt_regs *, long);
> diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
> index ec57daf87f40..0550eceab3ca 100644
> --- a/arch/powerpc/include/asm/debug.h
> +++ b/arch/powerpc/include/asm/debug.h
> @@ -52,8 +52,7 @@ extern void do_send_trap(struct pt_regs *regs, unsigned long address,
>   			 unsigned long error_code, int brkpt);
>   #else
>   
> -extern void do_break(struct pt_regs *regs, unsigned long address,
> -		     unsigned long error_code);
> +void do_break(struct pt_regs *regs);
>   #endif
>   
>   #endif /* _ASM_POWERPC_DEBUG_H */
> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
> index 8cdc8bcde703..eb97df234a0c 100644
> --- a/arch/powerpc/kernel/entry_32.S
> +++ b/arch/powerpc/kernel/entry_32.S
> @@ -657,10 +657,6 @@ ppc_swapcontext:
>   	.globl	handle_page_fault
>   handle_page_fault:
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
> -#ifdef CONFIG_PPC_BOOK3S_32
> -	andis.  r0,r5,DSISR_DABRMATCH@h
> -	bne-    handle_dabr_fault
> -#endif
>   	bl	do_page_fault
>   	cmpwi	r3,0
>   	beq+	ret_from_except
> @@ -668,19 +664,17 @@ handle_page_fault:
>   	lwz	r0,_TRAP(r1)
>   	clrrwi	r0,r0,1
>   	stw	r0,_TRAP(r1)
> -	mr	r5,r3
> +	mr	r4,r3		/* err arg for bad_page_fault */
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
> -	lwz	r4,_DAR(r1)
> +#ifdef CONFIG_PPC_BOOK3S_32
> +	blt	handle_dabr_fault
> +#endif
>   	bl	bad_page_fault
>   	b	ret_from_except_full
>   
>   #ifdef CONFIG_PPC_BOOK3S_32
>   	/* We have a data breakpoint exception - handle it */
>   handle_dabr_fault:
> -	SAVE_NVGPRS(r1)
> -	lwz	r0,_TRAP(r1)
> -	clrrwi	r0,r0,1
> -	stw	r0,_TRAP(r1)
>   	bl      do_break
>   	b	ret_from_except_full
>   #endif
> diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
> index 25fa7d5a643c..dc728bb1c89a 100644
> --- a/arch/powerpc/kernel/exceptions-64e.S
> +++ b/arch/powerpc/kernel/exceptions-64e.S
> @@ -1018,9 +1018,8 @@ storage_fault_common:
>   	bne-	1f
>   	b	ret_from_except_lite
>   1:	bl	save_nvgprs
> -	mr	r5,r3
> +	mr	r4,r3
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
> -	ld	r4,_DAR(r1)
>   	bl	bad_page_fault
>   	b	ret_from_except
>   
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 1f34cfd1887c..e6558c4d3f81 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -2135,8 +2135,7 @@ EXC_COMMON_BEGIN(h_data_storage_common)
>   	GEN_COMMON h_data_storage
>   	addi    r3,r1,STACK_FRAME_OVERHEAD
>   BEGIN_MMU_FTR_SECTION
> -	ld	r4,_DAR(r1)
> -	li	r5,SIGSEGV
> +	li	r4,SIGSEGV
>   	bl      bad_page_fault
>   MMU_FTR_SECTION_ELSE
>   	bl      unknown_exception
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index 0cd95b633e2b..13eda7154695 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -408,10 +408,9 @@ do_databreakpoint:
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>   	mfspr	r4,SPRN_BAR
>   	stw	r4,_DAR(r11)
> -#ifdef CONFIG_VMAP_STACK
> -	lwz	r5,_DSISR(r11)
> -#else
> +#ifndef CONFIG_VMAP_STACK
>   	mfspr	r5,SPRN_DSISR
> +	stw	r5,_DSISR(r11)
>   #endif
>   	EXC_XFER_STD(0x1c00, do_break)
>   
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index d421a2c7f822..0bdd3ed653df 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -660,11 +660,10 @@ static void do_break_handler(struct pt_regs *regs)
>   	}
>   }
>   
> -void do_break (struct pt_regs *regs, unsigned long address,
> -		    unsigned long error_code)
> +void do_break(struct pt_regs *regs)
>   {
>   	current->thread.trap_nr = TRAP_HWBKPT;
> -	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
> +	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
>   			11, SIGSEGV) == NOTIFY_STOP)
>   		return;
>   
> @@ -682,7 +681,7 @@ void do_break (struct pt_regs *regs, unsigned long address,
>   		do_break_handler(regs);
>   
>   	/* Deliver the signal to userspace */
> -	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)address);
> +	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
>   }
>   #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
>   
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 5006dcbe1d9f..902fcbd1a778 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -1641,7 +1641,7 @@ void alignment_exception(struct pt_regs *regs)
>   	if (user_mode(regs))
>   		_exception(sig, regs, code, regs->dar);
>   	else
> -		bad_page_fault(regs, regs->dar, sig);
> +		bad_page_fault(regs, sig);
>   
>   bail:
>   	exception_exit(prev_state);
> diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
> index 0f0bd4af4b2d..731518e7d56f 100644
> --- a/arch/powerpc/mm/book3s64/hash_utils.c
> +++ b/arch/powerpc/mm/book3s64/hash_utils.c
> @@ -1537,7 +1537,7 @@ long do_hash_fault(struct pt_regs *regs)
>   	 * the access, or panic if there isn't a handler.
>   	 */
>   	if (unlikely(in_nmi())) {
> -		bad_page_fault(regs, ea, SIGSEGV);
> +		bad_page_fault(regs, SIGSEGV);
>   		return 0;
>   	}
>   
> @@ -1576,7 +1576,7 @@ long do_hash_fault(struct pt_regs *regs)
>   			else
>   				_exception(SIGBUS, regs, BUS_ADRERR, ea);
>   		} else {
> -			bad_page_fault(regs, ea, SIGBUS);
> +			bad_page_fault(regs, SIGBUS);
>   		}
>   		err = 0;
>   
> diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
> index cc34d50874c1..ae89ad516247 100644
> --- a/arch/powerpc/mm/book3s64/slb.c
> +++ b/arch/powerpc/mm/book3s64/slb.c
> @@ -898,7 +898,7 @@ void do_bad_slb_fault(struct pt_regs *regs)
>   		if (user_mode(regs))
>   			_exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
>   		else
> -			bad_page_fault(regs, regs->dar, SIGSEGV);
> +			bad_page_fault(regs, SIGSEGV);
>   	} else if (err == -EINVAL) {
>   		unrecoverable_exception(regs);
>   	} else {
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 390a296b16a3..49fbe564ea2b 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -375,7 +375,7 @@ static void sanity_check_fault(bool is_write, bool is_user,
>   #elif defined(CONFIG_PPC_BOOK3E_64)
>   #define page_fault_is_bad(__err)	((__err) & DSISR_BAD_FAULT_64S)
>   #else
> -#define page_fault_is_bad(__err)	((__err) & DSISR_BAD_FAULT_32S)
> +#define page_fault_is_bad(__err)	((__err) & DSISR_BAD_FAULT_32S | DSISR_DABRMATCH)
>   #endif
>   #endif
>   
> @@ -408,7 +408,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
>   		return 0;
>   
>   	if (unlikely(page_fault_is_bad(error_code))) {
> -		if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && (error_code & DSISR_DABRMATCH))
> +		if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (error_code & DSISR_DABRMATCH))
>   			return -1;
>   
>   		if (is_user) {
> @@ -562,14 +562,14 @@ long do_page_fault(struct pt_regs *regs)
>   	/* 32 and 64e handle errors in their asm code */
>   	if (unlikely(err)) {
>   		if (err > 0) {
> -			bad_page_fault(regs, address, err);
> +			bad_page_fault(regs, err);
>   			err = 0;
>   		} else {
>   			/*
>   			 * do_break() may change NV GPRS while handling the
>   			 * breakpoint. Return -ve to caller to do that.
>   			 */
> -			do_break(regs, address, error_code);
> +			do_break(regs);
>   		}
>   	}
>   #endif
> @@ -591,14 +591,14 @@ long hash__do_page_fault(struct pt_regs *regs)
>   	err = __do_page_fault(regs, address, error_code);
>   	if (unlikely(err)) {
>   		if (err > 0) {
> -			bad_page_fault(regs, address, err);
> +			bad_page_fault(regs, err);
>   			err = 0;
>   		} else {
>   			/*
>   			 * do_break() may change NV GPRS while handling the
>   			 * breakpoint. Return -ve to caller to do that.
>   			 */
> -			do_break(regs, address, error_code);
> +			do_break(regs);
>   		}
>   	}
>   
> @@ -612,7 +612,7 @@ NOKPROBE_SYMBOL(hash__do_page_fault);
>    * It is called from the DSI and ISI handlers in head.S and from some
>    * of the procedures in traps.c.
>    */
> -void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
> +void bad_page_fault(struct pt_regs *regs, int sig)
>   {
>   	const struct exception_table_entry *entry;
>   	int is_write = page_fault_is_write(regs->dsisr);
> diff --git a/arch/powerpc/platforms/8xx/machine_check.c b/arch/powerpc/platforms/8xx/machine_check.c
> index 88dedf38eccd..656365975895 100644
> --- a/arch/powerpc/platforms/8xx/machine_check.c
> +++ b/arch/powerpc/platforms/8xx/machine_check.c
> @@ -26,7 +26,7 @@ int machine_check_8xx(struct pt_regs *regs)
>   	 * to deal with that than having a wart in the mcheck handler.
>   	 * -- BenH
>   	 */
> -	bad_page_fault(regs, regs->dar, SIGBUS);
> +	bad_page_fault(regs, SIGBUS);
>   	return 1;
>   #else
>   	return 0;
> 

^ permalink raw reply

* Re: [PATCH 02/18] powerpc: remove arguments from fault handler functions
From: Christophe Leroy @ 2020-11-06  7:59 UTC (permalink / raw)
  To: Nicholas Piggin, linuxppc-dev
In-Reply-To: <20201105143431.1874789-3-npiggin@gmail.com>



Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
> Make mm fault handlers all just take the pt_regs * argument and load
> DAR/DSISR from that. Make those that return a value return long.
> 
> This is done to make the function signatures match other handlers, which
> will help with a future patch to add wrappers. Explicit arguments could
> be added for performance but that would require more wrapper macro
> variants.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>   arch/powerpc/include/asm/asm-prototypes.h |  4 ++--
>   arch/powerpc/include/asm/bug.h            |  4 ++--
>   arch/powerpc/kernel/exceptions-64e.S      |  2 --
>   arch/powerpc/kernel/exceptions-64s.S      | 14 ++------------
>   arch/powerpc/kernel/head_40x.S            | 10 +++++-----
>   arch/powerpc/kernel/head_8xx.S            |  6 +++---
>   arch/powerpc/kernel/head_book3s_32.S      |  6 ++----
>   arch/powerpc/kernel/head_booke.h          |  4 +---
>   arch/powerpc/mm/book3s64/hash_utils.c     |  8 +++++---
>   arch/powerpc/mm/book3s64/slb.c            | 11 +++++++----
>   arch/powerpc/mm/fault.c                   | 16 +++++++++-------
>   11 files changed, 38 insertions(+), 47 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
> index d0b832cbbec8..22c9d08fa3a4 100644
> --- a/arch/powerpc/include/asm/asm-prototypes.h
> +++ b/arch/powerpc/include/asm/asm-prototypes.h
> @@ -82,8 +82,8 @@ void kernel_bad_stack(struct pt_regs *regs);
>   void system_reset_exception(struct pt_regs *regs);
>   void machine_check_exception(struct pt_regs *regs);
>   void emulation_assist_interrupt(struct pt_regs *regs);
> -long do_slb_fault(struct pt_regs *regs, unsigned long ea);
> -void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err);
> +long do_slb_fault(struct pt_regs *regs);
> +void do_bad_slb_fault(struct pt_regs *regs);
>   
>   /* signals, syscalls and interrupts */
>   long sys_swapcontext(struct ucontext __user *old_ctx,
> diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
> index d714d83bbc7c..2fa0cf6c6011 100644
> --- a/arch/powerpc/include/asm/bug.h
> +++ b/arch/powerpc/include/asm/bug.h
> @@ -111,8 +111,8 @@
>   #ifndef __ASSEMBLY__
>   
>   struct pt_regs;
> -extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
> -extern int hash__do_page_fault(struct pt_regs *, unsigned long, unsigned long);
> +extern long do_page_fault(struct pt_regs *);
> +extern long hash__do_page_fault(struct pt_regs *);

extern is pointless

>   extern void bad_page_fault(struct pt_regs *, unsigned long, int);
>   extern void _exception(int, struct pt_regs *, int, unsigned long);
>   extern void _exception_pkey(struct pt_regs *, unsigned long, int);
> diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
> index f579ce46eef2..25fa7d5a643c 100644
> --- a/arch/powerpc/kernel/exceptions-64e.S
> +++ b/arch/powerpc/kernel/exceptions-64e.S
> @@ -1011,8 +1011,6 @@ storage_fault_common:
>   	std	r14,_DAR(r1)
>   	std	r15,_DSISR(r1)
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
> -	mr	r4,r14
> -	mr	r5,r15
>   	ld	r14,PACA_EXGEN+EX_R14(r13)
>   	ld	r15,PACA_EXGEN+EX_R15(r13)
>   	bl	do_page_fault
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index f830b893fe03..1f34cfd1887c 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1437,8 +1437,6 @@ EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
>   EXC_VIRT_END(data_access, 0x4300, 0x80)
>   EXC_COMMON_BEGIN(data_access_common)
>   	GEN_COMMON data_access
> -	ld	r4,_DAR(r1)
> -	ld	r5,_DSISR(r1)
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>   BEGIN_MMU_FTR_SECTION
>   	bl	do_hash_fault
> @@ -1491,10 +1489,9 @@ EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
>   EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
>   EXC_COMMON_BEGIN(data_access_slb_common)
>   	GEN_COMMON data_access_slb
> -	ld	r4,_DAR(r1)
> -	addi	r3,r1,STACK_FRAME_OVERHEAD
>   BEGIN_MMU_FTR_SECTION
>   	/* HPT case, do SLB fault */
> +	addi	r3,r1,STACK_FRAME_OVERHEAD
>   	bl	do_slb_fault
>   	cmpdi	r3,0
>   	bne-	1f
> @@ -1506,8 +1503,6 @@ MMU_FTR_SECTION_ELSE
>   ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>   	std	r3,RESULT(r1)
>   	RECONCILE_IRQ_STATE(r10, r11)
> -	ld	r4,_DAR(r1)
> -	ld	r5,RESULT(r1)
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>   	bl	do_bad_slb_fault
>   	b	interrupt_return
> @@ -1542,8 +1537,6 @@ EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
>   EXC_VIRT_END(instruction_access, 0x4400, 0x80)
>   EXC_COMMON_BEGIN(instruction_access_common)
>   	GEN_COMMON instruction_access
> -	ld	r4,_DAR(r1)
> -	ld	r5,_DSISR(r1)
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>   BEGIN_MMU_FTR_SECTION
>   	bl	do_hash_fault
> @@ -1587,10 +1580,9 @@ EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
>   EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
>   EXC_COMMON_BEGIN(instruction_access_slb_common)
>   	GEN_COMMON instruction_access_slb
> -	ld	r4,_DAR(r1)
> -	addi	r3,r1,STACK_FRAME_OVERHEAD
>   BEGIN_MMU_FTR_SECTION
>   	/* HPT case, do SLB fault */
> +	addi	r3,r1,STACK_FRAME_OVERHEAD
>   	bl	do_slb_fault
>   	cmpdi	r3,0
>   	bne-	1f
> @@ -1602,8 +1594,6 @@ MMU_FTR_SECTION_ELSE
>   ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>   	std	r3,RESULT(r1)
>   	RECONCILE_IRQ_STATE(r10, r11)
> -	ld	r4,_DAR(r1)
> -	ld	r5,RESULT(r1)
>   	addi	r3,r1,STACK_FRAME_OVERHEAD
>   	bl	do_bad_slb_fault
>   	b	interrupt_return
> diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
> index 44c9018aed1b..ea31f75e9692 100644
> --- a/arch/powerpc/kernel/head_40x.S
> +++ b/arch/powerpc/kernel/head_40x.S
> @@ -179,9 +179,9 @@ _ENTRY(saved_ksp_limit)
>    */
>   	START_EXCEPTION(0x0300,	DataStorage)
>   	EXCEPTION_PROLOG
> -	mfspr	r5, SPRN_ESR		/* Grab the ESR, save it, pass arg3 */
> +	mfspr	r5, SPRN_ESR		/* Grab the ESR, save it */
>   	stw	r5, _ESR(r11)
> -	mfspr	r4, SPRN_DEAR		/* Grab the DEAR, save it, pass arg2 */
> +	mfspr	r4, SPRN_DEAR		/* Grab the DEAR, save it */
>   	stw	r4, _DEAR(r11)
>   	EXC_XFER_LITE(0x300, handle_page_fault)
>   
> @@ -191,9 +191,9 @@ _ENTRY(saved_ksp_limit)
>    */
>   	START_EXCEPTION(0x0400, InstructionAccess)
>   	EXCEPTION_PROLOG
> -	mr	r4,r12			/* Pass SRR0 as arg2 */
> -	stw	r4, _DEAR(r11)
> -	li	r5,0			/* Pass zero as arg3 */
> +	li	r5,0
> +	stw	r5, _ESR(r11)		/* Zero ESR */
> +	stw	r12, _DEAR(r11)		/* SRR0 as DEAR */

I think we should avoid this, see below

>   	EXC_XFER_LITE(0x400, handle_page_fault)
>   
>   /* 0x0500 - External Interrupt Exception */
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index 9f359d3fba74..0cd95b633e2b 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -356,14 +356,14 @@ DataStoreTLBMiss:
>   	. = 0x1300
>   InstructionTLBError:
>   	EXCEPTION_PROLOG
> -	mr	r4,r12
>   	andis.	r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */

Could avoid this, see below

>   	andis.	r10,r9,SRR1_ISI_NOPT@h
>   	beq+	.Litlbie
> -	tlbie	r4
> +	tlbie	r12
>   	/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
>   .Litlbie:
> -	stw	r4, _DAR(r11)
> +	stw	r12, _DAR(r11)
> +	stw	r5, _DSISR(r11)

And this

>   	EXC_XFER_LITE(0x400, handle_page_fault)
>   
>   /* This is the data TLB error on the MPC8xx.  This could be due to
> diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
> index 5eb9eedac920..81c69769cec6 100644
> --- a/arch/powerpc/kernel/head_book3s_32.S
> +++ b/arch/powerpc/kernel/head_book3s_32.S
> @@ -369,9 +369,9 @@ BEGIN_MMU_FTR_SECTION
>   	bl	hash_page
>   END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
>   #endif	/* CONFIG_VMAP_STACK */
> -1:	mr	r4,r12
>   	andis.	r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
> -	stw	r4, _DAR(r11)
> +	stw	r5, _DSISR(r11)
> +	stw	r12, _DAR(r11)

And this including the andis.

>   	EXC_XFER_LITE(0x400, handle_page_fault)
>   
>   /* External interrupt */
> @@ -698,8 +698,6 @@ handle_page_fault_tramp_1:
>   #ifdef CONFIG_VMAP_STACK
>   	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
>   #endif
> -	lwz	r4, _DAR(r11)
> -	lwz	r5, _DSISR(r11)
>   	/* fall through */
>   handle_page_fault_tramp_2:
>   	EXC_XFER_LITE(0x300, handle_page_fault)
> diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
> index 71c359d438b5..1da0c1d1b0a1 100644
> --- a/arch/powerpc/kernel/head_booke.h
> +++ b/arch/powerpc/kernel/head_booke.h
> @@ -477,9 +477,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
>   	NORMAL_EXCEPTION_PROLOG(INST_STORAGE);		      \
>   	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
>   	stw	r5,_ESR(r11);						      \
> -	mr      r4,r12;                 /* Pass SRR0 as arg2 */		      \
> -	stw	r4, _DEAR(r11);						      \
> -	li      r5,0;                   /* Pass zero as arg3 */		      \
> +	stw	r12, _DEAR(r11);	/* Pass SRR0 as arg2 */		      \

And this

>   	EXC_XFER_LITE(0x0400, handle_page_fault)
>   
>   #define ALIGNMENT_EXCEPTION						      \
> diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
> index bfa1b1966218..0f0bd4af4b2d 100644
> --- a/arch/powerpc/mm/book3s64/hash_utils.c
> +++ b/arch/powerpc/mm/book3s64/hash_utils.c
> @@ -1510,13 +1510,15 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
>   }
>   EXPORT_SYMBOL_GPL(hash_page);
>   
> -int do_hash_fault(struct pt_regs *regs, unsigned long ea, unsigned long dsisr)
> +long do_hash_fault(struct pt_regs *regs)
>   {
> +	unsigned long ea = regs->dar;
> +	unsigned long dsisr = regs->dsisr;
>   	unsigned long access = _PAGE_PRESENT | _PAGE_READ;
>   	unsigned long flags = 0;
>   	struct mm_struct *mm;
>   	unsigned int region_id;
> -	int err;
> +	long err;
>   
>   	if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_DABRMATCH | DSISR_KEYFAULT)))
>   		goto _do_page_fault;
> @@ -1580,7 +1582,7 @@ int do_hash_fault(struct pt_regs *regs, unsigned long ea, unsigned long dsisr)
>   
>   	} else if (err) {
>   _do_page_fault:
> -		err = hash__do_page_fault(regs, ea, dsisr);
> +		err = hash__do_page_fault(regs);
>   	}
>   
>   	return err;
> diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
> index c30fcbfa0e32..cc34d50874c1 100644
> --- a/arch/powerpc/mm/book3s64/slb.c
> +++ b/arch/powerpc/mm/book3s64/slb.c
> @@ -837,8 +837,9 @@ static long slb_allocate_user(struct mm_struct *mm, unsigned long ea)
>   	return slb_insert_entry(ea, context, flags, ssize, false);
>   }
>   
> -long do_slb_fault(struct pt_regs *regs, unsigned long ea)
> +long do_slb_fault(struct pt_regs *regs)
>   {
> +	unsigned long ea = regs->dar;
>   	unsigned long id = get_region_id(ea);
>   
>   	/* IRQs are not reconciled here, so can't check irqs_disabled */
> @@ -889,13 +890,15 @@ long do_slb_fault(struct pt_regs *regs, unsigned long ea)
>   	}
>   }
>   
> -void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err)
> +void do_bad_slb_fault(struct pt_regs *regs)
>   {
> +	int err = regs->result;
> +
>   	if (err == -EFAULT) {
>   		if (user_mode(regs))
> -			_exception(SIGSEGV, regs, SEGV_BNDERR, ea);
> +			_exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
>   		else
> -			bad_page_fault(regs, ea, SIGSEGV);
> +			bad_page_fault(regs, regs->dar, SIGSEGV);
>   	} else if (err == -EINVAL) {
>   		unrecoverable_exception(regs);
>   	} else {
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index e65a49f246ef..390a296b16a3 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -549,11 +549,12 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
>   }
>   NOKPROBE_SYMBOL(__do_page_fault);
>   
> -int do_page_fault(struct pt_regs *regs, unsigned long address,
> -		  unsigned long error_code)
> +long do_page_fault(struct pt_regs *regs)
>   {
>   	enum ctx_state prev_state = exception_enter();
> -	int err;
> +	unsigned long address = regs->dar;
> +	unsigned long error_code = regs->dsisr;
> +	long err;

By doing something more or less like this (need to be tuned for bookE as well):

+	int is_exec = TRAP(regs) == 0x400;
+	unsigned long address = is_exec ? regs->ssr0 : regs->dar;
+	unsigned long error_code = is_exec ? (regs->ssr1 & DSISR_SRR1_MATCH_32S) : regs->dsisr;

>   
>   	err = __do_page_fault(regs, address, error_code);
>   
> @@ -580,11 +581,12 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
>   NOKPROBE_SYMBOL(do_page_fault);
>   
>   #ifdef CONFIG_PPC_BOOK3S_64
> -/* Same as do_page_fault but interrupt entry has already run in do_hash_fault */
> -int hash__do_page_fault(struct pt_regs *regs, unsigned long address,
> -		  unsigned long error_code)
> +/* Same as do_page_fault but no interrupt entry */
> +long hash__do_page_fault(struct pt_regs *regs)
>   {
> -	int err;
> +	unsigned long address = regs->dar;
> +	unsigned long error_code = regs->dsisr;
> +	long err;
>   
>   	err = __do_page_fault(regs, address, error_code);
>   	if (unlikely(err)) {
> 

There is probably also something we can simplify around get_and_save_dar_dsisr_on_stack() macro in 
head_32.h, no need to reload DAR, at least for 8xx. Maybe as a followup patch later.

Christophe

^ permalink raw reply

* Re: [PATCH 18/18] powerpc/64s: move power4 idle entirely to C
From: kernel test robot @ 2020-11-06  7:34 UTC (permalink / raw)
  To: Nicholas Piggin, linuxppc-dev; +Cc: kbuild-all, Nicholas Piggin
In-Reply-To: <20201105143431.1874789-19-npiggin@gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1626 bytes --]

Hi Nicholas,

I love your patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v5.10-rc2 next-20201105]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/powerpc-interrupt-wrappers/20201105-231909
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allyesconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/561aae13dd3400b772b91d60681d55937e046cbc
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Nicholas-Piggin/powerpc-interrupt-wrappers/20201105-231909
        git checkout 561aae13dd3400b772b91d60681d55937e046cbc
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   {standard input}: Assembler messages:
>> {standard input}:662: Error: unsupported relocation against r13

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 71461 bytes --]

^ permalink raw reply


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